Effect of camostat mesilate on the expression of pancreatitis-associated protein (PAP), p8, and cytokines in rat spontaneous chronic pancreatitis

Novel therapeutics to treat chronic pancreatitis: targeting pancreatic stellate cells and macrophages

INTRODUCTION

Chronic pancreatitis (CP) is a persistent, recurrent, and progressive disorder that is characterized by chronic inflammation and irreversible fibrosis of the pancreas. It is associated with severe morbidity, resulting in intense abdominal pain, diabetes, exocrine and endocrine dysfunction, and an increased risk of pancreatic cancer. The etiological factors are diverse and the major risk factors include smoking, chronic alcoholism, as well as other environmental and genetic factors. The treatment and management of CP is challenging, and no definitive curative therapy is currently available.

AREAS COVERED

This review paper aims to provide an overview of the different cell types in the pancreas that is known to mediate disease progression and outline potential novel therapeutic approaches and drug targets that may be effective in treating and managing CP. The information presented in this review was obtained by conducting a NCBI PubMed database search, using relevant keywords.

EXPERT OPINION

In recent years, there has been an increased interest in the development of novel therapeutics for CP. A collaborative multi-disciplinary approach coupled with a consistent funding for research can expedite progress of translating the findings from bench to bedside.

Targeting Fibrosis: The Bridge That Connects Pancreatitis and Pancreatic Cancer

Pancreatic fibrosis is caused by the excessive deposits of extracellular matrix (ECM) and collagen fibers during repeated necrosis to repair damaged pancreatic tissue. Pancreatic fibrosis is frequently present in chronic pancreatitis (CP) and pancreatic cancer (PC). Clinically, pancreatic fibrosis is a pathological feature of pancreatitis and pancreatic cancer. However, many new studies have found that pancreatic fibrosis is involved in the transformation from pancreatitis to pancreatic cancer. Thus, the role of fibrosis in the crosstalk between pancreatitis and pancreatic cancer is critical and still elusive; therefore, it deserves more attention. Here, we review the development of pancreatic fibrosis in inflammation and cancer, and we discuss the therapeutic strategies for alleviating pancreatic fibrosis. We further propose that cellular stress response might be a key driver that links fibrosis to cancer initiation and progression. Therefore, targeting stress proteins, such as nuclear protein 1 (NUPR1), could be an interesting strategy for pancreatic fibrosis and PC treatment.

Targeting host cell proteases as a potential treatment strategy to limit the spread of SARS-CoV-2 in the respiratory tract

As the death toll of Coronavirus disease 19 (COVID-19) continues to rise worldwide, it is imperative to explore novel molecular mechanisms for targeting SARS-CoV-2. Rather than looking for drugs that directly interact with key viral proteins inhibiting its replication, an alternative and possibly add-on approach is to dismantle the host cell machinery that enables the virus to infect the host cell and spread from one cell to another. Excellent examples of such machinery are host cell proteases whose role in viral pathogenesis has been demonstrated in numerous coronaviruses. In this review, we propose two therapeutic modalities to tackle SARS-CoV-2 infections; the first is to transcriptionally modulate the expression of cellular proteases and their endogenous inhibitors and the second is to directly inhibit their enzymatic activity. We present a nonexhaustive collection of clinically investigated drugs that act by one of these mechanisms and thus represent promising candidates for preclinical in vitro testing and hopefully clinical testing in COVID-19 patients.

A clinical study of insulin resistance in patients with chronic pancreatitis

OBJECTIVE

Insulin resistance (IR) and beta cell dysfunction are the pathophysiological determinants of the diabetes mellitus (DM). We investigated the presence of IR in patients with chronic pancreatitis (CP) and compared the same with the underlying etiology.

METHODS

In this cross-sectional, observational study, we included serial patients of CP presented to our hospital. The study population is in different stages of CP and are grouped as alcoholic CP (Group 1; N=67) and tropical CP (Group 2; N=35). IR was estimated by the homeostasis model assessment (HOMA) method. The results were analyzed by appropriate statistical methods.

