Fetal growth restriction (FGR) is a major cause of neonatal mortality, but no therapeutic options are available for the intrauterine period. Hydroxychloroquine (HCQ), a drug used to treat malaria and autoimmune diseases, reportedly has beneficial effects on pregnancy outcomes in women with lupus or antiphospholipid antibody syndrome, which is often associated with FGR. We investigated the effect of HCQ on fetal growth using a dexamethasone (DEX)-induced FGR rat model. Pregnant Sprague-Dawley rats were divided into three groups (n = 10 for each group): control, DEX (using an osmotic pump), and DEX plus HCQ (administered on gestational days 13-19). All animals were sacrificed on gestational day 20. The weight of each pup was recorded. Maternal serum and placental proteins in each group were compared using an Olink proteomics tool. Administration of DEX induced the FGR (<10th percentile; P < 0.001) , which was marginally recovered by HCQ (P = 0.087). However, systolic blood pressure, serum soluble fms-like kinase-1 levels, and placental thickness were not affected by DEX or the addition of HCQ. Olink proteomic analysis revealed that multiple maternal serum proteins involved in embryonic and placental development were significantly decreased in the DEX-induced FGR rat model but restored by HCQ. Our data showed that HCQ partially restored decreased fetal weight in DEX-induced FGR rats, and these changes involved embryonic and placental development-related signaling pathways during pregnancy. Collectively, these results suggest that HCQ can serve a therapeutic drug to mitigate intrauterine FGR.

This study aimed to investigate biochemically and histopathologically the protective effect of adenosine triphosphate (ATP) and coenzyme Q10 (CoQ10) against potential hydroxychloroquine (HCQ)-induced retinal damage in rats. Twenty-four male albino Wistar-type rats were randomly separated into four groups: healthy (HG), receiving HCQ (HQG), receiving ATP + HCQ (AHQ), and receiving CoQ10 + HCQ (CoQHQ). ATP (4 mg/kg, intraperitoneal) was given to the AHQ, and CoQ10 (10 mg/kg, oral) to the CoQHQ. Rats in the HQG, AHQ, and CoQHQ were given HCQ (120 mg/kg, oral) 1 h after administering ATP and CoQ10. Treatments continued once a day for seven days. On the 8th day, the rats were sacrificed with 50 mg/kg sodium thiopental, and the eyes were removed. Malondialdehyde (MDA), total glutathione (tGSH), superoxide dismutase (SOD), and catalase (CAT), and interleukin-6 (IL-6) levels were measured in the retrieved eye tissues and retinal tissues were assessed histopathologically. An increase in MDA and IL-6 levels and a decrease in tGSH, SOD, and CAT levels were detected in the eye tissues of the HQGcompared to the HG. HCQ-induced changes in oxidant and antioxidant levels were significantly suppressed by ATP and CoQ10 treatment. ATP was more successful than CoQ10 in this inhibition. Severe damage was observed in the eye tissues of the HQG group, whereas the damage was mild in the AHQ and moderate in the CoQHQ. Although both ATP and CoQ10 have the potential to be effective in the prevention of HCQ-induced retinal damage through antioxidative activity, ATP appears to be the more preferable treatment approach.

Dysfunction of the lysosome and autophagy-lysosome pathway is closely associated with various diseases, such as neurodegenerative diseases, non-alcoholic fatty liver disease (NAFLD), etc. Additionally, chloroquine is a clinically widely used drug for treating malaria and autoimmune diseases, but long-term or high-dose administration may lead to significant toxic side effects. Attapulgite (ATT), a natural nanomaterial with excellent adsorption capacity and biocompatibility, herein demonstrated a novel biological function in regulating the lysosomal and autophagy-lysosome pathway. ATT could be effectively internalized into lysosome-related acidic compartments. Further study revealed that ATT could restore lysosomal pH, activate cathepsin D, alleviate autophagy blockage in chloroquine-treated cells, and reduce chloroquine-elicited cell death. In a cell model related to Huntington's disease, treatment with ATT reinforced the degradation of the mutant huntingtin proteins by increasing cathepsin D maturation and autophagy flux. ATT could also promote lipid droplet clearance in hepatocytes with palmitic acid-induced steatosis, reduce hepatic lipid accumulation, and improve fasting blood glucose in high-fat-diet-induced NAFLD mice. These findings establish ATT as a lysosomal modulator, providing a foundation for its therapeutic potential in mitigating the adverse effects associated with long-term chloroquine use, especially improving neurodegenerative and metabolic disorders.

The application of swept-source optical coherence tomography angiography (SS-OCTA) technique is used to detect the effects of long-term use of hydroxychloroquine (HCQ) on retinal structure and microcirculation in patients with systemic lupus erythematosus (SLE) before visual dysfunction occurs.

Retrospective case-control study. A total of 73 SLE patients (73 eyes) who had taken HCQ regularly for a long period of time were included as the SLE patient group, while 21 healthy individuals (21 eyes) were included as the control group. Based on the duration of HCQ use (HCQ course), the SLE patient group was divided into baseline group (6 months ≤ medication time < 1 year), low-risk group ( 1 year ≤ medication time < 5 years), and high-risk group (medication time ≥ 5 years). All participants underwent bilateral SS-OCTA macular imaging (6 mm*6 mm), slit-lamp examination, non-contact tonometry, computerized visual field (30 - 2) test, and fundus autofluorescence imaging (FAF).

