HRD1-induced TMEM2 ubiquitination promotes ER stress-mediated apoptosis through a non-canonical pathway in intestinal ischemia/reperfusion.

Intestinal ischemia/reperfusion (I/R) injury is a typical pathological course in the clinic with a high morbidity rate. Recent research has pointed out the critical role of ubiquitination during the occurrence and development of intestinal I/R by precisely mediating protein quality control and function. Here, we conducted an integrated multiomic analysis to identify critical ubiquitination-associated molecules in intestinal I/R and identified endoplasmic reticulum-located HRD1 as a candidate molecule. During intestinal I/R, excessive ER stress plays a central role by causing apoptotic pathway activation. In particular, we found that ER stress-mediated apoptosis was mitigated by HRD1 knockdown in intestinal I/R mice. Mechanistically, TMEM2 was identified as a new substrate of HRD1 in intestinal I/R by mass spectrometry analysis, which has a crucial role in attenuating apoptosis and promoting non-canonical ER stress resistance. A strong negative correlation was found between the protein levels of HRD1 and TMEM2 in human intestinal ischemia samples. Specifically, HRD1 interacted with the lysine 42 residue of TMEM2 and reduced its stabilization by K48-linked polyubiquitination. Furthermore, KEGG pathway analysis revealed that TMEM2 regulated ER stress-mediated apoptosis in association with the PI3k/Akt signaling pathway rather than canonical ER stress pathways. In summary, HRD1 regulates ER stress-mediated apoptosis through a non-canonical pathway by ubiquitinating TMEM2 and inhibiting PI3k/Akt activation during intestinal I/R. The current study shows that HRD1 is an intestinal I/R critical regulator and that targeting the HRD1/TMEM2 axis may be a promising therapeutic approach.

Critical role of caveolin-1 in intestinal ischemia reperfusion by inhibiting protein kinase C ßII.

Intestinal ischemia reperfusion (I/R) is a common clinical pathological process. We previously reported that pharmacological inhibition of protein kinase C (PKC) ßII with a specific inhibitor attenuated gut I/R injury. However, the endogenous regulatory mechanism of PKCßII inactivation is still unclear. Here, we explored the critical role of caveolin-1 (Cav1) in protecting against intestinal I/R injury by regulating PKCßII inactivation. PKCßII translocated to caveolae and bound with Cav1 after intestinal I/R. Cav1 was highly expressed in the intestine of mice with I/R and IEC-6 cells stimulated with hypoxia/reoxygenation (H/R). Cav1-knockout (KO) mice suffered from worse intestinal injury after I/R than wild-type (WT) mice and showed extremely low survival due to exacerbated systemic inflammatory response syndrome (SIRS) and remote organ (lung and liver) injury. Cav1 deficiency resulted in excessive PKCßII activation and increased oxidative stress and apoptosis after intestinal I/R. Full-length Cav1 scaffolding domain peptide (CSP) suppressed excessive PKCßII activation and protected the gut against oxidative stress and apoptosis due to I/R injury. In summary, Cav1 could regulate PKCßII endogenous inactivation to alleviate intestinal I/R injury. This finding may represent a novel therapeutic strategy for the prevention and treatment of intestinal I/R injury.

Autoamputation of the appendix and survival of the amputated part: a rare case report and literature review.

BACKGROUND: Autoamputation of the appendix, i.e., complete separation of a part of the appendix without any surgical intervention, has been rarely documented in the literature in recent years. Herein, we report a case where the amputated part of the appendix was viable after autoamputation and reviewed the related literature. CASE PRESENTATION: A 39-year-old female patient was admitted to our hospital complaining of abdominal pain and subsequently underwent an emergency laparoscopic appendectomy (LA). Intraoperatively, we found an abnormally short appendix protruding from the cecum and a strip-like tissue attached to the mesoappendix, considered a duplex appendix, was resected. Finally, in conjunction with the histopathology findings and the past medical history, the patient was diagnosed with "Pseudo-duplication of the Appendix". CONCLUSIONS: Autoamputation of the appendix resulting in preserved tissue viability and absence of necrosis at both ends, can be termed as "Pseudo-duplication of the Appendix". This condition is very rare in clinical practice and has not been reported in China, to the best of our knowledge. It has been established that the autoamputated appendix can produce chronic inflammation, intestinal fistulae and even cancer, affecting the patient's quality of life. Accordingly, a clear diagnosis and timely management are essential. In this report, we established a novel classification for "Pseudo-duplication of the Appendix", hoping that our report will help surgeons better understand this anatomical anomaly of the appendix, to help during the differential diagnosis process and avoid confusion.

