Xenogeneic mesenchymal stem cell biocurative improves skin wounds healing in diabetic mice by increasing mast cells and the regenerative profile.

Introduction: Diabetes mellitus (DM) is a chronic disease and a major cause of mortality and morbidity worldwide. The hyperglycemia caused by DM induces micro and macrovascular complications that lead, among other consequences, to chronic wounds and amputations. Cell therapy and tissue engineering constitute recent therapeutic alternatives to improve wound healing in diabetic patients. The current study aimed to analyze the effectiveness of biocuratives containing human mesenchymal stem cells (MSCs) associated with a hydrogel matrix in the wound healing process and related inflammatory cell profile in diabetic mice. Methods: Biocuratives containing MSCs were constructed by 3D bioprinting, and applied to skin wounds on the back of streptozotocin (STZ)-induced type 1 diabetic (T1D) mice. The healing process, after the application of biocuratives with or without MSCs was histologically analyzed. In parallel, genes related to growth factors, mast cells (MC), M1 and M2 macrophage profiles were evaluated by RT-PCR. Macrophages were characterized by flow cytometry, and MC by toluidine blue staining and flow cytometry. Results: Mice with T1D exhibited fewer skin MC and delayed wound healing when compared to the non-diabetic group. Treatment with the biocuratives containing MSCs accelerated wound healing and improved skin collagen deposition in diabetic mice. Increased TGF-ß gene expression and M2 macrophage-related markers were also detected in skin of diabetic mice that received MSCs-containing biocuratives. Finally, MSCs upregulated IL-33 gene expression and augmented the number of MC in the skin of diabetic mice. Conclusion: These results reveal the therapeutic potential of biocuratives containing MSCs in the healing of skin wounds in diabetic mice, providing a scientific base for future treatments in diabetic patients.

NLR and Intestinal Dysbiosis-Associated Inflammatory Illness: Drivers or Dampers?

The intestinal microbiome maintains a close relationship with the host immunity. This connection fosters a health state by direct and indirect mechanisms. Direct influences occur mainly through the production of short-chain fatty acids (SCFAs), gastrointestinal hormones and precursors of bioactive molecules. Indirect mechanisms comprise the crosstalk between bacterial products and the host's innate immune system. Conversely, intestinal dysbiosis is a condition found in a large number of chronic intestinal inflammatory diseases, such as ulcerative colitis and Crohn's disease, as well as in diseases associated with low-grade inflammation, such as obesity, type 1 and 2 diabetes mellitus and cardiovascular diseases. NOD-Like receptors (NLRs) are cytoplasmic receptors expressed by adaptive and innate immune cells that form a multiprotein complex, termed the inflammasome, responsible for the release of mature interleukin (IL)-1ß and IL-18. NLRs are also involved in the recognition of bacterial components and production of antimicrobial molecules that shape the gut microbiota and maintain the intestinal homeostasis. Recent novel findings show that NLRs may act as positive or negative regulators of inflammation by modulating NF-κB activation. This mini-review presents current and updated evidence on the interplay between NLRs and gut microbiota and their dual role, contributing to progression or conferring protection, in diabetes and other inflammatory diseases.

Constrictor responses to noradrenaline, hemodynamic profile, and superoxide levels measured by hydroethidine oxidation in diabetic rats.

The aim of this study was to test the hypothesis that vascular dysfunction in neonatal streptozotocin (n-STZ)-induced diabetic rats could be associated with alterations in blood pressure, hemodynamic profile, and levels of superoxide anion. Diabetes was induced by STZ injection (160 mg/kg, i.p.) in neonate (2-d-old) Wistar rats. Using intravital microscopy the changes in mesenteric arteriolar diameters to vasoconstrictor agent noradrenaline (NA) and the levels of superoxide anion, measured by hydroethidine microfluorography, were determined in anaesthetized control and n-STZ rats. Blood pressure (BP) was determined in anaesthetized and unanaesthetized animals. Heart rate, shear rate, and blood flow velocity were also assessed. n-STZ rats showed, after 8 weeks of STZ injection, increased BP (unanaesthetized animals), hyperactivity to NA, and increased superoxide anion levels. However, heart rate, arteriolar shear rate, and blood flow velocity were unchanged in n-STZ. In conclusion, the results of the current study describe a significant increase in blood pressure, hyperactivity to NA-mediated vasoconstriction, and increased superoxide levels measured by hydroethidine oxidation. Taken together, our findings demonstrate that the compromised ability of mesenteric microvessels to respond properly in n-STZ diabetic rats is associated with several vascular alterations.