Compared among the groups, the full-layer retinal thickness and superficial blood vessel density of the fovea, below the inner circle, temporal side of the outer circle and above the outer circle decreased in the macular area (6 mm*6 mm) in high-risk group of SLE patients, while the area and circumference of FAZ increased (P < 0.0125). Correlation analysis suggested that the duration of SLE disease and HCQ cumulative dose were negatively correlated with superficial retinal capillary plexus vessel density (SCP-VD) in the three regions of inner retina, full-layer retinal thickness in the fovea, fovea, temporal side of the inner circle, and above the inner circle (r < 0,P < 0.05), and positively correlated with the area and circumference of FAZ (r > 0,P < 0.05).

Analysis by SS-OCTA examination showed that long-term HCQ treatment had adverse effects on the inner retina, SCP-VD and FAZ parameters in subclinical SLE patients without visual impairment.

An initial series of NLRP3 agonist antibody-drug conjugates (ADCs) failed to induce IL-1β in vitro due to lysosomal trapping of the payload. To address this, we developed assays and computational tools to identify a new payload that could diffuse out of the lysosomes. ADCs derived from this payload were active, emphasizing the need to avoid payload lysosomal accumulation for nonlysosomal targets. Two active ADCs necessitated attaching a cleavable valine-citrulline recognition element to the payload via a noncanonical ester linkage, rather than a canonical carbamate one, since the payload did not contain a basic amine. The citrulline stereocenter configuration was found to affect the payload release and in vitro activity. The ADC with the (L)-Val-(L)-Cit ester configuration showed superior in vitro activity, high stability in mouse serum, and rapid cleavage in human liver lysosomes. These properties suggest that this noncanonical (L)-Val-(L)-Cit ester attachment may be valuable to the ADC community moving forward.

Despite remarkable progress in designing RNA delivery systems, endosomal escape remains a recognized challenge for efficient RNA delivery. In this study, we develop a robust mRNA delivery platform termed endosomolytic chloroquine-like optimized lipid nanoparticles (ecoLNPs) for versatile mRNA delivery in vitro and in vivo via integrating the signature scaffold extracted from endosomolytic chloroquine into ionizable lipids. RNase-resistant ecoLNPs are capable of delivering a broad variety of mRNA payloads to diverse cell types, even hard-to-transfect 3D cells, with an efficiency of up to 18.9-fold higher than that of commercial transfection reagents. The pH-responsive endosomolytic activity of ecoLNPs can be largely attributed to the proton sponge effect and saposin B-promoted membrane disruption. In vivo, ecoLNPs enable potent local and systemic mRNA delivery and exhibit comparable potency to the clinically approved mRNA vaccine carrier, but strong tropism for lymph nodes following intramuscular injection. Furthermore, ecoLNPs are able to retain in vivo delivery potency for at least one week under non-frozen conditions and induce efficient genome editing in transgenic mice. Overall, the structure-guided integration strategy provides a pathway for de novo design of endosomolytic mRNA delivery systems.

Advances in small RNA sequencing have revealed diverse small noncoding RNAs (sncRNAs) beyond microRNAs (miRNAs), derived from transfer RNAs (tRNAs), ribosomal RNAs (rRNAs), small nuclear RNAs (snRNAs), and Y RNAs, carrying distinct RNA modifications. These emerging sncRNAs can function beyond RNA interference (RNAi), adopting aptamer-like roles by interacting with Toll-like receptors 7 and 8 (TLR7 and TLR8) via specific sequences, modifications, and structures. We propose a Sequential Activation Hypothesis where initial abnormal sncRNAs - triggered by infections or stresses - activate TLR7/8, leading to autoantibody production against autoantigens like RNA-binding proteins La and Ro. These autoantibody-antigen complexes further promote secondary immunogenic sncRNA production and repetitive TLR7/8 activation, perpetuating a vicious cycle sustaining autoimmunity. TLR7/8's X chromosome location and sex-biased expression contribute to female-dominant autoimmune diseases. Understanding sncRNA-TLR interactions is essential for designing novel therapeutic strategies.

To explore the potential combined effects of hydroxycholoroquine (HCQ) and its metabolites on blood lipids and glucose in the treatment of rheumatoid arthritis (RA).

In the HCQ group, the concentrations of HCQ and its metabolites, including desethylhydroxychloroquine (DHCQ), esethylchloroquine (DCQ) and bisdesethylchloroquine (BDCQ), were detected by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The relationships between the levels of blood lipid and glucose and concentrations of HCQ and its metabolites were also analysed. Further, a multiple regression model was employed to evaluate the actual roles of HCQ and its metabolites in various factors affecting blood lipids and glucose.

Significant higher high-density lipoprotein cholesterol (HDL) and lower low-density lipoprotein cholesterol (LDL) are found in the HCQ group than in the control group [1.63 ± 0.39 mmol/l vs. 1.39 ± 0.35 mmol/l, p < 0.001; 2.15 (1.80, 2.81) mmol/l vs. 2.54 (2.24, 3.10) mmol/l, p = 0.017, respectively]. Multivariate regression analysis indicates only HCQ concentration might act as an independent factor influencing the levels of HDL, VLDL, and TG in RA patients.