Bioinformatics analysis reveals the clinical significance of GIPC2/GPD1L for colorectal cancer using TCGA database.

Background: Colorectal cancer (CRC) causes 700,000 deaths annually and is the fourth deadliest cancer in the world after lung, liver, and stomach cancer. Since CRC is difficult to detect early and has a poor prognosis, it is critical to develop novel biomarkers for its diagnosis, prognosis, and treatment. Methods: The GIPC2 expression in colorectal cancer was examined by the TCGA database analysis, IHC from the human protein atlas and qRT-PCR tests. GO and KEGG enrichment analyses were performed for genes that were both correlated with the expression of GIPC2 and GPD1L. The receiver operating characteristic curve (ROC) analysis and Kaplan-Meier (KM) survival analysis were applied to analyze the prognostic value of GIPC2 and GPD1L for overall survival (OS) and progress free interval (PFI) of CRC patients. Results: We found that GIPC2 was low expressed in colorectal cancer and highly related with the CRC clinical-stage grade and TNM stage. Furthermore, GPD1L is correlated with GIPC2 via the correlation analysis in CRC and they were associated with several important cancer-related pathways. GIPC2 and GPD1L exhibited good diagnostic and prognostic predictive ability for patients with CRC. Conclusions: These results revealed new biomarkers in CRC, we proposed that the GIPC2/GPDL1 might be potential diagnostic and prognostic indicators for CRC, which provides a theoretical basis for our subsequent cellular and animal experiments, so as to reveal the occurrence and development mechanism of CRC more comprehensively.

Ring finger protein 128 promotes, rather than inhibits, colorectal cancer progression by regulating the Hippo signaling pathway.

Background: Colorectal cancer is a common malignancy of the gastrointestinal tract, and its incidence and mortality rates have increased in recent years. RNF128 is an E3 ubiquitin ligase that plays an important role as a suppressor gene or oncogene in various cancers, but its mechanism in colorectal cancer is not yet clear. The aim of this study was to investigate the role and mechanism of RNF128 in colorectal cancer. Methods: The expression of RNF128 in colorectal cancer tissues was assessed by immunohistochemistry and western blotting. The proliferation ability of colorectal cancer cells was measured by colony formation assay and CCK-8 assay, the migration and invasion ability of colorectal cancer cells was measured by wound healing assay and transwell assay, and the protein expression levels of the Hippo signaling pathway and its target gene were examined by western blotting. Immunoprecipitation was used to assess the interaction of RNF128 with MST. In vivo, a xenograft tumor model was used to detect the effect of RNF128 on tumor growth. Results: At the tissue level, the expression level of RNF128 was significantly higher in colorectal cancer tissues than in adjacent normal tissues. In LoVo cells and HCT116 cells, the proliferation, migration and invasion abilities were significantly reduced with RNF128 knockdown. At the protein level, knockdown of RNF128 resulted in significant activation of the Hippo signaling pathway. In vivo experiments, the volume and weight of xenograft tumors in nude mice were significantly decreased compared with those in the normal control group with RNF128 knockdown. Conclusion: RNF128 promotes the malignant behaviors of colorectal cancer cells by inhibiting the Hippo signaling pathway, which may provide a new target for colorectal cancer prevention and treatment.

Olaparib effectively treats local recurrence of extrahepatic cholangiocarcinoma in a patient harboring a BRCA2-inactivating mutation: a case report.

