Reduced Follicular Regulatory T Cells in Spleen and Pancreatic Lymph Nodes of Patients With Type 1 Diabetes.

In the attempt to understand the origin of autoantibody (AAb) production in patients with and at risk for type 1 diabetes (T1D), multiple studies have analyzed and reported alterations in T follicular helper (Tfh) cells in presymptomatic AAb+ subjects and patients with T1D. Yet, whether the regulatory counterpart of Tfh cells, represented by T follicular regulatory (Tfr) cells, is similarly altered is still unclear. To address this question, we performed analyses in peripheral blood, spleen, and pancreatic lymph nodes (PLN) of organ donor subjects with T1D. Blood analyses were also performed in living AAb- and AAb+ subjects. While negligible differences in the frequency and phenotype of blood Tfr cells were observed among T1D, AAb-, and AAb+ adult subjects, the frequency of Tfr cells was significantly reduced in spleen and PLN of T1D as compared with nondiabetic control subjects. Furthermore, adoptive transfer of Tfr cells delayed disease development in a mouse model of T1D, a finding that could indicate that Tfr cells play an important role in peripheral tolerance and regulation of autoreactive Tfh cells. Together, our findings provide evidence of Tfr cell alterations within disease-relevant tissues in patients with T1D, suggesting a role for Tfr cells in defective humoral tolerance and disease pathogenesis.

Endoplasmic Reticulum Oxidative Stress Triggers Tgf-Beta-Dependent Muscle Dysfunction by Accelerating Ascorbic Acid Turnover.

Endoplasmic reticulum (ER) and oxidative stress are two related phenomena that have important metabolic consequences. As many skeletal muscle diseases are triggered by oxidative stress, we explored the chain of events linking a hyperoxidized ER (which causes ER and oxidative stress) with skeletal muscle dysfunction. An unbiased exon expression array showed that the combined genetic modulation of the two master ER redox proteins, selenoprotein N (SEPN1) and endoplasmic oxidoreductin 1 (ERO1), led to an SEPN1-related myopathic phenotype due to excessive signalling of transforming growth factor (TGF)-beta. The increased TGF-beta activity in the genetic mutants was caused by accelerated turnover of the ER localized (anti-oxidant) ascorbic acid that affected collagen deposition in the extracellular matrix. In a mouse mutant of SEPN1, which is dependent on exogenous ascorbic acid, a limited intake of ascorbic acid revealed a myopathic phenotype as a consequence of an altered TGF-beta signalling. Indeed, systemic antagonism of TGF-beta re-established skeletal muscle function in SEPN1 mutant mice. In conclusion, this study sheds new light on the molecular mechanism of SEPN1-related myopathies and indicates that the TGF-beta/ERO1/ascorbic acid axis offers potential for their treatment.

Terapeutic Potential of Microencapsulated Sertoli Cells in Huntington Disease.

INTRODUCTION: Immune dysfunction, promoted by pro-inflammatory cytokines, plays a pivotal role in neurodegeneration associated with Huntington's disease. AIMS: The aim of this study was to investigate the emerging immunoregulatory and antiinflammatory properties of Sertoli cells in Huntington's disease. METHODS: The experimental R6/2 mouse model of Huntington's disease was treated by a single intraperitoneal injection of microencapsulated prepubertal porcine Sertoli cells and lifespan, motor performance and striatal inflammatory pattern have been evaluated. RESULTS: The results of this study demonstrated that a single intraperitoneal injection of microencapsulated prepubertal porcine Sertoli cells uniquely improved performances and extended the life expectancy of R6/2 Huntington's disease mice, by immune dysfunction modulation in brain. CONCLUSIONS: This study highlights the immunomodulatory and trophic role of Sertoli cells that could be of help in the treatment of neurodegenerative disorders.

Pridopidine, a dopamine stabilizer, improves motor performance and shows neuroprotective effects in Huntington disease R6/2 mouse model.

Huntington disease (HD) is a neurodegenerative disorder for which new treatments are urgently needed. Pridopidine is a new dopaminergic stabilizer, recently developed for the treatment of motor symptoms associated with HD. The therapeutic effect of pridopidine in patients with HD has been determined in two double-blind randomized clinical trials, however, whether pridopidine exerts neuroprotection remains to be addressed. The main goal of this study was to define the potential neuroprotective effect of pridopidine, in HD in vivo and in vitro models, thus providing evidence that might support a potential disease-modifying action of the drug and possibly clarifying other aspects of pridopidine mode-of-action. Our data corroborated the hypothesis of neuroprotective action of pridopidine in HD experimental models. Administration of pridopidine protected cells from apoptosis, and resulted in highly improved motor performance in R6/2 mice. The anti-apoptotic effect observed in the in vitro system highlighted neuroprotective properties of the drug, and advanced the idea of sigma-1-receptor as an additional molecular target implicated in the mechanism of action of pridopidine. Coherent with protective effects, pridopidine-mediated beneficial effects in R6/2 mice were associated with an increased expression of pro-survival and neurostimulatory molecules, such as brain derived neurotrophic factor and DARPP32, and with a reduction in the size of mHtt aggregates in striatal tissues. Taken together, these findings support the theory of pridopidine as molecule with disease-modifying properties in HD and advance the idea of a valuable therapeutic strategy for effectively treating the disease.

FTY720 (fingolimod) is a neuroprotective and disease-modifying agent in cellular and mouse models of Huntington disease.

Huntington disease (HD) is a genetic neurodegenerative disorder for which there is currently no cure and no way to stop or even slow the brain changes it causes. In the present study, we aimed to investigate whether FTY720, the first approved oral therapy for multiple sclerosis, may be effective in HD models and eventually constitute an alternative therapeutic approach for the treatment of the disease. Here, we utilized preclinical target validation paradigms and examined the in vivo efficacy of chronic administration of FTY720 in R6/2 HD mouse model. Our findings indicate that FTY720 improved motor function, prolonged survival and reduced brain atrophy in R6/2 mice. The beneficial effect of FTY720 administration was associated with a significant strengthening of neuronal activity and connectivity and, with reduction of mutant huntingtin aggregates, and it was also paralleled by increased phosphorylation of mutant huntingtin at serine 13/16 residues that are predicted to attenuate protein toxicity.