HCQ might increase HDL level and reduce LDL, VLDL, TC, and TG levels in RA treatment. These beneficial effects on modifying lipid profile might be counteracted to various degrees by some of its metabolites (DHCQ and BDCQ). Therefore, for RA patients with HCQ in their treatment regime, it might facilitate the improvement of lipids profile by promoting the excretion of HCQ metabolites. This study did not demonstrate the significant hypoglycemic effect of HCQ and its metabolites.

Statins, commonly used to lower cholesterol, are associated with improved prognosis in colorectal cancer (CRC), though their effectiveness varies. This study investigates the anti-cancer effects of atorvastatin in CRC using patient-derived organoids (PDOs) and PDO-derived xenograft (PDOX) models. Our findings reveal that atorvastatin induces mitochondrial dysfunction, leading to apoptosis in cancer cells. In response, cancer cells induce mitophagy to clear damaged mitochondria, enhancing survival and reducing statin efficacy. Analysis of a clinical cohort confirms mitophagy's role in diminishing statin effectiveness. Importantly, inhibiting mitophagy significantly enhances the anti-cancer effects of atorvastatin in CRC PDOs, xenograft models, and azoxymethane (AOM)-dextran sulfate sodium (DSS) mouse models. These findings identify mitophagy as a critical pro-survival mechanism in CRC during statin treatment, providing insights into the variable responses observed in epidemiological studies. Targeting this vulnerability through combination therapy can elicit potent therapeutic responses.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by KRAS- and autophagy-dependent growth. Inhibition of the KRAS-RAF-MEK-ERK pathway enhances autophagic flux and dependency, and concurrent treatment with the nonspecific autophagy inhibitor chloroquine (CQ) and ERK-MAPK pathway inhibitors can synergistically block PDAC growth. However, CQ is limited in terms of specificity and potency. To find alternative anti-autophagy strategies, in this study, we performed a CRISPR-Cas9 loss-of-function screen in PDAC cell lines that identified the lipid kinase phosphatidylinositol-3-phosphate 5-kinase (PIKfyve) as a growth-promoting gene. PIKfyve inhibition by the small molecule apilimod resulted in durable growth suppression, with much greater potency than CQ treatment. PIKfyve inhibition caused lysosomal dysfunction, reduced autophagic flux, and led to the accumulation of autophagy-related proteins. Furthermore, PIKfyve inhibition blocked the compensatory increases in autophagic flux associated both with MEK inhibition and with direct RAS inhibition. Accordingly, combined inhibition of PIKfyve and the RAS-MAPK pathway showed robust growth suppression across a panel of KRAS-mutant PDAC models. Growth suppression was due, in part, to potentiated cell-cycle arrest and induction of apoptosis following loss of inhibitor of apoptosis proteins. These findings indicate that concurrent inhibition of RAS and PIKfyve is a synergistic, cytotoxic combination that may represent a therapeutic strategy for PDAC. Significance: PIKfyve inhibition effectively blocks autophagy in multiple models of KRAS-mutant pancreatic cancer and can synergize with inhibitors of members of the RAS-MAPK pathway, providing an effective combination strategy for pancreatic cancer.

Exposure to particles is a driver of several inflammatory diseases. Here, we investigated macrophage responses to monosodium urate crystals, calcium pyrophosphate crystals, aluminum salts, and silica nanoparticles. While each particle induced a distinct gene expression pattern, we identified a common inflammatory signature and acute activation of lysosomal acidification genes. Using monosodium urate crystals as a model, we demonstrated that this lysosomal gene program is regulated by a 5'-prime-AMP-activated protein kinase (AMPK)-dependent transcriptional network, including TFEB, TFE3, and the epigenetic regulators DNA methyl transferase 3a (DNMT3A) and DOT1L. This lysosomal acidification program operates in parallel with, but largely independently of, a JNK-AP-1-dependent network driving crystal-induced chemokine and cytokine expression. These findings reveal a bifurcation in pathways governing inflammatory and lysosomal responses, offering insights for treating particle-associated diseases.

Idiopathic pulmonary hemosiderosis (IPH) is a rare interstitial lung disease. Glucocorticosteroids and hydroxychloroquine are the most commonly used treatments. Although neuropsychiatric side effects related to hydroxychloroquine use are seen in adult cases, only one paediatric patient has been reported in the literature.

We report a case of a 6-year-old girl with IPH, who developed neuropsychiatric symptoms, including restlessness, confusion and myoclonic movements, after the therapeutic use of hydroxychloroquine.

With increasing knowledge and experience of interstitial lung disease, the use of hydroxychloroquine treatment is increasing. It is important to remember that hydroxychloroquine is a central nervous system stimulant, and neuropsychiatric side effects may be seen in children. This report highlights the importance of recognising potential neuropsychiatric side effects in paediatric patients using hydroxychloroquine, especially when combined with corticosteroids or other risk factors.