Cholangiocarcinoma (CCA) is a malignant tumor with poor prognosis and high recurrence rate. There is no standard treatment for advanced CCA beyond first-line chemotherapy, which provides only limited benefits. In this study, we report a case of a postoperative recurrence ECC patient harboring a breast cancer 2 (BRCA2)-inactivating rearrangement mutation that had an obvious reaction to olaparib therapy. The patient was a 68-year-old man with postoperative recurrence of extrahepatic CCA (ECC) who declined systemic chemotherapy. In August 2015, abdominal computed tomography (CT) of the patient revealed intrahepatic bile duct dilatation, obstruction at the hepatic hilar region proximal to the common hepatic duct, and splenomegaly, and radical surgical resection was performed. Postoperative histopathology diagnosis was ECC without metastases. In February 2017, abdominal CT revealed local recurrence, and the patient refused chemotherapy. BRCA2 rearrangement were detected by next-generation sequencing. Oral administration of olaparib was initiated. The patient achieved stable disease 1 month later, progression-free survival for >10 months without any significant adverse reactions, and an overall survival (OS) of 27 months. This is the first report demonstrating the clinical benefits of olaparib in a BRCA2 rearrangement-harboring patient with ECC. This observation would help determine the best treatment option for advanced ECC patients.

Peroxiredoxin 3 Inhibits Acetaminophen-Induced Liver Pyroptosis Through the Regulation of Mitochondrial ROS.

Pyroptosis is a newly discovered form of cell death. Peroxiredoxin 3 (PRX3) plays a crucial role in scavenging reactive oxygen species (ROS), but its hepatoprotective capacity in acetaminophen (APAP)-induced liver disease remains unclear. The aim of this study was to assess the role of PRX3 in the regulation of pyroptosis during APAP-mediated hepatotoxicity. We demonstrated that pyroptosis occurs in APAP-induced liver injury accompanied by intense oxidative stress and inflammation, and liver specific PRX3 silencing aggravated the initiation of pyroptosis and liver injury after APAP intervention. Notably, excessive mitochondrial ROS (mtROS) was observed to trigger pyroptosis by activating the NLRP3 inflammasome, which was ameliorated by Mito-TEMPO treatment, indicating that the anti-pyroptotic role of PRX3 relies on its powerful ability to regulate mtROS. Overall, PRX3 regulates NLRP3-dependent pyroptosis in APAP-induced liver injury by targeting mitochondrial oxidative stress.

Haemorrhagic retroperitoneal paraganglioma initially manifesting as acute abdomen: a rare case report and literature review.

BACKGROUND: Paragangliomas (PGLs) are extremely rare neuroendocrine tumours arising from extra-adrenal chromaffin cells. PGLs are clinically rare, difficult to diagnose and usually require surgical intervention. PGLs mostly present catecholamine-related symptoms. We report a case of Acute abdomen as the initial manifestation of haemorrhagic retroperitoneal PGL. There has been only one similar case reported in literature. CASE PRESENTATION: We present a unique case of a 52-year-old female with acute abdomen induced by haemorrhagic retroperitoneal PGL. The patient had a 5-h history of sudden onset of serve right lower quadrant abdominal pain radiating to the right flank and right lumbar region. Patient had classic symptoms of acute abdomen. Abdominal ultrasound revealed a large abdominal mass with a clear boundary. A Computed Tomography Angiography (CTA) of superior mesenteric artery was also performed to in the emergency department. The CTA demonstrated a large retroperitoneal mass measured 9.0 × 7.3 cm with higher density inside. A provisional diagnosis of retroperitoneal tumour with haemorrhage was made. The patient received intravenous fluids, broad-spectrum antibiotics and somatostatin. On the 3rd day of admission, her abdominal pain was slightly relieved, but haemoglobin decreased from 10.9 to 9.4 g/dL in 12 h suggesting that there might be active bleeding in the abdominal cavity. Thus, we performed a midline laparotomy for the patient. Haemorrhage was successfully stopped during operation. The retroperitoneal tumour with haemorrhage was completely removed. The abdominal pain was significantly relieved after surgery. The patient initially presented with acute abdomen instead of catecholamine-related symptoms. The diagnosis of retroperitoneal PGL with haemorrhage was finally confirmed by postoperative pathological and immunohistochemical results. The postoperative course was uneventful. At the 1-year follow-up visit, no tumour recurrence was observed by Single Photon Emission Computed Tomography. A literature review was performed to further understand and analyse the aforementioned disease. CONCLUSION: Acute abdomen as the initial manifestation of haemorrhagic retroperitoneal paraganglioma is extremely rare. Abdominal Computed Tomography is essential to locate the lesion and differentiate between other causes of acute abdomen. PGLs are hypervascular tumours. We should be aware that ruptured retroperitoneal PGL with massive bleeding could be life threatening and require emergency laparotomy.

circ-PRKCB acts as a ceRNA to regulate p66Shc-mediated oxidative stress in intestinal ischemia/reperfusion.

