Biology subjects

Zhao, C.

Publications and source records attributed to Zhao, C..

At least 235 records · Page 13Linked to original sources

bioRxiv2022

Study on gene knockout mice and human mutant individual reveals absence of CEP78 causes photoreceptor and sperm flagella impairments

BackgroundCone-rod dystrophy (CRD) is a genetically inherited retinal disease characterized by photoreceptor degeneration. In some rare cases, CRD and hearing loss can be associated with male fertility, while the underlying mechanism is not well known. MethodsUsing CRISPR/Cas9 system, we generated Cep78-/- mice. And electroretinogram (ERG), immunofluorescence staining and transmission electron microscopy (TEM) were used to analyze visual function and photoreceptor ciliary structure changes in Cep78-/- mouse. HE/PAS staining, scanning-electron microscopy (SEM) were conducted to Cep78-/- mice and human CRD patient with CEP78 protein loss to illustrate male infertility and multiple morphological abnormalities of the sperm flagella (MMAF) caused by CEP78 deficiency. TEM and immunofluorescence staining were performed to characterize morphological and molecular changes of sperm flagella microtubule arrangement, centriole development and spermatid head shaping in Cep78-/- mice. Mass-spectrometry analyses were conducted to identify protein abnormalities after Cep78 deletion and Cep78 interacting proteins in spermiogenesis. Co-immunoprecipitation was used to show the Cep78-Ift20-Ttc21a trimer. The role of Cep78-Ift20-Ttc21a trimer in cilliogenesis and centriole elongation was assessed by cilia induction assay. ResultsCep78 knockout mice exhibited impaired function and morphology of photoreceptors, typified by reduced electroretinogram amplitudes, disrupted translocation of cone arrestin, attenuated and disorganized photoreceptor outer segments (OS) disks and widen OS bases, as well as interrupted cilia elongations and structures. Cep78 deletion also caused male infertility and MMAF, with disordered "9 + 2" structure and triplet microtubules in sperm flagella. CEP78 forms a trimer with intraflagellar transport (IFT) proteins IFT20 and TTC21A essential for sperm flagella formation, is essential for their interaction and stability, and recruits IFT20 to centrosome. Insufficiency of any component in the trimer causes centriole elongation and cilia shortening. Additionally, absence of CEP78 protein in human leaded to similar phenotypes in vision and MMAF as Cep78-/- mice. ConclusionsWe found CEP78 as the causative gene of CRD with MMAF in human and mouse. Cep78 forms a trimer with Ift20 and Ttc21a, and regulate the interaction, stability and localization of the trimer proteins, which regulate cilliogenesis, centriole length, and sperm flagella formation. FundingThis work was supported by the National Key R&D Program (2021YFC2700200 to X.G); National Natural Science Foundation of China (82020108006, 81730025 to C.Z, 81971439, 81771641 to X.G, 82070974 to X.C, 82060183 to X.S); Shanghai Outstanding Academic Leaders (2017BR013 to C.Z); and Six Talent Peaks Project in Jiangsu Province (YY-019 to X.G). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

developmental biology↗

bioRxiv2022

Close relatives of MERS-CoV in bats use ACE2 as their functional receptors

Middle East Respiratory Syndrome coronavirus (MERS-CoV) and several bat coronaviruses employ Dipeptidyl peptidase-4 (DPP4) as their functional receptors1-4. However, the receptor for NeoCoV, the closest MERS-CoV relative yet discovered in bats, remains enigmatic5. In this study, we unexpectedly found that NeoCoV and its close relative, PDF-2180-CoV, can efficiently use some types of bat Angiotensin-converting enzyme 2 (ACE2) and, less favorably, human ACE2 for entry. The two viruses use their spikes S1 subunit carboxyl-terminal domains (S1-CTD) for high-affinity and species-specific ACE2 binding. Cryo-electron microscopy analysis revealed a novel coronavirus-ACE2 binding interface and a protein-glycan interaction, distinct from other known ACE2-using viruses. We identified a molecular determinant close to the viral binding interface that restricts human ACE2 from supporting NeoCoV infection, especially around residue Asp338. Conversely, NeoCoV efficiently infects human ACE2 expressing cells after a T510F mutation on the receptor-binding motif (RBM). Notably, the infection could not be cross-neutralized by antibodies targeting SARS-CoV-2 or MERS-CoV. Our study demonstrates the first case of ACE2 usage in MERS-related viruses, shedding light on a potential bio-safety threat of the human emergence of an ACE2 using "MERS-CoV-2" with both high fatality and transmission rate.

