Calcium signaling of pancreatic acinar cells in the pathogenesis of pancreatitis

Pancreatitis is an increasingly common and sometimes severe disease that lacks a specific therapy. The pathogenesis of pancreatitis is still not well understood. Calcium (Ca2+) is a versatile carrier of signals regulating many aspects of cellular activity and plays a central role in controlling digestive enzyme secretion in pancreatic acinar cells. Ca2+ overload is a key early event and is crucial in the pathogenesis of many diseases. In pancreatic acinar cells, pathological Ca2+ signaling (stimulated by bile, alcohol metabolites and other causes) is a key contributor to the initiation of cell injury due to prolonged and global Ca2+ elevation that results in trypsin activation, vacuolization and necrosis, all of which are crucial in the development of pancreatitis. Increased release of Ca2+ from stores in the intracellular endoplasmic reticulum and/or increased Ca2+ entry through the plasma membrane are causes of such cell damage. Failed mitochondrial adenosine triphosphate (ATP) production reduces re-uptake and extrusion of Ca2+ by the sarco/endoplasmic reticulum Ca2+-activated ATPase and plasma membrane Ca2+-ATPase pumps, which contribute to Ca2+ overload. Current findings have provided further insight into the roles and mechanisms of abnormal pancreatic acinar Ca2+ signals in pancreatitis. The lack of available specific treatments is therefore an objective of ongoing research. Research is currently underway to establish the mechanisms and interactions of Ca2+ signals in the pathogenesis of pancreatitis.

Pancreatic acinar cell carcinoma: A review on molecular profiling of patient tumors

Pancreatic carcinomas with acinar differentiation are rare,accounting for 1%-2% of adult pancreatic tumors; they include pancreatic acinar cell carcinoma(PACC),pancreatoblastoma,and carcinomas of mixed differentiation. Patients with PACC have a prognosis better than pancreatic ductal adenocarcinomas but worse than pancreatic neuroendocrine tumors. Reports of overall survival range from 18 to 47 mo. A literature review on PACCs included comprehensive genomic profiling and whole exome sequencing on a series of more than 70 patients as well as other diagnostic studies including immunohistochemistry. Surgical resection of PACC is the preferred treatment for localized and resectable tumors. The efficacy of adjuvant treatment is unclear. Metastatic PACCs are generally not curable and treated with systemic chemotherapy. They are moderately responsive to chemotherapy with different regimens showing various degrees of response in case reports/series. Most of these regimens were developed to treat patients with pancreatic ductal adenocarcinomas or colorectal adenocarcinomas. Review of PACC's molecular profiling showed a number of gene alterations such as: SMAD4,BRAF,BRCA2,TP53,RB1,MEN1,JAK-1,BRCA-1,BRCA-2,and DNA mismatch repair abnormalities. PACCs had multiple somatic mutations with some targetable with available drugs. Therefore,molecular profiling of PACC should be an option for patients with refractory PACC.

Functional Role of Micro RNA-19b in Acinar Cell Necrosis in Acute Necrotizing Pancreatitis

