ARHGAP4 promotes colon cancer metastasis through the TGF-ß signaling pathway and may be associated with T cell exhaustion.

BACKGROUND: Colon cancer is a prevalent invasive neoplasm in the gastrointestinal system with a high degree of malignancy. Despite extensive research, the underlying mechanisms of its recurrence and metastasis remain elusive.Rho GTPase activating protein 4 (ARHGAP4), a member of the small GTPases protein family, may be closely related to tumor metastasis, and its expression is increased in colon cancer. However, the role of ARHGAP4 in colon cancer metastasis is uncertain. This study investigates the impact of ARHGAP4 on the metastasis of colon cancer cells. Our objective is to determine the role of ARHGAP4 in regulating the invasive behavior of colon cancer cells. METHODS: We downloaded colon adenocarcinoma (COAD) data from the Cancer Genome Atlas (TCGA), and performed differential analysis and survival analysis. By using the CIBERSORT algorithm, we evaluated the proportion of infiltrating immune cells in colon cancer. We further analyzed whether ARHGAP4 is associated with T cell exhaustion. Finally, we investigated the impact of ARHGAP4 knockdown on the migration and invasion of colon cancer cells through in vitro cell experiments. Additionally, we utilized western blotting to assess the expression of protein related to the TGF-ß signaling pathway and epithelial-mesenchymal transition (EMT). RESULTS: We found that ARHGAP4 is upregulated in colon cancer. Subsequent survival analysis revealed that the high-expression group had significantly lower survival rates compared to the low-expression group. Immune infiltration analysis showed that ARHGAP4 was not only positively correlated with CD8+ T cells, but also positively correlated with T cell exhaustion markers programmed cell death 1 (PDCD-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), and lymphocyte activating 3 (LAG-3). In vitro cell experiments, the knockdown of ARHGAP4 inhibited the migration and invasion of colon cancer cells. Among EMT-related proteins, when ARHGAP4 was knocked down, the expression of E-cadherin was increased, while the expression of N-cadherin and Vimentin was decreased. Meanwhile, the expression of TGF-ß1, p-Smad2, and p-Smad3, which are associated with the TGF-ß/Smad pathway, all decreased. CONCLUSION: ARHGAP4 promotes colon cancer metastasis through the TGF-ß/Smad signaling pathway and may be associated with T cell exhaustion. It plays an important role in the progression of colon cancer and may serve as a potential target for diagnosis and treatment of colon cancer.

A huge bladder diverticulum in an elderly: A case report.

An 81-year-old male patient presented to the department of gastroenterology with increasing lower abdominal pain for 2 years, aggravated with bloody stool for 1 month. Computed tomographic examination revealed a huge cyst (207 × 93 × 208 mm3) in the abdominal cavity, absence of bladder, thickening and strengthening of the rectal wall, and benign prostatic hyperplasia. Colonoscopy showed colon cancer and surgery was planned. Interestingly, after magnetic resonance imaging and cystography, we found colon cancer and a large bladder diverticulum rather than tumor metastasis or others. Severe bacteremia occurred in the elderly chronic obstructive pulmonary disease patient before operation. After careful consideration, we decided to take a large risk and combined urology and gastrointestinal surgery professionals to carry out bladder diverticulectomy, cystostomy, radical resection of rectal carcinoma, and so on. Fortunately, the patient recovered well after the operation. In addition to the common tumor metastasis and cystadenoma, the abdominal mass should also be alert to the rare bladder diverticulum, which eventually leads to diagnostic confusion. Multidisciplinary diagnosis and treatment has become an important treatment for complex diseases.

Quantitative reduction in short-chain fatty acids, especially butyrate, contributes to the progression of chronic kidney disease.

