Biology subjects

Han, Y.

Publications and source records attributed to Han, Y..

At least 253 records · Page 14Linked to original sources

bioRxiv2021

Impact of Grain for Green Project on Water Resources and Ecological Water Stress in Yanhe River Basin

Grain for Green project (GGP) initialed by China government since 1999 has achieved substantial achievements accompanied with surface runoff decrease in the Loess Plateau but impacts of large-scale afforestation on regional water resources are uncertain. Hence, the objective of this study is to explore the impact of land use change on generalized water resources and ecological water stress using blue and green water concept taking Yanhe River Basin as a case study. Soil and Water Assessment Tool (SWAT) is applied to quantify summary of green and blue water which is defined as generalized water resources, ecological water requirement of vegetation (forest and grass), agricultural water footprint and virtual water flow are considered as regional water requirements. Land use types of 1980 (scenario I), 2017 (scenario II) are input in SWAT model while keeps other parameters constant in order to isolate the influence of land use changes. Results show that average annual difference of blue, green and generalized water resources is -72.08 million m3, 24.34 million m3, -47.74 million m3 respectively when simulation results of scenario II subtracts scenario I and it presents that land use change caused by GGP leads to decrease in blue and generalized water resources whereas increase in green water resources. SURQ in scenario I is more than that in scenario IIin all the study period from 1980-2017, green water storage in scenario I is more than that in scenario II in all the study period except in 1998; whereas LATQ in scenario I is less than that in scenario II except in 2000 and 2015, GWQ in 1992, 2000 and 2015, green water flow in 1998. Blue water, green water storage and green water flow in scenario II is less than that in scenario I in the whole basin, 12.89 percent of the basin and 99.21 percent of the basin respectively. Total WF increases from 1995 to 2010 because forest WF increases significantly in this period though agricultural WF and grass WF decreases. Ecological water stress index has no obvious temporal change trend in both land use scenarios but ecological water stress index in scenario II is more than that in scenario I which illustrates that GGP leads to increase of ecological water stress from perspective of generalized water resources

ecology↗

bioRxiv2021

Metastatic profiling of HER2-positive breast cancer cell lines in xenograft models

Most studies on breast cancer metastasis have been performed using triple-negative breast cancer (TNBC) cells; thus, subtype-dependent metastatic ability of breast cancer is poorly understood. In this research, we performed intravenous injection (IVI) and intra-caudal arterial injections (CAI) using nine human epidermal growth factor receptor-2 (HER2)-positive breast cancer cell lines for evaluating their metastatic abilities. Our results showed that MDA-MB-453, UACC-893, and HCC-202 had strong bone metastatic abilities, whereas HCC-2218 and HCC-1419 did not show bone metastasis. HER2-positive cell lines could hardly metastasize to the lung through IVI. From the genomic analysis, gene signatures were extracted according to the breast cancer subtypes and their metastatic preferences. The UACC-893 cell line was identified as a useful model for the metastasis study of HER2-positive breast cancer. Combined with our previous result on brain proliferation ability, we provide a characteristic metastasis profile of HER2-positive breast cancer cell lines in this study. Statements and DeclarationsO_ST_ABSFundingC_ST_ABSThis study was supported by JSPS KAKENHI (grant no. 18K16269: Grant-in-Aid for Early-Career Scientist to J.N.; grant no. 20J01794, Grant-in-Aid for JSPS fellows to J.N.; grant no. 20J23297, Grant-in-Aid for JSPS fellows to Y.H.) and partially supported by the grants for translational research programs from Fukushima Prefecture (S.W. and K.S.). AuthorshipYH and KA performed the in vivo experiments and bioinformatical analyses. SW, and KS interpreted the data. YH, KA, and JN wrote the manuscript. JN conceived and designed the study. All the authors reviewed and edited the manuscript. Competing InterestsThe authors declare that they have no competing interests. Ethical approvalThe animal experiments were conducted under the approval of the ethics committee of Waseda University (2020-A067, 2021-A074).