Background: Oxidative stress has emerged as an essential factor in the pathogenesis of intestinal ischemia/reperfusion (I/R) injury. The adaptor protein p66Shc is a key regulator of reactive oxygen species (ROS) generation and a mediator of I/R damage in the intestine, but the upstream mechanisms that directly regulate p66Shc expression during intestinal I/R remain largely unknown. Recent studies have suggested that noncoding RNAs, such as circular RNAs (circRNAs), are important players in physiological and pathological processes based on their versatile regulatory roles in gene expression. The aim of this study was to elucidate the contribution of p66Shc to oxidative damage in intestinal I/R and to investigate the regulation of p66Shc by circRNA sponges. Methods: Intestinal I/R was induced in mice via superior mesenteric artery (SMA) occlusion. A miR-339-5p agomir or circ-protein kinase C beta (PRKCB) siRNA was injected intravenously before I/R challenge. In addition, Caco-2 cells were subjected to hypoxia/reoxygenation (H/R) in vitro to simulate an in vivo I/R model. Results:In vitro, p66Shc deficiency significantly reduced H/R-induced ROS overproduction by attenuating mitochondrial superoxide anion (O2-) levels, suppressing NADPH oxidase activity and enhancing antioxidant enzyme expression. Moreover, miR-339-5p was identified to directly regulate p66Shc expression in the intestine. Furthermore, we found that a circRNA transcribed from the PRKCB gene, named circ-PRKCB, acted as an endogenous miR-339-5p sponge to regulate p66Shc expression. circ-PRKCB silencing or miR-339-5p overexpression significantly downregulated p66Shc expression and attenuated oxidative stress levels and I/R injury in vivo and in vitro. Notably, the increased circ-PRKCB levels and decreased miR-339-5p levels associated with murine intestinal I/R were consistent with those in patients with intestinal infarction. Conclusions: Our findings reveal a crucial role for the circ-PRKCB/miR-339-5p/p66Shc signaling pathway in regulating oxidative stress in the I/R intestine. This pathway may be a potential therapeutic target for intestinal I/R injury.

Pseudomyxoma peritonei induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer: a case report and literature review.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a disease involving the peritoneum characterized by the production of large quantities of mucinous ascites. PMP has a low incidence, is difficult to diagnose, and has a guarded prognosis. PMP induced by low-grade appendiceal mucinous neoplasm is extremely rare, and PMP accompanied by rectal cancer is even rarer. CASE PRESENTATION: We present a unique case of a 70-year-old male with PMP induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer. The patient's clinical, surgical, and histologic data were reviewed. The patient had persistent distended abdominal pain without radiating lower back pain, abdominal distension for 1 month, and no exhaustion or defecation for 4 days. A transabdominal ultrasound-guided biopsy was performed on the first day. The patient received an emergency exploratory laparotomy because of increased abdominal pressure. We performed cytoreductive surgery, enterolysis, intestinal decompression, special tumour treatment and radical resection of rectal carcinoma. The postoperative course was uneventful. The postoperative histological diagnoses were PMP, low-grade appendiceal mucinous neoplasm and rectal medium differentiated adenocarcinoma. At the 1-year follow-up visit, no tumour recurrence was observed by computed tomography (CT). We also performed a literature review. CONCLUSIONS: We should be aware that PMP can rarely be accompanied by rectal cancer, which represents an easily missed diagnosis and increases the difficulty of diagnosis and treatment. Additionally, there are some typical characteristics of PMP with respect to diagnosis and treatment.

Ischemia-induced ACSL4 activation contributes to ferroptosis-mediated tissue injury in intestinal ischemia/reperfusion.

