Mitochondrial dysfunction as a bridge to pathology in acute pancreatitis: From molecular insights to novel therapeutic strategies

Abstract

Acute pancreatitis (AP) is a life-threatening inflammatory condition triggered by the premature activation of trypsin. The limited understanding of its underlying pathophysiology remains a key obstacle to the development of targeted therapies. Mounting evidence now underscores mitochondrial dysfunction as a critical pathogenic driver in AP. Cellular mitochondrial dysfunction often precedes both cytokine release and trypsin activation, potentially serving as a primary initiator in the development and advancement of AP. Mitochondrial dysfunction is associated with calcium overload, inflammatory reactions, mitochondrial permeability transition pore opening, mitophagy damage, and other potential pathogenesis of pancreatic cell injury. Elucidating the impact of mitochondrial injury in AP may facilitate the development of innovative treatment approaches. This review provides a comprehensive and systematic analysis of the pivotal role of mitochondria in regulating pancreatic homeostasis, while evaluating emerging therapeutic strategies aimed at mitigating mitochondrial dysfunction. By integrating cutting-edge research findings, this work highlights the translational potential of these advancements in redefining diagnostic frameworks and optimizing therapeutic approaches for the management of AP.

Key Words: Acute pancreatitis; Mitochondria; Mitochondrial dysfunction; Molecular mechanism; Treatment

Core Tip: Mitochondrial dysfunction is increasingly recognized as a pivotal initiating factor in acute pancreatitis (AP), preceding trypsin activation and inflammatory amplification. Key mechanisms include calcium overload, oxidative stress, mitochondrial permeability transition pore opening, and impaired mitophagy. This review synthesizes current evidence on mitochondrial dysregulation in AP and highlights emerging therapeutic strategies targeting mitochondrial pathways, offering new avenues for transitioning from supportive care to mechanism-driven precision medicine in AP management.

INTRODUCTION

Acute pancreatitis (AP), a potentially fatal inflammatory disorder of the pancreas, arises from premature intra-acinar trypsin activation triggered by multifactorial etiologies including biliary obstruction, alcohol metabolites, hypertriglyceridemia, and genetic variants in cationic trypsinogen 1, or serine peptidase inhibitor Kazal type 1[1]. The pathophysiological cascade of AP is initiated by dysregulated intra-pancreatic trypsinogen activation, which precipitates acinar cell autodigestion and subsequent tissue injury. This process elicits a robust inflammatory cascade, culminating in hallmark pathological manifestations such as pancreatic edema, parenchymal hemorrhage, and focal or diffuse necrosis. Clinically, the disease spectrum is categorized into three distinct severity classifications: Mild AP, moderately severe AP, and severe AP (SAP), based on systemic complications and organ failure duration. Epidemiological studies reveal that approximately 80% of AP cases are self-limiting (mild AP), whereas 20% progress to SAP, a life-threatening condition associated with mortality rates exceeding 30% due to multi-organ dysfunction syndrome[2]. Elevated serum concentrations of pancreatic enzymes, particularly amylase and lipase, constitute biochemical hallmarks of AP, though their diagnostic specificity remains limited. The pathophysiological cascade involves premature activation of trypsinogen, a zymogen synthesized exclusively by pancreatic acinar cells. Under physiological conditions, this protease precursor undergoes site-specific activation through enteropeptidase-mediated cleavage in the duodenal lumen[3]. In AP pathogenesis, however, the aberrant intra-acinar conversion of trypsinogen to active trypsin represents a critical initiating event. This mechanistic paradigm has been rigorously validated across multiple experimental models, including caerulein-induced AP in mice and rats, demonstrating conserved activation pathways across species[4].

Despite substantial progress in elucidating AP pathophysiology, key mechanistic gaps remain in our understanding of the molecular pathways that orchestrate inflammatory activation and cellular injury, significantly impeding the development of targeted therapies. Although pancreatic autodigestion is widely recognized as a central pathogenic driver, recent studies highlight the critical involvement of gut-derived inflammation, microcirculatory disturbances, and dysregulated immunomodulatory networks in disease exacerbation and systemic complications[5,6]. Recent studies have increasingly highlighted the critical role of pancreatic acinar cell organelle disruption in AP pathogenesis[7]. The organelles of pancreatic cells, including mitochondria are destroyed and trigger the formation and development of AP[8]. Mitochondria are important organelles present in eukaryotes, known as energy factories of cells, which can produce energy required by the body[9]. At the same time, mitochondria are also involved in various signaling pathways and inflammation in cells. Increasing studies have been conducted on mitochondrial dysfunction and AP in recent years[10,11].

Mitochondrial dysfunction represents a pivotal pathogenic axis in AP, driving both disease onset and progression through multiple interconnected mechanisms. Under physiological conditions, mitochondria-derived reactive oxygen species (ROS), primarily generated via electron transport chain (ETC) activity during oxidative phosphorylation, serve as critical regulators of redox signaling and cellular homeostasis[12].