Benzo[ghi] perylene (b[ghi]p) is classified as non-carcinogenic to humans, and there are currently no occupational exposure models available to identify its effects. The aim of this work was to evaluate the effect of b[ghi]p on the lysosomes of NL-20 cells (a human bronchial cell line) exposed to 4.5 μM for 3 h. The effect was evaluated through an ultrastructural evaluation, morphological changes, and acridine orange staining of lysosomes. Superoxide was quantified; and SOD1, cathepsin B, LAMP1, galectin-3 and LC3α/β, and Rab7 expression was evaluated by immunocytochemistry. The expression of genes related to oxidative stress responses (NRF2, NQO1, HMOX1 and PRDX1) and genes related to autophagy (ULK1, ATG9, BCN1, VMP1, TMEM41B and p62) were quantified by RT-qPCR. The ultrastructural evaluation revealed an increase in autophagic vesicles and phagophores in cells exposed to b[ghi]p, as well as vesicles derived from mitochondria. Based on morphology, there were vesicles in the cytoplasm. B[ghi]p significantly decreased the number of lysosomes (p < 0.05), and NAC reverse this effect (p < 0.05). Superoxide production was observed from 30 min to 3 h (p < 0.05). Immunocytochemistry revealed increased galectin-3 and LC3α/β. All oxidative stress-related genes showed high expression (p < 0.05), and the expression of ATG9 gene was decreased (p < 0.05). These results demonstrate that b[ghi]p induces oxidative stress, responsible for producing the toxic effects in the lysosomes of NL-20 cells.

Hydroxychloroquine (HCQ), a synthetic antimalarial, is recognized for its immunomodulatory, anti-inflammatory and vascular-protective effects. In 20-30% of cases of primary obstetrical antiphospholipid syndrome (APS), the combination of antiplatelet aggregation and prophylactic anticoagulation fails to prevent obstetrical complications, a situation referred to as refractory obstetrical APS. This is partly due to the pro-inflammatory effects of antiphospholipid antibodies (aPL) binding to decidual and trophoblastic cells, which compromise embryonic implantation and placentation. Experimental studies in vitro and in mouse models have shown that HCQ can inhibit the detrimental effect of aPLs on trophoblastic invasion, findings corroborated by retrospective observational clinical studies. However, no randomized controlled trial has evaluated the addition of HCQ to conventional therapy for refractory obstetric APS. The hypothesis of allo-immune and/or autoimmune mechanisms involved in cases of recurrent pregnancy loss (RPL) with no identified cause and in chronic intervillositis of unknown etiology (CIUE) has led to the empirical use of HCQ in these indications. However, current evidence does not support its use in unexplained RPL. A few clinical studies of low scientific evidence suggest a benefit of HCQ in CIUE, but further data are needed. Finally, pre-eclampsia (PE) is another pregnancy-related condition at risk of recurrence, and its pathogenesis also seems to involve an imbalance in immune responses. HCQ's antioxidant properties could have a positive effect on endothelial dysfunction, a key component of PE.

Hydroxychloroquine (HCQ) is an antimalarial drug that has historically been used to treat and prevent malaria. However, its mechanism of action has not yet been fully elucidated. HCQ affects various cellular and molecular pathways through different mechanisms. HCQ has also been shown to be a disease‑improving agent for the treatment of rheumatic diseases, including systemic lupus erythematosus, antiphospholipid syndrome, rheumatoid arthritis and primary Sjögren's syndrome. Although generally considered safe, adverse reactions have been reported with the use of HCQ and clinicians should carefully monitor patients with rheumatism when prescribing these drugs. The purpose of the present review is to strengthen the clinical use of HCQ for autoimmune diseases while highlighting the adverse effects that may occur during treatment.

Hydroxychloroquine (HCQ) is a medication that is commonly used as an antimalarial or disease-modifying anti-rheumatic drug (DMARD). Adverse side effects typically include retinal damage, cardiomyopathy, and neuromyopathy. However, there has been relatively little documentation on the effects of HCQ toxicity on the liver. We describe a case of HCQ-induced hepatic failure in a 31-year-old female patient on HCQ for systemic lupus erythematous who presented with three days of fever, diarrhea, and non-bilious, non-bloody vomiting. Labs showed massively elevated liver function tests (LFTs) and negative viral serology. The abdominal ultrasound and magnetic resonance cholangiopancreatography were unremarkable. A liver biopsy showed portal tracts with mild to moderate expansion by mixed inflammatory infiltrates, including scattered eosinophils and rare plasma cells with occasional mild interface activity focally close to bridging inflammation. These findings are consistent with drug-induced liver injury (DILI). HCQ was subsequently held, and the patient was admitted to the ICU for conservative management. Repeat LFTs showed down-trending over the course of the patient's four days of admission after discontinuation of HCQ and returned to baseline within a two-month timeframe.

To evaluate the use of hydroxychloroquine (HCQ) and its impact on the Health Assessment Questionnaire disability index(HAQ-DI) and the Cochin Hand Function Status(CHFS) in a large Systemic Sclerosis (SSc) cohort.

SSc patients from the European Scleroderma Trials and Research (EUSTAR) database treated with HCQ for at least 6 months were evaluated and compared to a matched group of SSc patients not using HCQ. Demographic and clinical data, concomitant drugs, HAQ-DI and CHFS (at least 2 evaluations) were recorded and were the outcome variables of interest. Statistical analysis was performed using propensity score matching for age, gender, disease duration, corticosteroids, immunosuppressives, vasoactive drugs in a 3:1 control: HCQ ratio. Standard descriptive statistics and Student's t-test and Chi-square test were used to assess the propensity-matched groups.

Out of 17,805 SSc patients evaluated, 468 (2.6%) used HCQ and constituted the HCQ group. Among them, 50 (10.7%) had at least a baseline and follow-up HAQ-DI evaluation and 44 (9.4%) had at least a baseline and follow-up CHFS evaluation. Propensity matching assured that patients were matched for female gender (HCQ vs. control 92.0% vs. 85.3%), mean age (49.8 vs. 50.0 years) disease duration (8.3 vs. 9.1 years), limited disease (55.3 vs. 62.6%) as well as background medications (all P > 0.1). We did not find any significant differences among the two groups in the change of HAQ-DI or CHFS, over up to 365 days (all P > 0.05).