cancer biology↗

bioRxiv2021

Remarkable Adsorption Performance of Rutile TiO2 (110) Nanosheet for DNA Nucleobases: A First-Principles Study

The remarkable biocompatibility and supreme physical properties of nanostructured TiO2 have promised itself a strong future for biomedical applications. The present study reported a theoretical study on the adsorption of rutile TiO2 (110) nanosheet for DNA nucleobases using first-principles calculations. The calculations of the binding energy and work function demonstrate that the TiO2 nanosheet has remarkable adsorption strength to the DNA nucleobases, being more than 20 times larger than that of graphene and its derivatives. Further electronic band structure and density of state calculations elucidate the interaction mechanisms, which originate from dramatically reduced energy levels and strong hybridization of the 2p orbital of C, N and/or O with 3d orbital of Ti atoms near the Fermi level. The study directs a promising material at applications in DNA sensors and sequencers.

bioengineering↗

bioRxiv2021

SARS-CoV-2 variants exhibit increased kinetic stability of open spike conformations as an evolutionary strategy

SARS-CoV-2 variants of concern harbor mutations in the Spike (S) glycoprotein that confer more efficient transmission and dampen the efficacy of COVID-19 vaccines and antibody therapies. S mediates virus entry and is the primary target for antibody responses. Structural studies of soluble S variants have revealed an increased propensity towards conformations accessible to receptor human Angiotensin-Converting Enzyme 2 (hACE2). However, real-time observations of conformational dynamics that govern the structural equilibriums of the S variants have been lacking. Here, we report single-molecule Forster Resonance Energy Transfer (smFRET) studies of S variants containing critical mutations, including D614G and E484K, in the context of virus particles. Investigated variants predominantly occupied more open hACE2-accessible conformations, agreeing with previous structures of soluble trimers. Additionally, these S variants exhibited decelerated transitions in hACE2-accessible/bound states. Our finding of increased S kinetic stability in the open conformation provides a new perspective on SARS-CoV-2 adaptation to the human population.

microbiology↗

bioRxiv2021

Effects of chronic dietary hexavalent chromium on bioaccumulation and immune responses in the sea cucumber Apostichopus japonicus

Sea cucumbers Apostichopus japonicus (3.54 {+/-} 0.01 g of wet weight) were exposed to five concentrations of dietary hexavalent chromium [0 (control), 100, 200, 400, and 800 mg Cr6+/kg dry weight] amended with K2Cr2O7 for 30 days. The bioaccumulation and immune responses [antioxidant enzymes: superoxide dismutase (SOD) and catalase (CAT); hydrolytic enzymes: acid phosphatase (ACP) and alkaline phosphatase (AKP)] of sea cucumbers were subsequently evaluated. This study found that the order of Cr accumulation in the experimental tissues was respiratory tree > intestine > body wall. Significantly lower SOD activities occurred in the 400 mg/kg group compared to that in the control group. Higher dietary Cr6+ exposure (400 and 800 mg Cr6+ /kg dry weight) did not negatively alter the CAT activities, but significantly inhibited CAT activities in 100 mg/kg group, compared to control group. ACP activities in groups 200, 400 and 800 mg/kg were significantly lower than those in control group, while no significant differences occurred in AKP activities among groups. The present study provides important information into the bioaccumulation and immune responses of the sea cucumber A. japonicus in response to chronic dietary Cr6+ exposure.

pharmacology and toxicology↗

bioRxiv2021

Rod-genesis driven by mafba in an nrl knockout zebrafish model with altered photoreceptor compositions and progressive retinal degeneration