Ferroptosis is a recently identified form of regulated cell death defined by the iron-dependent accumulation of lipid reactive oxygen species. Ferroptosis has been studied in various diseases such as cancer, Parkinson's disease, and stroke. However, the exact function and mechanism of ferroptosis in ischemia/reperfusion (I/R) injury, especially in the intestine, remains unknown. Considering the unique conditions required for ferroptosis, we hypothesize that ischemia promotes ferroptosis immediately after intestinal reperfusion. In contrast to conventional strategies employed in I/R studies, we focused on the ischemic phase. Here we verified ferroptosis by assessing proferroptotic changes after ischemia along with protein and lipid peroxidation levels during reperfusion. The inhibition of ferroptosis by liproxstatin-1 ameliorated I/R-induced intestinal injury. Acyl-CoA synthetase long-chain family member 4 (ACSL4), which is a key enzyme that regulates lipid composition, has been shown to contribute to the execution of ferroptosis, but its role in I/R needs clarification. In the present study, we used rosiglitazone (ROSI) and siRNA to inhibit ischemia/hypoxia-induced ACSL4 in vivo and in vitro. The results demonstrated that ACSL4 inhibition before reperfusion protected against ferroptosis and cell death. Further investigation revealed that special protein 1 (Sp1) was a crucial transcription factor that increased ACSL4 transcription by binding to the ACSL4 promoter region. Collectively, this study demonstrates that ferroptosis is closely associated with intestinal I/R injury, and that ACSL4 has a critical role in this lethal process. Sp1 is an important factor in promoting ACSL4 expression. These results suggest a unique and effective mechanistic approach for intestinal I/R injury prevention and treatment.

Autophagy Induction Ameliorates Inflammatory Responses in Intestinal Ischemia-Reperfusion Through Inhibiting NLRP3 Inflammasome Activation.

Intestinal ischemia/reperfusion (I/R)-induced systemic inflammation leads to multiple organ dysfunction syndrome. Previous studies have indicated that the NOD-like receptor protein (NLRP)3 inflammasome modulates intestinal inflammation; however, the pathophysiological mechanisms remain unclear. Autophagy is a critical metabolic mechanism that promotes cellular survival following ischemic injury. Recently, basal autophagy has been implicated in the alleviation of extensive inflammation. However, the role of autophagy in NLRP3 inflammasome activation in intestinal I/R-induced inflammatory injury remains undefined. In the present study, we examined whether NLRP3 inflammasome activation is induced in mice subjected to intestinal I/R injury, which is measured as increased apoptosis-associated speck-like protein containing a CARD levels, caspase-1 activity, and interleukin-1ß (IL-1ß) secretion. Importantly, the in-vitro results showed that NLRP3 knockdown decreases proinflammatory cytokine production and increases resistance to hypoxia/reoxygenation (H/R)-triggered inflammation. Subsequently, we demonstrated a critical role for autophagy in suppressing intestinal I/R-induced NLRP3 inflammasome activation in vivo. Furthermore, we showed that the loss of autophagy activates inflammasome-mediated IL-1ß secretion, which aggravates H/R injury, and NLRP3 knockdown reverses these effects. Collectively, these results directly implicated the homeostatic process of autophagy and NLRP3 inflammasome in ischemic bowel disease and identified a novel pathway for therapeutic intervention in intestinal I/R.

CDC27 Facilitates Gastric Cancer Cell Proliferation, Invasion and Metastasis via Twist-Induced Epithelial-Mesenchymal Transition.

BACKGROUND/AIMS: Lymph node metastasis is the primary cause of cancer-related death among patients with gastric cancer (GC), and cell division cycle 27 (CDC27) promotes the metastasis and epithelial-mesenchymal transition in many cancers. Till now, the mechanisms underlying CDC27-induced the epithelial-mesenchymal transition (EMT) of GC are still unclear. METHODS: We analyzed the expression levels of CDC27 and EMT-related biomarkers using immunohistochemistry and Western blot in 60 cases of GC tissues, and then GC cells with CDC27 shRNAs or plasmids were subjected to in vitro and in vivo assays, including CCK-8, wound healing and transwell assays. RESULTS: The CDC27 expression was obviously increased in GC tissues, and significantly correlates with EMT-related biomarkers, lymph node metastasis and poor 5-year overall survival. Additionally, in vitro and in vivo assays demonstrated that silencing of CDC27 expression effectively inhibited GC cell proliferation, invasion and metastasis. Conversely, CDC27 overexpression led to the opposite results. Finally, we demonstrated that Twist shRNA inhibited CDC27-meditated invasion and EMT of GC cells. CONCLUSION: CDC27 facilitates gastric cancer cell proliferation, invasion and metastasis via Twist-induced EMT; thus, this study offered a new therapy method for GC patients.