RESULTS

The study participants (85M and 17F) had a mean age 40.8±12.6 yr, CP duration 3.7±4.7 yr and body mass index (BMI) of 22.5±3.2kg/m². DM was seen in 54 patients with average glycosylated hemoglobin of 7.5±1.6%. A total of 9 patients had HOMA-IR more than 3 suggestive of IR with no significant difference between the two groups. The duration of the DM correlated negatively with glycemic parameters and BMI showed a positive correlation with the fasting insulin and HOMA-IR.

CONCLUSION

IR was seen in a minority of patients with CP and is not a significant contributor to the pancreatogenic diabetes.

[Effects of Chinese herbal medicines on spontaneous chronic pancreatitis in rats and the pathological relationships between formulas and syndromes]

OBJECTIVE

To investigate the effects of Guizhi Decoction, Chaihu Guizhi Decoction, Xiaochaihu Decoction and camostat on rat spontaneous chronic pancreatitis and the pathological relationships between formulas and syndromes.

METHODS

Fifty-seven male WBN/Kob rats at age of 4 weeks were divided into five groups: untreated group (n=18), Guizhi Decoction-treated group (n=9), Chaihu Guizhi Decoction-treated group (n=9), Xiaochaihu Decoction-treated group (n=9) and camostat-treated group (n=12). The rats in each group were fed with corresponding drugs for 12 weeks. The pancreatic wet weight and histopathological changes of pancreatic tissue were observed every four weeks. Meanwhile, the expression level of pancreatitis-associated protein (PAP) in pancreas was detected by RT-PCR technique and immunohistochemical method.

RESULTS

In the untreated group, the histopathological changes in pancreas were observed in rats at 12-week age, while such changes were absent in the Guizhi Decoction-treated group. The histopathological changes in pancreas were quite remarkable in rats at 16-week age in both the Xiaochaihu Decoction-treated and the camostat-treated groups. The expression level of PAP mRNA was lower in the Guizhi Decoction-treated group than those in the other groups. The PAP expressions were absent in rats at 12-week age in the Guizhi Decoction-treated and the Chaihu Guizhi Decocion-treated groups.

CONCLUSION

Guizhi Decoction, Chaihu Guizhi Decoction, Xiaochaihu Decoction and camostat are all beneficial to prevention and cure of chronic pancreatitis, and Guizhi Decoction is the most effective one. It is speculated that Taiyang exterior syndrome may be the pathogenesis of basic syndrome may be the pathogenesis of basic syndrome of spontaneous chronic pancreatitis, and the expression of PAP may be its pathological basis.

Meaning of tumor protein 53-induced nuclear protein 1 in the molecular mechanism of gemcitabine sensitivity

Stress proteins of the pancreas, such as tumor protein 53-induced nuclear protein 1 (TP53INP1), are important factors in the invasion and metastasis of pancreatic cancer. TP53INP1 is a pro-apoptotic factor and is transcriptionally regulated in p53-dependent and -independent manners. A previous study proved that gemcitabine induces TP53INP1 expression in pancreatic cancer cells and the pancreatic cancer cell line (PANC-1). The present study aimed to clarify the association between TP53INP1 and gemcitabine sensitivity. The expression of TP53INP1 and its related factors, such as cell growth and cell cycle status in TP53INP1-knockout mouse embryonic fibroblasts [TP53INP1^-/--mouse embryonic fibroblasts (MEFs)] to those in wild-type counterparts (TP53INP1^+/+-MEFs) were compared. Flow cytometric analysis demonstrated no difference of the checkpoint function in TP53INP1^-/--MEFs and TP53INP1^+/+-MEFs when exposed to 10 ng/ml of gemcitabine. No significant difference was found in the level of p53 expression in the cell types, although the base level and gemcitabine-induced expression of p21 were significantly decreased in TP53INP1^-/--MEFs, compared to those in wild-type counterparts. Results showed that gemcitabine induced the p21 expression in TP53INP1^+/+-MEFs, although not in TP53INP1^-/--MEFs. However, their respective cell-cycle checkpoints were not different. Therefore, TP53INP1 was found to be associated with drug sensitivity through control of the cell cycle.