The neural retina leucine zipper (NRL) is an essential gene for the fate determination and differentiation of rod photoreceptors in mammals. Mutations in NRL have been associated with autosomal recessive enhanced S-cone syndrome and autosomal dominant retinitis pigmentosa. However, the exact role of Nrl in regulating the development and maintenance of photoreceptors in zebrafish, a popular animal model used for retinal degeneration and regeneration studies, has not been fully determined. In this study, we generated an nrl knockout zebrafish model by CRISPR-Cas9 technology and observed a surprising phenotype characterized by the reduction but not total elimination of rods and the over-grown of green-cones. By tracing the developmental process of rods, we discovered two waves of rod genesis in zebrafish, emerging at the embryonic stage with an nrl-dependent pattern and the post-embryonic stage with an nrl-independent pattern, respectively. Through bulk and single-cell RNA sequencing, we constructed the gene expression profiles for the whole retinal tissues and each of the retinal cell types in WT and nrl knockout zebrafish. We detected the rod/green-cone intermediate photoreceptors in nrl knockout zebrafish, suggesting that there may be a kind of rod/green-cone bipotent precursors and its fate choice between rod and green-cone is controlled by nrl. Besides, we identified the mafba gene as a novel regulator for nrl-independent rods, based on the cell-type-specific expression pattern and the retinal phenotype of nrl/mafba double knockout zebrafish. Furthermore, the altered photoreceptor compositions and abnormal gene expression caused progressive retinal degeneration and subsequent regeneration in nrl knockout zebrafish. Our work revealed a novel function of mafba gene in rod development and established a more suitable model for the developmental processes and regulatory mechanisms of rod and green-cone photoreceptors in zebrafish. Author SummaryVision is mediated by two types of light-sensing cells named rod and cone photoreceptors in animal eyes. Abnormal generation, dysfunction or death of photoreceptor cells can all cause irreversible vision problems. NRL is the most important gene for the occurrence and function of rod cells in mice and humans. Surprisingly, we found that in zebrafish, a popular animal model used for mimicking human diseases and testing treatments, there are two types of rod cells and breaking the function of nrl gene only affects the generation of rod cells at the embryonic stage but not the juvenile and adult stages. The rod cells produced later are proved to be driven by the mafba gene, which has not been reported to play a role in rod cells. In addition to the reduction of rod cells, deletion of nrl also results in the occurrence of rod/green-cone hybrid cells and the increasing number of green-cones. The combination of changes at cellular and molecular levels finally lead to a disease condition named retinal degeneration. These findings add new knowledge to the research field and highlight the conserved and species-specific regulatory mechanisms of photoreceptor development and maintenance.

genetics↗

bioRxiv2021

Isolation, identification and molecular characterization of Aeromonas spp. from farmed loach (Misgurnus anguillicaudatus)

Gram-negative Aeromonas bacteria is known to contaminate aquaculture products and retains the ability to infect wide range of host including fishes, shrimps and humans. This study is designed to evaluate the presence of Aeromonas in healthy loaches (Misgurnus anguillicaudatus) collected from the markets in Hainan and Guangdong provinces of China. Based on the molecular sequencing and phylogenetic analysis with single 16S rRNA and concatenated genes (gyrA and ropD), 104 isolates were identified as Aeromonas species followed by further classification to A. veronii (83.65%), A. jandaei (9.62%), A. hydrophila (3.85%) and A. allosaccharophila (2.88%). More than half of the isolates displayed hemolytic activity of 87.5% and were able to form moderate biofilm (78.26%). Fourteen antibiotics from ten representative classes were screened that demonstrated complete resistance to ampicillin, 89.4% and 68.3% to lincomycin and nalidixic acid. Moreover, a notable detection and prevalence was found in screening of ten virulence-related and nine resistance genes. To our knowledge, it is the first report of its kind demonstrating potential threat of the commercial loaches carrying Aeromonas to human health. These findings will assist professionals working in clinical settings to optimize their prescription accordingly and researchers to access the impacts of Aeromonas resistance on human health. ImportanceThis study demonstrates high infection rate of loaches by Aeromonas spp. in Hainan and Guangdong provinces of China. The most prevalent species was Aeromonas veronii. Most of the isolates displayed hemolytic activity and formed moderate biofilm. Multiple virulence genes, resistance genes and multi-antibiotic resistance were detected. Aeromonads risks should be considered in loach industry.

