ß-Arrestin1 alleviates acute pancreatitis via repression of NF-κBp65 activation.

BACKGROUND AND AIM: ß-Arrestins (ß-arrs) are regulators and mediators of G protein-coupled receptor signaling that are functionally involved in inflammation. Nuclear factor-κB p65 (NF-κBp65) activation has been observed early in the onset of pancreatitis. However, the effect of ß-arrs in acute pancreatitis (AP) is unclear. The aim of this study is to investigate whether ß-arrs are involved in AP through activation of NF-κBp65. METHODS: Acute pancreatitis was induced by either caerulein injection or choline-deficient supplemented with ethionine diet (CDE). ß-arr1 wild-type and ß-arr1 knockout mice were used in the experiment. The survival rate was calculated in the CDE model mice. Histological and western blot analyses were performed in the caerulein model. Inflammatory mediators were detected by real-time polymerase chain reaction in the caerulein-induced AP mice. Furthermore, AR42J and PANC-1 cell lines were used to further study the effects of ß-arr1 in caerulein-induced pancreatic cells. RESULTS: ß-Arr1 but not ß-arr2 is significantly downregulated in caerulein-induced AP in mice. Targeted deletion of ß-arr1 notably upregulated expression of the pancreatic inflammatory mediators including tumor necrosis factor α and interleukin 1ß as well as interleukin 6 and aggravated AP in caerulein-induced mice. ß-Arr1 deficiency increased mortality in mice with CDE-induced AP. Further, ß-arr1 deficiency enhanced caerulein-induced phosphorylation of NF-κBp65 both in vivo and in vitro. CONCLUSION: ß-Arr1 alleviates AP via repression of NF-κBp65 activation, and it is a potentially therapeutic target for AP.

The effect of intravenous granisetron on prophylactic ephedrine for preventing hypotension after general anaesthesia induction in elderly patients: a randomized controlled trial.

Serotonin 3 receptor antagonists, a commonly used drug for preventing postoperative nausea and vomiting, have recently been reported to decrease the incidence of hypotension and the need for vasoactive drugs after spinal anaesthesia in obstetric surgery. However, it remains unknown whether they could also prevent hypotension after induction of general anaesthesia. In the current study, we aimed to investigate the effect of intravenous granisetron on prophylactic ephedrine for preventing hypotension after general anaesthesia induction in elderly patients. Sixty elderly patients were randomly assigned to receive granisetron or saline control 30 min before induction of general anaesthesia. The first patient in each group received a prophylactic dose of ephedrine (0.15 mg kg-1) to prevent hypotension. The prophylactic dose for each patient was increased or decreased by 0.05 mg/kg based on the efficacy results of the previous patient. The up-down sequential allocation analysis and probit regression was used to calculate the effective dose for 50% of patients (ED50) with prophylactic ephedrine. In the up-down sequential allocation analysis, the ED50 of ephedrine was significantly lower in group granisetron (0.08 mg kg-1 [95% CI, 0.06-0.11 mg kg-1]) when compared with group control (0.14 mg kg-1 [95% CI, 0.13-0.16 mg kg-1]) (P < 0.001). The conclusion was further supported by probit regression analysis (0.09 mg kg-1 [95% CI, 0.05-0.12 mg kg-1] in group granisetron and 0.14 mg kg-1 [95% CI, 0.12-0.16 mg kg-1] in group control). Intravenous granisetron reduced the requirement of prophylactic ephedrine in preventing hypotension after general anaesthesia induction in elderly patients.

Peripheral immune characteristics of hepatitis B virus-related hepatocellular carcinoma.