microbiology↗

bioRxiv2022

A retroviral origin of vertebrate myelin

Myelin, the insulating sheath that surrounds neuronal axons, is produced by oligodendrocytes in the central nervous system (CNS). This evolutionary innovation, which first appears in jawed vertebrates, enabled rapid transmission of nerve impulses, more complex brains and greater morphological diversity. Here we report that RNA level expression of RNLTR12-int, a retrotransposon of retroviral origin, is essential for myelination. We show RNLTR12-int-encoded non-coding RNA binds to the transcription factor SOX10 to regulate transcription of myelin basic protein (Mbp, the major constituent of myelin) in rodents. RNLTR12-int like sequences (which we name RetroMyelin) are found in all jawed-vertebrates and we further demonstrate their function in regulating myelination in two different vertebrate phyla (zebrafish and frogs). Our study therefore suggests that retroviral endogenization was a key step in the emergence of vertebrate myelin.

neuroscience↗

bioRxiv2022

A GSVA based gene set synergizing with CD4+T cell bearing harmful factors yield risk signals in HBV related diseases via amalgamation of artificial intelligence

Genes encoding chemokines and extracellular matrix (ECM) play pivotal roles in chronic HBV infection (CHB), HBV related fibrosis (HBV-LF) and hepatocellular carcinoma (HBV-HCC). The landscape and potential of these genes in prognosis across diseases stages have not been fully and systemically understood. In this study, we defined an HBV-LF associated gene set comprised of chemokines and ECM related genes directly induced by initial HBV infection through GSVA algorithm that named as CLST (C stands for CXCL9, CXCL10, CCL19 and CCL20; L for LUM; S for SOX9 and SPP1; T for THBS1, THBS2) and evaluated its biomarker values in CHB and HBV-LF. Enrichment scores (ES) of CLST was subsequently observed synergized with activated CD4+T cells (aCD4) highly related to T helper cell 17 (TH17) associated genes and immune checkpoints and addressed as risk signals due to bearing harmful prognosis factors in tumor tissues of patients with HBV-HCC. Dual higher enrichment score (ES) of CLST and aCD4 in HBV-HCC patients exhibited worse overall survival (OS). Feature genes specific to these two gene sets showed promising clinical relevance in early-stage of HBV-HCC definition and OS prediction incorporating laboratory parameters via artificial intelligence (AI) systems. Finally, a novel mechanistic insight into the issue was proposed that PEG IFN- as an immunotherapy through modulating CLST signal in treatment responders and these immune signals down-regulation could be beneficial for HBV related diseases control and prevention. Together, our study provides GSVA and AI derived immunogenomic prognosis signatures and clinical utility of these signals will be benefit for HBV related diseases cure.

immunology↗

bioRxiv2022

Liver-derived cell lines from cavefish Astyanax mexicanus as an in vitro model for studying metabolic adaptation

Cell lines have become an integral resource and tool for conducting biological experiments ever since the Hela cell line was first developed (1). They not only allow detailed investigation of molecular pathways but are faster and more cost-effective than most in vivo approaches. The last decade saw many emerging model systems strengthening basic science research. However, lack of genetic and molecular tools in these newer systems pose many obstacles. Astyanax mexicanus is proving to be an interesting new model system for understanding metabolic adaptation. To further enhance the utility of this system, we developed liver-derived cell lines from both surface-dwelling and cave-dwelling morphotypes. In this study, we provide detailed methodology of the derivation process along with a comprehensive biochemical and molecular characterization of the cell lines, which reflects key metabolic traits of cavefish adaptation. We anticipate these cell lines to become a useful resource for the Astyanax community as well as researchers investigating fish biology, comparative physiology, and metabolism.

evolutionary biology↗

bioRxiv2022

Encoding of speech in convolutional layers and the brain stem based on language experience

Comparing artificial neural networks with outputs of neuroimaging techniques has recently seen substantial advances in (computer) vision and text-based language models. Here, we propose a framework to compare biological and artificial neural computations of spoken language representations and propose several new challenges to this paradigm. The proposed technique is based on a similar principle that underlies electroencephalography (EEG): averaging of neural (artificial or biological) activity across neurons in the time domain, and allows to compare encoding of any acoustic property in the brain and in intermediate convolutional layers of an artificial neural network. Our approach allows a direct comparison of responses to a phonetic property in the brain and in deep neural networks that requires no linear transformations between the signals. We argue that the brain stem response (cABR) and the response in intermediate convolutional layers to the exact same stimulus are highly similar and quantify this observation. The proposed technique not only reveals similarties, but also allows for analysis of the encoding of actual acoustic properties in the two signals: we compare peak latency (i) in cABR relative to the stimulus in the brain stem and in (ii) intermediate convolutional layers relative to the input/output in deep convolutional networks. We also examine and compare the effect of prior language exposure on the peak latency in cABR and in intermediate convolutional layers. Substantial similarities in peak latency encoding between the human brain and intermediate convolutional networks emerge based on results from eight trained networks (including a replication experiment). The proposed technique can be used to compare encoding between the human brain and intermediate convolutional layers for any acoustic property and for other neuroimaging techniques.

