Functional role of MicroRNA-19b in acinar cell necrosis in acute necrotizing pancreatitis. ACTA ACUST UNITED AC. 2016;36:221-225. [PMID: 27072966 DOI: 10.1007/s11596-016-1570-2]

The Role of MicroRNAs in Pancreatitis Development and Progression

Pancreatitis (acute and chronic) is an inflammatory disease associated with significant morbidity, including a high rate of hospitalization and mortality. MicroRNAs (miRs) are essential post-transcriptional modulators of gene expression. They are crucial in many diseases' development and progression. Recent studies have demonstrated aberrant miRs expression patterns in pancreatic tissues obtained from patients experiencing acute and chronic pancreatitis compared to tissues from unaffected individuals. Increasing evidence showed that miRs regulate multiple aspects of pancreatic acinar biology, such as autophagy, mitophagy, and migration, impact local and systemic inflammation and, thus, are involved in the disease development and progression. Notably, multiple miRs act on pancreatic acinar cells and regulate the transduction of signals between pancreatic acinar cells, pancreatic stellate cells, and immune cells, and provide a complex interaction network between these cells. Importantly, recent studies from various animal models and patients' data combined with advanced detection techniques support their importance in diagnosing and treating pancreatitis. In this review, we plan to provide an up-to-date summary of the role of miRs in the development and progression of pancreatitis.

Downregulation of miR-146a-5p Promotes Acute Pancreatitis through Activating the TLR9/NLRP3 Signaling Pathway by Targeting TRAF6 In Vitro Rat Model

Acute pancreatitis (AP) is mainly caused by acinar cells releasing various inflammatory factors, causing inflammatory storms and leading to severe pancreatitis. Detection methods and treatment targets for pancreatitis are lacking, raising the urgency of identifying diagnostic markers and therapeutic targets for AP. MicroRNAs (miRNAs) have recently been identified as molecular markers for various biological processes such as tumors, immunity, and metabolism, and the involvement of miRNAs in inflammatory responses has been increasingly studied. To explore the role of miRNAs in AP is the primary objective of this study. By using qPCR on our cerulein-induced pancreatitis cell model, it is worth noting that the change of miR-146a-5p expression in inflammation-related miRNAs in AP was predominant. Next, ELISA, CCK8, and flow cytometry were used to inspect the impact of miR-146a-5p on pancreatitis. BiBiServ bioinformatics anticipated binding ability of miR-146a-5p and 3′-untranslated region (3′UTR) of TNF receptor-associated factor 6 (TRAF6), and the dual-luciferase assay verified the combination of the two. TRAF6 knockdown verified the effect of TRAF6 on the progression of pancreatitis. Finally, rescue experiments verified the capability of miR-146a-5p and TRAF6 interaction on the Toll-like receptor 9 (TLR9)/NOD-like receptor protein 3 (NLRP3) signaling pathway and cell function. The expression of miR-146a-5p decreased in cerulein-induced AR42J pancreatic acinar cells. Functional experiments verified that miR-146a-5p facilitated the proliferation of AR42J pancreatic acinar cells and inhibited their apoptosis. Bioinformatic predictions and dual-luciferase experiments verified the actual binding efficiency between miR-146a-5p and 3′UTR of TRAF6. Our study confirmed that knockdown of TRAF6 restrained the progression of pancreatitis, and knockdown of TRAF6 rescued pancreatitis caused by miR-146a-5p downregulation by the TLR9/NLRP3 signaling pathway. Therefore, downregulation of miR-146a-5p in the induced pancreatitis cell model promotes the progression of pancreatitis via the TLR9/TRAF6/NLRP3 signaling pathway. There is potential for miR-146a-5p to serve as a diagnostic marker and therapeutic nucleic acid drug for AP.

New challenges for microRNAs in acute pancreatitis: progress and treatment

Acute pancreatitis (AP) is a common clinical abdominal emergency, with a high and increasing incidence each year. Severe AP can easily cause systemic inflammatory response syndrome, multiple organ dysfunction and other complications, leading to higher hospitalization rates and mortality. Currently, there is no specific treatment for AP. Thus, we still need to understand the exact AP pathogenesis to effectively cure AP. With the rise of transcriptomics, RNA molecules, such as microRNAs (miRNAs) transcribed from nonprotein-coding regions of biological genomes, have been found to be of great significance in the regulation of gene expression and to be involved in the occurrence and development of many diseases. Increasing evidence has shown that miRNAs, as regulatory RNAs, can regulate pancreatic acinar necrosis and apoptosis and local and systemic inflammation and play an important role in the development and thus potentially the diagnosis and treatment of AP. Therefore, here, the current research on the relationship between miRNAs and AP is reviewed.