Background: Liver cancer is the sixth most common cancer worldwide and the third leading cause of cancer-related death. As a chronic liver disease, many studies have shown that the immune response plays a key role in the progression of liver cancer. Chronic hepatitis B virus (HBV) infection is one of the high-risk factors for HCC, accounting for 50%-80% of HCC cases worldwide, and little is known about the immune status of HBV associated hepatocellular carcinoma (HBV-HCC), therefore, we aimed to explore the changes in peripheral immunity in patients with HBV-HCC. Methods: In this study, patients with HBV-HCC (n=26), patients with hepatitis B-related cirrhosis (HBV-LC) (n=31) and healthy volunteers (n=49) were included. The lymphocytes and their subpopulation phenotypes in peripheral blood were characterized. In addition, we explored the effect of viral replication on peripheral immunity in patients with HCC and analyzed the circulating immunophenotypic characteristics at different stages of HCC with flow cytometry. Results: Firstly, our results showed that the percentages of total αß T cells in the peripheral blood of HBV-HCC patients was significantly decreased compared to healthy subjects. Secondly, we found that naïve CD4+ T cells in HBV-HCC patients were significantly reduced, terminally differentiated CD8+ T cells, homing memory CD8+ T cells and Th2 cells were increased in peripheral circulation in HBV-HCC patients. Moreover, in the peripheral blood of HBV-HCC patients, expression of TIGIT on CD4+ T cells and PD-1 on the surface of Vδ 1 T cells was increased. In addition, we found that sustained viral replication resulted in up-regulation of TIM3 expression on CD4+ T cells, and TIM3+ γδ T cells increased in peripheral circulation in patients with advanced HBV-HCC. Conclusion: Our study showed that circulating lymphocytes in HBV-HCC patients exhibited features of immune exhaustion, especially in HCC patients with persistent viral replication and in patients with intermediate and advanced HBV-HCC, including decreased frequency of T cells and elevated expression of inhibitory receptors including TIGIT and TIM3 on CD4+ T cells and γδ T cells. Meanwhile, our research suggests that the combination of CD3+ T cell and CD8+HLADR+CD38+ T cell may be a potential diagnostic indicator for HBV-HCC. These findings could help us to better understand the immune characteristics of HBV-HCC and explore the immune mechanisms and immunotherapy strategies for HBV-HCC.

Aerobic glycolysis enhances HBx-initiated hepatocellular carcinogenesis via NF-κBp65/HK2 signalling.

BACKGROUND: Aerobic glycolysis has been recognized as one of the growth-promoting metabolic alterations of cancer cells. Emerging evidence indicates that nuclear factor κB (NF-κB) plays significant roles in metabolic adaptation in normal cells and cancer cells. However, whether and how NF-κB regulates metabolic reprogramming in hepatocellular carcinoma (HCC), specifically hepatitis B virus X protein (HBx)-initiated HCC, has not been determined. METHODS: A dataset of the HCC cohort from the TCGA database was used to analyse the expression of NF-κB family members. Expression of NF-κBp65 and phosphorylation of NF-κBp65 (p-p65) were detected in liver tissues from HBV-related HCC patients and normal controls. A newly established HBx+/+/NF-κBp65f/f and HBx+/+/NF-κBp65Δhepa spontaneous HCC mouse model was used to investigate the effects of NF-κBp65 on HBx-initiated hepatocarcinogenesis. Whether and how NF-κBp65 is involved in aerobic glycolysis induced by HBx in hepatocellular carcinogenesis were analysed in vitro and in vivo. RESULTS: NF-κBp65 was upregulated in HBV-related HCC, and HBx induced NF-κBp65 upregulation and phosphorylation in vivo and in vitro. Hepatocyte-specific NF-κBp65 deficiency remarkably decreased HBx-initiated spontaneous HCC incidence in HBx-TG mice. Mechanistically, HBx induced aerobic glycolysis by activating NF-κBp65/hexokinase 2 (HK2) signalling in spontaneous hepatocarcinogenesis, and overproduced lactate significantly promoted HCC cell pernicious proliferation via the PI3K (phosphatidylinositide 3-kinase)/Akt pathway in hepatocarcinogenesis. CONCLUSION: The data elucidate that NF-κBp65 plays a pivotal role in HBx-initiated spontaneous HCC, which depends on hyperactive NF-κBp65/HK2-mediated aerobic glycolysis to activate PI3K/Akt signalling. Thus, phosphorylation of NF-κBp65 will be a potential therapeutic target for HBV-related HCC.