Chronic kidney disease (CKD) affects 10-15% of the population worldwide, results in high morbidity and mortality, and requires costly treatment and renal replacement therapy. Glomerulosclerosis, tubulointerstitial fibrosis, and persistent intestinal flora disturbance are common in CKD. Short-chain fatty acids (SCFAs), produced by the intestinal microbiota, have been previously reported to ameliorate kidney injury; however, the specific concentrations and types that are required to improve renal function remain unknown. The present study aims to evaluate the levels of SCFAs in healthy and CKD patients, and to test the hypothesis that SCFAs play a critical role in delaying CKD progression. One hundred and twenty-seven patients with CKD and 63 healthy controls from China were enrolled in the present study. Butyrate, which is considered beneficial to humans, was almost three-times higher in healthy volunteers than that in CKD5 subjects (P=0.001). Moreover, the serum SCFA levels in controls were significantly higher than that in CKD patients (P<0.05), and the butyrate level among CKD5 patients (1.48 ± 0.60 µmol/l) was less than half of that in controls (3.44 ± 2.12 µmol/l, P<0.001). In addition, we observed an inverse correlation between butyrate level and renal function (P<0.05). A CKD rat model transplanted with microbiota obtained from CKD patients exhibited accelerated CKD progression via increased production of trimethylamine N-oxide (TMAO), which was reversed by supplementation with extra butyrate. Our results showed that SCFA levels were reduced in CKD patients and that butyrate supplementation might delay CKD progression.

Inhibition of TLR4 alleviates the inflammation and apoptosis of retinal ganglion cells in high glucose.

PURPOSE: To investigate the expression profiles of Toll-like receptor 4 (TLR4), the effect of TLR4 on inflammation, and apoptosis of retinal ganglion cells (RGCs) cultured in high glucose and the underlying mechanism. METHODS: A high-glucose model was established in RGCs isolated from Sprague-Dawley (SD) rats (2-3 days old) and identified with Brn3a. Primary cultured RGCs were divided into control (0 mM), HG1 (10 mM glucose), HG2 (20 mM glucose), HG3 (30 mM glucose), HG (20 mM glucose) + TAK-242 (1.0 µM), and HG (20 mM glucose) + vehicle (1% DMSO) groups. The expression levels of TLR4, its downstream signalling molecules, and pro-inflammatory cytokines were measured by real-time PCR, Western blot or ELISA at 24 h and 48 h. The apoptosis rate of RGCs was measured by flow cytometry. RESULTS: The mRNA and protein expression levels of TLR4 were increased in high-glucose groups (10 mM, 20 mM, 30 mM). Consistent with these findings, four TLR4 downstream signalling molecules (MyD88, NF-κB, TRAF6, NLRP3) and pro-inflammatory cytokines (IL-1ß, IL-18) were upregulated in the three high-glucose groups. Apoptosis of RGCs was clearly increased in the high-glucose group. The administration of TAK-242, an antagonist of TLR4, inhibited inflammation and apoptosis of RGCs in the high-glucose group. CONCLUSION: Our results demonstrated that TLR4 plays a critical role in the inflammation and apoptosis of RGCs induced by high glucose. TLR4 might become a novel potential pharmacological target for preventing the progression of DR.

Alteration of the gut microbiota in Chinese population with chronic kidney disease.

We evaluated differences in the compositions of faecal microbiota between 52 end stage renal disease (ESRD) patients and 60 healthy controls in southern China using quantitative real-time polymerase chain reaction (qPCR) and high-throughput sequencing (16S ribosomal RNA V4-6 region) methods. The absolute quantification of total bacteria was significantly reduced in ESRD patients (p < 0.01). In three enterotypes, Prevotella was enriched in the healthy group whereas Bacteroides were prevalent in the ESRD group (LDA score > 4.5). 11 bacterial taxa were significantly overrepresented in samples from ESRD and 22 bacterial taxa were overrepresented in samples from healthy controls. The butyrate producing bacteria, Roseburia, Faecalibacterium, Clostridium, Coprococcus and Prevotella were reduced in the ESRD group (LDA values > 2.0). Canonical correspondence analysis (CCA) indicated that Cystatin C (CysC), creatinine and eGFR appeared to be the most important environmental parameters to influence the overall microbial communities. In qPCR analysis, The butyrate producing species Roseburia spp., Faecalibacterium prausnitzii, Prevotella and Universal bacteria, were negatively related to CRP and CysC. Total bacteria in faeces were reduced in patients with ESRD compared to that in healthy individuals. The enterotypes change from Prevotella to Bacteroides in ESRD patients. The gut microbiota was associated with the inflammatory state and renal function of chronic kidney disease.

Research progress of stem cell-derived RPE cell transplantation therapy for retinal degenerative diseases / 国际眼科杂志(Guoji Yanke Zazhi)

·Age - related macular degeneration ( ARMD ) and Stargardt's macular dystrophy ( SMD ) are two kinds of degenerative retinal diseases that respectively lead to irreversible vision loss of the elderly and juvenile population. However, the severe visual impairment in dry ARMD and SMD remains untreatable. In recent years, with the advancement of stem cell technology, stem cell-derived RPE cell transplantation therapy of retinal degeneration has become new research hotspot and direction. This article reviewed the progress of stem cell based approaches for treating retinal degenerative diseases and discussed the prospect and challenges in this field.

