Regulation of the serotonin transporter in the pathogenesis of irritable bowel syndrome

Table 1 Summary of potential regulators of the serotonin transporter in irritable bowel syndrome

Regulatory factors	Ref.	Publication year	Study type
SERT gene polymorphisms
5-HTTLPR	Zhang et al[78]	2014	Meta-analysis
	Areeshi et al[35]	2013	Meta-analysis
	Wang et al[73]	2012	Case-control study
	Yeo et al[74]	2004	Case-control study
	Kumar et al[75]	2012	Case-control study
	Sikander et al[76]	2009	Case-control study
	Pata et al[77]	2002	Case-control study
STin2 VNTRs	Wang et al[79]	2004	Case-control study
	Yeo et al[74]	2004	Case-control study
SNPs	Kohen et al[58]	2009	Case-control study
MicroRNAs (↓)
MiR-16	Baudry et al[38]	2010	Experimental study
MiR-545	Jensen et al[94]	2009	Experimental study
MiR-15a	Moya et al[62]	2013	Experimental study
MiR-24	Liao et al[96]	2016	Case-control study
Immunity and inflammation
Immune cells (↓)
IELs	Foley et al[52]	2011	Experimental study
	Faure et al[34]	2010	Experimental study
Mast cells	Foley et al[52]	2011	Experimental study
T cells	Wheatcroft et al[104]	2005	Experimental study
	Faure et al[34]	2010	Experimental study
Inflammatory cytokines
IFN-γ and TNF-α (↓)	Foley et al[105]	2007	Experimental study
TGF-β1 (↑)	Nazir et al[107]	2015	Experimental study
Gut microbiota
EPEC (↓)	Esmaili et al[118]	2009	Experimental study
EcN (↓)	Nzakizwanayo et al[119]	2015	Experimental study
LGG (↑)	Wang et al[121]	2015	Experimental study
Growth factors (↑)
EGF	Kekuda et al[132]	1997	Experimental study
bFGF	Kubota et al[133]	2001	Experimental study
NGF	Gil et al[134]	2003	Experimental study

5-HTTLPR: 5-HT-transporter-gene-linked polymorphic region; STin2 VNTRs: Variable number of tandem repeats STin2; SNPs: Single nucleotide polymorphisms; IELs: Intraepithelial lymphocytes; IFN-γ and TNF-α: Interferon-γ and tumor necrosis factor-α; TGF-β1: Transforming growth factor-β1; EPEC: Enteropathogenic E. coli; EcN: Escherichia coli Nissle 1917; LGG: Lactobacillus rhamnosus GG supernatant; EGF: Epidermal growth factor; bFGF: Basic fibroblast growth factor; NGF: Nerve growth factor.