The Role of Transient Receptor Potential Channels in Blood-Brain Barrier Dysfunction after Ischemic Stroke.

Stroke is the leading cause of long-term disability, demanding an ever-increasing need to find treatment. Transient receptor potential (TRP) channels are nonselective Ca2+-permeable channels, among which TRPC, TRPM, and TRPV are widely expressed in the brain. Dysfunction of the blood brain barrier (BBB) is a core feature of stroke and is associated with severity of injury. As studies have shown, TRP channels influence various neuronal functions by regulating the BBB. Here, we briefly review the role of TRP channel in the BBB dysfunction after stroke, and explore the therapeutic potential of TRP-targeted therapy.

Mitophagy impairment is involved in sevoflurane-induced cognitive dysfunction in aged rats.

Postoperative cognitive dysfunction (POCD) is frequently observed in elderly patients following anesthesia, but its pathophysiological mechanisms have not been fully elucidated. Sevoflurane was reported to repress autophagy in aged rat neurons; however, the role of mitophagy, which is crucial for the control of mitochondrial quality and neuronal health, in sevoflurane-induced POCD in aged rats remains undetermined. Therefore, this study investigated whether mitophagy impairment is involved in sevoflurane-induced cognitive dysfunction. We found sevoflurane treatment inhibited mitochondrial respiration and mitophagic flux, changes in mitochondria morphology, impaired lysosomal acidification, and increased Tomm20 and deceased LAMP1 accumulation were observed in H4 cell and aged rat models. Rapamycin counteracted ROS induced by sevoflurane, restored mitophagy and improved mitochondrial function. Furthermore, rapamycin ameliorated the cognitive deficits observed in aged rats given sevoflurane anesthesia as determined by the Morris water maze test; this improvement was associated with an increased number of dendritic spines and pyramidal neurons. Overexpression of PARK2, but not mutant PARK2 lacking enzyme activity, in H4 cells decreased ROS and Tomm20 accumulation and reversed mitophagy dysfunction after sevoflurane treatment. These findings suggest that mitophagy dysfunction could be a mechanism underlying sevoflurane-induced POCD and that activating mitophagy may provide a new strategy to rescue cognitive deficits.

The potential mechanism of postoperative cognitive dysfunction in older people.

Postoperative cognitive dysfunction (POCD) is a common disorder following surgery, which seriously threatens the quality of patients' life, especially the older people. Accumulating attention has been paid to POCD worldwide in pace with the popularization of anesthesia/surgery. The development of medical humanities and rehabilitation medicine sets higher demands on accurate diagnosis and safe treatment system of POCD. Although the research on POCD is in full swing, underlying pathogenesis is still inconclusive due to these conflicting results and controversial evidence. Generally, POCD is closely related to neuropsychiatric diseases such as dementia, depression and Alzheimer's disease in molecular pathways. Researchers have come up with various hypotheses to reveal the mechanisms of POCD, including neuroinflammation, oxidative stress, autophagy disorder, impaired synaptic function, lacking neurotrophic support, etc. Recent work focused on molecular mechanism of POCD in older people has been thoroughly reviewed and summed up here, concerning the changes of peripheral circulation, pathological pathways of central nervous system (CNS), the microbiota-gut-brain axis and the related brain regions. Accordingly, this article provides a better perspective to understand the development situation of POCD in older people, which is conductive to uncover the pathological mechanism and exploit reasonable treatment strategy of POCD.

PTTG1 is involved in TNF-α-related hepatocellular carcinoma via the induction of c-myc.