Salidroside alleviates taurolithocholic acid 3-sulfate-induced AR42J cell injury

OBJECTIVES

To investigate the protective effects of Salidroside (Sal) on AP cell model induced by taurolithocholic acid 3-sulfate (TLC-S) as well as its underlying mechanism.

METHODS

AR42J cells were divided into normal group (N group), AP cell model group (Mod group), Sal treated alone group (S+N group) and Sal treated AP cell model group (S+Mod group). The cell viability was examined by CCK-8 assay. Secretion of lipase and trypsin by AR42J cells, quantified using commercial assay kits, was used as the markers of TLC-S-induced pancreatitis. The levels of TNF-α, IL-1β, IL-8, IL-6 and IL-10 in the cell supernatant were measured by ELISA. The effect of Sal on molecules in the NF-κB signaling pathway and autophagy was investigated by qRT-PCR and western blot.

RESULTS

The decreased cell viability in Mod group was increased by Sal (P < 0.01). The upheaved activities of lipase and trypsin in AP cell model were declined by Sal (P < 0.01). The levels of TNF-α, IL-1β, IL-8 and IL-6 in the cell supernatant, Beclin-1 and LC3-Ⅱ mRNA and protein, p-p65/p65 protein, which were increased in AP cell model, were decreased by Sal; and IL-10 in the cell supernatant, LAMP2 mRNA and protein, p-IκBα/IκBα protein which was declined in AP cell model, was increased by Sal (P < 0.05 or 0.01). There were no significant differences in all indexes between the N and S+N groups (P > 0.05).

CONCLUSIONS

Sal alleviated AR42J cells injury induced by TLC-S, inhibited the inflammatory responses and modulated the autophagy, mainly through inhibiting the NF-κB signaling pathway.

miR-135a deficiency inhibits the AR42J cells damage in cerulein-induced acute pancreatitis through targeting FAM129A

Acute pancreatitis (AP) is a common clinical critical disease with high mortality and the exact pathogenesis is not fully elucidated. The present study aimed to uncover the function of miR-135a in the proliferation, apoptosis, and inflammatory characteristics of diseased pancreatic cells and the potential molecular mechanisms. The expression patterns of miR-135a and family with sequence similarity 129 member A (FAM129A) in patients with AP were analyzed on the basis of the GEO database. The transfection efficiency and expression level of miR-135a in AR42J cells were determined by qRT-PCR. The biological characteristics of AR42J cells treated with cerulein were detected by cell counting kit-8 (CCK-8), flow cytometry, and western blot assays. The potential interaction between miR-135a and FAM129A was confirmed by bioinformatics prediction softwares and luciferase reporter assay. MiR-135a inhibitor and pcDNA3.1-FAM129A were co-transfected to determine the regulation of miR-135a/FAM129A on inflammatory AR42J cell injury. We observed that miR-135a was highly expressed in AP samples. Depletion of miR-135a could alleviate the condition so that the AR42J cells proliferation increased, apoptosis decreased, and the expression of inflammatory cytokines enhanced. In addition, mRNA and protein expression of FAM129A were negatively regulated by miR-135a, and over-expression of FAM129A could strengthen the relief effect of miR-135a inhibitor in AP induced by cerulein. In summary, our data demonstrates that silencing miR-135a reduces AR42J cells injury and inflammatory response in AP induced by cerulein through targeting FAM129A.

MicroRNAs in acute pancreatitis: From pathogenesis to novel diagnosis and therapy

Acute pancreatitis (AP) is an inflammatory disorder initiated by activation of pancreatic zymogens, leading to pancreatic injury and systemic inflammatory response. MicroRNAs (miRNAs) have emerged as important regulators of gene expression and key players in human physiological and pathological processes. Discoveries over the past decade have confirmed that altered expression of miRNAs is implicated in the pathogenesis of AP. Indeed, a number of miRNAs have been found to be dysregulated in various cell types involved in AP such as acinar cells, macrophages, and lymphocytes. These aberrant miRNAs can regulate acinar cell necrosis and apoptosis, local and systemic inflammatory response, thereby contributing to the initiation and progression of AP. Moreover, patients with AP possess unique miRNA signatures when compared with healthy individuals or those with other diseases. In view of their stability and easy detection, therefore, miRNAs have the potential to act as biomarkers for the diagnosis and assessment of patients with AP. In this review, we provide an overview of the novel cellular and molecular mechanisms underlying the roles of miRNAs during the disease processes of AP, as well as the potential diagnosis and therapeutic biomarkers of miRNAs in patients with AP.

miR-352 participates in the regulation of trypsinogen activation in pancreatic acinar cells by influencing the function of autophagic lysosomes