The expression of micro RNA-19b（mi R-19b） in acute necrotizing pancreatitis（ANP） and its functional role in acinar cell necrosis of SD rats were investigated. Twelve SD rats were divided into two groups randomly, including control group and ANP group. The rat ANP models were established by intraperitoneal injection of L-arginine（2400 mg/kg body weight）, and equal volume of 0.9% Na Cl was injected in the control group. Mi RNA chip assay was performed to examine the expression of mi RNAs in the pancreas in two different groups. Besides, to further explore the role of mi R-19 b in ANP in vitro, taurolithocholic acid 3-sulfate disodium salt（TLC-S）（200 μmol/L） was administrated to treat the rat pancreatic acinar cell line, AR42 J, for establishing the ANP cells model. The quantitative real-time PCR（q RT-PCR） was adopted to measure the mi R-19 b expression. Moreover, the mimic mi RNA, mi RNA antisense oligonucleotide（AMO） and control vector were used to transfect AR42 J cells, the expression of mi R-19 b was confirmed by q RT-PCR and the necrotizing rate of AR42 J cells was detected with AO/EB method. The expression of mi R-19 b was significantly higher in ANP group than in control group as displayed by the mi RNA chip assay. Furthermore, after inducing necrosis of AR42 J cells in vitro, the expression of mi R-19 b was significantly increased by 2.51±0.14 times in comparison with the control group. As revealed by q RT-PCR assay, the expression of mi R-19 b was 5.94±0.95 times higher in the mimic mi RNA group than in the control vector group, companied with an obviously increased acinar cell necrotizing rate（50.3%±1.5% vs. 39.6%±2.3%, P〈0.05）. Moreover, the expression of mi R-19 b in the mi RNA AMO group was 0.38±0.15 times lower than in the control vector group, and the cell necrosis rate was much lower accordingly（23.1%±3.3% vs. 39.6%±2.3%, P〈0.05）. Besides, there was no significant difference between the control vector cells and the cells without treatment（P〈0.05）. The expression of mi R-19 b was significantly induced in ANP. In addition, up-regulation of mi R-19 b could promote the necrosis of pancreatic acinar cells and mi R-19 b deficiency could decrease the rate of pancreatic acinar cell necrosis.

Effect of Tetrandrine on LPS-induced NF-κB activation in isolated pancreatic acinar cells of rat

AIM: To investigate the effect of Tetrandrine (Tet) on LPS-induced NF-κB activation and cell injury in pancreatic acinar cells and to explore the mechanism of Tetrandrine preventing LPS-induced acinar cell injury. METHODS: Male rat pancreatic acinar cells were isolated by collagenase digestion, then exposed to LPS (10 mg/L), Tet (50μmol/L, 100μmol/L) or normal media. At different time point (30 min, 1 h, 4 h, 10 h) after treatment with the agents, cell viability was determined by MTT, the product and nuclear translocation of subunit p65 of NF-κB was visualized by immunofluorescence staining and nuclear protein was extracted to perform EMSA which was used to assay the NF-κB binding activity. RESULTS: LPS induced cell damage directly in a time dependent manner and Tet attenuated LPS-induced cell damage (50μmol/L, P < 0.05; 100μmol/L, P < 0.01). NF-κB p65 immunofluorescence staining in cytoplasm increased and began showing its nuclear translocation within 30 min and the peak was shown at 1 h of LPS 10 mg/L treatment. NF-κB DNA binding activity showed the same alteration pattern as p65 immunofluorescence staining. In Tet group, the immunofluorescence staining in cytoplasm and nuclear translocation of NF-κB were inhibited significantly. CONCLUSION: NF-κB activation is an important early event that may contribute to inflammatory responses and cell injury in pancreatic acinar cells. Tet possesses the protective effect on LPS-induced acinar cell injury by inhibiting NF-κB activation.

Pancreatic acinar cell carcinoma:A comprehensive review

Acinar cell carcinoma(ACC)is a rare pancreatic malignancy with distinctive clinical,molecular,and morphological features.The long-term survival of ACC patients is substantially superior to that of pancreatic adenocarcinoma patients.As there are no significant patient series about ACCs,our understanding of this illness is mainly based on case reports and limited patient series.Surgical resection is the treatment of choice for patients with the disease restricted to one organ;however,with recent breakthroughs in precision medicine,medicines targeting the one-of-a-kind molecular profile of ACC are on the horizon.There are no standard treatment protocols available for people in which a total surgical resection to cure the condition is not possible.As a result of shared genetic alterations,ACCs are chemosensitive to agents with activity against pancreatic adenocarcinomas and colorectal carcinomas.The role of neoadjuvant or adjuvant chemoradiotherapy has not been established.This article aims to do a comprehensive literature study and present the most recent information on acinar cell cancer.