Hepatocellular carcinoma (HCC) is a malignant disease caused by a variety of factors. However, the genomic and molecular aberrations in HCC are largely unknown. Herein, pituitary tumor transforming gene 1 (PTTG1) was discovered as a potential inflammation-related oncogene in HCC, and its functions and molecular mechanisms were investigated. mRNA expression microarray, real-time polymerase chain reaction (PCR), immunohistochemistry, and western blotting analyses revealed that PTTG1 is upregulated in HCC. Further in vitro and in vivo studies indicated that the proinflammatory cytokine tumor necrosis factor-α (TNF-α) induces PTTG1 expression, and PTTG1 was found to upregulate c-myc, a well-known oncogene. Downregulation of PTTG1 reduced c-myc and proliferating cell nuclear antigen (PCNA) expression and inhibited cell proliferation. Interestingly, inhibition of c-myc by 10058-F4 did not affect PTTG1, which suggests that PTTG1 regulates c-myc expression. Furthermore, PTTG1 expression levels are inversely correlated with HCC patient survival, indicating an independent prognostic biomarker for patients with HCC. Our data demonstrate that PTTG1 is involved in TNF-α-related HCC via c-myc induction and that PTTG1 may be a potential therapeutic target for HCC.

Temporal Changes of Spinal Transcriptomic Profiles in Mice With Spinal Nerve Ligation.

Neuropathic pain (NP) is an intractable disease accompanying with allodynia, hyperalgesia and spontaneous pain. Accumulating evidence suggested that large volume of neurotransmitters, genes, and signaling pathways were implicated with the initiation and development of NP, while the underlying mechanism still remained poorly understood. Therefore, it was extremely important to further elucidate the potential regulatory networks for developing appropriate treatment options. Here, the RNA-Seq high-throughput sequencing was employed to determine the genes expression change in mice undergoing spinal nerve ligation (SNL). Meanwhile, the differentially expressed genes (DEGs) were analyzed by using integrated Differential Expression and Pathway analysis (iDEP) tools and String database. Then, quantitative real-time PCR (qRT-PCR) was employed to detect the expression of hub gens. The results showed that the DEGs mainly comprised 1712 upregulated and 1515 downregulated genes at 7 days, and consisted of 243 upregulated and 357 downregulated genes at 28 days after surgery, respectively. Additionally, 133 genes and two pathways including retrograde endocannabinoid signaling and cardiac muscle contraction collectively participated in biological reactions of 7th and 28th day after operation. Moreover, the results showed that the mRNA and protein expression of Ccl5, Cacna2d1, Cacna2d2, Cacnb2, Gabrb3, GluA1, and GluA2 were significantly upregulated in SNL-7/28d group than that of in Sham-7/28d group (SNL-7d vs. Sham-7d; SNL-28d vs. Sham-28d; P < 0.05). And the level of Glra2, Glra4, Glra3, Grik1, Grik2, NR1, NR2A, and NR2B was obviously increased in SNL-7d group compared to Sham-7d group (P < 0.05), but which was no statistical difference between SNL-28d group and Sham-28d group. Therefore, these results provided new perspectives and strategies for deeply illuminating the underlying mechanism, and identifying the key elements for treating NP.

Recurrent esophagogastric variceal bleeding due to portal vein thrombosis caused by protein S deficiency.

Background and study aims Esophagogastric variceal bleeding (EGVB) is common in patients with portal vein thrombosis (PVT). Hereditary deficiencies in natural anticoagulant proteins, such as protein S, might contribute to PVT. However, recurrent EGVB caused by PVT in patients with protein S deficiency is seldom reported. Herein, we present the case of a 38-year-old man with protein S deficiency complicated with PVT. The patient suffered recurrent EGVB for 7 years. He underwent splenectomy plus pericardial revascularization and sequential endoscopic therapy, including one gastric variceal obturation (GVO) procedure and two esophageal variceal ligations (EVL) to eradicate the varices. Rivaroxaban was administrated to reduce risk of thrombotic events. The patient is currently well without rebleeding after 1 year of follow-up. To our knowledge there is no consensus on management of recurrent EGVB on the basis of thrombophilia complicated with PVT. According to our practice, sequential endoscopic therapy combined with anticoagulant appears to be effective and safe.

