Search bioRxiv⌕ Search

Biology subjects

Hoch, L.

Publications and source records attributed to Hoch, L..

3 recordsLinked to original sources

Dual blockade of misfolded alpha-sarcoglycan degradation by bortezomib and givinostat combination

Limb-girdle muscular dystrophy type R3 (LGMD R3) is a rare genetic disorder characterized by a progressive proximal muscle weakness and caused by mutations in the SGCA gene encoding alpha-sarcoglycan (-SG). Here, we report the results of a mechanistic screening ascertaining the molecular mechanisms involved in the degradation of the most prevalent misfolded R77C--SG protein. We performed a combinatorial study to identify drugs potentializing the effect of a low dose of the proteasome inhibitor bortezomib on the R77C--SG degradation inhibition. Analysis of the screening associated to artificial intelligence-based predictive ADMET characterization of the hits led to identification of the HDAC inhibitor givinostat as potential therapeutical candidate. Functional characterization revealed that givinostat effect was related to autophagic pathway inhibition, unveiling new theories concerning degradation pathways of misfolded SG proteins. Beyond the identification of a new therapeutic option for LGMD R3 patients, our results shed light on the potential repurposing of givinostat for the treatment of other genetic diseases sharing similar protein degradation defects such as LGMD R5 and cystic fibrosis.

pharmacology and toxicology↗

Inheritance of associative memories in C. elegans ‎nematodes

The notion that associative memories may be transmitted across generations is intriguing, yet controversial. Here, we trained C. elegans nematodes to associate an odorant with stressful starvation conditions, and surprisingly, this associative memory was evident two generations down of the trained animals. The inherited memory endowed the progeny with a fitness advantage, as memory reactivation induced rapid protective stress responses that allowed the animals to prepare in advance for an impending adversity. Sperm, but not oocytes, transmitted the associative memory, and the inheritance required H3K9 and H3K36 methylations, the small RNA-binding Argonaute NRDE-3, and intact neuropeptide secretion. Remarkably, activation of a single chemosensory neuron sufficed to induce a serotonin-mediated systemic stress response in both the parental trained generation and in its progeny. These findings challenge long-held concepts by establishing that associative memories may indeed be transferred across generations.

neuroscience↗

Genome-wide epigenetic profiling of 5-hydroxymethylcytosine by long-read optical mapping

The epigenetic mark 5-hydroxymethylcytosine (5-hmC) is a distinct product of active enzymatic demethylation that is linked to gene regulation, development and disease. Genome-wide 5-hmC profiles generated by short-read next-generation sequencing are limited in providing long-range epigenetic information relevant to highly variable genomic regions, such as the 3.7 Mbp disease-related Human Leukocyte Antigen (HLA) region. We present a long-read, single-molecule mapping technology that generates hybrid genetic/epigenetic profiles of native chromosomal DNA. The genome-wide distribution of 5- hmC in human peripheral blood cells correlates well with 5-hmC DNA immunoprecipitation (hMeDIP) sequencing. However, the long read length of 100 kbp-1Mbp produces 5-hmC profiles across variable genomic regions that failed to showup in the sequencing data. In addition, optical 5-hmC mapping shows strong correlation between the 5-hmC density in gene bodies and the corresponding level of gene expression. The single molecule concept provides information on the distribution and coexistence of 5-hmC signals at multiple genomic loci on the same genomic DNA molecule, revealing long-range correlations and cell-to-cell epigenetic variation.

genomics↗