SP-1, a Serine Protease from the Gut Microbiota, Influences Colitis and Drives Intestinal Dysbiosis in Mice

Increased protease activity has been linked to the pathogenesis of IBD. While most studies have been focusing on host proteases in gut inflammation, it remains unclear how to address the potential contribution of their bacterial counterparts. In the present study, we report a functional characterization of a newly identified serine protease, SP-1, from the human gut microbiota. The serine protease repertoire of gut Clostridium was first explored, and the specificity of SP-1 was analyzed using a combinatorial chemistry method. Combining in vitro analyses and a mouse model of colitis, we show that oral administration of recombinant bacteria secreting SP-1 (i) compromises the epithelial barrier, (ii) alters the microbial community, and (ii) exacerbates colitis. These findings suggest that gut microbial protease activity may constitute a valuable contributor to IBD and could, therefore, represent a promising target for the treatment of the disease.

Gut Pathology and Its Rescue by ACE2 (Angiotensin-Converting Enzyme 2) in Hypoxia-Induced Pulmonary Hypertension

Therapeutic advances for pulmonary hypertension (PH) have been incremental because of the focus on the pulmonary vasculature in PH pathology. Here, we evaluate the concept that PH is, rather, a systemic disorder involving interplay among multiorgan systems, including brain, gut, and lungs. Therefore, the objective of this study was to evaluate the hypothesis that PH is associated with a dysfunctional brain-gut-lung axis and that global overexpression of ACE2 (angiotensin-converting enzyme 2) rebalances this axis and protects against PH. ACE2 knockin and wild-type (WT; C57BL/6) mice were subjected to chronic hypoxia (10% FIO2) or room air for 4 weeks. Cardiopulmonary hemodynamics, histology, immunohistochemistry, and fecal 16S rRNA microbial gene analyses were evaluated. Hypoxia significantly increased right ventricular systolic pressure, sympathetic activity as well as the number and activation of microglia in the paraventricular nucleus of the hypothalamus in WT mice. This was associated with a significant increase in muscularis layer thickening and decreases in both villi length and goblet cells and altered gut microbiota. Global overexpression of ACE2 prevented changes in hypoxia-induced pulmonary and gut pathophysiology and established distinct microbial communities from WT hypoxia mice. Furthermore, WT mice subjected to fecal matter transfer from ACE2 knockin mice were resistant to hypoxia-induced PH compared with their controls receiving WT fecal matter transfer. These observations demonstrate that ACE2 ameliorates these hypoxia-induced pathologies and attenuates PH. The data implicate dysfunctional brain-gut-lung communication in PH and provide novel avenues for therapeutic interventions.

Changes in biochemical parameters of oral fluid in patients during the orthodontic treatment with a bracket system under the action of a developed mucosal gel with probiotic

OBJECTIVE

Introduction: Many research studies involving orthodontic patients focus on changes in levels of oral microbiocenosis after bracket placement. Based upon this the objective of the current study was to determine the effect of the developed mucosal gel with probiotics on the biochemical parameters of the oral fluid of patients during the orthodontic treatment with a bracket system. The aim: Aim of our study is to determine the effect of the developed mucosal gel with probiotics on the biochemical parameters of the oral fluid of patients during the orthodontic treatment with a bracket system.

PATIENTS AND METHODS

Materials and methods: 45 patients at the age of 18-24, with 15 people in each group (control, main and comparison group) were examined. The main group was presented by patients who, in order to prevent dysbiosis of the oral cavity during orthodontic treatment, were prescribed local use of the developed mucosal gel with probiotic. The statistical processing of the results of the study was carried out using methods of variation statistics using the EXCEL program (the standard package of Microsoft Office).

RESULTS

Results: According to the results of biochemical studies, it was found that the use of orthodontic treatment of mucosal gel with probiotic in patients with crowded teeth contributes to the strengthening of antioxidant protection, an increase in nonspecific resistance, decrease in inflammation and normalization of microbiocenosis of the oral cavity.

CONCLUSION

Conclusion: These studies indicated that the use of the developed mucosal gel with probiotic in patients with maxillofacial anomalies from the first day after fixation, as indicated by the level of biochemical markers of inflammation.

[Role of cyclooxygenase in modification of intestinal microflora under stress condition]

Stress and nonsteroidal anti-inflammatory drugs, which act as nonselective inhibitors of cyclooxygenase, are the main factors of ulcerogenesis in digestive system. However, the peculiarities of their combined action upon the status of intestinal microflora and the parameters of NO-synthase system are still poorly understood. In experiments with rats we show that water-restrained stress was accompanied by a considerable increase of iNOS activity and intensity of lipoperoxidation processes. The increase of Escherichia coli content and the decrease in Enterococcus spp. concentration in the small intestine with their simultaneous rise in the large intestine were noticed under these conditions. Cyclooxygenese blockage with naproxen prior to induction of water-restrained stress was accompanied by the decease of iNOS in small and large intestines, with the synchronous rise of cNOS activity in the large intestine as compared with indexes in stress. The moderate increase in Enterococcus spp. content in duodenum with the rise of Escherichia coli concentration in the ileum was shown. The Escherichia coli content decreased in the proximal part of the large intestine and decreased in its distal part. Disbiosis, intensification of lipoperoxidation processes and changes in NO-synthase system parameters under condition of simultaneous action of stress and cyclooxygenase blockage can create preconditions for the development of destructive changes and enteropathias.