Comparing a single-staged laparoscopic cholecystectomy with common bile duct exploration versus a two-staged endoscopic sphincterotomy followed by laparoscopic cholecystectomy.

BACKGROUND: With the advent of minimally invasive surgery, the limits of surgery have been stretched by questioning the more usual, established 2-stage approach for choledocholithiasis with an initial endoscopic retrograde cholangiography and endoscopic biliary sphincterotomy followed by laparoscopic cholecystectomy in favor of the single-stage laparoscopic common bile duct exploration with laparoscopic cholecystectomy. The aim of this study was to compare the related benefits, difficulties, and outcomes of these 2 methods at a single institution. METHODS: A retrospective analysis of 128 patients satisfying the inclusion criteria was divided into 2 groups (n = 68 for the group with laparoscopic common bile duct exploration with laparoscopic cholecystectomy and n = 60 for the group with endoscopic retrograde cholangiography/laparoscopic cholecystectomy) between 2014 and 2017. Patient data including age, sex, duration of the operation, intraoperative and postoperative complications, and duration of hospital stay were reviewed. RESULTS: The group with laparoscopic common bile duct exploration with laparoscopic cholecystectomy had 24 men and 44 women (mean age 52 years), and the group with endoscopic retrograde cholangiography/laparoscopic cholecystectomy had 16 men and 44 women (mean age 47 years). Statistically significant results were found in the clearance range (100% in the group with laparoscopic common bile duct exploration with laparoscopic cholecystectomy versus 75% in the group with endoscopic retrograde cholangiography/laparoscopic cholecystectomy), a shorter total duration of hospitalization for the group with laparoscopic common bile duct exploration with laparoscopic cholecystectomy (4.1 days vs 8.4 days) (P < .05), but a great incidence of biliary leakage in the group with laparoscopic common bile duct exploration with laparoscopic cholecystectomy. Duration of surgery was not different between the 2 groups. CONCLUSION: Laparoscopic common bile duct exploration with laparoscopic cholecystectomy is a single-stage procedure that has many advantages over endoscopic retrograde cholangiography/laparoscopic cholecystectomy if appropriate experience and when expertise is available.

Targeting the miR-665-3p-ATG4B-autophagy axis relieves inflammation and apoptosis in intestinal ischemia/reperfusion.

Autophagy is an essential cytoprotective response against pathologic stresses that selectively degrades damaged cellular components. Impaired autophagy contributes to organ injury in multiple diseases, including ischemia/reperfusion (I/R), but the exact mechanism by which impaired autophagy is regulated remains unclear. Several researchers have demonstrated that microRNAs (miRNAs) negatively regulate autophagy by targeting autophagy-related genes (ATGs). Therefore, the effect of ATG-related miRNAs on I/R remains a promising research avenue. In our study, we found that autophagy flux is impaired during intestinal I/R. A miRNA microarray analysis showed that miR-665-3p was highly expressed in the I/R group, which was confirmed by qRT-PCR. Then, we predicted and proved that miR-665-3p negatively regulates ATG4B expression in Caco-2 and IEC-6 cells. In ileum biopsy samples from patients with intestinal infarction, there was an inverse correlation between miR-665-3p and ATG4B expression, which supports the in vitro findings. Moreover, based on miR-665-3p regulation of autophagy in response to hypoxia/reoxygenation in vitro, gain-of-function and loss-of-function approaches were used to investigate the therapeutic potential of miR-665-3p. Additionally, we provide evidence that ATG4B is indispensable for protection upon inhibition of miR-665-3p. Finally, we observed that locked nucleic acid-modified inhibition of miR-665-3p in vivo alleviates I/R-induced systemic inflammation and apoptosis via recovery of autophagic flux. Our study highlights miR-665-3p as a novel small molecule that regulates autophagy by targeting ATG4B, suggesting that miR-665-3p inhibition may be a potential therapeutic approach against inflammation and apoptosis for the clinical treatment of intestinal I/R.

PKCζ phosphorylates TRAF2 to protect against intestinal ischemia-reperfusion-induced injury.