Endoscopic Band Ligation Is Able to Close Perforations Caused by Colonoscopy: A Porcine Model Study.

OBJECTIVE: Diagnostic colonoscopy is important for diagnosing colorectal diseases, including inflammatory bowel disease and colorectal tumours. Perforation during diagnostic colonoscopy, a rare but serious complication, is a considerable factor before performing the procedure. Immediate endoluminal closure of a perforation could prevent the adverse consequences associated with general anaesthesia and surgery. This study is aimed at assessing the potential effectiveness and safety of endoscopic band ligation (EBL) in closing a colon perforation during endoscopy in a porcine model. METHODS: Colon perforations were created and then subsequently closed with EBL in six porcine models. After 28 days of careful follow-up, pigs were euthanized for clinical and pathologic evaluations. RESULTS: All colon perforations were successfully closed using EBL in pigs. The mean time of perforation closure with EBL was 244.3 seconds with one to two bands, and there were no immediate complications or clinical manifestations of peritonitis or sepsis in any animals. No pericolonic abscess or peritonitis was found during necropsy. Histopathology demonstrated reepithelialization of the mucosa at the perforation site. CONCLUSIONS: Immediate closure of perforations caused during colonoscopy with EBL is feasible and safe in a porcine model.

Let­7d inhibits colorectal cancer cell proliferation through the CST1/p65 pathway.

Cystatin SN (cystatin 1, CST1) is a member of the cystatin superfamily which inhibits the proteolytic activity of cysteine proteases. CST1 is a tumor biomarker that provides useful information for the diagnosis of esophageal, gastric and colorectal carcinomas. MicroRNAs (miRNAs or miRs) play an important role in tumor cell proliferation. However, the exact role of let­7d and CST1 in colon cancer remains unknown. The aim of this study was to assess whether let­7d inhibits colorectal carcinogenesis through the CST1/p65 pathway, and determine whether it may be used as a potential target for clinical therapy. Microarray analysis of mRNAs extracted from colon cancer and normal tissues was performed. The results of gene expression microanalysis revealed that CST1 expression was upregulated in colon cancer compared with normal tissues. In addition, the upregulation of CST1 expression and the downregulation of let­7d expression in patients with colon cancer and in several colorectal cancer cell lines were confirmed by reverse transcription-quantitative PCR (RT­qPCR), immunohistochemistry and western blot analysis. In addition, siRNA targeting CST1 (CST1­siRNA) and let­7d-mimics were used in the HCT116 cells, and the results revealed that CST1 and let­7d played a role in colorectal cancer cell proliferation. Let­7d inhibited colorectal carcinogenesis through the CST1/p65 pathway. Thus, the findings of the present study indicate that CST1 may be a potential target for the future clinical therapy of colorectal cancer.

Lnc-PCDH9-13:1 Is a Hypersensitive and Specific Biomarker for Early Hepatocellular Carcinoma.

BACKGROUND: Long non-coding RNAs (lncRNAs) show great potential as diagnostic tools in many diseases. We aimed to develop sensitive and noninvasive biomarkers in saliva for detecting early hepatocellular carcinoma (HCC). METHODS: Candidate lncRNA biomarkers identified by Agilent microarray were subjected to validation using qPCR for the quantification of their expression levels in independent tissue, plasma and saliva sample sets, including healthy controls, HBsAg carriers, patients with chronic Hepatitis B, liver cirrhosis, early HCC, and advanced HCC. Levels of candidate biomarkers were also measured in totally 108 saliva samples from patients with any one of other nine leading causes of cancer death in men and women. FINDINGS: Lnc-PCDH9-13:1 was significantly elevated in HCC tissues, plasma and saliva of HCC patients compared with healthy controls and groups of several benign liver diseases and other leading cancers. Its level was significantly reduced after curative hepatectomy but significantly elevated again if HCC recurrence occurred. Salivary lnc-PCDH9-13:1 showed reasonable specificities and sensitivities for detecting HCC compared with several control groups. Furthermore, the overexpression of lnc-PCDH9-13:1 promotes cell proliferation and migration in vitro. INTERPRETATION: Salivary lnc-PCDH9-13:1 is a desirable biomarker for early HCC. It may help warrant prospective validation with larger sample sizes in multi-centers.