Acinar cell carcinoma of the pancreas in a young patient with chronic pancreatitis

BACKGROUND:Acinar cell carcinoma (ACC) is a rare malignancy of the pancreas arising from acinar cells.Unlike ductal adenocarcinoma,this tumor rarely presents with pancreatitis.METHODS:We present a case of ACC associated with chronic calcifying pancreatitis,and a review of the literature focusing on diagnosis and management.RESULTS:A 43-year-old man was proposed for Wirsungojejunal derivation for chronic pancreatitis.Histopathological examination of the tissue extracted revealed an ACC.Duodenopancreatectomy was performed.Six months postoperatively,the patient developed hepatic metastasis and was treated with gemcitabine as palliative chemotherapy.CONCLUSIONS:The clinical presentation of ACC of the pancreas is not specific and the tumor can be underdiagnosed when associated with chronic pancreatitis.Data regarding course,treatment,and prognosis of this tumor are generally lacking.

Nicotine as a mitogenic stimulus for pancreatic acinar cell proliferation

Cell proliferation is an important process in life for growth of normal and cancer cells. The signal transduction pathways activated during this process are strictly regulated. This editorial focuses on the role of nicotine, a mitogen, in the induction of signaling pathways resulting in proliferation of pancreatic tumor cells and compares these events with those in normal acinar cells isolated from the rat pancreas. The data shows striking similarities between these two cellular systems. In addition, the editorial reviews very recent literature of the contribution of MAPK signaling in cell lines associated with human diseases. A prospective cellular model of nicotine induced activation of MAPK cascade is presented.

Involvement of M3 Cholinergic Receptor Signal Transduction Pathway in Regulation of the Expression of Chemokine MOB-1, MCP-1 Genes in Pancreatic Acinar Cells

Whether M3 cholinergic receptor signal transduction pathway is involved in regulation of the activation of NF-κB and the expression of chemokine MOB-1, MCP-1genes in pancreatic acinar cells was investigated. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, atropine and PDTC in vitro. The MOB-1 and MCP-1 mRNA expression was detected by using RT-PCR. The activation of NF-κB was monitored by using electrophoretic mobility shift assay. The results showed that as compared with control group, M3 cholinergic receptor agonist (10 -3 mol/L, 10 -4 mol/L carbachol) could induce a concentration-dependent and time-dependent increase in the expression of MOB-1, MCP-1 mRNA in pancreatic acinar cells. After treatment with 10 -3 mol/L carbachol for 2 h, the expression of MOB-1, MCP-1 mRNA was strongest. The activity of NF-κB in pancreatic acinar cells was significantly increased (P<0.01) after treated with M3 cholinergic receptor agonist (10 -3 mol/L carbachol) in vitro for 30 min. Either M3 cholinergic receptor antagonist (10 -5 mol/L atropine) or NF-κB inhibitor (10 -2 mol/L PDTC) could obviously inhibit the activation of NF-κB and the chemokine MOB-1, MCP-1 mRNA expression induced by carbachol (P<0.05). This inhibitory effect was significantly increased by atropine plus PDTC (P<0.01). The results of these studies indicated that M3 cholinergic receptor signal transduction pathway was likely involved in regulation of the expression of chemokine MOB-1 and MCP-1genes in pancreatic acinar cells in vitro through the activation of NF-κB.

Acinar Cell Carcinoma of the Pancreas

Acinar cell carcinoma of the pancreas is a rare tumor which is defined as a carcinoma that exhibits pancreatic enzyme production by neoplastic cells.This review includes re- cent developments in our understanding of the epidemiology and pathogenesis of ACC,imaging and pathological diagnosis and ap- proaches to treatment with reference to the literature.