microbiology↗

bioRxiv2021

A terrain treadmill to study small animal locomotion through large obstacles

A major challenge to understanding locomotion in complex 3-D terrain with large obstacles is to create tools for controlled, systematic lab experiments. Existing terrain arenas only allow observations at small spatiotemporal scales ([~]10 body length, [~]10 stride cycles). Here, we create a terrain treadmill to enable high-resolution observations of animal locomotion through large obstacles over large spatiotemporal scales. An animal moves through modular obstacles on an inner sphere, while a rigidly-attached, concentric, transparent outer sphere rotated with the opposite velocity via closed-loop feedback to keep the animal on top. During sustained locomotion, a discoid cockroach moved through pillar obstacles for 25 minutes ({approx} 2500 strides) over 67 m ({approx} 1500 body lengths), and was contained within a radius of 4 cm (0.9 body length) for 83% of the duration, even at speeds of up to 10 body length/s. The treadmill enabled observation of diverse locomotor behaviors and quantification of animal-obstacle interaction. Summary StatementA device keeps a small animal on top of a sphere while it traverses obstacles, creating a "terrain treadmill" to study locomotion over a long time and distance at high-resolution.

animal behavior and cognition↗

bioRxiv2021

Clock genes Period1 and Period2 in the hippocampal CA1 mediate depression-like behaviors and rapid antidepressant response

Accumulated reports have indicated that circadian rhythm is closely related to the pathogenesis of major depressive disorder (MDD). Recently, adenosine has been identified to modulate circadian clock via adenosine A1 and A2A receptor signaling pathways. Cyclic AMP-response element binding protein (CREB) is a convergent point that plays a critical role in the pathogenesis of depression and is a downstream molecule of adenosine A1 receptor signaling pathway as an endpoint that can regulate the expression of circadian genes Period1 (Per1) and Period2 (Per2). However, whether Per mediates the development of MDD via CREB has not been elucidated. We used chronic unpredictable stress (CUS) to induce depression-like behaviors and found that it could induce decrease in p-CREB and PER1 levels in the hippocampal CA1 region in rats. Both depression-like behaviors and the decreased protein levels could be rapidly rescued by the administration of adenosine A1 receptor agonist 2-Choro-N6-cyclopentyladenosine (CCPA). Furthermore, knockdown of Per1 in hippocampal CA1 region could also induce depression-like behaviors, which could also be rescued by CCPA. Interestingly, Per2 knockdown in hippocampal CA1 region resulted in potential antidepressant-like effect. In addition, knockout of CRE sequence in the promoter regions of either Per1 or Per2 led to depression-like behaviors, which could not be rescued by CCPA. These results indicated that clock genes Per1 and Per2 play critical roles in the pathophysiology of depression and CRE sequences in the promoter regions of Per1 and Per2 may be a critical antidepressant target. HighlightsO_LICUS induces both depression-like behaviors and decreases in the expression of p-CREB and PER1 levels in the hippocampal CA1 region in rats, which can be rapidly rescued by 2-Choro-N6-cyclopentyladenosine (CCPA). C_LIO_LIKnockdown of clock gene Per1 in the hippocampal CA1 brain region leads to depression-like behaviors in rats, which can be also rescued by CCPA. C_LIO_LIKnockdown of clock gene Per2 in the hippocampal CA1 brain region may have potential antidepressant-like effect. C_LIO_LIKnockout of the CRE sequence on the promoter region of the clock genes Per1 and Per2 produces depression-like behaviors, which cannot be rescued by CCPA. C_LI

neuroscience↗

bioRxiv2021

Voltage imaging in Drosophila using a hybrid chemical-genetic rhodamine voltage reporter