Nuclear protein 1 promotes pancreatic cancer development and protects cells from stress by inhibiting apoptosis

Pancreatic ductal adenocarcinoma (PDAC) has the lowest survival rate of all cancers and shows remarkable resistance to cell stress. Nuclear protein 1 (Nupr1), which mediates stress response in the pancreas, is frequently upregulated in pancreatic cancer. Here, we report that Nupr1 plays an essential role in pancreatic tumorigenesis. In a mouse model of pancreatic cancer with constitutively expressed oncogenic Kras(G12D), we found that loss of Nupr1 protected from the development of pancreatic intraepithelial neoplasias (PanINs). Further, in cultured pancreatic cells, nutrient deprivation activated Nupr1 expression, which we found to be required for cell survival. We found that Nupr1 protected cells from stress-induced death by inhibiting apoptosis through a pathway dependent on transcription factor RelB and immediate early response 3 (IER3). NUPR1, RELB, and IER3 proteins were coexpressed in mouse PanINs from Kras(G12D)-expressing pancreas. Moreover, pancreas-specific deletion of Relb in a Kras(G12D) background resulted in delayed in PanIN development associated with a lack of IER3 expression. Thus, efficient PanIN formation was dependent on the expression of Nupr1 and Relb, with likely involvement of IER3. Finally, in patients with PDAC, expression of NUPR1, RELB, and IER3 was significantly correlated with a poor prognosis. Cumulatively, these results reveal a NUPR1/RELB/IER3 stress-related pathway that is required for oncogenic Kras(G12D)-dependent transformation of the pancreas.

Stress-inducible protein p8 is involved in several physiological and pathological processes

p8 (NUPR1 (nuclear protein-1), Com1 (candidate of metastasis-1)) is a protein related to the high mobility group of transcriptional regulators. It is a key player in the cellular stress response and is involved in metastasis. p8 was first identified as a gene induced in pancreatitis but has been since found overexpressed in several cancers and pathological conditions. Despite its small size and apparently simple structure, p8 functions in several biochemical and genetic pathways, and its expression is crucial for in vivo metastasis in mice, for cytokine induction of metalloproteases, and for stress-induced cardiomyocyte hypertrophy. Understanding p8 functions will provide new opportunities for developing more effective therapeutic approaches to cancer and cardiovascular diseases.

Pancreatic stellate cells: new target in the treatment of chronic pancreatitis

Chronic pancreatitis (CP) is characterized by progressive fibrosis, pain and/or loss of exocrine and endocrine functions. Recent in vitro and in vivo experiments have proven objectively the role of activated pancreatic stellate cells (PSC) in fibrogenesis in CP. Molecular mediators shown to regulate the pathogenesis include transforming growth factor beta (TGF-beta), platelet-derived growth factor (PDGF), and pro-inflammatory cytokines such as IL-1, IL-6 and TNF-alpha. Furthermore, molecular pathways involving mitogen-activated protein kinases (MAPK), phosphatidyl inositol 3-kinase (PI3K), Ras superfamily G proteins, serine threonine protein kinase Raf-1 and peroxisome proliferator activated receptor gamma (PPAR-gamma) have been elucidated. Understanding of the pathogenesis has led to identification of novel molecular targets and development of potential newer therapeutic agents. Those found to retard the progression of experimental CP and fibrosis in animal models include interferon (IFN) beta and IFN-gamma; a Japanese herbal medicine called Saiko-keishi-to (TJ-10); curcumin; PPAR-gamma ligand (troglitazone); antioxidants (vitamin A, vitamin E, DA 9601 and epigallocatechin-3-gallate); a protease inhibitor (camostat mesilate) and hydroxymethylglutaryl-CoA inhibitor (lovastatin). This review summarizes the current literature addressing the role of different pharmacological agents aimed at reducing or preventing inflammation and the consequent fibrogenesis in CP.

Suppressive effect of herbal medicine saikokeishito on acinar cell apoptosis in rat spontaneous chronic pancreatitis

BACKGROUND/AIMS

Chronic pancreatitis is characterized by acinar destruction and fibrosis. We previously reported that apoptosis is involved in acinar destruction in chronic pancreatitis in the WBN/Kob rat. This study aimed to elucidate the antiapoptotic effect of Saikokeishito (TJ-10).