Pathological ROS overproduction triggers inflammatory cascades via activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and NLR family pyrin domain-containing protein 3 (NLRP3) inflammasome, driving transcriptional upregulation of pro-inflammatory cytokines, chemokines, and adhesion molecules that potentiate pancreatic inflammation[13]. Activation of the NF-κB pathway induces the expression of multiple inflammatory mediators, including cytokines, chemokines, immune receptors, and focal adhesion molecules, thereby triggering a sterile inflammatory response and propagating a cascade of pancreatic injury[14,15]. Acute cellular injury can cause important mitochondrial activities to be lost or deteriorate, which is linked to a reduction in adenosine triphosphate (ATP) synthesis and bioenergetic impairment[16]. Therefore, ATP has a dual function in the physiology and pathophysiology of the pancreas since it is essential for cell activity and, like many other systems, serves as a crucial messenger between cells[17]. Emerging research indicates that estrogen-related receptor γ, a key regulator of pancreatic acinar cell metabolism, can modulate cellular biology and energy homeostasis by disrupting mitochondrial function, subsequently inducing oxidative stress, and autophagic dysfunction[18]. In addition, Damage-associated molecular patterns (DAMPs) drive aseptic inflammation, which has been demonstrated in numerous studies to be a crucial process mediating subsequent pancreatic injury, downstream organ damage, and disease resolution[19]. DAMPs cannot activate pattern recognition receptors to cause inflammation in normal circumstances. Changes in membrane permeability during inflammation enable these chemicals to trigger pattern recognition receptors and propel the inflammatory process[20]. Several studies have demonstrated that mitochondrial damage can lead to energy generation disorders, Ca²⁺ homeostasis disorders, impaired autophagy, affecting cell function and even leading to cell death[3,10,11,21].

This review systematically elucidates the pivotal role of mitochondria in maintaining pancreatic homeostasis, while delineating their pathological contributions to AP via dysregulated calcium flux, impaired autophagy, oxidative stress-mediated damage, mitochondrial DNA (mtDNA) dysfunction and compromised membrane integrity. Furthermore, we evaluate emerging evidence on mitochondrial-centric signaling cascades implicated in AP progression and highlight novel therapeutic interventions targeting mitochondrial dysfunction, offering translational potential for refining diagnostic paradigms and treatment strategies in AP management.

A comprehensive systematic literature search was conducted across PubMed and Web of Science databases following PRISMA guidelines. The search strategy employed Boolean logic to combine Medical Subject Headings terms “acute pancreatitis” or “mild acute pancreatitis” or “severe acute pancreatitis” or “pancreatic acinar cells” and “mitochondria”. Our search encompassed articles published from January 1, 2000 to September 30, 2025, and Only publications in English language were included.

MITOCHONDRIAL STRUCTURE AND FUCTION IN PANCREATIC ACINAR CELLS

Mitochondria, double-membrane-bound organelles ubiquitous in eukaryotic cells, serve as the primary site for energy production through intracellular aerobic respiration, earning their designation as the “cellular powerhouses” (Figure 1)[22]. Beyond their role in energy metabolism, these organelles play crucial roles in cellular stress adaptation and programmed cell death regulation[23]. The mitochondrial inner membrane (IMM) exhibits a characteristic invaginated structure, forming cristae that house the respiratory chain complexes and essential enzymatic systems[24]. In contrast, the mitochondrial outer membrane (OMM) functions as both a selective barrier and molecular exchange interface. This membrane system serves a dual protective function: (1) Acting as a selective barrier that limits passive small-molecule diffusion; and (2) Maintaining cellular integrity by sequestering cytotoxic mitochondrial metabolites, including ROS and apoptotic signaling molecules[25].

Figure 1 Mitochondrial structure and function in pancreatic acinar cells. Cyp D: Cyclophilin D; ANT: Adenine nucleotide translocation; mtDNA: Mitochondrial deoxyribonucleic acid; SERCA: Sarco/endoplasmic reticulum Ca²⁺-ATPases; PMCA: Plasma membrane Ca²⁺-ATPases.

Pancreatic acinar cells exhibit a characteristic polarized architecture, compartmentalized into three distinct regions: The apical, basal, and mitochondrial (buffer) domains[26]. Physiologically, these cells orchestrate a compartmentalized mitochondrial architecture comprising three topographically segregated pools strategically positioned to regulate secretion-ready vesicles, membrane trafficking nodes, and nuclear-cytoplasmic signaling[27,28]. Mitochondria exhibit a polarized distribution, localized at the critical interface between the apical granule-rich domain and the basolateral compartment, where they execute indispensable physiological functions. This unique spatial organization facilitates essential cellular processes, including the establishment of a Ca²⁺ buffering barrier and the efficient synthesis of ATP[29].

Under physiological conditions, Ca²⁺ is released from the endoplasmic reticulum (ER), resulting in transient elevation of cytoplasmic Ca²⁺ levels[30]. During each cytosolic Ca²⁺ wave, calcium-induced calcium release mechanisms facilitate mitochondrial Ca²⁺ uptake. Subsequently, the Na⁺/Ca²⁺ exchanger gradually releases Ca²⁺, thereby modulating intracellular Ca²⁺ concentrations ([Ca²⁺]i). Importantly, mitochondria maintain physical connections with specialized ER subdomains, which serve as conduits for Ca²⁺ transfer to mitochondria, establishing dynamic Ca²⁺ exchange between these organelles. Upon reaching peak Ca²⁺ levels during ER depletion, store-operated calcium channels become activated, initiating Ca²⁺ replenishment[31]. This elevated Ca²⁺ level stimulates mitochondrial ATP production through activation of oxidative phosphorylation. The generated ATP subsequently energizes sarco/ER Ca²⁺-ATPases and plasma membrane Ca²⁺-ATPases, enabling Ca²⁺ sequestration into the ER lumen or extrusion across the plasma membrane. This regulatory mechanism prevents the accumulation of potentially cytotoxic Ca²⁺ concentrations within the cytoplasm[1].

Mitochondrial permeability transition pore (MPTP) is a group of protein complexes located between IMM and OMM. Most scholars believe that it consists of voltage-dependent anion channels in the OMM and adenine nucleotide translocation proteins and cyclophilin D (CypD) in the IMM[32]. The opening of MPTP underlies many forms of AP, and various factors, such as mitochondrial Ca²⁺ overload and overproduction of ROS, could lead to MPTP opening, which would activate pathological proenzymes within the acinar cells, and mediate impaired ATP production and necrosis[33,34]. Mitochondria regulate mitochondrial number and energy metabolism to maintain cellular homeostasis by producing ROS and causing cell death through autophagy or mitochondrial damage. As an MPTP-regulated degradation process, mitophagy modulates mitochondrial dynamics and suppresses ROS generation[30].