Diagnosis of eosinophilic gastroenteritis is easily missed.

AIM: To analyze the clinical characteristics of eosinophilic gastroenteritis (EGE) and to investigate the situations of missed diagnosis of EGE. METHODS: First, the clinical characteristics of 20 EGE patients who were treated at our hospital were retrospectively summarized. Second, 159 patients who underwent gastroscopy and 211 patients who underwent colonoscopy were enrolled. The pathological diagnosis showed only chronic inflammation in their medical records. The biopsy slides of these patients were reevaluated to determine the number of infiltrating eosinophils in order to assess the probability of a missed diagnosis of EGE. Finally, 122 patients who experienced refractory upper gastrointestinal symptoms for at least one month were recruited. At least 6 biopsy specimens were obtained by gastroscopy, and the number of eosinophils that had infiltrated was evaluated. Those who met the pathological diagnostic criteria of EGE underwent further examination to confirm the diagnosis of EGE. The probability of a missed diagnosis of EGE was prospectively investigated. RESULTS: Among the 20 patients with EGE, mucosal EGE was found in 15 patients, muscular EGE was found in 3 patients and serosal EGE was found in 2 patients. Abdominal pain was the most common symptom. The number of peripheral blood eosinophils was elevated in all 20 patients, all of whom were sensitive to corticosteroids. Second, among the 159 patients who underwent gastroscopy, 7 (4.40%) patients met the criteria for pathological EGE (eosinophil count ≥ 25/HPF). Among the 211 patients who underwent colonoscopy, 9 (4.27%) patients met the criteria for pathological EGE (eosinophil count ≥ 30/HPF). No patients with eosinophil infiltration were diagnosed with EGE in clinical practice before or after endoscopy. Although these patients did not undergo further examination to exclude other diseases that can also lead to gastrointestinal eosinophil infiltration, these might be the cases where the diagnosis of EGE was missed. Finally, among the 122 patients with refractory upper gastrointestinal symptoms, eosinophil infiltration was seen in 7 patients (5.74%). The diagnosis of EGE was confirmed in all 7 patients after the exclusion of other diseases that can also lead to gastrointestinal eosinophil infiltration. A positive correlation was observed between the duration of the symptoms and the risk of EGE (r = 0.18, P < 0.01). The patients whose symptoms persisted longer than 6 mo more readily developed EGE. None of the patients were considered to have EGE by their physicians before endoscopy. CONCLUSION: Although EGE is a rare inflammatory disorder, it is easily misdiagnosed. When a long history of abdominal symptoms fails to improve after conventional therapy, EGE should be considered.

Successful treatment of ileal ulcers caused by immunosuppressants in two organ transplant recipients.

Although gastroduodenal ulcers are common in solid organ transplant patients, there are few reports on multiple giant ulcers in the distal ileum and ileocecal valve caused by immunosuppressants Herein, we report on a liver transplant recipient and a renal transplant recipient with multiple large ulcers in the distal ileum and ileocecal valve who rapidly achieved ulcer healing upon withdrawal of sirolimus or tacrolimus and administration of thalidomide. In case 1, a 56-year-old man with primary hepatocellular carcinoma had received a liver transplantation. Tacrolimus combined with sirolimus and prednisolone was used as the anti-rejection regimen. Colonoscopy was performed because of severe abdominal pain and diarrhea at post-operative month 10. Multiple giant ulcers were found at the ileocecal valve and distal ileum. The ulcers healed rapidly with withdrawal of sirolimus and treatment with thalidomide. There was no recurrence during 2 years of follow-up. In case 2, a 34-year-old man with end-stage kidney disease received kidney transplantation and was put on tacrolimus combined with mycophenolate mofetil and prednisolone as the anti-rejection regimen. Twelve weeks after the operation, the patient presented with hematochezia and severe anemia. Colonoscopy revealed multiple large ulcers in the ileocecal valve and distal ileum, with massive accumulation of fresh blood. The bleeding ceased after treatment with intravenous somatostatin and oral thalidomide. Tacrolimus was withdrawn at the same time. Colonoscopy at week 4 of follow-up revealed remarkable healing of the ulcers, and there was no recurrence of bleeding during 1 year of follow-up. No lymphoma, tuberculosis, or infection of cytomegalovirus, Epstein-Barr virus, or fungus was found in either patient. In post-transplantation cases with ulcers in the distal ileum and ileocecal valve, sirolimus or tacrolimus should be considered a possible risk factor, and withdrawing them or switching to another immunosuppressant might be effective to treat these ulcers.

