Pericyte and their tunnelling nanotubes (P-TNTs) have been described as involved in the early phases of angiogenesis in the human normal developing brain and glioblastoma, being a common feature of combined endothelium/pericyte vessel sprouts. Based on the few data available so far about this ‘alternative’ pericyte-TNT-driven mode of angiogenesis, whose precise function in vessel growth through vascular cells communication, has still to be determined, this study aims to cast light on the regulative molecules involved in this process, governed by intimate pericyte-endothelial interactions. After considering the existence of the sprout guiding pericyte and P-TNT, as shown by pioneering ultrastructural studies as well as by more recent observations with NG2/CD146 pericyte markers and basal lamina molecules, a step-by-step profile of the process has been suggested and an investigation undertaken on ‘unconventional’, pro-angiogenic ligand/receptor systems, that may have a role aside from the canonical pathways. In this context, a possible candidate worthy of investigation is the c-KIT receptor, a member of the tyrosine kinase family of proteins, which also includes the well-known VEGFR and PDGFR. According to the obtained results showing a primary localization of c-KIT on endothelial cells and pointing out a differential distribution of the receptor on normal vs glioblastoma vessels, it seems conceivable to propose the stem cell factor/c-KIT signaling as a key factor in pericyte-TNT-driven angiogenesis, advancing this alternative mode of angiogenesis and the c- KIT pathway as possible targets for devising effective antiangiogenic therapeutic strategies.

Brain vascular health appears to be of critical importance for protection against the development of amyotrophic lateral sclerosis (ALS) as well as the slowing of disease progression. ALS patients often demonstrate cardiovascular risk factors and commonly suffer from cerebrovascular disease, with evidence of pathological alterations in the small cerebral vessels. Impaired vascular brain health has detrimental effects on motor neurons as lowered vascular endothelial growth factor levels compromise endothelial cell formation, promoting blood-brain barrier leakage and inflammation. Increased turnover of neurovascular unit cells precedes their senescence, which, together with pericyte alterations, further fosters the failure of toxic metabolite removal. We here provide a comprehensive overview of the pathogenesis of impaired brain vascular health in ALS and how novel magnetic resonance imaging techniques can aid its detection. In particular, we discuss vascular patterns of blood supply to the motor cortex with the number of branches from the anterior and middle cerebral arteries acting as a novel marker of resistance and resilience against downstream effects of vascular risk and events in ALS. We outline how certain interventions adapted to patient needs and capabilities have the potential to mechanistically target the brain microvasculature towards favorable motor cortex blood supply patterns. Through this strategy, we aim to guide novel approaches to ALS management and a better understanding of ALS pathophysiology.

Temporal lobe epilepsy (TLE) is associated with reorganization of hippocampal neuronal net-works, gliosis, neuroinflammation, loss of integrity of the blood-brain barrier (BBB) in humans and animal models. More than 30% of epilepsies remain intractable and characterization of the molecular mechanisms involved in BBB dysfunction is essential to the identification of new thera-peutic strategies. In this work, we induced status epilepticus in rats by injection of the proconvul-sant drug pilocarpine that leads to TLE. Using RT-qPCR, double immunohistochemistry and con-focal imaging, we studied at different time points of epileptogenesis (latent phase, 3, 7, 14 days; chronic phase, 1 and 3 months) the regulation of reactive glia and vascular markers. In the hippo-campus, increased expression of mRNA encoding the glial proteins GFAP and Iba1 confirmed neu-roinflammatory status. We report for the first time the concomitant induction in endothelial cells, pericytes and basement membrane of the BBB of specific proteins CD31, PDGFR and ColIV, that peaks at the same time points as inflammation. The altered expression of these proteins occurs ear-ly in TLE, during the latent phase, suggesting that they could be associated with early rupture and pathogenicity of the BBB that will contribute to the chronic phase of epilepsy.

The adipose-derived mesenchymal stem cells are becoming the tool of choice for many clinical applications and nowadays, nearly 200 clinical trials are running worldwide to prove the efficacy of this cell type for many diseases and pathological conditions. To reach the goal of cell therapies and produce ATMPs as drugs for regenerative medicine, it is necessary to properly standardize the GMP processes and thus collection methods, transportation strategies, extraction protocols and characterization procedures without forgetting that all the tissues of the human body are characterized by a wide inter-individual variability genetically determined and acquired during life. Here we compare 302 samples processed under GMP rules to exclude the influence of the operator and of the anatomical site of collection. Variability in the age of patients, gender and laboratory parameters like total cell number, cell viability, stem cell number and other stromal vascular fraction cell sub-populations have been compared to each other. Results show that, when the laboratory protocol is standardized, the variability in quantifiable cell parameters is widely statistically non-significant, meaning that we can make a further step toward standardized advanced cell therapy products.