MOLECULAR MECHANISMS UNDERLYING MITOCHONDRIAL DYSFUNCTION IN AP

Mitochondria serve dual essential roles as both the powerhouse of cellular energy metabolism and key regulators of fundamental cellular processes, including calcium homeostasis. In pancreatic acinar cells, mitochondria demonstrate heightened susceptibility to inflammatory insults, with mitochondrial impairment being recognized as a pivotal etiological factor in the pathogenesis of pancreatitis. The underlying mechanisms involve pathological calcium overload, defective mitophagy, oxidative stress accumulation, loss of mitochondrial membrane potential, and mtDNA leakage. These interconnected perturbations synergistically exacerbate disease progression by disrupting cellular metabolic equilibrium and amplifying pro-inflammatory pathways (Figure 2).

Figure 2 The molecular mechanisms underlying mitochondrial dysfunction in acute pancreatitis. SOCE: Store-operated calcium entry; Cyp D: Cyclophilin D; ROS: Reactive oxygen species; MPTP: Mitochondrial permeability transition pore; IP3Rs: Inositol triphosphate receptors; RyRs: Ryanodine receptors; STIM1: Stromal interaction molecule 1; SERCA: Sarco/endoplasmic reticulum Ca²⁺-ATPases; OXPHOS: Oxidative phosphorylation; LC3: Microtubule-associated protein light chain 3; LAMP-2: Lysosome-associated membrane protein-2; PINK1: PTEN-induced putative kinase 1; FUNDC1: FUN14 domain containing 1; mtROS: Mitochondrial reactive oxygen species; mtDNA: Mitochondrial DNA; cGAS: Cyclic GMP-AMP synthase; STING: Stimulator of interferon genes; IRF7: Interferon regulatory factor 7; IRF3: Interferon regulatory factor 3.

Calcium overload signals in AP

Ca²⁺ signaling research has primarily centered on pancreatic acinar cells, which play a pivotal role in secreting stored digestive enzymes essential for intestinal food digestion[35]. The secretion of these digestive enzymes is regulated through G-protein coupled receptors located on the basolateral membrane, which acetylcholine and cholecystokinin (CCK) act as key mediators. This process is modulated by an increase in intracellular free calcium concentration ([Ca²⁺]i), a response triggered by secretagogues that activate these receptors, which is crucial in both physiological and pathological conditions, particularly pancreatitis[17]. Pathological calcium signaling is predominantly characterized by a sustained, whole-cell, peak-plateau-type elevation in [Ca²⁺]i, often referred to as calcium overload. Scientific investigations dating back to 1995 have implicated calcium overload in pancreatic acinar cells as a critical factor in the initiation and progression of AP[36]. Among cellular organelles, mitochondria emerge as key regulators of Ca²⁺ homeostasis. While physiological Ca²⁺ signals induced by stimulation are transient and predominantly localized to the granule-containing apical pole, persistent global increases in cytosolic Ca²⁺ concentrations can be cytotoxic. Such Ca²⁺ overload triggers inappropriate intracellular trypsin activation, cellular vacuolization, and necrosis, leading to exacerbated cell damage and frequently fatal outcomes in cases of human AP[37,38]. The mitochondria act as a buffer for Ca²⁺ in the cell due to their quick calcium absorption. Mitochondria maintain calcium homeostasis in acinar cells through Ca²⁺ storage and coordination with ER and extracellular components[39]. In the granular region of pancreatic acinar cells, it has been observed that mitochondrial Ca²⁺ uptake begins as soon as the cytosolic Ca²⁺ concentration in the granular area increases following stimulation[40]. An aberrant Ca²⁺ concentration in the mitochondria can disrupt energy metabolism, resulting in excessive ROS buildup, mitochondrial damage, and either autophagy or death. Early and crucial signs of almost all types of pancreatitis include a persistent increase in the Ca²⁺ concentration and mitochondrial permeability[40].

Intracellular Ca²⁺ signaling in pancreatic acinar cells is precisely orchestrated through the coordinated action of multiple regulatory components, including Ca²⁺ release channels, endocytosis channels, efflux proteins, and mitochondria-mediated ATP synthesis. Among these, inositol triphosphate receptors and ryanodine receptors function as principal Ca²⁺ release channels, exhibiting polarized distribution patterns in both murine and human pancreatic acinar cells[41,42]. The activation of phospholipase C triggers the hydrolysis of phosphatidylinositol bisphosphate, generating inositol triphosphate that subsequently binds to inositol triphosphate receptors. This interaction induces Ca²⁺ release from ER stores into the cytoplasm, thereby initiating diverse Ca²⁺ dependent signaling cascades[43]. A critical regulator of sustained intracellular Ca²⁺ elevation is stromal interaction molecule 1, whose activation, oligomerization, and membrane translocation are essential for maintaining Ca²⁺ homeostasis[44]. Pathological conditions, particularly those induced by ethanol and its metabolites, demonstrate that aberrant Ca²⁺ influx mediated by efflux proteins contributes to trypsinogen activation and necrotic pathway induction in acinar cells[45]. Mitochondrial Ca²⁺ handling plays a dual role in cellular physiology, not only modulating Ca²⁺ signaling but also synchronizing energy production with secretory demands. The activation of secretion by acetylcholine or CCK-elicited Ca²⁺ signals necessitates a rapid upregulation of ATP synthesis. Glucose metabolism serves as the primary energy source, with hexokinases catalyzing the conversion to glucose-6-phosphate, initiating glycolysis and ultimately generating pyruvate to fuel mitochondrial ATP synthesis. During physiological stimulation of pancreatic acinar cells with acetylcholine or CCK, mitochondria maintain local Ca²⁺ oscillations in the apical region through the mitochondrial calcium uniporter, which facilitates Ca²⁺ transport across the inner mitochondrial membrane into the mitochondrial matrix[39].

