Deletion of the bis gene results in a marked increase in the production of corticosterone that is associated with thymic atrophy in mice

Microbial lysate upregulates host oxytocin

Neuropeptide hormone oxytocin has roles in social bonding, energy metabolism, and wound healing contributing to good physical, mental and social health. It was previously shown that feeding of a human commensal microbe Lactobacillus reuteri (L. reuteri) is sufficient to up-regulate endogenous oxytocin levels and improve wound healing capacity in mice. Here we show that oral L. reuteri-induced skin wound repair benefits extend to human subjects. Further, dietary supplementation with a sterile lysate of this microbe alone is sufficient to boost systemic oxytocin levels and improve wound repair capacity. Oxytocin-producing cells were found to be increased in the caudal paraventricular nucleus [PVN] of the hypothalamus after feeding of a sterile lysed preparation of L. reuteri, coincident with lowered blood levels of stress hormone corticosterone and more rapid epidermal closure, in mouse models. We conclude that microbe viability is not essential for regulating host oxytocin levels. The results suggest that a peptide or metabolite produced by bacteria may modulate host oxytocin secretion for potential public or personalized health goals.

Stress-protective effect of thymic peptides

Experiments on Wistar rats showed that thymic peptides produce a stress-protective effect that manifested in prevention of functional impairment of conditioned active avoidance response and a decrease in generalized motor activity typical of higher nervous activity failure. We concluded that thymic peptides significantly modulate integrative functions of the brain and produce a stress-protective effect.

Aggravation of diabetic nephropathy in BCL-2 interacting cell death suppressor (BIS)-haploinsufficient mice together with impaired induction of superoxide dismutase (SOD) activity

AIMS/HYPOTHESIS

B cell CLL/lymphoma 2 (BCL-2)-interacting cell death suppressor (BIS), known as an anti-stress and anti-apoptotic protein, has been reported to modulate susceptibility to oxidative stress. This study investigated the potential role of BIS as an antioxidant protein in diabetic nephropathy.

METHODS

Diabetes was induced in BIS-heterozygote (BIS-HT) mice via streptozotocin injections and the resulting phenotypes were compared with those of BIS-wild-type (BIS-WT) mice over the 20 weeks following diabetes induction.

RESULTS

Renal injuries, represented by increased plasma creatinine levels and increased albuminuria, were greater in diabetic BIS-HT mice than in diabetic BIS-WT mice, and were accompanied by a significant increase in reactive oxygen species (ROS) and oxidative stress markers. Moreover, renal pathological changes and the apoptotic process were accelerated in diabetic BIS-HT mice compared with diabetic BIS-WT mice with the same degree of hyperglycaemia; all were restored by 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol) treatment. The levels of NADPH oxidase and related proteins were not significantly higher in diabetic BIS-HT mice compared with diabetic BIS-WT mice. However, levels of superoxide dismutase (SOD)1 and SOD2 increased on the induction of diabetes in BIS-WT mice but not in BIS-HT mice, correlating with the total SOD activity. An in vitro study showed that knockdown of BIS production also resulted in impaired induction of SOD activity as well as SOD levels in HK-2 and NMS cells, concomitant with significant ROS accumulation.

CONCLUSION/INTERPRETATION

Our results suggest that the decreased antioxidant capacity of BIS aggravates diabetic nephropathy in diabetic BIS-HT mice, possibly as a result of the disruption in the regulation of SOD protein quality under oxidative stress.

Expression of Bis in the mouse gastrointestinal system

The Bcl-2 interacting death suppressor (Bis) protein is known to be involved in a variety of pathophysiological conditions. We recently generated bis-deficient mice, which exhibited early lethality with typical nutritional deprivation status. To further investigate the molecular basis for the malnutrition phenotype of bis deficient mice, we explored Bis expression in the digestive system of normal mice. Western blot analysis and quantitative real time reverse transcription polymerase chain reaction analysis indicated that Bis expression is highest in the esophagus, followed by the stomach, colon, jejunum and ileum. Immunohistochemical data indicated that Bis expression is restricted to the stratified squamous epitheliums in the esophagus and forestomach, and was not notable in the columnar epitheliums in the stomach, small intestine and colon. In addition, strong Bis immunoreactivity was detected in the striated muscles surrounding the esophagus and smooth muscles at a lesser intensity throughout the gastrointestinal (GI) tract. Ganglionated plexuses, located in submucous layers, as well as intermuscular layers, were specifically immunoreactive for Bis. Immunofluorescence studies revealed that Bis is co-localized in glial fibrillary acidic protein-expressing enteric glial cells. Immunostaining with neuron specific esterase antibodies indicate that Bis is also present in the cell bodies of ganglions in the enteric nervous system (ENS). Our findings indicate that Bis plays a role in regulating GI functions, such as motility and absorption, through modulating signal transmission between the ENS and smooth muscles or the intestinal epitheliums.