Obstructive Sleep Apnea-Induced Hypertension Is Associated With Increased Gut and Neuroinflammation.

Background Obstructive sleep apnea (OSA) is an independent risk factor for the development of hypertension. We have demonstrated that OSA induces gut dysbiosis, and this dysbiotic microbiota contributes to hypertension. However, the mechanisms linking gut dysbiosis to blood pressure regulation remain unclear. Recent studies demonstrate that gut dysbiosis can induce a proinflammatory response of the host resulting in peripheral and neuroinflammation, key factors in the development of hypertension. We hypothesized that OSA induces inflammation in the gut that contributes to neuroinflammation and hypertension. Methods and Results OSA was induced in 8-week-old male rats. After 2 weeks of apneas, lymphocytes were isolated from aorta, brain, cecum, ileum, mesenteric lymph node, and spleen for flow cytometry. To examine the role of interleukin-17a, a monoclonal antibody was administered to neutralize interleukin-17a. Lymphocytes originating from the gut were tracked by labeling with carboxyfluorescein succinimidyl ester dye. OSA led to a significant decrease in T regulatory cells along with an increase in T helper (TH) 17 cells in the ileum, cecum, and brain. Interleukin-17a neutralization significantly reduced blood pressure, increased T regulatory cells, and decreased TH1 cells in the ileum, cecum, and brain of OSA rats. TH1, TH2, and TH17 cells from the gut were found to migrate to the mesenteric lymph node, spleen, and brain with increased frequency in rats with OSA. Conclusions OSA induces a proinflammatory response in the gut and brain that involves interleukin-17a signaling. Gut dysbiosis may serve as the trigger for gut and neuroinflammation, and treatments to prevent or reverse gut dysbiosis may prove useful in reducing neuroinflammation and hypertension.

Alterations of the gut microbial community structure and function with aging in the spontaneously hypertensive stroke prone rat.

Gut dysbiosis, a pathological imbalance of bacteria, has been shown to contribute to the development of hypertension (HT), systemic- and neuro-inflammation, and blood-brain barrier (BBB) disruption in spontaneously hypertensive stroke prone rats (SHRSP). However, to date individual species that contribute to HT in the SHRSP model have not been identified. One potential reason, is that nearly all studies of the SHRSP gut microbiota have analyzed samples from rats with established HT. The goal of this study was to examine the SHRSP gut microbiota before, during, and after the onset of hypertension, and in normotensive WKY control rats over the same age range. We hypothesized that we could identify key microbes involved in the development of HT by comparing WKY and SHRSP microbiota during the pre-hypertensive state and longitudinally. Systolic blood pressure (SBP) was measured by tail-cuff plethysmography and fecal microbiota analyzed by16S rRNA gene sequencing. SHRSP showed significant elevations in SBP, as compared to WKY, beginning at 8 weeks of age (p < 0.05 at each time point). Bacterial community structure was significantly different between WKY and SHRSP as early as 4 weeks of age, and remained different throughout the study (p = 0.001-0.01). At the phylum level we observed significantly reduced Firmicutes and Deferribacterota, and elevated Bacteroidota, Verrucomicrobiota, and Proteobacteria, in pre-hypertensive SHRSP, as compared to WKY. At the genus level we identified 18 bacteria whose relative abundance was significantly different in SHRSP versus WKY at the pre-hypertensive ages of 4 or 6 weeks. In an attempt to further refine bacterial candidates that might contribute to the SHRSP phenotype, we compared the functional capacity of WKY versus SHRSP microbial communities. We identified significant differences in amino acid metabolism. Using untargeted metabolomics we found significant reductions in metabolites of the tryptophan-kynurenine pathway and increased indole metabolites in SHRSP versus WKY plasma. Overall, we provide further evidence that gut dysbiosis contributes to hypertension in the SHRSP model, and suggest for the first time the potential involvement of tryptophan metabolizing microbes.

