Cyclin C stimulates ß-cell proliferation in rat and human pancreatic ß-cells.

Activation of pancreatic ß-cell proliferation has been proposed as an approach to replace reduced functional ß-cell mass in diabetes. Quiescent fibroblasts exit from G0 (quiescence) to G1 through pRb phosphorylation mediated by cyclin C/cdk3 complexes. Overexpression of cyclin D1, D2, D3, or cyclin E induces pancreatic ß-cell proliferation. We hypothesized that cyclin C overexpression would induce ß-cell proliferation through G0 exit, thus being a potential therapeutic target to recover functional ß-cell mass. We used isolated rat and human islets transduced with adenovirus expressing cyclin C. We measured multiple markers of proliferation: [(3)H]thymidine incorporation, BrdU incorporation and staining, and Ki67 staining. Furthermore, we detected ß-cell death by TUNEL, ß-cell differentiation by RT-PCR, and ß-cell function by glucose-stimulated insulin secretion. Interestingly, we have found that cyclin C increases rat and human ß-cell proliferation. This augmented proliferation did not induce ß-cell death, dedifferentiation, or dysfunction in rat or human islets. Our results indicate that cyclin C is a potential target for inducing ß-cell regeneration.

Results of treatment with alemtuzumab in a Spanish cohort of patients with multiple sclerosis in the real world: The RealMS study.

Background: Alemtuzumab (ALZ) is a humanized monoclonal antibody approved for the treatment of patients with highly active relapsing-remitting multiple sclerosis (RRMS) administered in two annual courses. The objective of this study was to describe the effectiveness and safety data of ALZ and to report the health resource utilization in patients receiving this treatment. Methods: In this retrospective, non-interventional study, information was retrieved from patients' medical charts at one center in Spain. Included patients were ≥18 years old, and ALZ treatment was initiated between 1 March 2015 and 31 March 2019, according to routine clinical practice and local labeling. Results: Of 123 patients, 78% were women. The mean (standard deviation, SD) age of patients at diagnosis was 40.3 (9.1) years, and the mean time since diagnosis was 13.8 (7.3) years. Patients were previously treated with a median (interquartile range; IQR) number of two (2.0-3.0) disease-modifying treatments (DMTs). Patients were treated with ALZ for a mean (SD) of 29.7 (13.8) months. ALZ reduced the annualized relapse rate (ARR) (1.5 before vs. 0.05 after; p < 0.001) and improved the median EDSS (4.63 before vs. 4.00 after; p < 0.001). Most (90.2%) patients were relapse-free while receiving ALZ. The mean number of gadolinium-enhancing [Gd+] T1 lesions was reduced (1.7 before vs. 0.1 after; p < 0.001), and the mean number of T2 hyperintense lesions was maintained (35.7 before vs. 35.4 after; p = 0.392). A total of 27 (21.9%) patients reported 29 autoimmune diseases: hyperthyroidism (12), hypothyroidism (11), idiopathic thrombocytopenic purpura (ITP) (3), alopecia areata (1), chronic urticaria (1), and vitiligo (1). The mean number of health resources (outpatient visits, emergency room visits, hospital admissions, and tests performed in the hospital) used while patients were treated with ALZ progressively decreased from year 1 to year 4, except for a slight increase at year 2 of outpatient visits. Conclusion: The ReaLMS study provides real-world evidence that ALZ can promote clinical and magnetic resonance imaging disease remission, as well as disability improvement in patients with MS, despite several prior DMT failures. The ALZ safety profile was consistent with data available from clinical trials and other real-world studies. Healthcare resource use was reduced throughout the treatment period.

Epithelial to mesenchymal transition in human endocrine islet cells.

BACKGROUND: ß-cells undergo an epithelial to mesenchymal transition (EMT) when expanded in monolayer culture and give rise to highly proliferative mesenchymal cells that retain the potential to re-differentiate into insulin-producing cells. OBJECTIVE: To investigate whether EMT takes place in the endocrine non-ß cells of human islets. METHODOLOGY: Human islets isolated from 12 multiorgan donors were dissociated into single cells, purified by magnetic cell sorting, and cultured in monolayer. RESULTS: Co-expression of insulin and the mesenchymal marker vimentin was identified within the first passage (p1) and increased subsequently (insulin+vimentin+ 7.2±6% at p1; 43±15% at p4). The endocrine non-ß-cells did also co-express vimentin (glucagon+vimentin+ 59±1.5% and 93±6%, somatostatin+vimentin+ 16±9.4% and 90±10% at p1 and p4 respectively; PP+vimentin+ 74±14% at p1; 88±12% at p2). The percentage of cells expressing only endocrine markers was progressively reduced (0.6±0.2% insulin+, 0.2±0.1% glucagon+, and 0.3±0.2% somatostatin+ cells at p4, and 0.7±0.3% PP+ cells at p2. Changes in gene expression were also indicated of EMT, with reduced expression of endocrine markers and the epithelial marker CDH-1 (p<0.01), and increased expression of mesenchymal markers (CDH-2, SNAI2, ZEB1, ZEB2, VIM, NT5E and ACTA2; p<0.05). Treatment with the EMT inhibitor A83-01 significantly reduced the percentage of co-expressing cells and preserved the expression of endocrine markers. CONCLUSIONS: In adult human islets, all four endocrine islet cell types undergo EMT when islet cells are expanded in monolayer conditions. The presence of EMT in all islet endocrine cells could be relevant to design of strategies aiming to re-differentiate the expanded islet cells towards a ß-cell phenotype.

Epoxypukalide induces proliferation and protects against cytokine-mediated apoptosis in primary cultures of pancreatic ß-cells.

There is an urgency to find new treatments for the devastating epidemic of diabetes. Pancreatic ß-cells viability and function are impaired in the two most common forms of diabetes, type 1 and type 2. Regeneration of pancreatic ß-cells has been proposed as a potential therapy for diabetes. In a preliminary study, we screened a collection of marine products for ß-cell proliferation. One unique compound (epoxypukalide) showed capability to induce ß-cell replication in the cell line INS1 832/13 and in primary rat cell cultures. Epoxypukalide was used to study ß-cell proliferation by [(3)H]thymidine incorporation and BrdU incorporation followed by BrdU/insulin staining in primary cultures of rat islets. AKT and ERK1/2 signalling pathways were analyzed. Cell cycle activators, cyclin D2 and cyclin E, were detected by western-blot. Apoptosis was studied by TUNEL and cleaved caspase 3. ß-cell function was measured by glucose-stimulated insulin secretion. Epoxypukalide induced 2.5-fold increase in ß-cell proliferation; this effect was mediated by activation of ERK1/2 signalling pathway and upregulation of the cell cycle activators, cyclin D2 and cyclin E. Interestingly, epoxypukalide showed protection from basal (40% lower versus control) and cytokine-induced apoptosis (80% lower versus control). Finally, epoxypukalide did not impair ß-cell function when measured by glucose-stimulated insulin secretion. In conclusion, epoxypukalide induces ß-cell proliferation and protects against basal and cytokine-mediated ß-cell death in primary cultures of rat islets. These findings may be translated into new treatments for diabetes.