Autophagy and mitophagy in AP

Autophagy represents a fundamental cellular process that facilitates the transport and degradation of surplus or dysfunctional cytoplasmic components and organelles within lysosomes, maintaining cellular homeostasis and organelle renewal through the regulation of autophagy-related genes (ATGs)[46]. Emerging evidence implicates defective autophagy mechanisms in the pathogenesis of AP, particularly through their contribution to acinar cell vacuolization and inappropriate zymogen activation[47]. During AP progression, pancreatic acinar cells exhibit distinct autophagy dysregulation, manifesting as enhanced autophagosome biogenesis coupled with impaired lysosomal degradation capacity. This perturbation results in inflammatory cell infiltration and exacerbates acinar cell necrosis and apoptosis[11]. The lysosome-associated membrane protein-2 (LAMP-2), a crucial mediator of autophagosome-lysosome fusion events, is abundantly expressed in pancreatic tissue[48]. Experimental evidence from rat models of acute necrotizing pancreatitis demonstrates that LAMP-2 deficiency leads to intracellular accumulation of undegraded substrates within abnormally enlarged vacuoles, indicative of autophagy impairment[49]. Genetic ablation of LAMP-2 exacerbates AP severity by disrupting autophagosome-lysosome complex formation, resulting in autophagosome accumulation, impaired zymogen granule degradation, and aberrant trypsinogen activation[50]. Recent investigations have highlighted the role of sequestosome 1 (SQSTM1/p62), a multifunctional protein involved in substrate recognition during macroautophagy. Notably, extracellular SQSTM1 derived from monocytes and macrophages has been implicated in AP pathogenesis by promoting autophagy-dependent ferroptotic cell death during bacterial infections[51]. Quantitative assessment of pancreatic autophagy markers reveals that elevated levels of ubiquitinated proteins, microtubule-associated protein light chain 3 (LC3)-II, and SQSTM1/p62 serve as specific indicators of impaired autophagic flux in AP[52]. Therapeutic strategies targeting the modulation of LC3 and SQSTM1/p62 expression demonstrate promising potential in restoring autophagic function and ameliorating pancreatic tissue damage in AP models[53].

Mitophagy, a highly selective form of autophagy, serves as a critical quality control mechanism that orchestrates the targeted degradation of impaired mitochondria through lysosomal pathways. This evolutionarily conserved process is dynamically regulated in response to diverse cellular stressors, including oxidative damage, senescence-associated signals, and inflammatory cascades, thereby maintaining mitochondrial homeostasis and cellular integrity[46]. This essential cellular mechanism serves as a critical stress response mechanism, maintaining mitochondrial network integrity and functionality. The timely removal of compromised mitochondria through various mitophagy pathways is fundamental for cellular survival and function[54]. In the context of AP, the activation of mitophagy becomes crucial in mitigating cellular damage by preventing excessive inflammatory cell infiltration and ROS accumulation, thereby reducing cellular necrosis and apoptosis[11] (Figure 2). Aberrant mitophagy flux disrupts mitochondrial quality control, leading to pathological accumulation of depolarized mitochondria with impaired oxidative phosphorylation capacity. This dysfunction fundamentally alters the cellular death paradigm by skewing the necrosis-to-apoptosis equilibrium, a molecular switch that directly governs pancreatic acinar cell fate determination and ultimately dictates the clinical trajectory of pancreatitis progression[7]. The cellular machinery employs multiple molecular pathways to execute mitophagy, with three primary mechanisms being particularly well-characterized: PTEN-induced putative kinase 1 (PINK1)/Parkin RBR E3 ubiquitin-protein ligase (Parkin) axis, the Bnip3 L/Nix pathway, and the FUN14 domain containing 1 (FUNDC1)-mediated mechanism[55]. The PINK1/Parkin pathway initiates when mitochondrial membrane potential collapse leads to PINK1 accumulation on the outer mitochondrial membrane, subsequently recruiting Parkin, an E3 ubiquitin ligase. Parkin then ubiquitinates mitochondrial surface proteins, marking them for autophagosomal degradation[55]. The FUNDC1-mediated pathway, particularly responsive to hypoxic conditions, represents another crucial mitophagy mechanism. FUNDC1, an outer mitochondrial membrane protein, interacts with LC3 to facilitate the removal of damaged mitochondria. Hypoxia-induced FUNDC1 dephosphorylation enhances its binding affinity with LC3, promoting mitophagy activation and cellular protection during pathological conditions such as AP[56]. These coordinated molecular pathways collectively maintain mitochondrial quality control and cellular homeostasis under stress conditions[57].

As a fundamental mitochondrial quality control mechanism, mitophagy selectively eliminates dysfunctional, impaired, or redundant mitochondria to maintain cellular homeostasis. This evolutionarily conserved process represents a critical biological safeguard for preserving mitochondrial integrity and functional stability. Mounting evidence indicates that precise regulation of autophagosome biogenesis can effectively inhibit pancreatic zymogen activation, mitigate autophagy-associated cellular injury, and attenuate the inflammatory cascade in AP[58]. In subsequent sections, we will systematically elucidate the regulatory mechanisms of autophagy-associated pathways and their therapeutic implications in AP management. Future investigations should prioritize the comprehensive characterization of autophagy dynamics in AP pathogenesis, with particular emphasis on developing targeted strategies to restore normal autophagic flux in pancreatic acinar cells.