METHODS

Four-week-old male WBN/Kob rats were fed a special pellet diet (MB-3) with or without TJ-10 (80 mg/100 g body weight) for 20 weeks. Pancreas was histopathologically examined every 4 weeks, and the expression of apoptosis-related factors such as Fas and Fas ligand (FasL) mRNA and protein was analyzed with RT-PCR, in situ hybridization and immunohistochemistry. Apoptosis was detected with a TUNEL method.

RESULTS

In untreated WBN/Kob rats, chronic pancreatitis developed at 12 weeks and progressed with marked acinar cell destruction at 16 weeks. The expression of Fas and FasL peaked at 12 and 20 weeks. An apoptotic index in acinar cells correlated to the expression of Fas and FasL mRNA. However, in the TJ-10-treated rats, the rate of pancreatic acinar cell destruction, the apoptotic index at 12-20 weeks, and the expression of Fas and FasL at 12 and 20 weeks decreased significantly compared to those in untreated rats.

CONCLUSION

These results suggest that TJ-10 has a therapeutic effect on chronic pancreatitis by the suppression of acinar cell apoptosis via the Fas/FasL system.

[Pathogenesis and treatment of pain in chronic pancreatitis]

Chronic pancreatitis is an inflammatory, usually painful disease characterized by progressive fibrosis and the loss of exocrine and endocrine functions. Pain influences the quality of life of patients and may lead to inability to work and frequent hospitalisation. The pathogenesis of pain in chronic pancreatitis is still unclear. Several different mechanisms of pain have been proposed, but pain in chronic pancreatitis is most probably multifactorial. Pain management in chronic pancreatitis is difficult. This is due to the multifactorial origin, there are no standardized methods to quantify pain and patients are often addicted to alcohol in chronic pancreatitis. This review summarises the different hypotheses of pain and the possibilities of pain management in chronic pancreatitis.

Chronic pancreatitis: evolving paradigms

Chronic pancreatitis (CP) is characterized by progressive fibrosis, pain and/or loss of exocrine and endocrine functions. With the identification and characterization of pancreatic stellate cells (PSCs), the pathogenesis of CP and pancreatic fibrosis is now better understood. Molecular mediators shown to regulate the pathogenesis include transforming growth factor-beta, platelet-derived growth factor, and proinflammatory cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor-alpha. Besides these, the roles of cyclooxygenase (COX)-2 and apoptosis-related proteins have also been implicated in the pathogenesis. Furthermore, molecular pathways involving mitogen-activated protein kinases, phosphatidylinositol 3-kinase, Ras superfamily G proteins, serine threonine protein kinase Raf-1 and peroxisome proliferator-activated receptor-gamma (PPAR-gamma) have been elucidated. Newer pathobiologic concepts concerning pain generation have also been put forward. Understanding the pathogenesis has led to the identification of novel molecular targets and the development of newer potential therapeutic agents. Those found to retard the progression of experimental CP and fibrosis in animal models include antioxidants, a Japanese herbal medicine called Saiko-keisi-to (TJ 10), the PPAR-gamma ligand troglitazone, the protease inhibitor Camostat mesilate, and Lovastatin.

Camostat, an oral trypsin inhibitor, reduces pancreatic fibrosis induced by repeated administration of a superoxide dismutase inhibitor in rats

BACKGROUND AND AIM

An oral trypsin inhibitor, camostat (CM), has a beneficial effect on chronic pancreatitis, but its mechanism is not yet fully understood. Recently, pancreatic stellate cells (PSC) have been reported to play an essential role in pancreatic fibrosis. An experimental model of pancreatic fibrosis induced by a superoxide dismutase (SOD) inhibitor (diethyldithiocarbamate [DDC]) was developed in rats. Thus, the effect of an oral trypsin inhibitor on pancreatic fibrosis and PSC was investigated.

METHODS

Pancreatic fibrosis was induced in rats using DDC (DDC rats). DDC + CM rats were administered DDC, and subsequently were fed a diet containing CM. Immunohistochemistry of the pancreas was performed with monoclonal anti-alpha-smooth muscle actin (alpha-SMA) antibody and anti-desmin antibody.