Relationship between Carbachol Hyperstimulation-Induced Pancreatic Acinar Cellular Injury and Trypsinogen or NF-κB Activation in Rats in vitro

The relationship between M3 cholinergic receptor agonist （carbachol） hyperstimulationinduced pancreatic acinar cellular injury and trypsinogen activation or NF-κB activation in rats was studied in vitro. Rat pancreatic acinar ceils were isolated, cultured and treated with carbachol, the active protease inhibitor （pefabloc）, and NF-κB inhibitor （PDTC） in vitro. Intracellular trypsin activity was measured by using a fluorogenic substrate. The cellular injury was evaluated by measuring the leakage of LDH from pancreatic acinar ceils. The results showed that as compared with control group, 10-3 mol/L carbachol induced a significant increase of the intracellular trypsin activity and the leakage of LDH from pancreatic acinar cells. Pretreatment with 2 mmol/L pefabloc could significantly decrease the activity of trypsin and the leakage of LDH from pancreatic acinar cells （P〈0. 01） following the treatment with a high concentration of carbachol （10^-3 mol/L） in vitro. The addition of 10^-2mol/L PDTC didn＇t result in a significant decrease in the activity of trypsin and the leakage of LDH from pancreatic acinar cells treated with a high concentration of carbachol （10^-3 mol/L） in vitro （P〉0. 05）. It was concluded that intracellular trypsinogen activation is likely involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro. NF-κB activation may not be involved in pancreatic acinar cellular injury induced by carbachol hyperstimulation in vitro.

Primary extra-pancreatic pancreatic-type acinar cell carcinoma in the right perinephric space: A case report and review of literature

BACKGROUND Primary extra-pancreatic pancreatic-type acinar cell carcinoma(ACC)is a rare malignancy,and has only been reported in the gastrointestinal tract,liver,and lymph nodes until now.Extra-pancreatic pancreatic-type ACC in the perinephric space has not been reported.Herein,we report the first case of ACC in the perinephric space and describe its clinical and imaging features,which should be considered when differentiating perinephric space neoplasms.CASE SUMMARY A 48-year-old man with a 5-year history of hypertension was incidentally found to have an asymptomatic right retroperitoneal mass during a routine health check-up.Laboratory tests were normal.Abdominal computed tomography and magnetic resonance imaging showed an oval hypervascular mass with a central scar and enhanced capsule in the right perinephric space.After surgical resection of the neoplasm,the diagnosis was primary extra-pancreatic pancreatic-type ACC.The patient was alive without recurrence or metastasis during a 15-mo follow-up.CONCLUSION This is the first report of an extra-pancreatic ACC in right perinephric space,which should be considered as a possible diagnosis in perinephric tumors.

Pancreatic panniculitis and elevated serum lipase in metastasized acinar cell carcinoma of the pancreas: A case report and review of literature

BACKGROUND Pancreatic panniculitis is an extremely rare condition associated with different underlying pancreatic disorders and characterized by subcutaneous fat necrosis induced by elevated serum lipase levels.These lesions usually affect the lower extremities and may precede abdominal symptoms of pancreatic disease.Acinar cell carcinoma(ACC)of the pancreas is a rare pancreatic neoplasm,accounting for only 1%-2%of pancreatic tumors in adults.We present the case of a 72-year-old man with ACC of the pancreatic head and synchronous liver metastases.Both the primary tumor and liver metastases were resected.Serum lipase was elevated before surgery and decreased to normal postoperatively.Rising serum lipase levels at follow-up led to the diagnosis of hepatic recurrence.This disease progression was then accompanied by pancreatic panniculitis,with subcutaneous fat necrosis and acute arthritis.To the best of our knowledge,only 4 cases have been reported in the literature and each showed a similar association of serum lipase levels with pancreatic panniculitis and progression of ACC.CONCLUSION Clinical symptoms and progression of ACC may correlate with serum lipase levels,suggesting potential usefulness as a follow-up biomarker.