Results from the EUSTAR registry showed that HCQ was used by 2.6% of SSc patients. HCQ use did not improve the HAQ-DI, or CHFS when comparing HCQ users to non-HCQ users.

Systemic lupus erythematosus (SLE) is a chronic inflammatory illness with heterogeneous clinical manifestations covering multiple organs. Diversified types of medications have been shown effective for alleviating SLE syndromes, ranging from cytokines, antibodies, hormones, molecular inhibitors or antagonists, to cell transfusion. Drugs developed for treating other diseases may benefit SLE patients, and agents established as SLE therapeutics may be SLE-inductive. Complexities regarding SLE therapeutics render it essential and urgent to identify the mechanisms-of-action and pivotal signaling axis driving SLE pathogenesis, and to establish innovative SLE-targeting approaches with desirable therapeutic outcome and safety. After introducing the research history of SLE and its epidemiology, we categorized primary determinants driving SLE pathogenesis by their mechanisms; combed through current knowledge on SLE diagnosis and grouped them by disease onset, activity and comorbidity; introduced the genetic, epigenetic, hormonal and environmental factors predisposing SLE; and comprehensively categorized preventive strategies and available SLE therapeutics according to their functioning mechanisms. In summary, we proposed three mechanisms with determinant roles on SLE initiation and progression, i.e., attenuating the immune system, restoring the cytokine microenvironment homeostasis, and rescuing the impaired debris clearance machinery; and provided updated insights on current understandings of SLE regarding its pathogenesis, diagnosis, prevention and therapeutics, which may open an innovative avenue in the fields of SLE management.

Hydroxychloroquine (HCQ), by virtue of its ability to reduce proteinuria, is an alternative therapy for Immunoglobulin A nephropathy (IgAN). This study investigated the effects of different doses of HCQ on the structure of intestinal flora and glycosyltransferase activity in IgAN rats.

IgAN model rats constructed by treatment of bovine serum albumin, castor oil and lipopolysaccharide were administered with HCQ (18 or 36 mg/kg) by gavage. Then the number of urine erythrocyte and the renal function of rats were evaluated. The levels of galactose-deficient IgA1 (Gd-IgA1), B cell activation factor (BAFF) and C-reactive protein (CRP) in serum and those of inflammatory factors in renal tissue were detected by ELISA. Renal tissue injury and IgA deposition were assessed by histological analysis. The expressions of Core 1 beta1,3-galactosyltransferase (C1GALT1), Core 1 synthase specific molecular chaperone (COSMC) and ST6 N-acetylgalactosaminide alpha-2,6-sialyltransferase 2 (ST6GALNAC2) were quantified by qRT-PCR, Western blot or in vitro enzyme assays. 16 s rDNA sequencing was used to analyze the structure of intestinal flora in rats.

HCQ dose-dependently decreased the levels of serum creatinine, UREA, Gd-IgA1, BAFF, CRP and urine protein, waned the number of urine erythrocyte, inhibited the expressions of inflammatory factors and IgA deposition in renal tissue, and up-regulated the expressions of C1GALT1, COSMC and down-regulated ST6GALNAC2 expression in peripheral blood mononuclear cells (PBMCs).

HCQ could reduce glomerular swelling in mesangial area and improve the imbalance of intestinal flora in IgAN rats.

Autophagy impairments have been implicated in various aging conditions. Previous studies in cervical motor neurons show an age-dependent increase in the key autophagy proteins LC3 and p62, reflecting autophagy impairment and autophagosome accumulation. Chloroquine is commonly used to inhibit autophagy by preventing autophagosome-lysosome fusion and may thus emulate the effects of aging on the neuromuscular system. Indeed, acute chloroquine administration in old mice decreases maximal transdiaphragmatic pressure generation, consistent with aging effects. We hypothesized that chloroquine alters diaphragm muscle neuromuscular junction (NMJ) morphology and increases denervation. Adult male and female C57BL/6 × 129J mice between 5 and 8 months of age were used to examine diaphragm muscle NMJ morphology and denervation following daily intraperitoneal injections of chloroquine (10 mg/kg/d) or vehicle for 7 days. The motor end-plates and pre-synaptic terminals were fluorescently labeled with α-bungarotoxin and anti-synaptophysin, respectively. Confocal microscopy was used to assess pre- and post-synaptic morphology and denervation. At diaphragm NMJs, chloroquine treatment decreased pre-synaptic volume by 12% compared to the vehicle (p < 0.05), with no change in post-synaptic volume. Chloroquine treatment increased the proportion of partially denervated NMJs by 2.7-fold compared to vehicle treatment (p < 0.05). The morphological changes observed were similar to those previously reported in the diaphragm muscles of 18-month-old mice. These findings highlight the importance of autophagy in the maintenance of the structural properties at adult NMJs in vivo.