We combine a chemically-synthesized, voltage-sensitive fluorophore with a genetically encoded, self-labeling enzyme to enable voltage imaging in Drosophila melanogaster. Previously, we showed that a rhodamine voltage reporter (RhoVR) combined with the HaloTag self-labeling enzyme could be used to monitor membrane potential changes from mammalian neurons in culture and brain slice. Here, we apply this hybrid RhoVR-Halo approach in vivo to achieve selective neuron labeling in intact fly brains. We generate a Drosophila UAS-HaloTag reporter line in which the HaloTag enzyme is expressed on the surface of cells. We validate the voltage sensitivity of this new construct in cell culture before driving expression of HaloTag in specific brain neurons in flies. We show that selective labeling of synapses, cells, and brain regions can be achieved with RhoVR-Halo in either larval neuromuscular junction (NMJ) or in whole adult brains. Finally, we validate the voltage sensitivity of RhoVR-Halo in fly tissue via dual-electrode/imaging at the NMJ, show the efficacy of this approach for measuring synaptic excitatory post-synaptic potentials (EPSPs) in muscle cells, and perform voltage imaging of carbachol-evoked depolarization and osmolarity-evoked hyperpolarization in projection neurons and in interoceptive subesophageal zone neurons in fly brain explants following in vivo labeling. We envision the turn-on response to depolarizations, fast response kinetics, and two-photon compatibility of chemical indicators, coupled with the cellular and synaptic specificity of genetically-encoded enzymes, will make RhoVR-Halo a powerful complement to neurobiological imaging in Drosophila. Significance StatementVoltage imaging is a powerful method for interrogating neurobiology. Chemical indicators possess fast response kinetics, turn-on responses to membrane depolarization, and can be compatible with two-photon excitation. However, selective cell labeling in intact tissues and in vivo remains a challenge for completely synthetic fluorophores. Here, we show that a chemical - genetic hybrid approach in Drosophila enables cell-specific staining in vivo and voltage imaging in whole-brain explants and at neuromuscular junction synapses.

neuroscience↗

bioRxiv2021

Non-specific adhesive forces between filaments and membraneless organelles

Membraneless organelles are liquid-like domains that form inside living cells by phase-separation. While standard physical models of their formation assume their surroundings to be a simple liquid, the cytoplasm is an active viscoelastic environment. To investigate potential coupling of phase separation with the cytoskeleton, we quantify structural correlations of stress granules and microtubules in a human-derived epithelial cell line. We find that microtubule networks are significantly perturbed in the vicinity of stress granules, and that large stress granules conform to the local pore-structure of the microtubule network. When microtubules are depolymerized by nocodazole, tubulin enrichment is localized near the surface of stress granules. We interpret these data using a thermodynamic model of partitioning of particles to the surface and bulk of droplets. This analysis shows that proteins generically have a non-specific affinity for droplet interfaces, which becomes most apparent when they weakly partition to the bulk of droplets and have a large molecular weight. In this framework, our data is consistent with a weak ([lsim] kbT) affinity of tubulin sub-units for stress granule interfaces. As microtubules polymerize their affinity for interfaces increases, providing sufficient adhesion to deform droplets and/or the network. We validate this basic physical phenomena in vitro through the interaction of a simple protein-RNA condensate with tubulin and microtubules.

biophysics↗

bioRxiv2021

Sex differences in tissue gene regulation -- contributions of three classes of sex-biasing factors

Sex differences in physiology and disease in mammals result from the effects of three classes of factors that are inherently unequal in males and females: reversible (activational) effects of gonadal hormones, permanent (organizational) effects of gonadal hormones, and cell-autonomous effects of sex chromosomes, as well as genes driven by these classes of factors. Often, these factors act together to cause sex differences in specific phenotypes, but the relative contribution of each and the interactions among them remain unclear. Here, we used the Four Core Genotypes (FCG) mouse model with or without hormone replacement to distinguish the effects of each class of sex-biasing factors on transcriptome regulation in liver and adipose tissues. We found that the activational hormone levels have the strongest influence on gene expression, followed by the organizational gonadal sex effect and, lastly, sex chromosomal effect, along with interactions among the three factors. Tissue specificity was prominent, with a major impact of estradiol on adipose tissue gene regulation, and of testosterone on the liver transcriptome. The networks affected by the three sex-biasing factors include development, immunity and metabolism, and tissue-specific regulators were identified for these networks. Furthermore, the genes affected by individual sex-biasing factors and interactions among factors are associated with human disease traits such as coronary artery disease, diabetes, and inflammatory bowel disease. Our study offers a tissue-specific account of the individual and interactive contributions of major sex-biasing factors to gene regulation that have broad impact on systemic metabolic, endocrine, and immune functions.