neuroscience↗

bioRxiv2021

PCBP1 Deficient Pigs Hold the Potential to Inhibit CSFV Infection

Classical swine fever virus (CSFV), pathogen of classic swine fever, has caused severe economic losses worldwide. Poly (rC)-binding protein 1 (PCBP1), interacting with Npro of CSFV, plays a vital role in CSFV growth. Here, our research is the first report to generate PCBP1 knockout pigs via gene editing technology. The PCBP1 knockout pigs exhibited normal birth weight, reproductive-performance traits, and developed normally. Viral challenge results indicated that primary cells isolated from F0 and F1 generation pigs could significantly reduce CSFV infection. Additional mechanism exploration further confirmed that PCBP1 KO mediated antiviral effect is related with the activation of type I interferon. Beyond showing that gene editing strategy can be used to generate PCBP1 KO pigs, our study introduces a valuable animal model for further investigating infection mechanisms of CSFV that help to develop better antiviral solution. ImportanceAs a negative regulator in immune modulation, the effects of PCBP1 on viral replication have been found to be valuable. Here, this study was the first report to generate PCBP1 knockout pigs with normal pregnancy rate and viability. Primary cells isolated from F0 and F1 generation PCBP1 knockout pigs could significantly reduce CSFV infection. The PCBP1 knockout pigs could be used as a natural host models for investigating the effects of PCBP1-mediating critical interactions on viral replication and helping to develop better antiviral solution.

molecular biology↗

bioRxiv2021

Interpreting ruminant specific conserved non-coding elements by developmental gene regulatory network

BackgroundBiologists long recognized that the genetic information encoded in DNA leads to trait innovation via gene regulatory network (GRN) in development. ResultsHere, we generated paired expression and chromatin accessibility data during rumen and esophagus development in sheep and revealed 1,601 active ruminant-specific conserved non-coding elements (active-RSCNEs). To interpret the function of these active-RSCNEs, we developed a Conserved Non-coding Element interpretation method by gene Regulatory network (CNEReg) to define toolkit transcription factors (TTF) and model its regulation on rumen specific gene via batteries of active-RSCNEs during development. Our developmental GRN reveals 18 TTFs and 313 active-RSCNEs regulating the functional modules of the rumen and identifies OTX1, SOX21, HOXC8, SOX2, TP63, PPARG and 16 active-RSCNEs that functionally distinguish the rumen from the esophagus. ConclusionsWe argue that CNEReg is an attractive systematic approach to integrate evo-devo concepts with omics data to understand how gene regulation evolves and shapes complex traits.

genomics↗

bioRxiv2021

Severe fever with thrombocytopenia syndrome virus and parthenogenetic Asian longhorned tick Haemaphysalis longicornis (Acari: Ixodidae)

Severe fever with thrombocytopenia syndrome virus (SFTSV) is spreading rapidly in Asia. It is transmitted by Haemaphysalis longicornis (Asian longhorned tick, ALT), which has both parthenogenetically and sexually reproducing populations. Parthenogenetic populations were found in at least 15 provinces in China and strongly correlated with the distribution of SFTS. The distribution of SFTS cases was however poorly correlated with the distribution of populations of bisexual ALTs. Phylogeographic analysis suggested that the parthenogenetic population spread much faster than bisexual population because colonization is independent of sexual reproduction. A higher proportion of parthenogenetic ALTs were collected from migratory birds captured at an SFTS endemic area, implicating the contribution to the long-range movement of ALTs in China. The SFTSV susceptibility of parthenogenetic females was like that of bisexual females under laboratory conditions. These results suggest that parthenogenetic ALT, probably transported by migratory birds, play a major role in the rapid spread of SFTSV. Article Summary LineThe parthenogenetic population of Asian longhorned tick is broadly distributed in China and plays a major role in the long-distance spread of SFTSV and perhaps future invasion of countries outside of Asia.

evolutionary biology↗

bioRxiv2021

14-3-3ζ constrains insulin secretion in pancreatic β-cells by regulating mitochondrial function

