UropathogenicEscherichia coli(UPEC) is a causative agent in the vast majority of urinary tract infections (UTIs), including cystitis and pyelonephritis, and infectious complications, which may result in acute renal failure in healthy individuals as well as in renal transplant patients. UPEC expresses a multitude of virulence factors to break the inertia of the mucosal barrier. In response to the breach by UPEC into the normally sterile urinary tract, host inflammatory responses are triggered leading to cytokine production, neutrophil influx, and the exfoliation of infected bladder epithelial cells. Several signaling pathways activated during UPEC infection, including the pathways known to activate the innate immune response, interact with calcium-dependent signaling pathways. Some UPEC isolates, however, might possess strategies to delay or suppress the activation of components of the innate host response in the urinary tract. Studies published in the recent past provide new information regarding how virulence factors of uropathogenicE. coliare involved in activation of the innate host response. Despite numerous host defense mechanisms, UPEC can persist within the urinary tract and may serve as a reservoir for recurrent infections and serious complications. Presentation of the molecular details of these events is essential for development of successful strategies for prevention of human UTIs and urological complications associated with UTIs.
24 July 2012 in Therapeutic Advances in Gastroenterology
Gut microbiota is a compilation of microorganisms dwelling in the entire mammalian gastrointestinal tract. They display a symbiotic relationship with the host contributing to its intestinal health and disease. Even a slight fluctuation in this equipoise may be deleterious to the host, leading to many pathological conditions like Clostridium difficile infection or inflammatory bowel disease (IBD). In this review, we focus on the role of microbial dysbiosis in initiation of C. difficile infection and IBD, and we also touch upon the role of specific pathogens, particularly C. difficile, as causative agents of IBD. We also discuss the molecular mechanisms activated by C. difficile that contribute to the development and exacerbation of gastrointestinal disorders.
Background: Hepatocellular carcinoma (HCC) represents a major health burden with limited curative treatment options. There is a substantial unmet need to develop innovative approaches to impact the progression of advanced HCC. Haprolid is a novel natural component isolated from myxobacteria. Haprolid has been reported as a potent selective cytotoxin against a panel of tumor cells in recent studies including HCC cells. The aims of this study are to evaluate the antitumor effect of haprolid in HCC and to understand its underlying molecular mechanisms. Methods: The efficacy of haprolid was evaluated in human HCC cell lines (Huh-7, Hep3B and HepG2) and xenograft tumors (NMRI-Foxn1nu mice with injection of Hep3B cells). Cytotoxic activity of haprolid was determined by the WST-1 and crystal violet assay. Wound healing, transwell and tumorsphere assays were performed to investigate migration and invasion of HCC cells. Apoptosis and cell-cycle distribution were measured by flow cytometry. The effects of haprolid on the Rb/E2F and Akt/mTOR pathway were examined by immunoblotting and immunohistochemistry. Results: haprolid treatment significantly inhibited cell proliferation, migration and invasion in vitro. The epithelial–mesenchymal transition (EMT) was impaired by haprolid treatment and the expression level of N-cadherin, vimentin and Snail was downregulated. Moreover, growth of HCC cells in vitro was suppressed by inhibition of G1/S transition, and partially by induction of apoptosis. The drug induced downregulation of cell cycle regulatory proteins cyclin A, cyclin B and CDK2 and induced upregulation of p21 and p27. Further evidence showed that these effects of haprolid were associated with Rb/E2F downregulation and Akt/mTOR inhibition. Finally, in vivo nude mice experiments demonstrated significant inhibition of tumor growth upon haprolid treatment. Conclusion: Our results show that haprolid inhibits the growth of HCCthrough dual inhibition of Rb/E2F and Akt/mTOR pathways. Therefore, haprolid might be considered as a new and promising candidate for the palliative therapy of HCC.
Background: Cholangiocarcinoma (CCA) is the second most common hepatobiliary cancer and associated with a poor prognosis. Only one-third of CCA cases are diagnosed at operable stages. However, a high rate of relapse has been observed postoperatively. Besides screening for operable individuals, efficacious therapeutic for recurrent and advanced CCA is urgently needed. The treatment outcome of available therapeutics is important to clarify clinical indication and facilitate the development of treatment strategies. Objective: This review aims to compare the treatment outcome of different therapeutics based on both overall survival and progression-free survival. Methods: Over one hundred peer-reviewed articles were examined. We compared the treatment outcome between different treatment methods, including tumor resection with or without postoperative systematic therapy, chemotherapies including FOFLOX, and targeted therapies, such as IDH1, K-RAS, and FGFR inhibitors. Notably, the scientific basis and outcome of available treatment methods were compared with the standard first-line therapy. Results: CCAs at early stages should firstly undergo tumor resection surgery, followed by postoperative treatment with Capecitabine. Chemotherapy can be considered as a preoperative option for unresectable CCAs. Inoperable CCAs with genetic aberrances like FGFR alterations, IDH1, and KRAS mutations should be considered with targeted therapies. Fluoropyrimidine prodrug (S-1)/Gemcitabine/Cisplatin and nab-Paclitaxel/Gemcitabine/Cisplatin show favorable outcome which hints at the triplet regimen to be superior to Gemcitabine/Cisplatin on CCA. The triplet chemotherapeutic should be tested further compared to Gemcitabine/Cisplatin among CCAs without genetic alterations. Gemcitabine plus S-1 was recently suggested as the convenient and equivalent standard first-line for advanced/recurrent biliary tract cancer. Conclusions: This review provides a comparative outcome between novel targeted therapies and currently available therapeutics.