RESULTS

The DDC rats showed a significant increase in alpha-SMA-positive cells or desmin-positive cells compared with control rats. These significant increases in the fibrotic area improved after treatment with CM. The level of prolyl hydroxylase in the pancreas, which significantly increased as a result of DDC, decreased after treatment with CM.

CONCLUSION

Camostat has a beneficial effect on pancreatic fibrosis induced by the administration of a SOD inhibitor, which inhibits the proliferation and activation of PSC.

Cytokines and peroxisome proliferator-activated receptor gamma ligand regulate phagocytosis by pancreatic stellate cells

BACKGROUND & AIMS

Pancreatic stellate cells have been characterized as the major source of extracellular matrix and cytokine production in the pancreas. This study showed that pancreatic stellate cells have a phagocytic function.

METHODS

The morphological features of periacinar phagocytic cells were investigated by immunohistochemically staining serial sections of the pancreas from male WBN/Kob rats and an animal model of acute pancreatitis for glial fibrillary acidic protein and alpha-smooth muscle actin. Pancreatic stellate cells were assayed for phagocytic activity by incubating them with senescent polymorphonuclear neutrophils or fluorescence-labeled latex beads in the presence or absence of cytokines, growth factors, and peroxisome proliferator-activated receptor gamma ligand. The role of CD36 and peroxisome proliferator-activated receptor gamma in phagocytosis was investigated by blocking endogenous CD36 and peroxisome proliferator-activated receptor gamma activity with anti-CD36 antibody and peroxisome proliferator-activated receptor gamma small interfering RNAs, respectively.

RESULTS

Phagocytic cells were observed in areas of inflammation, and they were identical to the glial fibrillary acidic protein-positive and alpha-smooth muscle actin-positive cells, thus suggesting that they were pancreatic stellate cells. Aged polymorphonuclear neutrophils were ingested into the cytoplasm of the pancreatic stellate cells. Transforming growth factor beta, tumor necrosis factor alpha, and interleukin 1beta decreased the phagocytic activity of pancreatic stellate cells, whereas troglitazone induced a dose-dependent increase in both phagocytic activity and expression of CD36. Blockade of CD36 reduced troglitazone-induced phagocytosis. Silencing of the peroxisome proliferator-activated receptor gamma gene decreased phagocytosis and expression of CD36.

CONCLUSIONS

Pancreatic stellate cells act as resident phagocytic cells, and CD36 promotes troglitazone-induced phagocytic activity via peroxisome proliferator-activated receptor gamma transactivation. Because phagocytosis is essential to limit the extent of inflammation, enhancement of phagocytic activity may provide an important approach to the treatment of pancreatic diseases.

Synthetic protease inhibitor camostat prevents and reverses dyslipidemia, insulin secretory defects, and histological abnormalities of the pancreas in genetically obese and diabetic rats

BACKGROUND

Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of type 2 diabetes, lacks the expression of cholecystokinin-1 receptor mRNA and exhibits inflammation and degeneration of the pancreas and eventually develops insulinopenic diabetes. Protease inhibitors are known to modulate inflammatory response and fibrosis as well as inhibit proteases activity.

AIM

To examine the effects of long-term treatment with camostat, a synthetic protease inhibitor, on metabolic and histopathological changes in the islets of OLETF rats.

METHOD

OLETF rats were fed either camostat-containing food (200 mg/100 g) from 12 or 28 weeks of age to 72 weeks of age, or fed standard rat diet.

RESULTS

Camostat-fed rats gained less weight or lost weight, although they consumed more food than the control rat when food intake was adjusted for body weight. Camostat reduced visceral adipose depots and fasting serum concentrations of triglyceride, free fatty acids, cholesterol, glucose, and insulin. Pancreatic insulin content in camostat-treated rats was significantly higher than in control rats. Immunohistochemistry revealed marked suppression of expressions of tumor necrosis factor alpha , interleukin 1 beta , interleukin 6, and alpha-smooth muscle actin in the islets of camostat-treated rats, compared with control rats. Histologically, disruption of the islets and pancreatic fibrosis were noted in control rats but not in camostat-fed rats.