The unique immunomodulatory properties of hydroxychloroquine (HCQ) have attracted considerable interest beyond its use for malaria and rheumatological diseases, including a variety of dermatological conditions. Over recent years, especially after the coronavirus disease 2019 (COVID-19) pandemic, the prescription of HCQ has also significantly expanded, sometimes inappropriately, thus posing additional challenges on its optimal use, due to emerging safety issues. In this review, we provide dermatologists with the latest advancements on selected clinically relevant toxicities, namely retinopathy, pro-arrhythmia, cutaneous reactions, and neuropsychiatric effects. It is hoped this update can assist dermatologists to identify high-risk patients for tailored monitoring, screening, and risk minimization strategies, thus supporting safer HCQ prescribing.

Systemic lupus erythematosus is considered a prototype of human autoimmune disease based on the appearance of multiple autoantibodies, some of which can have a direct pathogenic effect on tissues. Most therapeutic modalities aim to check the enhanced humoral responses by targeting T and B cells with conventional or biologic drugs. However, in some cases, the clinical response is limited and frequently takes a high toll of toxicity in patients. The last 2 decades have brought up novel discoveries showing profound disturbances of innate immune cell function in systemic lupus erythematosus, including dysregulated NETosis, increased apoptosis, type 1 interferon, and granulopoiesis signatures that are grounded in basic cell biology abnormalities, including response to excessive oxidative stress, mitochondrial dysfunction, and upregulation of the cGAS-STING pathway. Whether the prominent autoimmunity component of lupus patients is sufficient to drive this chronic disease or follows a breakdown of innate immune homeostasis in response to the environmental factors triggering disease is the subject of this revision.

Cells and tissues turn over their aged and damaged components in order to adapt to a changing environment and maintain homeostasis. These functions rely on lysosomes, dynamic and heterogeneous organelles that play essential roles in nutrient redistribution, metabolism, signaling, gene regulation, plasma membrane repair, and immunity. Because of metabolic fluctuations and pathogenic threats, lysosomes must adapt in the short and long term to maintain functionality. In response to such challenges, lysosomes deploy a variety of mechanisms that prevent the breaching of their membrane and escape of their contents, including pathogen-associated molecules and hydrolases. While transient permeabilization of the lysosomal membrane can have acute beneficial effects, supporting inflammation and antigen cross-presentation, sustained or repeated lysosomal perforations have adverse metabolic and transcriptional consequences and can lead to cell death. This review outlines factors contributing to lysosomal stress and damage perception, as well as remedial processes aimed at addressing lysosomal disruptions. We conclude that lysosomal stress plays widespread roles in human physiology and pathology, the understanding and manipulation of which can open the door to novel therapeutic strategies.

To describe the clinical features of Chinese patients with HCQ-induced pigmentation and analyse the potential risk factors associated with HCQ-induced pigmentation.

A cross-sectional study was conducted over a duration of 7 months, during which patients who had received HCQ treatment for >6 months were included. Data was collected through a structured questionnaire that encompassed demographic and geographic characteristics, information on HCQ and concomitant medication usage, sun exposure characteristics and hyperpigmentation-related characteristics. Univariate and multivariate analyses were employed to calculate the statistical association between HCQ-induced pigmentation and multiple variables.

Out of 316 patients, 83 (26.3%) patients presented hyperpigmentation during HCQ treatment. Hyperpigmentation was presented after a median duration of HCQ treatment of 12 months (interquartile range, 6.0-30.0 months) with a median cumulative dose of 108 g of HCQ (interquartile range, 36-288 g). The most frequently affected sites of pigmentation were the face (60.2%), lower limbs (36.1%) and hands (20.5%). There was a linear decrease in the incidence of pigmentation with increasing daily sun exposure time (P = 0.030). In the multivariate analysis, variables (cumulative HCQ dose and daily sun exposure time) were included in the final models. The results revealed an independent correlation between HCQ-induced pigmentation and daily sun exposure exceeding 1 h (OR: 0.431; 95% CI: 0.208-0.892; P = 0.023).

The occurrence of HCQ-induced pigmentation is not uncommon, with an incidence rate of 26.3%. Daily sun exposure time exhibited a protective effect against HCQ-induced pigmentation.

To investigate the proportion of low-density granulocytes (LDGs), circulating plasma neutrophil extracellular traps (NETs) and serum-induced NET formation in patients with incomplete SLE (iSLE) and SLE.

LDGs were measured cross-sectionally in 18 iSLE patients, 11 SLE patients and 14 healthy controls (HCs), whereas circulating NETs and serum-induced NET formation were assessed in 35 iSLE patients, 41 SLE patients and 16 HCs. LDGs (CD14lowCD15+) were measured in peripheral blood mononuclear cells (PBMCs) using flow cytometry, and circulating plasma NETs were measured using anti-myeloperoxidase-DNA, anti-citrullinated histone H3 and anti-elastase-DNA complex ELISAs. Serum-induced NET formation was assessed by incubating healthy neutrophils with serum from iSLE patients, SLE patients or HCs and visualizing NETs with fluorescence microscopy.

Proportions of LDGs and circulating plasma NETs were similarly elevated in iSLE and SLE patients compared with those in HCs. Furthermore, patients under HCQ treatment had lower proportions of LDGs than those without. Serum from iSLE and SLE patients similarly induced NET formation in healthy neutrophils. In iSLE patients, myeloperoxidase-DNA complexes were correlated with proportions of age-associated B-cells, memory B-cells and negatively with naïve B-cells, while we did not find associations between measures of NETs or serum-induced NET formation and interferon score or clinical parameters.