Oxidative stress in AP

Oxidative stress arises from disrupted equilibrium between ROS production and cellular antioxidant capacity[59]. Mitochondria constitute the predominant intracellular source of ROS, which at physiological levels act as crucial secondary messengers regulating redox-sensitive signaling cascades. Under pathological inflammatory states, however, uncontrolled ROS production exceeds endogenous antioxidant defenses, precipitating mitochondrial dysfunction through oxidative to ETC components, ultimately triggering programmed cell death pathways[12] (Figure 2). Substantial clinical and experimental evidence demonstrates that oxidative stress manifests in the initial phase of AP, with pancreatic acinar cells and tissue releasing copious oxygen free radicals that exacerbate disease progression[60].

The role of ROS in AP extends beyond cellular damage, as it significantly modulates inflammatory responses. The persistent release of inflammatory mediators in AP subjects mitochondria to sustained stress, compromising respiratory chain function and contributing to pathological ROS accumulation, a critical determinant of disease progression[61]. Experimental studies utilizing the oxidant menadione have established a direct correlation between escalating ROS levels and increased apoptotic cell death, highlighting the detrimental impact of oxidative stress on pancreatic acinar cell viability[62].

Mitochondrial dysfunction significantly impairs ATP synthesis, a critical process for maintaining essential cellular functions. In pancreatitis pathogenesis, excessive mitochondrial ROS (mitoROS) plays a pivotal role by activating multiple inflammatory signaling cascades and promoting cytokine production[12]. Experimental evidence reveals that mitoROS serves as a signaling molecule, inducing pro-inflammatory cytokine release through both inflammasome-dependent and independent mechanisms[63]. Specifically, mitoROS reduction has been shown to inhibit lipopolysaccharide-induced MAP kinase pathway activation and subsequent tumor necrosis factor-α and interleukin-6 production via an inflammasome-independent process[64]. Notably, mtDNA release, which amplifies inflammatory responses, requires coordinated activation of the NLRP inflammasome and mitoROS generation[65]. Inhibition of autophagy or mitophagy pathways leads to the accumulation of dysfunctional, ROS-generating mitochondria and cytoplasmic mtDNA release, subsequently triggering caspase-1 activation and NLRP3 inflammasome assembly[66]. Pancreatitis-induced mitochondrial dysfunction elevates intracellular oxidative stress, increasing mitoROS production that directly damages cellular components including proteins, nucleic acids, and membrane structures, ultimately culminating in necrotic and apoptotic cell death[67].

MPTP dysfunction in acute pancreatitis

The MPTP is a non-selective channel facilitating the passage of molecules under 1.5 kD across the inner mitochondrial membrane, and its opening would cause the loss of mitochondrial membrane potential, which is necessary for the synthesis of ATP[34]. Structural analyses reveal that MPTP comprises three core components: CypD in the inner membrane, adenine nucleotide translocator proteins, and voltage-dependent anion channels in the outer membrane. While transient MPTP opening facilitates physiological signal transduction, including Ca²⁺ and ROS exchange between the mitochondrial matrix and cytoplasm, persistent activation induces mitochondrial swelling, ultimately triggering apoptotic cell death[68]. In AP, MPTP activation mediates key pathological processes, including intra-acinar zymogen activation, ATP depletion, inflammatory cascades, and necrotic cell death, representing molecular, cellular, and systemic manifestations of the disease[33]. CypD, a member of the peptidyl-prolyl cis-trans isomerase family, catalyzes proline imidic peptide bond isomerization and facilitates protein folding[69]. Under conditions of elevated Ca²⁺ concentrations, CypD translocates to the inner mitochondrial membrane, where it interacts with adenine nucleotide translocator to induce MPTP opening while inhibiting ATP/adenosine diphosphate binding[33]. Genetic ablation of CypD in murine models demonstrates its critical role in AP pathogenesis, as CypD deficiency attenuates mitochondrial damage, preserves pancreatic ATP production, and mitigates key pathological features of arginine-induced AP, including inflammatory responses, necrotic/apoptotic cell death, trypsinogen activation, and acinar cell vacuolization[11]. These findings imply that blocking CypD as a novel strategy for AP management.

MtDNA integrity and dysfunction in AP

MtDNA, a critical DAMP, is typically sequestered within the mitochondrial matrix, shielded from innate immune recognition[70]. However, cellular stress conditions disrupt mitochondrial integrity, leading to mtDNA leakage into the cytosol, where it activates multiple signaling cascades and initiates immune responses[71]. MtDNA exhibits dual roles, functioning both as a pathophysiological mediator and a potential biomarker for disease severity assessment in pancreatitis pathogenesis. Clinical researches have established circulating mtDNA levels as a sensitive early indicator of AP severity, demonstrating strong correlations with clinical manifestations[72]. The association between mtDNA dysfunction and pancreatitis is further evidenced by recurrent AP cases in patients with Kearns-Sayre syndrome, a mitochondrial disorder linked to mtDNA abnormalities[73]. Experimental studies using premature aging models reveal that mtDNA mutations, particularly those affecting mitochondrial complex I, induce pancreatic α-cell proliferation, suggesting both detrimental and adaptive roles in pancreatic tissue homeostasis[45].

Mechanistically, mtDNA drives pancreatitis progression through multifaceted pathways. It coordinates mitochondrial dynamics by inducing fission and facilitating vacuole membrane protein 1-mediated selective mitophagy, thereby exerting cytoprotective effects during AP[74]. Furthermore, mtDNA regulates cell fate decisions by modulating the apoptosis-necrosis balance, a critical determinant of disease severity[7]. which is supported by the research that mtDNA plays a crucial part in the pathophysiology of pancreatitis by causing apoptosis in acinar cells and contributing to mitochondrial malfunction[75]. In pancreatic β-cells, mtDNA-mediated mitochondrial fusion events trigger lipid peroxidation and mitochondrial dysfunction, while cytosolic mtDNA fragments activate the stimulator of interferon genes (STING) pathway, culminating in apoptotic cell death[76]. Single-cell sequencing and experimental studies have elucidated that mtDNA leakage perpetuates pancreatic acinar cell damage through the cyclic GMP-AMP synthase-STING-NF-κB signaling axis[77]. In SAP cases, mtDNA-driven cyclic GMP-AMP synthase-STING signaling exacerbates lung injury by promoting macrophage pyroptosis through interferon regulatory factor 7/interferon regulatory factor 3 activation[78].

