Search bioRxiv⌕ Search

Biology subjects

Chandrasekhar, V.

Publications and source records attributed to Chandrasekhar, V..

3 recordsLinked to original sources

Brain shuttle target expression levels vary by individual, not by brain region, disease, age, or sex

Therapeutics fused to brain shuttles that exploit endogenous receptor-mediated transport at the blood-brain barrier (BBB) offer a promising strategy to deliver large molecule drugs and biologics to the CNS. A fundamental but untested assumption underlying their clinical development is that their endothelial receptor targets are consistently expressed between individuals and between patient populations. Here, we analyzed gene and protein expression of eleven canonical brain shuttle targets in isolated human brain microvascular endothelial cells and brain microvessels from 11 large cohorts, using single-cell and single-nucleus transcriptomics and quantitative proteomics. Expression was remarkably stable between brain regions, sexes, ages, and normal health versus four major neurodegenerative conditions, Alzheimers disease, Parkinsons disease, Huntingtons disease, and amyotrophic lateral sclerosis, with 612 of 631 comparisons (97%) showing no significant difference. Regional heterogeneity of brain shuttle targets previously reported in rodent models was not observed in human tissue, and disease states had minimal impact in all diseases examined. In striking contrast, target abundance differed consistently among individuals in every demographic and clinical group, for all eleven targets and all data modalities. These findings establish individual receptor abundance as a critical and previously uncharacterized variable for brain shuttle translational research, including clinical trial design and patient stratification.

neuroscience↗

Target-agnostic discovery of Rett Syndrome therapeutics by coupling computational network analysis and CRISPR-enabled in vivo disease modeling

Many neurodevelopmental genetic disorders, such as Rett syndrome, are caused by a single gene mutation but trigger changes in expression and regulation of numerous other genes. This severely impair functions of multiple organs and organ systems beyond the central nervous system (CNS), adding to the challenge of developing broadly effective treatments based on a single drug target. This challenge is further complicated by the lack of sufficiently broad and biologically relevant drug screens, and the inherent complexity in identifying clinically relevant targets responsible for diverse phenotypes. Here, we combined human gene regulatory network-based computational drug prediction with in vivo screening in a population-level diversity, CRISPR-edited, Xenopus laevis tadpole model of Rett syndrome to carry out target-agnostic drug discovery, which rapidly led to the identification of the FDA-approved drug vorinostat as a potential repurposing candidate. Vorinostat broadly improved both CNS and non-CNS (e.g., gastrointestinal, respiratory, inflammatory) abnormalities in a pre-clinical mouse model of Rett syndrome. This is the first Rett syndrome treatment to demonstrate pre-clinical efficacy across multiple organ systems when dosed after the onset of symptoms, and network analysis revealed a putative therapeutic mechanism for its cross-organ normalizing effects based on its impact on acetylation metabolism and post-translational modifications of microtubules. Although traditionally considered an inhibitor of histone deacetylases (HDAC), vorinostat unexpectedly restored protein acetylation across both hypo- and hyperacetylated tissues, suggesting non-HDAC-mediated therapeutic mechanisms supported by proteomic analysis.

neuroscience↗

Modular biomaterials vaccine technology protects against multiple pathogens and septic shock

Broad spectrum vaccines could provide a solution to the emergence of antibiotic resistant microbes, pandemics and engineered biothreat agents. Here, we describe a modular vaccine (composite infection vaccine technology (ciVAX)) which can be rapidly assembled and in which 4 of the 5 components are already approved for human use. ciVAX consists of an injectable biomaterial scaffold with factors to recruit and activate dendritic cells (DC) in vivo and microbeads conjugated with the broad-spectrum opsonin Fc-Mannose-binding Lectin (FcMBL) that is pre-bound to polysaccharide-rich cell wall antigens, such as the pathogen-associated molecular patterns (PAMPs) fractions, captured from whole inactivated bacteria. Vaccination of mice and rabbits with ciVAX generates potent humoral and T cell responses to PAMPs isolated from native antibiotic-resistant E. coli and S. aureus, and ciVAX protects mice and pigs against lethal E coli challenge in sepsis and septic shock models. In addition to the efficacy of ciVAX against homologous challenge, PAMPS isolated from an infected animal protects other animals against infection by heterologous challenge using different E. coli serotypes - demonstrating the potential for use of ciVAX in controlling pandemics. The advantage of the ciVAX technology is the strong immunogenicity with limited reactogenicity, the use of inactivated pathogens, and the modular manufacture using cGMP approved products which can be stockpiled ready for the next pandemic. One Sentence SummaryBiomaterial vaccine induces strong immunogenicity, weak reactogenicity, and protects from E. coli sepsis in rodents and pigs, and MRSA skin abscess.

immunology↗