systems biology↗

bioRxiv2021

ECM dimensionality tunes actin tension to modulate the endoplasmic reticulum and spheroid phenotype

Primary tissue organoids and cell spheroids recapitulate tissue physiology with remarkable fidelity. We investigated how engagement with a three dimensional laminin-rich extracellular matrix supports the polarized, stress resilient spheroid phenotype of mammary epithelial cells. Cells within a three dimensional laminin-rich extracellular matrix decreased and redistributed the actin crosslinker filamin to reduce their cortical actin tension. Cells with low cortical actin tension had increased plasma membrane protrusions that promoted negative plasma membrane curvature and fostered protein associations with the plasma membrane, consistent with efficient protein secretion. By contrast, cells engaging a laminin-rich extracellular matrix in two dimensions had high filamin-dependent cortical actin tension, exhibited compromised endoplasmic reticulum function including increased expression of PKR-like Endoplasmic Reticulum Kinase signaling effectors, and had compromised protein secretion. Cells with low filamin-mediated cortical actin tension and reduced endoplasmic reticulum stress response signaling secreted, and assembled, a polarized endogenous basement membrane and survived better, and their spheroids were more resistant to exogenous stress. The findings implicate filamin-dependent cortical actin tension in endoplasmic reticulum function and highlight a role for mechanics in organoid homeostasis.

cell biology↗

bioRxiv2021

Fully resolved assembly of Cryptosporidium parvum

BackgroundCryptosporidium parvum is an apicomplexan parasite commonly found across many host species with a global infection prevalence in human populations of 7.6%. As such, it is important to understand the diversity and genomic makeup of this prevalent parasite to fight established infections and prohibit further transmission. The basis of every genomic study is a high quality reference genome that has continuity and completeness, thus enabling comprehensive comparative studies. FindingsHere, we provide a highly accurate and complete reference genome of Cryptosporidium parvum. The assembly is based on Oxford Nanopore reads and was improved using Illumina reads for error correction. We also outline how to evaluate and choose from different assembly methods based on two main approaches that can be applied to other Cryptosporidium species. The assembly encompasses 8 chromosomes and includes 13 telomeres that were resolved. Overall, the assembly shows a high completion rate with 98.4% single copy BUSCO genes. ConclusionsThis high quality reference genome of a zoonotic IIaA17G2R1 C. parvum subtype isolate provides the basis for subsequent comparative genomic studies across the Cryptosporidium clade. This will enable improved understanding of diversity, functional and association studies.

genomics↗

bioRxiv2021

Construction of a new chromosome-scale, long-read reference genome assembly of the Syrian hamster, Mesocricetus auratus

BackgroundThe Syrian hamster (Mesocricetus auratus) has been suggested as a useful mammalian model for a variety of diseases and infections, including infection with respiratory viruses such as SARS-CoV-2. The MesAur1.0 genome assembly was generated in 2013 using whole-genome shotgun sequencing with short-read sequence data. Current more advanced sequencing technologies and assembly methods now permit the generation of near-complete genome assemblies with higher quality and greater continuity. FindingsHere, we report an improved assembly of the M. auratus genome (BCM_Maur_2.0) using Oxford Nanopore Technologies long-read sequencing to produce a chromosome-scale assembly. The total length of the new assembly is 2.46 Gbp, similar to the 2.50 Gbp length of a previous assembly of this genome, MesAur1.0. BCM_Maur_2.0 exhibits significantly improved continuity with a scaffold N50 that is 6.7 times greater than MesAur1.0. Furthermore, 21,616 protein coding genes and 10,459 noncoding genes are annotated in BCM_Maur_2.0 compared to 20,495 protein coding genes and 4,168 noncoding genes in MesAur1.0. This new assembly also improves the unresolved regions as measured by nucleotide ambiguities, where approximately 17.11% of bases in MesAur1.0 were unresolved compared to BCM_Maur_2.0 in which the number of unresolved bases is reduced to 3.00%. ConclusionsAccess to a more complete reference genome with improved accuracy and continuity will facilitate more detailed, comprehensive, and meaningful research results for a wide variety of future studies using Syrian hamsters as models.