The impact of specific mtDNA mutations on pancreatitis susceptibility has been demonstrated through genetic studies. Notably, the A3243G mutation in the mtDNA has been associated with increased diabetes prevalence and recurrent pancreatitis in specific familial cohorts[79]. These findings collectively underscore the critical role of mtDNA integrity in pancreatic pathophysiology and highlight the complex interplay between mitochondrial function and pancreatic disease progression.

ADVANCES IN THERAPEUTIC STRATEGIES TARGETING MITOCHONDRIAL DYSFUNCTION IN AP

Despite the current lack of specific therapeutics for AP, emerging research has elucidated the relationship between mitochondrial dysfunction and AP pathogenesis, revealing promising therapeutic targets (Table 1). Current strategies primarily target core pathological mechanisms underlying mitochondrial dysfunction, including calcium dysregulation, mitochondrial membrane disruption, oxidative stress, and impaired mitophagy flux.

Table 1 Studies about therapeutic strategies targeting mitochondrial dysfunction in acute pancreatitis.

Ref.	Journal	Evidence level	Treatment	Model	Target
Gerasimenko et al[45], 2013	Proc Natl Acad Sci U S A	In vitro	GSK-7975A	Pancreatic acinar cells	Ca2+ channels
Wen et al[81], 2015	Gastroenterology	In vivo	GSK-7975A, CM_128	TLCS-AP in mice, CER-AP in mice, FAEE-AP in mice	ORAI1 channel
Muili et al[82], 2013	J Biol Chem	In vivo	FK506, cyclosporine A, calcineurin inhibitory peptide	TLCS-AP in mice	Ca2+ channels
Farooq et al[83], 2022	Am J Physiol Gastrointest Liver Physiol	In vivo	Phosphate supplementation	CER-AP in mice	ATP synthesis
Farooq et al[84], 2021	Gastroenterology	In vivo	Phosphate supplementation	Alcohol-induced AP in mice	ATP synthesis
Javed et al[85], 2018	Pancreas	In vivo	TRO40303	FAEE-AP in mice	CypD channels
Tóth et al[88], 2019	J Physiol	In vivo	NIM811	FAEE-AP in mice	MPTP
Márta et al[89], 2017	BMJ Open	Clinical trial1	ATP supplementation	Patients with AP	Energy nutritional support
Hu et al[90], 2023	Adv Sci (Weinh)	In vitro	Hypoxia-treated functional mitochondria	Pancreatic acinar cells	MPTP
Zhang et al[91], 2024	Phytomedicine	In vivo	Rhizoma Alismatis decoction	CER-AP in mice, HFD-AP in mice	Mitophagy
Yuan et al[92], 2021	Oxid Med Cell Longev	In vivo	Vitamin B12	3% NaT induced AP in mice	CBS/SIRT1
Lee et al[57], 2021	Int J Mol Sci	In vivo	Lycopene	Pancreatic acinar cells	ROS
Piplani et al[94], 2019	Biochim Biophys Acta Mol Basis Dis	In vivo	Simvastatin	CER-AP in mice	Mitophagy
Shen et al[95], 2018	Br J Pharmacol	In vivo	Dihydrodiosgenin	Tauro-induced AP in rats, CER-AP in mice, FAEE-AP in mice	PI3Kγ/Akt
Li et al[96], 2022	Free Radic Res	In vivo	Deoxyarbutin	3.5% NaT induced AP in mice	HtrA2/PGC-1α
Li et al[97], 2024	Int J Mol Sci	In vivo	Isorhamnetin	3.5% NaT induced AP in mice	HtrA2/GSK-3β/PGC-1α
Hoque et al[99], 2011	Gastroenterology	In vivo	TLR9 antagonist	CER-AP in mice	DAMP

¹Registration number: ISRCTN63827758.

TLCS-AP: Taurolithocholate acid sulphate-acute pancreatitis; CER-AP: Cerulein-acute pancreatitis; FAEE-AP: Fthanol and palmitoleic acid-acute pancreatitis; ORAI1: Calcium release-activated calcium modulator; AP: Acute pancreatitis; CypD: Cyclophilin D; MPTP: Mitochondrial permeability transition pore; HFD: High fat diet; NaT: Sodium taurine; CBS: Cystathionine β-synthase; SIRT1: Sirtuin 1; ROS: Reactive oxygen species; PI3Kγ/Akt: Phosphoinositide 3-kinase gamma/protein kinase B; HtrA2/PGC-1α: HtrA serine peptidase 2/peroxisome proliferator-activated receptor gamma coactivator 1-alpha; DAMP: Damage-associated molecular pattern.

A pathogenic hallmark shared across diverse AP etiologies is the dysregulation of calcium homeostasis, manifesting as sustained intracellular Ca²⁺ overload and mitochondrial permeability alterations. Recent studies indicate that pharmacologically inhibiting store-operated calcium entry or calcium release-activated calcium channels attenuates ER Ca²⁺ depletion-induced cytosolic Ca²⁺ accumulation, thereby effectively preventing trypsinogen activation and acinar cell necrosis in alcohol-related AP models[45]. However, the potential adverse effects associated with Ca²⁺ influx inhibition necessitate the exploration of alternative strategies, such as modulation of acinar cell Ca²⁺ channels, which may offer safer therapeutic approaches[80].