Clostridium Difficile Infection Worsen Outcome of Hospitalized Patients with Inflammatory Bowel Disease.

The prevalence of Clostridium difficile infection (CDI) in patients suffering from inflammatory bowel disease (IBD) has increased rapidly over the past several decades in North America and Europe. However, the exact global epidemiology remains unclear because of insufficient data from developing countries. A total of 646 hospitalized adult IBD patients were enrolled; and their fresh stool specimens were obtained and used for Clostridium difficile detection. The incidence of CDI in Crohn's disease (CD) patients (12.7%) was significantly lower than that in Ulcerative disease (UC) patients (19.3%). Among the toxin types, A(+)B(+) strain was the most common. Length of stay, hospitalization frequency and bowel surgery rate were significantly higher in the CDI than in the non-CDI group in CD or UC patients. More patients in CDI-CD group were still in active and even clinical moderate or severe CD stage than non-CDI-CD group after 2 years of following-up. Fistula, antibiotics and infliximab usage likely increased the CDI rate in CD patients, Infliximab treatment was considered a risk factor in UC patients. CDI is an exacerbating public health issue that may influence IBD course, increase expenditures, and delay the remission of IBD patients. IBD patients with CDI require urgent attention.

A reduction in the butyrate producing species Roseburia spp. and Faecalibacterium prausnitzii is associated with chronic kidney disease progression.

The human gut microbiota plays an important role in human health and might also be implicated in kidney disease. The interest in butyrate producing bacteria has recently increased and is a poorly understood faecal condition in chronic kidney disease (CKD). Therefore, we evaluated differences of the butyrate producing species Roseburia spp. and Faecalibacterium prausnitzii in the faeces of Chinese patients with CKD. A case-control study was carried out for 65 CKD patients and 20 healthy controls. Differences were quantitatively validated using quantitative real-time polymerase chain reaction (qPCR). Spearman rank correlation was used to analyse the correlation between gut microbiota and clinical variables. Roseburia spp. and F. prausnitzii were significantly different in CKD patients and controls (p = 0.001; p = 0.025, respectively) and reduced more markedly in end stage renal disease (p = 0.000; p = 0.003, respectively) and microinflammation (p = 0.004; p = 0.001, respectively). Roseburia spp. and F. prausnitzii were negatively associated with C-reactive protein in plasma (r = -0.493, p = 0.00; r = -0.528, p = 0.000; respectively) and Cystatin C (r = -0.321, p = 0.006; r = -0.445, p = 0.000; respectively). They were positively associated with eGFR (r = 0.347, p = 0.002; r = 0.416, p = 0.000; respectively). The negative correlation between Roseburia spp., F. prausnitzii and CRP and renal function suggested that the depletion of butyrate producing bacteria may contribute to CKD-associated inflammation and CKD progression. Roseburia spp. and F. prausnitzii may thus serve as 'microbiomarkers'.

Effects of calcium signaling on coagulation factor VIIa-induced proliferation and migration of the SW620 colon cancer cell line.

Tissue factor (TF)/VIIa/protease­activated receptor 2 (PAR2) has been shown to trigger the ERK1/2 signaling pathway. This was shown to be closely associated with the proliferation and migration of SW620 colon cancer cells; however, the detailed mechanisms remain unclear. The aim of the present study was to elucidate the effects of calcium signaling on the proliferation and migration of SW620 cells induced by coagulation factor VIIa. The results demonstrated that VIIa and PAR2 agonist PAR2­AP increased [Ca2+]i in SW620 cells. In addition, VIIa­and PAR2­AP­induced ERK1/2 activation was inhibited by thapsigargin (TG)­induced depletion of intracellular Ca2+ stores and EGTA­mediated removal of extracellular Ca2+. It was also identified that VIIa and PAR2­AP­induced proliferation and migration of SW620 cells was modulated by EGTA and TG. Taken together, the present results indicate that VIIa triggers calcium signaling in SW620 cells, in a TF­dependent manner, which is critical for VIIa­induced ERK1/2 activation in SW620 cells. These results suggested that calcium signaling had a vital role in the proliferation and migration of SW620 cells.