While critical for neurotransmitter synthesis in the brain, members of the 14-3-3 protein family are often assumed to have redundant, over-lapping roles due to their high sequence homology and ubiquitous expression. Despite this assumption, various mammalian 14-3-3 isoforms have now been implicated in regulating cellular and organismal metabolism; however, these functions were primarily observed in cell lines or from systemic knockout mouse models. To date, we have begun to define the contributions of 14-3-3{zeta} in adipocytes, but whether 14-3-3{zeta} has additional metabolic roles in other cell types, such as the pancreatic {beta}-cell, is unclear. We previously documented a pro-survival role of 14-3-3{zeta} in MIN6 insulinoma cells, as depletion of 14-3-3{zeta} induced cell death, but paradoxically, whole-body deletion of 14-3-3{zeta} in mice resulted in significantly enlarged {beta}-cell area with no effects on insulin secretion. To better understand the role of 14-3-3{zeta} in {beta}-cells, we generated {beta}-cell-specific 14-3-3{zeta} knockout ({beta}14-3-3{zeta}KO) mice, and while no differences in {beta}-cell mass were observed, {beta}14-3-3{zeta}KO mice displayed potentiated insulin secretion due to enhanced mitochondrial function and ATP synthesis. Deletion of 14-3-3{zeta} led to profound changes to the {beta}-cell transcriptome, where pathways associated with mitochondrial respiration and oxidative phosphorylation were upregulated. Acute treatment of mouse islets and human islets with pan-14-3-3 inhibitors recapitulated the potentiation in glucose-stimulated insulin secretion (GSIS) and mitochondrial function, suggesting that 14-3-3{zeta} is a critical isoform in {beta}-cells that regulates GSIS. In dysfunctional db/db islets and islets from type 2 diabetic donors, expression of Ywhaz/YWHAZ, the gene encoding 14-3-3{zeta}, was inversely associated with insulin secretory capacity, and pan-14-3-3 protein inhibition was capable of enhancing GSIS and mitochondrial function. Taken together, this study demonstrates important regulatory functions of 14-3-3{zeta} and its related isoforms in insulin secretion and mitochondrial function in {beta}-cells. A deeper understanding of how 14-3-3{zeta} influences {beta}-cell function will further advance our knowledge of how insulin secretion from {beta}-cells is regulated.

physiology↗

bioRxiv2021

pVHL regulates protein stability of TCF/LEF transcription factor family via ubiquitin-independent proteasomal degradation

The Wnt/{beta}-catenin signaling pathway plays key roles in development and adult tissue homeostasis by controlling cell proliferation and cell fate decisions. In this pathway, transcription factors TCF/LEFs are the key components to repress target gene expression by recruiting co-repressors or to activate target gene expression by recruiting {beta}-catenin when the Wnt signals are absent or present, respectively. While progress has been made in our understanding of Wnt signaling regulation, the underlying mechanism that regulates the protein stability of the TCF/LEF family is far less clear. Here, we show that von Hippel-Lindau protein (pVHL), which is the substrate recognition component in an E3 ubiquitin ligase complex, controls TCF/LEF protein stability. Unexpectedly, pVHL directly binds to TCF/LEFs and promotes their proteasomal degradation independent of E3 ubiquitin ligase activity. Knockout of vhl in zebrafish embryos leads to a reduction of dorsal habenular neurons and this effect is upstream of dorsal habenular neurons phenotype in tcf7l2-null mutants. Our study uncovers a previously unknown mechanism for the protein stability regulation of the TCF/LEF transcription factors and demonstrates that pVHL contains a 26S proteasome binding domain that drives ubiquitin-independent proteasomal degradation. These findings provide new insights into the ubiquitin-independent actions of pVHL and uncover novel mechanistical regulation of Wnt/{beta}-catenin signaling.

cell biology↗

bioRxiv2021

Intriguing Role of Water in Plant Hormone Perception

Plant hormones are small molecules that regulate plant growth, development, and responses to biotic and abiotic stresses. Plant hormones are specifically recognized by the binding site of their receptors. In this work, we investigated the role of water displacement and reorganization at the binding site of plant receptors on the binding of eight classes of phytohormones (auxin, jasmonate, gibberellin, strigolactone, brassinosteroid, cytokinin, salicylic acid, and abscisic acid) using extensive molecular dynamics simulations and inhomogeneous solvation theory. Our findings demonstrated that displacement of water molecules by phytohormones contributes to free energy of binding via entropy gain and is associated with free energy barriers. Also, our results have shown that displacement of unfavorable water molecules in the binding site can be exploited in rational agrochemical design. Overall, this study uncovers the role of water molecules in plant hormone perception, which creates new avenues for agrochemical design to target plant growth and development.