Intestinal ischemia-reperfusion (I/R) is a common clinical problem that occurs during various clinical pathological processes. Excessive apoptosis has an indispensable role in intestinal I/R injury. Tumor necrosis factor receptor-associated factor 2 (TRAF2) and PKCζ have an essential role in apoptosis. Here, we aimed to investigate the effects of PKCζ and TRAF2 and to explore the correlation between PKCζ and TRAF2 in intestinal I/R injury. Mice were subjected to intestinal I/R injury in vivo. In vitro experiments were conducted by treating Caco-2 cells with hypoxia/reoxygenation (H/R) stimulation to simulate intestinal I/R. Intestinal tissue samples and Caco-2 cells were examined using various approaches. Intestinal I/R induced the membrane translocation and phosphorylation of PKCζ. Pretreatment with the PKCζ activator phosphatidylcholine remarkably attenuated gut injury by suppressing apoptosis. H/R induced PKCζ to combine with TRAF2, which was phosphorylated by PKCζ at Ser55, but not at Ser11, under intestinal I/R or H/R conditions. In addition, TRAF2 Ser55 phosphorylation increased cell survival by inhibiting cell apoptosis in the H/R model. Mechanistically, TRAF2 Ser55 phosphorylation promoted NF-κB activation but suppressed c-Jun activation in Caco-2 cells under H/R conditions. The results of this study demonstrate that the PKCζ/TRAF2 pathway represents a novel protective mechanism against intestinal I/R injury. Therefore, the PKCζ/TRAF2 pathway is a novel target for potential treatments of intestinal I/R injury-related diseases.

Inhibition of p66Shc-mediated mitochondrial apoptosis via targeting prolyl-isomerase Pin1 attenuates intestinal ischemia/reperfusion injury in rats.

Intestinal epithelial oxidative stress and apoptosis constitute key pathogenic mechanisms underlying intestinal ischemia/reperfusion (I/R) injury. We previously reported that the adaptor 66 kDa isoform of the adaptor molecule ShcA (p66Shc)-mediated pro-apoptotic pathway was activated after intestinal I/R. However, the upstream regulators of the p66Shc pathway involved in intestinal I/R remain to be fully identified. Here, we focused on the role of a prolyl-isomerase, peptidyl-prolyl cis-trans isomerase (Pin1), in the regulation of p66Shc activity during intestinal I/R. Intestinal I/R was induced in rats by superior mesenteric artery (SMA) occlusion. Juglone (Pin1 inhibitor) or vehicle was injected intraperitoneally before I/R challenge. Caco-2 cells were exposed to hypoxia/reoxygenation (H/R) in vitro to simulate an in vivo I/R model. We found that p66Shc was significantly up-regulated in the I/R intestine and that this up-regulation resulted in the accumulation of intestinal mitochondrial reactive oxygen species (ROS) and massive epithelial apoptosis. Moreover, intestinal I/R resulted in elevated protein expression and enzyme activity of Pin1 as well as increased interaction between Pin1 and p66Shc. This Pin1 activation was responsible for the translocation of p66Shc to the mitochondria during intestinal I/R, as Pin1 suppression by juglone or siRNA markedly blunted p66Shc mitochondrial translocation and the subsequent ROS generation and cellular apoptosis. Additionally, Pin1 inhibition alleviated gut damage and secondary lung injury, leading to improvement of survival after I/R. Collectively, our findings demonstrate for the first time that Pin1 inhibition protects against intestinal I/R injury, which could be partially attributed to the p66Shc-mediated mitochondrial apoptosis pathway. This may represent a novel prophylactic target for intestinal I/R injury.

Nurr1 promotes intestinal regeneration after ischemia/reperfusion injury by inhibiting the expression of p21 (Waf1/Cip1).