Synchronous concomitant pancreatic acinar cell carcin and gastric adenocarcinoma:A case report and review of literature

BACKGROUND Multiple primary malignant tumors are two or more malignancies in an individual without any relationship between the neoplasms.In recent years,an increasing number of cases have been reported.However,concomitant primary gastric and pancreatic cancer reported a relatively small incidence,involving no pancreatic acinar cell carcinoma reports.Here,we present the first case of concomitant pancreatic acinar cell carcinoma and gastric adenocarcinoma.CASE SUMMARY A 69-year-old male presented to our department with a history of vomiting,epigastric pain,and weight loss.Imaging revealed space-occupying lesions in the stomach and the tail of the pancreas,respectively.The patient underwent laparo-scopic radical gastrectomy and pancreatectomy simultaneously.The pathologies of surgical specimens were completely different:The resected gastric specimen was moderate to poorly differentiated adenocarcinoma,whereas the pancreatic tumor was consistent with acinar cell carcinoma.The patient was treated with six cycles of oxaliplatin and S-1 chemotherapy.As of March 2021,the patient was healthy without any recurrence or metastasis.After thoroughly reviewing the literature on simultaneous pancreatic and gastric cancers at home and abroad,we discussed the clinical characteristics of these rare synchronous double cancers.Most of the cases had undergone surgery and adjuvant chemotherapy,and all of the cases were pathologically confirmed by the postoperative specimen.CONCLUSION Synchronous pancreatic acinar cells and gastric adenocarcinoma can occur and should be considered when tumors are found in these organs.

Rare ROS1-CENPW gene in pancreatic acinar cell carcinoma and the effect of crizotinib plus AG chemotherapy:A case report

BACKGROUND This is the first report of an ROS1-CENPW fusion gene in pancreatic malignancies.CASE SUMMARY A 77-year-old woman with a pancreatic tumor and multiple liver metastases was admitted to our hospital.Genetic testing revealed the presence of the ROS1-CENPW fusion gene,a rare fusion gene that has not been previously reported in the field of pancreatic cancer.The patient received crizotinib plus AG(albumin paclitaxel plus gemcitabine)chemotherapy.After treatment,the patient’s condition stabilized,and her prognosis was good.CONCLUSION The ROS1-CENPW gene treatment regimen used in this case is an excellent treatment option that provides new hope for patients with advanced pancreatic cancer and similar genetic mutations.To date,owing to the rarity of the ROS1-CENPW fusion gene,our team has encountered only a single case.Therefore,the efficacy of crizotinib plus AG chemotherapy in patients with pancreatic acinar cell carcinoma harboring the ROS1-CENPW fusion gene requires further validation.

Inflammatory role of the acinar cells during acute pancreatitis

Pancreatic acinar cells are secretory cells whose main function is to synthesize, store and f inally release digestive enzymes into the duodenum. However, in response to noxious stimuli, acinar cells behave like real inflammatory cells because of their ability to activate signalling transduction pathways involved in the expression of inflammatory mediators. Mediated by the kinase cascade, activation of Nuclear factor-κB, Activating factor-1 and Signal transducers and activators of transcription transcription factors has been demonstrated in acinar cells, resulting in overexpression of inflammatory genes. In turn, kinase activity is down-regulated by protein phosphatases and the f inal balance between kinase and phosphatase activity will determine the capability of the acinar cells to produce inflammatory factors. The kinase/ phosphatase pair is a redox-sensitive system in which kinase activation overwhelms phosphatase activity under oxidant conditions. Thus, the oxidative stress developed within acinar cells at early stages of acute pancreatitis triggers the activation of signalling pathways involved in the up-regulation of cytokines, chemokines and adhesion molecules. In this way, acinar cells trigger the release of the f irst inflammatory signals which can mediate the activation and recruitment of circulating inflammatorycells into the injured pancreas. Accordingly, the role of acinar cells as promoters of the inflammatory response in acute pancreatitis may be considered. This concept leads to amplifying the focus from leukocyte to acinar cells themselves, to explain the local inflammation in early pancreatitis.