This study was performed to screen miRNAs and mRNAs that are differentially expressed during trypsinogen activation in acute pancreatitis and to verify their role in the process of trypsinogen activation. The function enrichment analysis showed that the functions of miR-352 and its regulatory targets lysosome-associated membrane protein 2 (LAMP2) and cathepsin L1 (CTSL1) were lysosome related. The results of the verification experiment showed that in the TLC-S-treated AR42J (pancreatic cell line) cells, miR-352 expression increased, expression levels of LAMP2 and CTSL1 were significantly reduced, trypsinogen activation was increased, and the autophagy pathway was blocked. In the miR-352 mimic-transfected cells, miR-352 expression increased, expression levels of LAMP2 and CTSL1 were significantly reduced, trypsinogen activation was increased, intracellular lysosomal pH increased, cathepsins L activity decreased and the amount of autophagolysosomes increased. In the miR-352 inhibitor-transfected cells, miR-352 expression was reduced, expression levels of LAMP2 and CTSL1 were significantly increased, trypsinogen activation was decreased, intracellular lysosomal pH decreased, cathepsins L activity increased and the amount of autophagolysosomes decreased. In the process of taurolithocholic acid 3-sulfate (TLC-S) induced trypsinogen activation, overexpression of miR-352 could down-regulate LAMP2 and CTSL1, resulting in the dysfunction of autophagic lysosome. Thus, the autophagy pathway was blocked, and trypsinogen activation was enhanced.

Targeting MicroRNA Function in Acute Pancreatitis

Acute pancreatitis (AP) is a common gastrointestinal disorder that featured by acute inflammatory responses leading to systemic inflammatory response syndrome (SIRS) or multiple organ failure. A worldwide increase in annual incidence has been observed during the past decade with high acute hospitalization and mortality. Lack of any specific treatment for AP, even to this day, is a reminder that there is much to be learned about the exact pathogenesis of AP. Fortunately, the discovery of microRNA (miRNA) has started an entirely new thought process regarding the molecular mechanism associated with the disease processes. Given the extensive effort made on miRNA research, certain types of miRNA have been identified across a variety of biological processes, including cell differentiation, apoptosis, metabolism, and inflammatory responses. Mutations in miRNA sequences or deregulation of miRNA expression may contribute to the alteration of a pivotal physiological function leading to AP. Designing miRNA-related tools for AP diagnosis and treatment presents a novel and potential research frontier. In this mini-review, we summarize the current knowledge of various miRNAs closely interacting with AP and the possible development of targeted miRNA therapies in this disease, which may benefit the development of potential disease biomarkers and novel treatment targets for future medical implications.

Effect of triptolide on expression of oxidative carbonyl protein in renal cortex of rats with diabetic nephropathy

The traditional Chinese medicine (Tripterygium wilfordiiHook.f., TWH) has been clinically used to treat primary and secondary renal diseases and proteinuria for nearly 40 years. However, there is a rare literature about the effect of triptolide (the main active ingredient of TWH) on the expression of oxidative carbonyl protein (OCP) in diabetic nephropathy (DN). This study aimed to provide experimental evidence for triptolide treatment on DN through its effect on the expression of OCP, in order to investigate the effects of triptolide on the expression of OCP in rats with DN. Sixty SD rats were randomly divided into five groups: control group, high-dose triptolide (Th) group, low-dose triptolide (Tl) group, DN model group, and positive control (benazepril) group. The DN model was established using streptozotocin. Urinary protein excretion, fasting blood glucose (FBG), superoxide dismutase (SOD) in renal homogenate, malondialdehyde (MDA) in renal homogenate and renal nitrotyrosine by immunohistochemistry, and the expression of OCP by oxyblotimmune blotting were detected. In the DN model group, rat urinary protein excretion and renal MDA were significantly increased, while renal SOD significantly decreased and nitrotyrosine expression was obviously upregulated in the kidney. After triptolide treatment, 24-h urinary protein excretion (61.96±19.00 vs. 18.32±4.78 mg/day, P<0.001), renal MDA (8.09±0.79 vs. 5.45±0.68 nmol/L, P<0.001), and nitrotyrosine expression were decreased. Furthermore, renal OCP significantly decreased, while renal SOD (82.50±19.10 vs. 124.00±20.52 U/L, P<0.001) was elevated. This study revealed that triptolide can down-regulate the expression of OCP in the renal cortex of DN rats.

MicroRNAs in acute pancreatitis

Acute pancreatitis is an acute inflammatory condition of the pancreas that can develop into a complicated clinical course with severe local and systemic complications, resulting in a prolonged clinical course with considerable mortality. MicroRNAs (miRNAs), a class of small non-coding RNA molecules that negatively regulate gene expression, have potential value in clinical research and biomarker discovery. In recent years, accumulating evidence suggests that miRNAs may act as potential biomarkers for pancreatic tissue injury, and much attention has been paid to those miRNAs involved in acute pancreatitis. However, the role of miRNAs in acute pancreatitis has been validated in very few clinical studies. A better understanding of the role that miRNAs play in acute pancreatitis can lead to the development of new diagnostic and prognostic tools for future clinical applications.