Accumulating mechanistic evidence indicates that mitochondrial stabilization via calcium homeostasis modulation represents a promising therapeutic strategy to ameliorate AP severity. Notably, calcium release-activated calcium modulator calcium channel inhibitors, which block pathological Ca²⁺ influx into acinar cells, demonstrate consistent protective effects in both preclinical models and primary human acinar cells, attenuating pancreatic injury and systemic complications[45,81]. Additionally, BAPTA, a membrane-permeable calcium chelator, has been shown to prevent bile acid-induced mitochondrial damage and CCK-stimulated vacuolization in pancreatic acinar cells[82]. Recent investigations have further revealed that phosphate administration improves mitochondrial activity and attenuates pathological Ca²⁺ elevation, providing protection against experimental pancreatitis[83,84].

The opening of the MPTP has been implicated in the pathogenesis of various forms of AP. Cyclosporine A, currently the only clinically approved experimental inhibitor of MPTP formation, exerts its therapeutic effect through specific inhibition of CypD[85]. As a member of the peptidyl prolyl cis-trans isomerase family, CypD plays a pivotal role in MPTP regulation, and its inhibition through genetic, molecular, or pharmacological approaches effectively prevents MPTP opening, thereby mitigating mitochondrial dysfunction and cellular necrosis in AP. Experimental evidence demonstrates that autophagy blockade through genetic deletion of ATG5, ATG7, or NF-κB kinase subunit inhibitors induces ER stress and promotes the accumulation of dysfunctional mitochondria, leading to ATP depletion. Conversely, CypD gene ablation has been shown to restore mitochondrial function and alleviate ER stress[86,87]. In the search for novel therapeutic agents, TRO40303 has emerged as a promising MPTP inhibitor. This compound interacts with the exo-mitochondrial translocation protein, delaying MPTP opening through a CypD-independent mechanism, preserving mitochondrial membrane potential, and reducing acinar cell necrosis, while demonstrating systemic protective effects in AP models[85]. Recent advancements in drug development have identified N-methyl-4-isoleucine cyclosporin, a cyclosporin A derivative, as a potent MPTP inhibitor. This compound not only rescues calcium overload-induced mitochondrial dysfunction in both pancreatic acinar and ductal cells but also dose-dependently attenuates pancreatic injury across diverse experimental AP models without observable toxicity at relevant preclinical doses[88].

Various pathological stimuli, including bile acids, ethanol, fatty acids, and their metabolites (fatty acid ethyl esters), induce mitochondrial dysfunction and ATP depletion in both pancreatic acinar and ductal cells, ultimately leading to cellular death and pancreatic necrosis. Experimental evidence demonstrates that ATP restoration in these cell types not only prevent cell death but also partially rescues cellular function. This therapeutic potential is currently being evaluated in a multicenter clinical trial investigating the efficacy of ATP supplementation combined with caloric support in AP management[89].

Hypoxic preconditioning of mitochondria has emerged as a promising therapeutic strategy, as preconditioned mitochondria can be internalized by pancreatic acinar cells, enhancing their resistance to toxic stimuli through metabolic stabilization and sustained energy supply. This protective mechanism involves hypoxia-mediated suppression of mitochondrial superoxide accumulation and upregulation of membrane potential, resulting in metabolic reprogramming[90]. In the realm of traditional medicine, Rhizoma Alismatis decoction (RAD), a two-component formulation comprising Rhizoma Alismatis and Atractylodes macrocephala rhizoma, has demonstrated significant therapeutic potential. RAD, recognized for its anti-inflammatory and lipid-modulating effects, significantly improves mitochondrial membrane potential and oxidative phosphorylation function. Mechanistic studies reveal that RAD modulates key autophagy markers, reducing beclin-1 and LC3-II expression while upregulating LAMP-1 and the Parkin-PINK pathway, thereby ameliorating hyperlipidemic AP-induced mitochondrial dysfunction through suppression of oxidative damage and enhancement of mitophagic flux[91].

Vitamins have antioxidant activity and have also been shown to negatively correlate with AP[92]. Vitamin B12 has been shown to enhance mitochondrial function repair through mitophagy activation, subsequently attenuating pancreatic edema, inflammatory responses, and necrotic damage[93]. Lycopene, a potent antioxidant, exhibits protective effects in AP by reducing ROS generation and modulating inflammatory pathways. Experimental studies demonstrate that lycopene effectively prevents palmitoleic acid-induced mitochondrial membrane potential collapse and ATP depletion in pancreatic acinar cells, suggesting that dietary lycopene supplementation may mitigate alcoholic pancreatitis progression[57].

The PINK1/Parkin2-mediated mitophagy pathway plays a crucial regulatory role in pancreatitis pathogenesis. Activation of this pathway has been shown to alleviate pancreatic inflammation through modulation of NLRP3 inflammasome activity[93]. Simvastatin, a well-known statin, demonstrates therapeutic potential in AP by reducing pancreatic edema, cellular apoptosis, and trypsin activation through Parkin-dependent mechanisms. Furthermore, simvastatin maintains autophagic flux and promotes autophagosome-lysosome fusion, thereby preventing mtDNA release[94].

Recent pharmacological research has identified dihydrodiosgenin, a diosgenin derivative, as a promising mitochondrial protectant. This compound prevents mitochondrial depolarization, ATP depletion, ROS overproduction, and excessive inflammatory responses, offering protection against pancreatitis-associated acute lung injury[95]. Deoxyarbutin has also shown therapeutic efficacy by restoring mitochondrial function and enhancing autophagic processes in pancreatic injury models[96]. Isorhamnetin, a naturally occurring flavonoid with potent antioxidant and anti-inflammatory properties, exerts protective effects in SAP through lysine (K)-specific demethylase 5B/HtrA serine peptidase 2 signaling pathway regulation. This mechanism maintains mitochondrial membrane potential, sustains ATP production, and prevents oxidative damage and mtDNA release, thereby reducing mitochondrial dysfunction in SAP[97].

