Immune marker reductions in black and white Americans following sleeve gastrectomy in the short-term phase of surgical weight loss.

BACKGROUND: Surgical weight loss procedures like vertical sleeve gastrectomy (SG) are sufficient in resolving obesity comorbidities and are touted to reduce the burden of pro-inflammatory cytokines and augment the release of anti-inflammatory cytokines. Recent reports suggest a reduced improvement in weight resolution after SG in Black Americans (BA) versus White Americans (WA). The goal of this study was to determine if differences in immunoglobulin levels and general markers of inflammation after SG in Black Americans (BA) and White Americans (WA) may contribute to this differential resolution. METHODS: Personal information, anthropometric data, and plasma samples were collected from 58 participants (24 BA and 34 WA) before and 6 weeks after SG for the measurement of immunoglobulin A (IgA), IgG, IgM, C-reactive protein (CRP), and transforming growth factor (TGFß). Logistic regression analysis was used to determine the relationship of measures of body size and weight and inflammatory markers. RESULTS: Both IgG and CRP were significantly elevated in BA in comparison to WA prior to weight loss. Collectively, IgG, TGFß, and CRP were all significantly reduced at six weeks following SG. CRP levels in BA were reduced to a similar extent as WA, but IgG levels were more dramatically reduced in BA than WA despite the overall higher starting concentration. No change was observed in IgA and IgM. CONCLUSIONS: These data suggest that SG improves markers of immune function in both BA and WA. More diverse markers of immune health should be studied in future work.

Regional heterogeneity in rat Peyer's patches through whole transcriptome analysis.

Peyer's patches are gut-associated lymphoid tissue located throughout the intestinal wall. Peyer's patches consist of highly organized ovoid-shaped follicles, classified as non-encapsulated lymphatic tissues, populated with B cells, T cells, macrophages, and dendritic cells and function as an organism's intestinal surveillance. Limited work compares the gene profiles of Peyer's patches derived from different intestinal regions. In the current study, we first performed whole transcriptome analysis using RNAseq to compare duodenal and ileal Peyer's patches obtained from the small intestine of Long Evans rats. Of the 12,300 genes that were highly expressed, 18.5% were significantly different between the duodenum and ileum. Using samples obtained from additional subjects (n = 10), we validated the novel gene expression patterns in Peyer's patches obtained from the three regions of the small intestine. Rats had a significantly reduced number of Peyer's patches in the duodenum in comparison to either the jejunum or ileum. Regional differences in structural, metabolic, and immune-related genes were validated. Genes such as alcohol dehydrogenase 1, gap junction protein beta 2, and serine peptidase inhibitor clade b, member 1a were significantly reduced in the ileum in comparison to other regions. On the other hand, genes such as complement C3d receptor type, lymphocyte cytosolic protein 1, and lysozyme C2 precursor were significantly lower in the duodenum. In summary, the gene expression pattern of Peyer's patches is influenced by intestinal location and may contribute to its role in that segment.

Cardiovascular Risk Factors Following Vertical Sleeve Gastrectomy in Black Americans Compared with White Americans.

OBJECTIVE: Bariatric surgery presents a long-term solution for clinical obesity. Given that Black Americans (BA) carry a greater burden of obesity-related comorbidities than White Americans (WA), understanding the racial disparities regarding remission of obesity comorbidities following the most common bariatric surgery, sleeve gastrectomy (SG). The goal of the current study was to provide quantitative values related to cardiovascular and lipid outcomes following SG and determine if racial disparities exist between BA and WA. METHODS: Data was collected from de-identified electronic medical records for patients receiving SG surgery at the University of Mississippi Medical Center in Jackson, MS, USA. RESULTS: Of 464 patients who obtained SG from (2013-2019), 64% were WA, and 36% were BA. Before surgery, BA had significantly greater body weight (BW), body mass index (BMI), and systolic (SBP) and diastolic (DBP) blood pressures (BP) in comparison with WA. Compared with WA, BA were predicted to lose 5.1 kg less BW than WA at 1-year follow-up. Reduction in SBP (- 0.96 vs. - 0.60 mmHg/doubling of days) and DBP (- 0.51 vs. - 0.26 mmHg/doubling of days) was significantly higher in WA compared with BA. There was no racial difference in the change to total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, or triglycerides by race. When normalized to weight loss, the racial disparity in BP reduction was mitigated. CONCLUSIONS: These data indicate that BA lose less body weight following SG; however, loss of excess body weight loss is associated with improvement to BP similarly in both BA and WA.

Dysregulated appetitive leptin signaling in male rodent offspring from post-bariatric dams.

Bariatric surgery produces significant positive benefits to recipients such as significant body fat loss and resolution of the various obesity-related comorbidities, such as reduced reproductive function. Females of childbearing age seek bariatric surgical remedies to improve their chance of successful pregnancy; however, limited knowledge exists on the impact of surgical weight loss to subsequently born offspring. We previously reported that circulating leptin levels were reduced in pregnant females having previously received vertical sleeve gastrectomy (VSG) in comparison to control dams having received Sham surgery. Furthermore, the levels of leptin receptors in the VSG placenta were also reduced in VSG. These data suggest a significant difference in leptin signaling during pregnancy that may produce an altered developmental environment for the offspring. Here, we investigate the adult offspring of dams having received VSG or Sham-VSG prior to pregnancy. Endogenous fasting plasma leptin levels were not different between Sham and VSG offspring. Fasting leptin receptor mRNA in the medial basal hypothalamus (MBH) was elevated in VSG offspring in comparison to Sham. Intraperitoneal administration of exogenous leptin produced reductions in acute food intake in male Sham offspring, but did not reduce food intake at any time point measured in male VSG offspring. Using Western blot, we identified elevated pSTAT3 and pSTAT3/STAT3 ratios in the MBH of post-VSG offspring in comparison to controls. Using immunohistochemistry, we found an increased number of pSTAT positive cells in the arcuate nucleus in the Sham offspring in comparison to VSG. In contrast, within the paraventricular and ventromedial nuclei in the hypothalamus of the VSG offspring had elevated numbers of pSTAT-positive cells in comparison to controls. Collectively, these data support our hypothesis that leptin signaling is dysregulated in VSG offspring and may be partially responsible for the long-term impact of maternal bariatric surgery on the metabolic health of offspring.

Toward the development of peptide nanofilaments and nanoropes as smart materials.

Protein design studies using coiled coils have illustrated the potential of engineering simple peptides to self-associate into polymers and networks. Although basic aspects of self-assembly in protein systems have been demonstrated, it remains a major challenge to create materials whose large-scale structures are well determined from design of local protein-protein interactions. Here, we show the design and characterization of a helical peptide, which uses phased hydrophobic interactions to drive assembly into nanofilaments and fibrils ("nanoropes"). Using the hydrophobic effect to drive self-assembly circumvents problems of uncontrolled self-assembly seen in previous approaches that used electrostatics as a mode for self-assembly. The nanostructures designed here are characterized by biophysical methods including analytical ultracentrifugation, dynamic light scattering, and circular dichroism to measure their solution properties, and atomic force microscopy to study their behavior on surfaces. Additionally, the assembly of such structures can be predictably regulated by using various environmental factors, such as pH, salt, other molecular crowding reagents, and specifically designed "capping" peptides. This ability to regulate self-assembly is a critical feature in creating smart peptide biomaterials.