Comparison of pancreatic acinar cell carcinoma and adenocarcinoma using multidetector-row computed tomography

AIM:To distinguish acinar cell carcinoma(ACC)from pancreatic adenocarcinoma(AC)by comparing their computed tomography findings.METHODS:Patients with ACC and AC were identified on the basis of results obtained using surgically resected pancreatectomy specimens.The preoperative computer tomographic images of 6 acinar cell carcinoma patients and 67 pancreatic adenocarcinoma patients in 4 phases(non-contrast,arterial,portal venous,and delayed phase)were compared.The scan delay times were 40,70,and 120 s for each contrast-enhanced phase.The visual pattern,tomographic attenuation value,and time attenuation curve were assessed and compared between AC and ACC cases using the 2test,Wilcoxon signed-rank test,and Mann Whitney U test.RESULTS:The adenocarcinomas tended to be hypodense in all 4 phases.The acinar cell carcinomas also tended to be hypodense in the 3 contrast-enhancedphases,although their computed tomographic attenuation values were higher.Further,5 of the 6 acinar cell carcinomas(83%)were isodense in the non-contrast phase.The time attenuation curve of the adenocarcinomas showed a gradual increase through the 4 phases,and all adenocarcinomas showed peak enhancement during the delayed phase.The time attenuation curve of the acinar cell carcinomas showed peak enhancement during the portal venous phase in 4 cases and during the arterial phase in 2 cases.None of the 6 acinar cell carcinomas showed peak enhancement during the delayed phase.CONCLUSION:The tumor density in the non-contrast phase and time attenuation curve pattern clearly differ between acinar cell carcinomas and adenocarcinomas,and multidetector-row computed tomography can thus distinguish these tumors.

Emodin and baicalein inhibit sodium taurocholate-induced vacuole formation in pancreatic acinar cells

AIM To investigate the effects of combined use of emodin and baicalein(CEB) at the cellular and organism levelsin severe acute pancreatitis(SAP) and explore the underlying mechanism.METHODS SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatic duct in 48 male SD rats. Pancreatic histopathology score, serum amylase activity, and levels of tumour necrosis factor alpha(TNf-α), interleukin 6(IL-6), and IL-10 were determined to assess the effects of CEB at 12 h after the surgery. The rat pancreatic acinar cells were isolated from healthy male SD rats using collagenase. The cell viability, cell ultrastructure, intracellular free Ca2+ concentration, and inositol(1,4,5)-trisphosphate receptor(IP3 R) expression were investigated to assess the mechanism of CEB.RESULTS Pancreatic histopathology score(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05) and serum amylase activity(2866.2 ± 617.7 vs 5241.3 ± 1410.0, P < 0.05) were significantly decreased in the CEB(three doses) treatment group compared with the SAP group(2.07 ± 1.20 vs 6.84 ± 1.13, P < 0.05). CEB dose-dependently reduced the levels of the pro-inflammatory cytokines IL-6(466.82 ± 48.55 vs 603.50 ± 75.53, P < 0.05) and TNF-α(108.04 ± 16.10 vs 215.56 ± 74.67, P < 0.05) and increased the level of the anti-inflammatory cytokine IL-10(200.96 ± 50.76 vs 54.18 ± 6.07, P < 0.05) compared with those in the SAP group. CEB increased cell viability, inhibited cytosolic Ca2+ concentration, and significantly ameliorated intracellular vacuoles and IP3 m RNA expression compared with those in the SAP group(P < 0.05). There was a trend towards decreased IP3 R protein in the CEB treatment group; however, it did not reach statistical significance(P > 0.05).CONCLUSION These results at the cellular and organism levels reflect a preliminary mechanism of CEB in SAP and indicate that CEB is a suitable approach for SAP treatment.