CONCLUSION

Our findings suggest that camostat prevents and reverses obesity, hyperinsulinemia, hyperglycemia, and hyperlipidemia and markedly inhibits inflammation, fibrosis, and disruption of the islets in the genetically obese diabetic OLETF rats.

Camostat mesilate attenuates pancreatic fibrosis via inhibition of monocytes and pancreatic stellate cells activity

Camostat mesilate (CM), an oral protease inhibitor, has been used clinically for the treatment of chronic pancreatitis in Japan. However, the mechanism by which it operates has not been fully understood. Our aim was to evaluate the therapeutic efficacy of CM in the experimental pancreatic fibrosis model induced by dibutyltin dichloride (DBTC), and we also determined the effect of CM on isolated monocytes and panceatic stellate cells (PSCs). In vivo, chronic pancreatitis was induced in male Lewis rats by single administration of 7 mg/kg DBTC and a special diet containing 1 mg/g CM was fed to the DBTC+CM-treated group from day 7, while the DBTC-treated group rats were fed a standard diet. At days 0, 7, 14 and 28, the severity of pancreatitis and fibrosis was examined histologically and enzymologically in both groups. In vitro, monocytes were isolated from the spleen of a Lewis rat, and activated with lipopolysaccharide stimulation. Thereafter, the effect of CM on monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) production from monocytes was examined. Subsequently, cultured rat PSCs were exposed to CM and tested to see whether their proliferation, MCP-1 production and procollagen alpha1 messenger RNA expression was influenced by CM. In vivo, the oral administration of CM inhibited inflammation, cytokines expression and fibrosis in the pancreas. The in vitro study revealed that CM inhibited both MCP-1 and TNF-alpha production from monocytes, and proliferation and MCP-1 production from PSCs. However, procollagen alpha1 expression in PSCs was not influenced by CM. These results suggest that CM attenuated DBTC-induced rat pancreatic fibrosis via inhibition of monocytes and PSCs activity.

Gene expression analysis of the pro-oestrous-stage rat uterus reveals neuroligin 2 as a novel steroid-regulated gene

In the present study, differential gene expression in the uteri of ovariectomised (OVX) and pro-oestrous rats (OVX v. pro-oestrus pair) was investigated using cDNA expression array analysis. Differential uterine gene expression in OVX rats and progesterone (P4)-injected OVX rats (OVX v. OVX + P4 pair) was also examined. The uterine gene expression profiles of these two sets of animals were also compared for the effects of P4 treatment. RNA samples were extracted from uterine tissues and reverse transcribed in the presence of [α32P]-dATP. Membrane sets of rat arrays were hybridised with cDNA probe sets. Northern blot analysis was used to validate the relative gene expression patterns obtained from the cDNA array. Of the 1176 cDNAs examined, 23 genes showed significant (>two-fold) changes in expression in the OVX v. pro-oestrus pair. Twenty of these genes were upregulated during pro-oestrus compared with their expression in the OVX rat uterus. In the OVX v. OVX + P4 pair, 22 genes showed significant (>two-fold) changes in gene expression. Twenty of these genes were upregulated in the OVX + P4 animals. The genes for nuclear factor I–XI, afadin, neuroligin 2, semaphorin Z, calpain 4, cyclase-associated protein homologue, thymosin β-4X and p8 were significantly upregulated in the uteri of the pro-oestrus and OVX + P4 rats of both experimental pairs compared with the OVX rat uteri. These genes appear to be under the control of P4. One of the most interesting findings of the present study is the unexpected and marked expression of the neuroligin 2 gene in the rat uterus. This gene is expressed at high levels in the central nervous system and acts as a nerve cell adhesion factor. According to Northern blot analysis, neuroligin 2 gene expression was higher during the pro-oestrus and metoestrus stages than during the oestrus and dioestrus stages of the oestrous cycle. In addition, neuroligin 2 mRNA levels were increased by both 17β-oestradiol (E2) and P4, although P4 administration upregulated gene expression to a greater extent than injection of E2. These results indicate that neuroligin 2 gene expression in the rat uterus is under the control of both E2 and P4, which are secreted periodically during the oestrous cycle.