Restructuring the Gut Microbiota by Intermittent Fasting Lowers Blood Pressure.

[Figure: see text].

3D in situ imaging of the female reproductive tract reveals molecular signatures of fertilizing spermatozoa in mice.

Out of millions of ejaculated sperm, a few reach the fertilization site in mammals. Flagellar Ca2+ signaling nanodomains, organized by multi-subunit CatSper calcium channel complexes, are pivotal for sperm migration in the female tract, implicating CatSper-dependent mechanisms in sperm selection. Here using biochemical and pharmacological studies, we demonstrate that CatSper1 is an O-linked glycosylated protein, undergoing capacitation-induced processing dependent on Ca2+ and phosphorylation cascades. CatSper1 processing correlates with protein tyrosine phosphorylation (pY) development in sperm cells capacitated in vitro and in vivo. Using 3D in situ molecular imaging and ANN-based automatic detection of sperm distributed along the cleared female tract, we demonstrate that spermatozoa past the utero-tubal junction possess the intact CatSper1 signals. Together, we reveal that fertilizing mouse spermatozoa in situ are characterized by intact CatSper channel, lack of pY, and reacted acrosomes. These findings provide molecular insight into sperm selection for successful fertilization in the female reproductive tract.

When mammals mate, males ejaculate millions of sperm cells into the females' reproductive tract. But as the sperm travel up the tract, only a handful of the 'fittest' sperm will actually manage to reach the egg. This process of elimination prevents the egg from being fertilized by multiple sperm cells and stops the eggs from being fertilized outside of the womb. A lot of what is known about fertilization in mammals has come from studying how sperm and eggs cells interact in a Petri dish. However, this approach cannot explain how sperm are selected and removed as they journey towards the egg. Previous work suggests that a calcium channel, which sits in the membrane surrounding the sperm tail, may provide some answers. The core of this channel, known as CatSper, is made up of four proteins arranged into a unique pattern similar to racing stripes. Without this specific arrangement, sperm cells cannot move forward and fertilize the egg in time. To investigate the role of this protein in more depth, Ded et al. established a new way to image the minute structures of sperm cells, such as CatSper, in the reproductive tract of female mice. Experiments in a Petri dish revealed that sperm cells that have been primed to fertilize the egg are a diverse population: in some cells one of the proteins that make up the calcium channel, known as CatSper1, is cleaved, while in other cells this protein remains intact. Visualizing this protein in the female reproductive tract showed that sperm cells close to the site of fertilization contain non-cleaved CatSper1. Whereas sperm cells further away from the egg ­ and thus closer to the uterus ­ are more likely to contain broken down CatSper1. Taken together, these findings suggest that the state of the CatSper1 protein may be used to select sperm that are most likely to reach and fertilize the egg. Future studies should address what happens to the calcium channel once the CatSper1 protein is cleaved, and how this channel controls the movements and lifespan of sperm. This could help identify new targets for contraception and improve current strategies for assisted reproduction.

Young versus aged microbiota transplants to germ-free mice: increased short-chain fatty acids and improved cognitive performance.

Aging is associated with cognitive decline and decreased concentrations of short-chain fatty acids (SCFAs) in the gut. SCFAs are significant in that they are protective to the gut and other organs. We tested the hypothesis that the aged gut microbiome alone is sufficient to decrease SCFAs in the host and produce cognitive decline. Fecal transplant gavages (FTGs) from aged (18-20 months) or young (2-3 months) male C57BL/6 mice into germ-free male C57BL/6 mice (N = 11 per group) were initiated at ~3 months of age. Fecal samples were collected and behavioral testing was performed over the study period. Bacterial community structures and relative abundances were measured in fecal samples by sequencing the bacterial 16S ribosomal RNA gene. Mice with aged and young microbiomes showed clear differences in bacterial ß diversity at 30, 60, and 90 d (P = .001 for each) after FTGs. The fecal SCFAs, acetate, propionate, and butyrate (microbiome effect, P < .01 for each) were decreased in mice with an aged microbiome. Mice with an aged microbiome demonstrated depressive-like behavior, impaired short-term memory, and impaired spatial memory over the 3 months following the initial FTG as assessed by the tail suspension (P = .008), the novel object recognition (P < .001), and the Barnes Maze (P = .030) tests, respectively. We conclude that an aged microbiome alone is sufficient to decrease SCFAs in the host and to produce cognitive decline.