Emerging evidence highlights the immunostimulatory properties of mtDNA, which contains abundant unmethylated cytosine-phosphate-guanine dinucleotide sequences capable of activating Toll-like receptor 9 (TLR9) and triggering subsequent inflammatory cascades[98,99]. Experimental studies demonstrate that both TLR9 gene silencing and pharmacological inhibition significantly attenuate pancreatic edema and inflammatory cell infiltration: TLR9 antagonists have shown efficacy in reducing pancreatic necrosis and pulmonary inflammation in taurolithocholic acid 3-sulfate-induced AP models, positioning TLR9 inhibition as a promising therapeutic strategy for AP management[94]. Mounting evidence underscores the translational value of mitochondrial biomarkers in AP. Macrophage-derived MAP kinase 14 modulates potentially regulate inflammation in SAP[100], while cytochrome C release from the inner mitochondrial membrane, may serve as an independent prognostic indicator for SAP[101].

Moreover, the role of mitochondrial metabolic regulation is also receiving increasing attention. Emerging evidence implicates the sirtuin 5-succinyl-CoA ligase ADP-forming subunit beta axis in mitochondrial dysfunction during AP, where cytochrome C1 succinylation modulates ETC complex III activity. Experimental manipulation of protein succinylation through sirtuin 5 overexpression or succinyl-CoA ligase ADP-forming subunit beta desuccinylation reduced macrophage activation and inflammation, highlighting its therapeutic potential[102]. Research demonstrates that pharmacological activation of histidine triad nucleotide-binding protein 2 alleviates inflammatory responses and pancreatic necrosis in AP by restoring mitochondrial oxidative phosphorylation via AMP-activated protein kinase/peroxisome proliferator-activated receptor gamma coactivator-1α signaling axis[103]. Furthermore, mechanistic investigations revealed that chromatin remodeler mortality factor 4-like protein 1 exacerbates apoptosis in lipidemic AP by suppressing FUNDC1-dependent mitophagy, thereby disrupting mitochondrial quality control and amplifying caspase-3 activation[104].

While targeted therapies modulating Ca²⁺, ROS, or MPTP show therapeutic promise, their translational potential requires careful risk-benefit analysis. As fundamental regulators of cellular homeostasis, global inhibition or activation may induce off-target effects in non-diseased tissues. Compared to systemic administration, tissue-specific delivery systems could enhance specificity[105-108]. Notably, interspecies differences in drug metabolism may render compounds safe in animal models yet clinically hazardous. More evidence is needed.

LIMITATIONS

Our study has several limitations that warrant consideration. First, despite employing systematic search strategies, the included literature may not be exhaustive. This is particularly relevant for studies investigating mitochondrial involvement in AP pathogenesis but lacking explicit terminology in titles or keywords. Additionally, potential publication bias may have led to underrepresentation of negative or null results in the available literature. Second, substantial heterogeneity exists among the included AP research models, which may compromise cross-study comparability and generalizability of findings. Third, the translational implications of our findings are constrained by the predominance of preclinical evidence, as the majority of included studies utilized animal models or in vitro systems, with limited representation of clinical trials or human cohort studies. Finally, while this work specifically examines mitochondrial dysfunction and related therapeutic targets, we acknowledge that AP involves complex interplay among multiple pathways, including calcium dysregulation, ER stress, and etc., which were not the primary focus of this investigation but may functionally interact with mitochondrial mechanisms.

Future research recommendations

Despite compelling preclinical evidence linking mitochondrial dysfunction to AP, including impaired oxidative phosphorylation, ROS overproduction, and MPTP opening, no clinically validated mitochondrial biomarkers currently exist for AP severity stratification. The development of such translational biomarkers may revolutionize AP management by enabling early risk prediction and personalized therapeutic interventions. Furthermore, AP pathogenesis involves a complex interplay of multiple pathological mechanisms, notably calcium overload-induced acinar cell injury, ER stress-mediated apoptosis, and mitochondrial bioenergetic failure. This multi-hit pathophysiology suggests that single-target therapies may be insufficient, whereas multi-target strategies could offer synergistic benefits. Such precision medicine approaches may improve AP outcomes by addressing its multidimensional pathophysiology, ultimately reducing disease progression and organ failure. Inflammatory diseases may share the common feature of mitochondrial dysfunction. Specifically, hepatitis or myocarditis shared mechanisms including MPTP dysregulation, mitochondrial redox imbalance, DAMP release, and etc. This mechanistic overlap suggests therapeutic cross-reactivity: Mitochondrial-protective agents effective in hepatitis or myocarditis may demonstrate efficacy in AP. It is important to emphasize that current evidence remains confined to preclinical studies, with a translational gap persisting between bench-scale discoveries and clinical applications.

CONCLUSION

Mitochondrial dysfunction emerges as a pivotal factor in the pathophysiological cascade of AP, a severe inflammatory disorder of the pancreatic tissue. The onset and progression of AP are fundamentally associated with impaired mitochondrial performance, characterized by diminished ATP synthesis, elevated oxidative stress markers, and disruption of mitochondrial membrane integrity. These alterations lead to excessive generation of mitoROS, thereby amplifying cellular injury and inflammatory responses. The compromised mitochondrial function initiates programmed cell death pathways through the cytoplasmic release of pro-apoptotic factors, particularly cytochrome C. Additionally, AP-induced oxidative modifications and genetic alterations in mtDNA further deteriorate mitochondrial bioenergetics and cellular metabolic homeostasis. These molecular insights underscore the critical role of mitochondria in AP pathogenesis and highlight their potential as therapeutic targets.