bioRxiv Science⌕ Search

Biology subjects

Telen, M. J.

Publications and source records attributed to Telen, M. J..

5 recordsLinked to original sources

Cannabidiol Inhibits PIEZO Channels to Mitigate Red Blood Disorders

Hyperactivity of the mechanosensitive ion channel PIEZO1 promotes pathologic Ca{superscript 2} overload in red blood cells (RBCs), driving dehydration, TMEM16F-dependent phosphatidylserine (PS) exposure, microparticle shedding, and increased thrombotic and vaso-occlusive risks in hereditary xerocytosis (HX) and sickle cell disease (SCD). However, clinically deployable PIEZO inhibitors to treat these blood disorders are lacking. Here we report that cannabidiol (CBD), a non-psychoactive cannabinoid commonly used in SCD patients for pain management, inhibits PIEZO1 activity and restores aberrant mechanotransduction in HX and SCD RBCs. Micromolar concentrations of CBD blocks PIEZO1 currents and suppresses PIEZO1-mediate Ca{superscript 2} entry. In HX and SCD RBCs, CBD attenuates PIEZO1-TMEM16F coupling, thereby reducing PS exposure, microparticle release, thrombin generation, RBC-endothelium adhesion, and sickling. Beyond RBCs, CBD also blocks PIEZO2 currents and PIEZO2-dependent mechanical sensation in mice, suggesting broader effects of CBD-mediated PIEZO inhibition on nociceptive functions. Together, our findings identify CBD as a potent PIEZO inhibitor that restores calcium and membrane homeostasis, supporting the repurposing of CBD or the development of CBD-derived, PIEZO-selective analogs as a promising disease-modifying strategy for SCD, HX, and other PIEZO-mediated mechanosensing disorders. HighlightsO_LICBD inhibits PIEZO channels and disrupts the PIEZO1-TMEM16F axis in diseased RBCs C_LIO_LICBD shows a therapeutic window to prevent PS exposure and translational promise for HX and SCD C_LI

pharmacology and toxicology↗

Targeting PIEZO1-TMEM16F Coupling to Mitigate Sickle Cell Disease Complications

A deeper understanding of sickle cell disease (SCD) pathophysiology is critical for identifying novel therapeutic targets. A hallmark of SCD is abnormal phosphatidylserine (PS) exposure on sickle red blood cells (RBCs), which contributes to anemia, thrombosis, and vaso-occlusive crises (VOC). However, the mechanisms underlying this excessive PS exposure remain unclear. Here, we identify TMEM16F, a Ca2+-activated lipid scramblase, as a key mediator of PS exposure downstream of Ca2+ influx through the mechanosensitive channel PIEZO1 in sickle RBCs. Electrophysiology, imaging and flow cytometry reveal that deoxygenation-induced sickling promotes PIEZO1 activation, triggering Ca2+ entry, TMEM16F activation, and PS exposure. This cascade enhances PS+ microparticle release, thrombin generation, and RBC adhesion to endothelial cells. Notably, partial PIEZO1 inhibition with benzbromarone, an anti-gout drug, suppresses these changes. Our findings thus define a previously unrecognized mechanotransduction pathway in sickle RBCs and propose a unique therapeutic strategy to mitigate hypercoagulability and vaso-occlusion associated with SCD. Brief SummaryEnhanced PIEZO1 activation in sickle red blood cells promotes TMEM16F scramblase-mediated phosphatidylserine exposure and subsequent sickle cell disease complications. Disrupting this coupling presents a potential therapeutic strategy.

physiology↗

Whole genome association testing in 333,100 individuals across three biobanks identifies rare non-coding single variant and genomic aggregate associations with height

The role of rare non-coding variation in complex human phenotypes is still largely unknown. To elucidate the impact of rare variants in regulatory elements, we performed a whole-genome sequencing association analysis for height using 333,100 individuals from three datasets: UK Biobank (N=200,003), TOPMed (N=87,652) and All of Us (N=45,445). We performed rare (<0.1% minor-allele-frequency) single-variant and aggregate testing of non-coding variants in regulatory regions based on proximal, intergenic and deep-intronic annotation. We observed 29 independent variants associated with height at P < 6 x 10-10 after conditioning on previously reported variants, with effect sizes ranging from -7cm to +4.7cm. We also identified and replicated non-coding aggregate-based associations proximal to HMGA1 containing variants associated with a 5cm taller height and of highly-conserved variants in MIR497HG on chromosome 17. We have developed a novel approach for identifying non-coding rare variants in regulatory regions with large effects from whole-genome sequencing data associated with complex traits.

genetics↗

Validation of human telomere length trans-ancestry meta-analysis association signals identifies POP5 and KBTBD6 as novel human telomere length regulation genes

Telomere length genome-wide association studies (GWAS) have become well-powered to detect novel genes in telomere length regulation. However, no prior work has validated these putative novel genes to confirm the contribution of GWAS loci to telomere length regulation. We conducted a trans-ancestry meta-analysis of 211,369 individuals. Through enrichment analyses of chromatin state and cell-type heritability we identified blood and immune cells as the most relevant cell type to examine telomere length association signals. We validated specific GWAS associations by overexpressing KBTBD6, a component of an E3 ubiquitin ligase complex, and POP5, a component of the Ribonuclease P/MRP complex, and demonstrating that both lengthened telomeres as predicted by our statistical analyses. CRISPR/Cas9 deletion of the predicted causal regions of these association peaks in K562 immortalized blood cells reduced expression of these genes, demonstrating that these loci are related to transcriptional regulation of KBTBD6 and POP5, respectively. Together our results demonstrate the utility of telomere length GWAS in the identification of novel telomere length regulation mechanisms and highlight the importance of the proteasome-ubiquitin pathway in telomere length regulation.

genetics↗

Gene-metabolite annotation with shortest reactional distance enhances metabolite genome-wide association studies results

Studies combining metabolomics and genetics, known as metabolite genome-wide association studies (mGWAS), have provided valuable insights into our understanding of the genetic control of metabolite levels. However, the biological interpretation of these associations remains challenging due to a lack of existing tools to annotate mGWAS gene-metabolite pairs beyond the use of conservative statistical significance threshold. Here, we computed the shortest reactional distance (SRD) based on the curated knowledge of the KEGG database to explore its utility in enhancing the biological interpretation of results from three independent mGWAS, including a case study on sickle cell disease patients. Results show that, in reported mGWAS pairs, there is an excess of small SRD values and that SRD values and p-values significantly correlate, even beyond the standard conservative thresholds. The added-value of SRD annotation is shown for identification of potential false negative hits, exemplified by the finding of gene-metabolite associations with SRD [&le;]1 that did not reach standard genome-wide significance cut-off. The wider use of this statistic as an mGWAS annotation would prevent the exclusion of biologically relevant associations and can also identify errors or gaps in current metabolic pathway databases. Our findings highlight the SRD metric as an objective, quantitative and easy-to-compute annotation for gene-metabolite pairs that can be used to integrate statistical evidence to biological networks.

systems biology↗