Intestinal ischemia/reperfusion (I/R) injury is a potentially life-threatening condition that can cause injuries to remote organs at the end stage. The damage caused by intestinal I/R insult induces changes in the barrier functions of the intestine, and the intrinsic mechanism of regeneration is often insufficient to restore barrier functions, as indicated by the high mortality rate of patients experiencing intestinal I/R injury. However, little is known about the mechanisms of intestinal regeneration after I/R injury. Here, we reported that nuclear receptor-related protein 1 (Nurr1), a nuclear orphan receptor, was induced during intestinal regeneration after I/R. Our findings showed that Nurr1 expression was consistent with the expression of Ki-67 and phosphorylated histone H3 (pH 3) in the intestine after I/R injury. Nurr1 knockdown led to G1-phase arrest mediated by p21 (Waf1/Cip1) activation, but Nurr1 overexpression reduced the proportion of IEC-6 cells in G1 phase as a result of p21 inhibition in a p53-independent manner. Using chromatin immunoprecipitation assays, luciferase assays, and mutational analysis, we demonstrated that Nurr1 directly inhibited the transcription of p21. These results define a novel Nurr1/p21 pathway that is involved in intestinal regeneration after I/R injury. These findings provide novel molecular insights into the pathogenesis of intestinal regeneration after I/R and possibly support the development of new potential therapies for intestinal I/R injury. KEY MESSAGE: Nurr1 was induced during intestinal regeneration after I/R injury. Nurr1 promoted proliferation of intestinal epithelial cells after H/R injury. Nurr1 inhibited p21 expression in a p53-independent manner. Nurr1 inhibited p21 gene transcription by binding to p21 promoter directly.

Splenic abscess owing to cancer at the splenic flexure: A case report and comprehensive review.

BACKGROUND: The cancer of the splenic flexure of the colon is a rare medical entity with severe morbidity because of its insidious onset. METHODS: We present the case of a 59-year-old male patient with dull left upper quadrant pain, leukocytosis, and anemia. A splenic abscess described as an air-fluid level with splenocolic fistula was found on CT scan imaging. Surgery was done for splenic pus drainage. He was again admitted 2 months later for intestinal obstruction. RESULTS: An exploratory laparotomy showed multiple hard, gray liver nodules as well as a hard mass in the small bowel. Owing to extensive adhesions and a late stage of cancer involvement, the splenic flexure tumor was not resected. A loop transverse colostomy was done and a Coloplast Colostomy bag placed. We also reviewed the literature-linking colon cancer and splenic abscess with specific attention to the carcinoma of the splenic flexure. As the latter invades through the spleen matter, there is the creation of a splenocolic fistula, which allows the migration of normal gut flora into the spleen. This leads to the formation of the splenic abscess. CONCLUSION: This is the 13 case report pertaining to invading colonic cancer causing a splenic abscess. Although the treatment for splenic abscesses is shifting from splenectomy to image-guided percutaneous pus drainage, the few reported cases make the proper management of such complication still unclear.

Protective effects of icariin-mediated SIRT1/FOXO3 signaling pathway on intestinal ischemia/reperfusion-induced acute lung injury.

Acute lung injury (ALI) is a common complication following intestinal ischemia/reperfusion (I/R) and is a major contributing factor to its high mortality rate. Sirtuin 1 (SIRT1), a NAD+-dependent deacetylase, has been reported to have an important role in apoptosis inhibition, oxidative stress resistance and cell lifespan extension through its deacetylation of forkhead box protein O3 (FOXO3). It has been demonstrated that icariin (ICA), a flavonoid extracted from Epimedium, upregulates SIRT1 expression. The aim of the present study was to examine whether ICA-mediated SIRT1/FOXO3 signaling pathway activation had a protective effect on intestinal I/R-induced ALI. The effects of ICA on intestinal I/R-induced ALI and its regulation of the SIRT1/FOXO3 signaling pathway on intestinal I/R-induced ALI were investigated in rats. The results demonstrated that ICA pretreatment markedly reduced intestinal I/R-induced ALI as indicated by histological alterations, including decreased tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), reduced oxidative stress, acetylated FOXO3 and B-cell lymphoma 2 (Bcl-2)-interacting mediator of cell death levels, and increased glutathione (GSH), GSH peroxidase, SIRT1, manganese superoxide dismutase and Bcl-2 levels in rat lung tissues. Furthermore, ICA pretreatment upregulated SIRT1 expression, which then downregulated FOXO3 acetylation. In conclusion, ICA exhibited significant protective effects in intestinal I/R-induced ALI. The protective effect of ICA may be attributed to the upregulation of SIRT1, which contributed to FOXO3 deacetylation and the modulation of downstream antioxidative and anti-apoptotic factors.