bioRxiv Science⌕ Search

Biology subjects

Yang, R.-Z.

Publications and source records attributed to Yang, R.-Z..

4 recordsLinked to original sources

Optogenetic Control of cAMP Levels and HCN Channels: Implications in Cardiac Physiology and Parkinsons Disease

Cyclic adenosine monophosphate (cAMP) is a second messenger that regulates various cellular processes, including the activity of hyperpolarization-activated channels (HCN), which are implicated in cardiac physiology and neurodegenerative diseases such as Parkinsons disease (PD). In this study, we used a photoactivated adenylyl cyclase (PAC) S27A mutant to optogenetically control intracellular cAMP levels. We demonstrated that light-induced elevation of cAMP activated HCN4 channels, leading to increased beating rates in cardiomyocytes. Unilateral expression of PAC(S27A) in the substantia nigra pars compacta of mice induced rotation behavior upon light stimulation, which could be attenuated by HCN inhibitors. Furthermore, PAC(S27A) activation partially recovered motor deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model, accompanied by increased HCN2 channel expression in ipsilateral basal ganglia. Our findings highlight the potential of using optogenetics to modulate cAMP and HCN channel activity for the treatment of cardiac and neurological disorders.

cell biology↗

Optogenetic Regulation of Mitochondrial Function to Modulate Cell Death

Cell death is a critical process involved in physiological and pathological conditions, including neurodegenerative diseases and cancer. This study explores the use of optogenetic techniques to induce cell death by employing light sensitive proteins. By manipulating mitochondrial function with light-sensitive proteins, we investigated three distinct strategies: 1) inhibiting oxidative phosphorylation through Gloeobacter rhodopsin-mediated alkalization, 2) inducing mitochondrial depolarization with reverse proton-pumping rhodopsins (RPPR) and anion-conducting channelrhodopsins, and 3) generating reactive oxygen species (ROS) using mitochondria-targeted miniSOG. Our findings highlight the potential of optogenetic approaches to induce cell death, offering promising avenues for therapeutic interventions in diseases characterized by aberrant cell survival.

cell biology↗

Mitochondrial DNA Release and Activation of the cGAS-STING Pathway in Lethal Stx12 Knockout Mice

STX12 (syntaxin12 or syntaxin13), a member of the SNARE protein family, plays a crucial role in intracellular vesicle transport and membrane fusion. Our previous research has demonstrated that Stx12 knockout mice exhibit perinatal lethality with iron deficiency anemia. Despite its importance, the comprehensive physiological and pathological mechanism of STX12 remain largely unknown. Here, we uncover that STX12 deficiency causes the depolarization of mitochondrial membrane potential in zebrafish embryos and mouse embryonic fibroblasts. Additionally, the loss of STX12 decreases levels of mitochondrial complex subunits, accompanying mitochondrial DNA (mtDNA) release and activating cGAS-STING pathway and Type I interferon pathway in the lung tissue of Stx12-/- mice. Additionally, we have observed a substantial increase in cytokines and neutrophil infiltration within the lung tissues of Stx12 knockout mice, indicating a severe inflammation, which could be a contributing factor for Stx12-/-mortality. Various interventions have failed to rescue the lethal phenotype, suggesting that systemic effects may contribute to lethality. Further research is warranted to elucidate potential intervention strategies. Overall, our findings uncover the critical role of STX12 in maintaining mitochondrial function and mtDNA stability in pulmonary cells, and reveal that STX12 depletion results in pulmonary mtDNA release and activates mtDNA-dependent innate immunity.

molecular biology↗

Ancient DNA Reveals China as a Historical Genetic Melting Pot in Tiger Evolution

The contrast between the tigers (Panthera tigris) 2-3 My age and extant tigers coalescence approximately 110,000 years ago suggests an ancient demographic bottleneck. Here we collected over 60 extinct specimens across mainland Asia and generated whole genome sequences from a 10,600-year-old Russian Far East (RFE) specimen (RUSA21, 8{xi} coverage), 14 South China tigers (0.1-12{xi}), three Caspian tigers (4-8{xi}), plus 17 new mitogenomes. RUSA21 clustered within modern Northeast Asian phylogroups and partially derived from an extinct Late Pleistocene lineage. While some 8,000-10,000-year-old RFE mitogenomes are basal to all tigers, one 2,000-year-old specimen resembles present Amur tigers. The Caspian tiger likely dispersed from an ancestral Northeast Asian population and experienced gene flow from southern Bengal tigers. Lastly, genome-wide monophyly supported the South China tiger as a distinct subspecies, albeit with mitochondrial paraphyly, hence resolving its longstanding taxonomic controversy. The distribution of mitochondrial haplogroups corroborated by biogeographical modeling suggested Southwest China was a Late Pleistocene refugium for a relic basal lineage. As suitable habitat returned, Eastern China became a genetic melting pot to foster divergent lineages to merge into South China tigers and other subsequent northern subspecies to develop. Genomic information retrieved from ancient tigers hence sheds light on the species full evolutionary history leading to nine modern subspecies and resolves the natural history of surviving tigers.

evolutionary biology↗