[Accordion operation for the bone transport in treating tibial bone defect].

OBJECTIVE: To discuss clinical outcomes of accordion operation for the Ilizarov technique in treating tibial bone defects. METHODS: From January 2014 to June 2016, 22 patients with tibial bone defects were treated by Ilizarov bone-transport technique, including 19 males and 3 females with an average age of 44.04 years old ranging from 23 to 60 years old;the length of the bone defects before the bone transport was 5 to 11 cm with an average 7.68 cm; Cause of injury invlved traffic accidents in 14 cases, fall injury in 3, smashing injury in 4, high drop injury in 1; 6 cases were on the left and 16 cases were on the right. The patients were divided into two groups: 11 cases in accordion group were treated by "accordion operation" after bone transport was completed;11 cases in control group were treated by the external fixator locked waiting for bone consolidation after bone transport was completed. All patients were followed up for 18 to 36 months with an average time of 27.9 months. There was no statistical significance between two groups, such as sex, age, length of bone defect(P>0.05). Analysis of healing time, healing index and other indicators, and Paley's criterion was used to evaluate the healing effect of bone healing and function recovery of the limb. RESULTS: The result of X-ray evaluation was all patients achieved bone healing. In accordion group, the bone healing time was (365±91) days, the bone healing index was (46.2±3.5) d/cm; in control group, the bone healing time was(435±108) days, the bone healing index was (57.8±3.5) d/cm. There was no statistical significance in the bone healing time between the two groups(t=1.648, P=0.115);There was statistical significance in the bone healing index between the two groups(t=7.754, P=0.000). At the final follow-up, according to Paley's criterion, the result in accordion group was excellent in 9 cases, good in 2 cases; in control group, excellent in 8 cases, good in 3 cases. Score was not statistically significant(z=-0.479, P=0.619). Complications involved nail infection (9 cases in accordion group, 10 cases in control group);local traction pain (2 cases in accordion group, 1 case in control group); axial malalignment>10°(4 cases in accordion group, 3 cases in control group);location difference of the junction of bone defects (3 cases in accordion group, 2 cases in control group);Complications were not statistically significant(P>0.05). CONCLUSIONS: Accordion operation for the Ilizarov technique in treating tibial bone defects can shorten the treatment time and consolidation time, and improve the healing index.

CatSperζ regulates the structural continuity of sperm Ca2+ signaling domains and is required for normal fertility.

We report that the Gm7068 (CatSpere) and Tex40 (CatSperz) genes encode novel subunits of a 9-subunit CatSper ion channel complex. Targeted disruption of CatSperz reduces CatSper current and sperm rheotactic efficiency in mice, resulting in severe male subfertility. Normally distributed in linear quadrilateral nanodomains along the flagellum, the complex lacking CatSperζ is disrupted at ~0.8 µm intervals along the flagellum. This disruption renders the proximal flagellum inflexible and alters the 3D flagellar envelope, thus preventing sperm from reorienting against fluid flow in vitro and efficiently migrating in vivo. Ejaculated CatSperz-null sperm cells retrieved from the mated female uterus partially rescue in vitro fertilization (IVF) that failed with epididymal spermatozoa alone. Human CatSperε is quadrilaterally arranged along the flagella, similar to the CatSper complex in mouse sperm. We speculate that the newly identified CatSperζ subunit is a late evolutionary adaptation to maximize fertilization inside the mammalian female reproductive tract.