Therapeutic potential of targeting acinar cell reprogramming in pancreatic cancer

Pancreatic ductal adenocarcinoma(PDAC) is a common pancreatic cancer and the fourth leading cause of cancer death in the United States. Treating this life-threatening disease remains challenging due to the lack of effective prognosis, diagnosis and therapy. Apart from pancreatic duct cells, acinar cells may also be the origin of PDAC. During pancreatitis or combined with activating KRasG12 D mutation, acinar cells lose their cellular identity and undergo a transdifferentiation process called acinarto-ductal-metaplasia(ADM), forming duct cells which may then transform into pancreatic intraepithelial neoplasia(Pan IN) and eventually PDAC. During ADM, the activation of mitogen-activated protein kinases, Wnt, Notch and phosphatidylinositide 3-kinases/Akt signaling inhibits the transcription of acinar-specific genes, including Mist and amylase, but promotes the expression of ductal genes, such as cytokeratin-19. Inhibition of this transdifferentiation process hinders the development of Pan IN and PDAC. In addition, the transdifferentiated cells regain acinar identity, indicating ADM may be a reversible process. This provides a new therapeutic direction in treating PDAC through cancer reprogramming. Many studies have already demonstrated the success of switching Pan IN/PDAC back to normal cells through the use of PD325901, the expression of E47, and the knockdown of Dickkopf-3. In this review, we discuss the signaling pathways involved in ADM and the therapeutic potential of targeting reprogramming in order to treat PDAC.

Acinar cell injury induced by inadequate unfolded protein response in acute pancreatitis

Acute pancreatitis (AP) is an inflammatory disorder of pancreatic tissue initiated in injured acinar cells. Severe AP remains a significant challenge due to the lack of effective treatment. The widely-accepted autodigestion theory of AP is now facing challenges, since inhibiting protease activation has negligible effectiveness for AP treatment despite numerous efforts. Furthermore, accumulating evidence supports a new concept that malfunction of a self-protective mechanism, the unfolded protein response(UPR), is the driving force behind the pathogenesis of AP. The UPR is induced by endoplasmic reticulum(ER) stress, a disturbance frequently found in acinar cells, to prevent the aggravation of ER stress that can otherwise lead to cell injury. In addition, the UPR's signaling pathways control NFκB activation and autophagy flux, and these dysregulations cause acinar cell inflammatory injury in AP, but with poorly understood mechanisms. We therefore summarize the protective role of the UPR in AP, propose mechanistic models of how inadequate UPR could promote NFκB's pro-inflammatory activity and impair autophagy's protective function in acinar cells, and discuss its relevance to current AP treatment. We hope that insight provided in this review will help facilitate the research and management of AP.

Ghrelin-induced cSrc activation through constitutive nitric oxide synthase-dependent S-nitrosylation in modulation of salivary gland acinar cell inflammatory responses to <i>Porphyromonas gingivalis</i>

A peptide hormone, ghrelin, recognized for its role in the regulation of nitric oxide production has emerged as an important modulator of oral mucosal inflammatory responses to periodontopathic bacterium, P. gingivalis. As cSrc kinase plays a major role in controlling the activity of nitric oxide synthase (NOS) system, in this study we investigated the influence of P. gingivalis LPS on the processes of Src activation in rat sublingual gland acinar cells. The LPS-induced enhancement in the activity of inducible (i) iNOS and the impairment in constitutive (c) cNOS were reflected in the suppression in cSrc activity and the extent of its phosphorylation at Tyr416. Further, we show that the countering effect of ghrelin on the LPS-induced changes in cSrc activity and the extent of its phosphorylation was accompanied by a marked reduction in iNOS and the increase in cNOS activation through phosphorylation at Ser1179. Moreover, the effect of ghrelin on cSrc activation was associated with the kinase S-nitrosylation that was susceptible to the blockage by cNOS inhibition. Our findings suggest that P. gingivalis-induced up-regulation in iNOS leads to disturbances in cNOS phosphorylation that exerts the detrimental effect on the processes of cSrc activation through cNOS mediated S-nitrosylation. We also show that the effect of ghrelin on P. gingivalis-induced inflammatory changes are manifested in the enhancement in cSrc activation through S-nitrosylation and the increase in its phosphorylation at Tyr416.