[Clinical research of qingkailing soft capsules in treating acute upper respiratory infection].

OBJECTIVE: To discuss the efficacy of Qingkailing soft capsules in treating acute fever, and the relationship between symptoms-effect and time effect. METHOD: Qingkailing soft capsules was taken orally, 4 times a day, 1.6 g each time. Shuanghuanglian kou fu liquid was taken as control. 129 patients with acute upper respiratory tract infection were recruited. RESULT: There were 73.34% of patients cured by Qingkailing soft capsules and 43.59% cured by Shuanghuanglian kou fu liquid. The efficacy of the former was better than that of the latter (P < 0.05). The efficacy of Qingkailing soft capsules in treating Fengrexing was better than that in Fenghanxing (P < 0.05). The efficacy of Qingkailing soft capsules in reducing rapid pulse and adding moderate pulse was more remarkable than Shuanghuanglian kou fu liquid (P < 0.05). Taking Qingkailing soft capsules seldom induced mild gastrointestinal disturbance. CONCLUSION: Qingkailing soft capsules showed good result in the treatment of acute upper respiratory tract infection with less adverse effect.

ß-Arrestin-1 protects against endoplasmic reticulum stress/p53-upregulated modulator of apoptosis-mediated apoptosis via repressing p-p65/inducible nitric oxide synthase in portal hypertensive gastropathy.

Portal hypertensive gastropathy (PHG) is a serious cause of bleeding in patients, and is associated with portal hypertension. ß-Arrestins (ß-arrestin-1 and ß-arrestin-2) are well-established mediators of endocytosis of G-protein-coupled receptors (GPCRs), ubiquitination, and G-protein-independent signaling. The role of ß-arrestin-1 (ß-arr1) in mucosal apoptosis in PHG remains unclear. The aim of this study was to investigate the involvement of ß-arr1 in PHG via its regulation of endoplasmic reticulum (ER) stress/p53-upregulated modulator of apoptosis (PUMA) apoptotic signaling. Gastric mucosal injury and apoptosis were studied in PHG patients and in PHG mouse models. The induction of ß-arr1 and the ER stress/PUMA signaling pathway were investigated, and the mechanisms of ß-arr1-regulated gastric mucosal apoptosis were analyzed in vivo and in vitro experiments. ß-arr1 and ER stress/PUMA signaling elements were markedly induced in the gastric mucosa of PHG patients and mouse models. Blockage of ER stress demonstrably attenuated the mucosal apoptosis of PHG, while targeted deletion of ß-arr1 significantly aggravated the injury and ER stress/PUMA-mediated apoptosis. ß-arr1 limited the activation of p65 to repress TNF-α-induced inducible nitric oxide synthase (iNOS) expression and NO release, which could regulate ER stress/PUMA-mediated mucosal apoptosis in PHG. In vivo and in vitro experiments further demonstrated that ß-arr1 protected against mucosal apoptosis by repressing TNF-α-induced iNOS expression via inhibiting the activation of p65. These results indicated that ß-arr1 regulated ER stress/PUMA-induced mucosal epithelial apoptosis through suppression of the TNF-α/p65/iNOS signaling pathway activation and that ß-arr1 is a potential therapeutic target for PHG.