Biology subjects

Weinstein, B. M.

Publications and source records attributed to Weinstein, B. M..

21 records · Page 2Linked to original sources

bioRxiv2019

A Hypomorphic Cystathionine β-Synthase Gene Contributes to Cavefish Eye Loss by Disrupting Optic Vasculature

Vestigial structures are key indicators of evolutionary descent but the mechanisms underlying their development are poorly understood. This study examines vestigial eye formation in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling morph and different populations of blind cave morphs. Cavefish embryos initially develop optic primordia but vestigial eyes are formed during larval development. Multiple genetic factors are involved in cavefish eye loss but none of the mutated genes have been identified. Here we identify cystathionine {beta}-synthase (cbsa), which encodes the key enzyme of the transsulfuration pathway, as a mutated gene responsible for eye degeneration in multiple cavefish populations. The inactivation of cbsa affects eye development by inducing accumulation of the transsulfuration intermediate homocysteine and defects in optic vasculature, including aneurysms and eye hemorrhages, leading to oxygen deficiency. Our findings suggest that localized modifications in the circulatory system and hypoxia had important roles in the evolution of vestigial eyes in blind cavefish.

developmental biology↗

bioRxiv2019

MicroRNA-mediated control of developmental lymphangiogenesis

The post-transcriptional mechanisms contributing to molecular regulation of developmental lymphangiogenesis and lymphatic network assembly are not well understood. Here, we use high throughput small RNA sequencing to identify miR-204, a highly conserved miRNA dramatically enriched in lymphatic vs. blood endothelial cells, and we demonstrate that this miRNA plays a critical role during lymphatic development. Suppressing miR-204 leads to loss of lymphatic vessel formation, while overproducing miR-204 in lymphatic vessels accelerates lymphatic vessel formation, suggesting a positive role during developmental lymphangiogenesis. We also identify the NFATC1 transcription factor as a key conserved target for post-transcriptional regulation by miR-204 during lymphangiogenesis. While miR-204 suppression leads to loss of lymphatics, knocking down its target NFATC1 leads to lymphatic hyperplasia, and the loss of lymphatics in miR-204-deficient animals can be rescued by NFATC1 knockdown. Together, our results highlight a miR-204/NFATC1 molecular regulatory axis required for proper lymphatic development.

developmental biology↗

bioRxiv2018

Anti-angiogenic effects of VEGF stimulation on endothelium deficient in phosphoinositide recycling

Anti-angiogenic therapies have generated significant interest for their potential to combat tumor growth (1-6). However, the ability of tumors to overproduce pro-angiogenic ligands and overcome targeted inhibitory therapies has hampered this approach (7, 8). A novel way to circumvent this problem might be to target the resynthesis of critical substrates consumed during intracellular transduction of pro-angiogenic signals in endothelial cells, thus harnessing the tumors own production of excess stimulatory ligands to deplete adjacent host endothelial cells of the capacity to respond to these signals (9-12). Here we show using zebrafish and human endothelial cells in vitro that endothelial cells deficient in CDP-diacylglycerol synthase 2 are uniquely sensitive to increased VEGF stimulation due to a reduced capacity to re-synthesize phosphoinositides, including phosphatidylinositol 4,5-bisphosphate (PIP2) a key substrate for VEGF signal transduction, resulting in VEGF-exacerbated defects in angiogenesis and angiogenic signaling (9-22). Using murine tumor allograft models (23) we show that either systemic or endothelial cell specific suppression of phosphoinositide recycling results in reduced tumor growth and reduced tumor angiogenesis. Our results suggest that inhibition of phosphoinositide recycling may provide a useful anti-angiogenic approach, and highlights the general potential of targeting the resynthesis of rate limiting signaling substrates as a valuable therapeutic strategy.\n\nSUMMARY STATEMENTTargeting phosphoinositide recycling during tumor angiogenesis provides a potentially uniquely effective anti-cancer therapy.

cell biology↗