genomics↗

bioRxiv2021

Essential role for Ggct in erythrocyte antioxidant defense

GGCT encodes {gamma}-glutamyl cyclotransferase enzyme activity, and its expression is up-regulated in various human cancers. {gamma}-glutamyl cyclotransferase enzyme activity was originally purified from human red blood cells (RBCs), however physiological function of GGCT in RBCs is still not clear. Here we reported that Ggct deletion in mouse leads to splenomegaly and progressive anemia phenotypes, due to elevated oxidative damage and shortened life span of Ggct-/- RBCs. Ggct-/- RBCs have increased reactive oxygen species (ROS), and are more sensitive to H2O2 induced damage compared to control RBCs. Glutathione (GSH) and GSH synthesis precursor L-cysteine are decreased in Ggct-/- RBCs. Our study suggests a critical function of Ggct in RBC redox balance and life span maintenance through regulating GSH metabolism.

genetics↗

bioRxiv2021

Transcriptome features of striated muscle aging and predictability of protein level changes

RNA and protein levels correlate only partially and some transcripts are better correlated with their protein counterparts than others. This suggests that in aging and disease studies, some transcriptomics markers may carry more information in predicting protein-level changes. Here we applied a computational data analysis workflow to predict which transcriptomic changes are more likely relevant to protein-level regulation in striated muscle aging. The protein predictability of each transcript is estimated from existing large proteogenomics data sets, then transferred to new total RNA sequencing data comparing skeletal muscle and cardiac muscle in young adult (~4 months) mice vs. early aging (~20 months) mice. Aging cardiac and skeletal muscles both invoke transcriptomic changes in innate immune system and mitochondria pathways but diverge in extracellular matrix processes. On an individual gene level, we identified 611 age-associated signatures in skeletal and cardiac muscles at 10% FDR, including a number of myokine and cardiokine encoding genes. We estimate that about 48% of the aging-associated transcripts may predict protein levels well (r [≥] 0.5). In parallel, a comparison of the identified aging-regulated genes with public human transcriptomics data showed that only 35-45% of the identified genes show an age-dependent expression in corresponding human tissues. Finally, integrating both RNA-protein correlation and human conservation across data sources, we nominate 134 prioritized aging striated muscle signature genes that are predicted to correlate strongly with protein levels and that show age-dependent expression in humans. These prioritized signatures may hold promise to understanding heart and skeletal muscle physiology in human and mouse aging.

physiology↗

bioRxiv2021

TMEM120 is a coenzyme A-binding membrane protein with structural similarities to ELOVL fatty acid elongase

TMEM120A, also named as TACAN, is a novel membrane protein highly conserved in vertebrates and was recently proposed to be a mechanosensitive channel involved in sensing mechanical pain. Here we present the single particle cryo-EM structure of human TMEM120A which forms a tightly packed dimer with extensive interactions mediate by the N-terminal coiled coil domain (CCD), the C-terminal transmembrane domain (TMD), and the re-entrant loop between the two domains. The TMD of each TMEM120A subunit contains six transmembrane helices (TMs) and has no clear structural feature of a channel protein. Instead, the six TMs form an -barrel with a deep pocket where a coenzyme A (CoA) molecule is bound. Intriguingly, some structural features of TMEM120A resemble those of elongase for very long-chain fatty acid (ELOVL) despite low sequence homology between them, pointing to the possibility that TEME120A may function as an enzyme for fatty acid metabolism, rather than a mechanosensitive channel.

biophysics↗