Improvement of human pancreatic islet quality after co-culture with human adipose-derived stem cells

The aim of this study was to investigate whether co-culture of human islets with adipose-derived stem cells (ASCs) can improve islet quality and to evaluate which factors play a role in the protective effect of ASCs against islet dysfunction. Islets and ASCs were cultured in three experimental groups for 24 h, 48 h, and 72 h: 1) indirect co-culture of islets with ASC monolayer (Islets/ASCs); 2) islets alone; and 3) ASCs alone. Co-culture with ASCs improved islet viability and function in all culture time-points analyzed. VEGFA, HGF, IL6, IL8, IL10, CCL2, IL1B, and TNF protein levels were increased in supernatants of islet/ASC group compared to islets alone, mainly after 24 h. Moreover, VEGFA, IL6, CCL2, HIF1A, XIAP, CHOP, and NFKBIA genes were differentially expressed in islets from the co-culture condition compared to islets alone. In conclusion, co-culture of islets with ASCs promotes improvements in islet quality.

Interaction of HSD11B1 and H6PD polymorphisms in subjects with type 2 diabetes are protective factors against obesity: a cross-sectional study

BACKGROUND

The enzyme 11-beta hydroxysteroid dehydrogenase type 1 (HSD11B1) converts inactive cortisone to active cortisol in a process mediated by the enzyme hexose-6-phosphate dehydrogenase (H6PD). The generation of cortisol from this reaction may increase intra-abdominal cortisol levels and contribute to the physiopathogenesis of obesity and metabolic syndrome (MetS). The relationship of HSD11B1 rs45487298 and H6PD rs6688832 polymorphisms with obesity and MetS was studied. We also studied how HSD11B1 abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) gene expression is related to body fat distribution.

METHODS

Rates of obesity and MetS features were cross-sectionally analyzed according to these polymorphisms in 1006 Brazilian white patients with type 2 diabetes (T2DM). Additionally, HSD11B1 expression was analyzed in VAT and SAT in a different cohort of 28 participants with and without obesity who underwent elective abdominal operations.

RESULTS

Although polymorphisms of the two genes were not individually associated with MetS features, a synergistic effect was observed between both. Carriers of at least three minor alleles exhibited lower BMI compared to those with two or fewer minor alleles adjusting for gender and age (27.4 ± 4.9 vs. 29.3 ± 5.3 kg/m²; P = 0.005; mean ± SD). Obesity frequency was also lower in the first group (24.4% vs. 41.6%, OR = 0.43, 95% CI 0.21-0.87; P = 0.019). In the second cohort of 28 subjects, HSD11B1 gene expression in VAT was inversely correlated with BMI (r = - 0.435, P = 0.034), waist circumference (r = - 0.584, P = 0.003) and waist-to-height ratio (r = - 0.526, P = 0.010).

CONCLUSIONS

These polymorphisms might interact in the protection against obesity in T2DM individuals. Obese individuals may have decreased intra-abdominal VAT HSD11B1 gene expression resulting in decreasing intra-abdominal cortisol levels as a compensatory mechanism against central and general adiposity.

Comparison of the characteristics of canine adipose tissue-derived mesenchymal stem cells extracted from different sites and at different passage numbers

Mesenchymal stem cells (MSCs) have desirable characteristics for use in therapy in animal models and veterinary medicine, due to their capacity of inducing tissue regeneration and immunomodulation. The objective of this study was to evaluate the differences between canine adipose tissue-derived MSCs (AD-MSCs) extracted from subcutaneous (Sc) and visceral (Vs) sites. Surface antigenic markers, in vitro differentiation, and mineralized matrix quantification of AD-MSCs at different passages (P₄, P₆, and P₈) were studied. Immunophenotypic analysis showed that AD-MSCs from both sites were CD44+, CD90+, and CD45-. Moreover, they were able, in vitro, to differentiate into fat, cartilage, and bone. Sc-AD-MSCs preserve in vitro multipotentiality up to P₈, but Vs-AD-MSCs only tri-differentiated up to P₄. In addition, compared to Vs-AD-MSCs, Sc-AD-MSCs had greater capacity for in vitro mineralized matrix synthesis. In conclusion, Sc-AD-MSCs have advantages over Vs-AD-MSCs, as Sc AD-MSCs preserve multipotentiality during a greater number of passages, have more osteogenic potential, and require less invasive extraction.

Cell therapy in the treatment of bipolar mania in an animal model: a proof of concept study

Abstract Introduction The rationale of mesenchymal stem cells (MSCs) as a novel therapeutic approach in certain neurodegenerative diseases is based on their ability to promote neurogenesis. Hippocampal atrophy has been related to bipolar disorder (BD) in preclinical, imaging and postmortem studies. Therefore, the development of new strategies to stimulate the neurogenesis process in BD is crucial. Objectives To investigate the behavioral and neurochemical changes induced by transplantation of MSCs in a model of mania-like behavior induced by lisdexamfetamine dimesylate (LDX). Methods Wistar rats (n=65) received one oral daily dose of LDX (10 mg/kg) or saline for 14 days. On the 8th day of treatment, the animals additionally received intrahippocampal saline or MSC (1 µL containing 25,000 cells) or lithium (47.5 mg/kg) as an internal experimental control. Two hours after the last administration, behavioral and neurochemical analyses were performed. Results LDX-treated rats had increased locomotor activity compared to saline-saline rats (p=0.004), and lithium reversed LDX-related hyperactive behavior (p<0.001). In contrast, the administration of MSCs did not change hyperlocomotion, indicating no effects of this treatment on LDX-treated rats (p=0.979). We did not find differences between groups in BDNF levels (p>0.05) in the hippocampus of rats. Conclusion Even though these results suggest that a single intrahippocampal injection of MSCs was not helpful to treat hyperactivity induced by LDX and neither influenced BDNF secretion, we cannot rule out the possible therapeutic effects of MSCs. Further research is required to determine direct effects of LDX on brain structures as well as in other pathophysiological targets related to BD.

Human pancreatic islet transplantation: an update and description of the establishment of a pancreatic islet isolation laboratory

Type 1 diabetes mellitus (T1DM) is associated with chronic complications that lead to high morbidity and mortality rates in young adults of productive age. Intensive insulin therapy has been able to reduce the likelihood of the development of chronic diabetes complications. However, this treatment is still associated with an increased incidence of hypoglycemia. In patients with "brittle T1DM", who have severe hypoglycemia without adrenergic symptoms (hypoglycemia unawareness), islet transplantation may be a therapeutic option to restore both insulin secretion and hypoglycemic perception. The Edmonton group demonstrated that most patients who received islet infusions from more than one donor and were treated with steroid-free immunosuppressive drugs displayed a considerable decline in the initial insulin independence rates at eight years following the transplantation, but showed permanent C-peptide secretion, which facilitated glycemic control and protected patients against hypoglycemic episodes. Recently, data published by the Collaborative Islet Transplant Registry (CITR) has revealed that approximately 50% of the patients who undergo islet transplantation are insulin independent after a 3-year follow-up. Therefore, islet transplantation is able to successfully decrease plasma glucose and HbA1c levels, the occurrence of severe hypoglycemia, and improve patient quality of life. The goal of this paper was to review the human islet isolation and transplantation processes, and to describe the establishment of a human islet isolation laboratory at the Endocrine Division of the Hospital de Clínicas de Porto Alegre - Rio Grande do Sul, Brazil.