These results show that neutrophil dysfunction, including higher proportions of LDGs, and increased NET formation, already occur in iSLE, similar to SLE, despite differences in disease manifestations. Thereby, neutrophil dysfunction may contribute to sustained exposure to autoantigens and autoreactivity in early stages of SLE.

The interactions of drugs with the host's immune cells determine the drug's efficacy and adverse effects in patients. Nonsteroidal Anti-Inflammatory Drugs (NSAID), such as corticosteroids, NSAIDs, and immunosuppressants, affect the immune cells and alter the immune response. Molecularly, drugs can interact with immune cells via cell surface receptors, changing the antigen presentation by modifying the co-stimulatory molecules and interacting with the signaling pathways of T cells, B cells, Natural killer (NK) cells, mast cells, basophils, and macrophages. Immunotoxicity, resulting from drug-induced changes in redox status, generation of Reactive Oxygen Species (ROS)/Reactive Nitrogen Species (RNS), and alterations in antioxidant enzymes within immune cells, leads to immunodeficiency. This, in turn, causes allergic reactions, autoimmune diseases, and cytokine release syndrome (CRS). The treatment options should include the evaluation of immune status and utilization of the concept of pharmacogenomics to minimize the chances of immunotoxicity. Many strategies in redox, like targeting the redox pathway or using redox-active agents, are available for the modulation of the immune system and developing drugs. Case studies highlight significant drug-immune cell interactions and patient outcomes, underscoring the importance of understanding these complexities. The future direction focuses on the drugs to deliver antiviral therapy, new approaches to immunomodulation, and modern technologies for increasing antidote effects with reduced toxicity. In conclusion, in-depth knowledge of the interaction between drugs and immune cells is critical to protect the patient from the adverse effects of the drug and improve therapeutic outcomes of the treatment process. This review focuses on the multifaceted interactions of drugs and their consequences at the cellular levels of immune cells.

There are an estimated 58 million cases of Hepatitis C (HCV) worldwide. Approximately 38-76% of individuals can develop extrahepatic manifestations such as mixed cryoglobulinemia (MC). Importantly, the appearance of symptoms due to MC is linked by detectable HCV RNA. A 38-year-old male with remote history of HCV infection diagnosed 8 years prior presented to the emergency department with subacute renal failure with proteinuria, hematuria, and WBC/RBC casts. Biopsy confirmed acute proliferative, non-crescentic, inflammatory glomerulonephritis. He also had new onset cryoglobulinemia. His HCV RNA was low-grade and liver function tests were all within the normal range. A liver biopsy showed signs of chronic hepatitis with mildly active portal fibrosis. The MC was cleared with steroids and a re-measured HCV RNA quantitative was negative. Seven months later, he was readmitted with glomerulonephritis and elevated MC. However, the patient's HCV viral load was undetectable. The patient underwent 6 rounds of plasmapheresis and 6 doses of Rituximab were given with suppression of cryoglobulin to nil. A month later, the MC levels rose again, while the viral load remained undetectable with the possibility of spontaneous remission. After initiation of maintenance hydroxychloroquine, his GFR improved to normal over the next 2 years. Multiple theories have been suggested for the phenomenon including presence of residual virus and lymphoproliferation effects. Hydroxychloroquine could be a successful option, though future studies should corroborate our outcome.

Hydroxychloroquine (HCQ), originally an antimalarial drug, is currently used to treat multiple disorders, especially rheumatic diseases. Given its good efficacy and safety, HCQ is widely administered in pregnant patients. However, the safety profile of HCQ during pregnancy remains controversial due to limited research. In addition, HCQ has been reported to reduce preeclampsia in patients with systemic lupus erythematosus (SLE) and could potentially alleviate the symptom of preeclampsia. However, the clinical profile and molecular mechanism of HCQ in preeclampsia is yet to be fully understood.

We reviewed the literature on HCQ treatment in pregnancy with rheumatic diseases and preeclamp-sia in PubMed and Web of Science. We also discussed the safety of long-term therapy with HCQ during pregnancy.

HCQ mainly modulates autoimmune response through inhibition of lysosomal function, toll-like receptor (TLR) signalling, nicotinamide adenine dinucleotide phosphate-mediated oxidative stress and autophagy. Benefits of HCQ in treating rheumatic diseases, including antiphospholipid syndrome, rheumatoid arthritis and Sjogren's syndrome during pregnancy, has been demonstrated in clinics. In particular, multiple clinical guidelines recommend HCQ as an indispensable therapeutic drug for pregnant patients with SLE. Additionally, it may potentially function in preeclampsia to improve clinical symptoms.

HCQ is effectively used for rheumatic diseases during pregnancy. The benefits of HCQ treatment in rheumatic diseases outweigh the risk of adverse reactions it induces in pregnant women.

Chronic autoimmune diseases often lead to long-term sequelae and require lifelong immunosuppression because of an incomplete understanding of the triggers and drivers in genetically predisposed patients. Gut bacteria that escape the gut barrier, known as translocating gut pathobionts, have been implicated as instigators and perpetuators of extraintestinal autoimmune diseases in mice. The gut microbial contributions to autoimmunity in humans remain largely unclear, including whether specific pathological human adaptive immune responses are triggered by such pathobionts. Here, we show that the translocating pathobiont Enterococcus gallinarum can induce both human and mouse interferon-γ+ T helper 17 (TH17) differentiation and immunoglobulin G3 (IgG3) subclass switch of anti-E. gallinarum RNA antibodies, which correlated with anti-human RNA autoantibody responses in patients with systemic lupus erythematosus (SLE) and autoimmune hepatitis, two extraintestinal autoimmune diseases. E. gallinarum RNA, but not human RNA, triggered Toll-like receptor 8 (TLR8), and TLR8-mediated human monocyte activation promoted human TH17 induction by E. gallinarum. Translocation of the pathobiont triggered increased anti-RNA autoantibody titers that correlated with renal autoimmune pathophysiology in murine gnotobiotic lupus models and with disease activity in patients with SLE. These studies elucidate cellular mechanisms of how a translocating gut pathobiont induces systemic human T cell- and B cell-dependent autoimmune responses and provide a framework for developing host- and microbiota-derived biomarkers and targeted therapies in autoimmune diseases.

The purpose of this review is to outline considerations for treating older adults with rheumatoid arthritis-associated interstitial lung disease (RA-ILD) as it relates to infection, comorbidities, cancer, and quality of life.

The recent 2023 American College of Rheumatology/American College of Chest Physicians guideline conditionally recommended specific disease-modifying antirheumatic drugs (DMARDs), antifibrotics, and short-term glucocorticoids to treat RA-ILD. Since RA-ILD often affects older adults, we contextualize these pharmacologic options related to infection, gastrointestinal (GI) effects, cancer, cardiovascular disease, and quality of life. Nearly all DMARDs and glucocorticoids are immunosuppressive and increase infection risk. Rituximab, mycophenolate, cyclophosphamide, and glucocorticoids may have particularly high infection risk. Many therapies recommended for treating RA-ILD have potential GI side effects. Antifibrotics have a high rate of nausea and diarrhea. Janus kinase inhibitors may increase risk of cancer and cardiovascular disease in older people. In older individuals, decisions must weigh the risks and benefits of drug options while considering clinical and social factors such as polypharmacy, adherence, cost, convenience, and social support. Management of RA-ILD in older individuals is complex and should consider risks and benefits, while optimizing quality and quantity of life through a shared decision-making process.

Th17 cells are activated by STAT3 factors in the nucleus, and these factors are correlated with the pathologic progression of rheumatoid arthritis (RA). Recent studies have demonstrated the presence of STAT3 in mitochondria, but its function is unclear. We investigated the novel role of mitochondrial STAT3 (mitoSTAT3) in Th17 cells and fibroblast-like synoviocytes (FLSs) and analyzed the correlation of mitoSTAT3 with RA. We used a collagen-induced arthritis (CIA) mouse model to determine the effect of mitochondrial STAT3. We observed changes in the RA mouse model via the use of a mitochondrial STAT3-inducing vector and inhibitor. We observed the accumulation of abnormal autophagosomes, increased inflammatory cell death signaling, and decreased mitoSTAT3 activity in FLSs from both patients with RA and patients with IL-17-treated FLSs. We first discovered that IL-17 increased the accumulation of abnormal autophagosomes and the expression of inflammatory cell death factors in synovial fibroblasts and decreased mitoSTAT3 activation. In a mouse model of CIA, arthritis and joint inflammation were decreased by injection vectors that induced mitoSTAT3 overexpression. The abnormal accumulation of autophagosomes and the expression of inflammatory cell death factors were also decreased in these mice. In mouse and human immune cells, ZnSO4, an inducer of mitochondrial STAT3, decreases the production of reactive oxygen species, the IL-17 concentration, and differentiation into Th17 cells. However, mitoSTAT3 blockade accelerated the development of arthritis, inflammatory cell death, and abnormal autophagosome/autophagolysosome formation. Therefore, this study suggests a novel inhibitory mechanism of RA using mitoSTAT3 via the regulation of autophagy, Th17 differentiation, and inflammatory cell death.

Activation of the aryl hydrocarbon receptor (AhR) ameliorates LL-37-induced rosacea-like dermatitis in mice, whereas mast cells and cytokine overexpression are prominent features in rosacea skin.

To evaluate the potential mechanisms of AhR activation on autophagy and degranulation of mast cells in rosacea.

LL-37 treated mast cells were used to mimic rosacea. An AhR agonist (tapinarof) was applied to LL-37 induced mast cells. Furthermore, an autophagy agonist (RAPA) and an inhibitor (CQ) was added to investigate the mechanisms of autophagy. Western blot and RT-qPCR assessed cell degranulation (Cma1, Tpsab1) and cytokines (MMP9, TNF-α, and IL-6). Changes in cell morphology were observed under a microscope. Autophagy markers (LC3 and p62) were examined using Western blot and cellular immunofluorescence.

LL-37 upregulated the expressions of Cma1, Tpsab1, MMP9, TNF-α, and IL-6, which were then reduced by tapinarof treatment for 24 h. LC3B-I was converted to LC3B-II and p62 was reduced gradually with increasing concentration of tapinarof, indicating that autophagy was enhanced. RAPA enhanced the expression of LC3B-II on LL-37-induced mast cells, similar to tapinarof, while CQ partially inhibited the ability of tapinarof to induce autophagy in mast cells. Moreover, CQ reversed tapinarof's suppression of Cma1, Tpsab1, MMP9, TNF-α and IL-6 on LL-37 treated mast cells.

The present study showed that activation of AhR ameliorated degranulation of LL-37-induced mast cells in rosacea through enhancing autophagy, offering a new option for rosacea treatment.