plant biology↗

bioRxiv2021

The role of complex IV activity in the axonal response of mitochondria to demyelination in experimental disease models of multiple sclerosis

Axon loss is a cardinal neuropathological feature of multiple sclerosis (MS). Axonal injury in MS and experimental disease models is most frequently detected in acutely demyelinating regions. Furthermore, acute axonal injury consistently correlates with the extent of inflammatory demyelination. Following lysolecithin-induced demyelination, we recently reported a compensatory response in neurons, where mitochondria move from the cell body to the acutely demyelinated axon and increase the mitochondrial content. We termed this energetics phenomenon, that is also evident in MS, the axonal response of mitochondria to demyelination (ARMD). In the present study, we assessed axonal mitochondrial content as well as axonal mitochondrial respiratory chain complex IV activity (COX) of axons and related these to axonal injury in nine different experimental disease models. We consistently found ARMD in all experimental disease models. However, the increase in mitochondrial content within demyelinated axons was not always accompanied by a proportionate increase in COX activity, particularly in experimental autoimmune encephalomyelitis (EAE). Axonal COX activity inversely correlated with the extent of axonal injury in experimental disease models. Our findings indicate that ARMD is a consistent and prominent finding and emphasises the need to preserve axonal mitochondrial COX activity in inflammatory demyelination, paving the way for the development of novel neuroprotective therapies.

neuroscience↗

bioRxiv2021

The Siberian wild apple, Malus baccata (L.) Borkh., is an additional contributor to the genomes of cultivated European and Chinese apples

It is crucial to understand domestication to unravel the evolutionary processes that shape the divergence of populations. Differences in life-history traits have probably led to marked differences in the mode and speed of evolution between trees and annuals, particularly the extent of crop-wild gene flow during domestication. Apple is an iconic tree and major fruit crop grown worldwide. The contribution of wild apple species to the genetic makeup of the cultivated apple genome remains a topic of intense investigations. We used population genomics in combination with SNPs to investigate the contributions of the two known wild apple relatives, Malus sylvestris and Malus sieversii, and a supposed contributor, Malus baccata, to European and Chinese rootstock and dessert genomes, with a focus on the extent of wild-crop gene flow during apple domestication. We showed that the European dessert and rootstock apples form a specific gene pool, whereas the Chinese dessert and rootstock apples were a mixture of three wild gene pools. Coalescent-based inferences and gene flow estimates indicated that M. baccata is an additional contributor to the genome of both European and Chinese cultivated apples through wild-to-crop introgressions. We also confirmed previous results on the contribution of M. sylvestris to the cultivated apple genome, and provided insights into the origin of the apple rootstock. This study further demonstrates the role of gene flow during apple domestication, as seen in other woody perennials, and show that domestication of the apple tree involved several wild apple species.

evolutionary biology↗

bioRxiv2021

Intronic elements associated with insomnia and restless legs syndrome exhibit cell type-specific epigenetic features contributing to MEIS1 regulation

A highly evolutionarily conserved MEIS1 intronic region is strongly associated with restless legs syndrome (RLS) and insomnia. To understand its regulatory function, we dissected the region by analyzing chromatin accessibility, enhancer-promoter contacts, DNA methylation, and eQTLs in different human neural cell types and tissues. We observed specific activity with respect to cell type and developmental maturation, indicating a prominent role for distinct highly conserved intronic elements in forebrain inhibitory neuron differentiation. Two elements were hypomethylated in neural cells with higher MEIS1 expression, suggesting a role of enhancer demethylation in gene regulation. MEIS1 eQTLs showed a striking modular chromosomal distribution, with forebrain eQTLs clustering in intron 8/9. CRISPR interference targeting of individual elements in this region attenuated MEIS1 expression, revealing a complex regulatory interplay of distinct elements. In summary, we found that MEIS1 regulation is organized in a modular pattern. Disease-associated intronic regulatory elements control MEIS1 expression with cell type and maturation stage specificity, particularly in the inhibitory neuron lineage. The precise spatiotemporal activity of these elements likely contributes to the pathogenesis of insomnia and RLS.

genetics↗

bioRxiv2021

Polycomb Repressive Complex 2 shields naïve human pluripotent cells from trophectoderm differentiation

The first lineage choice made in human embryo development separates trophectoderm from the inner cell mass, which proceeds to form the pluripotent epiblast and primitive endoderm. Trophectoderm on the other hand gives rise to the placenta. Naive pluripotent stem cells are derived from the pluripotent epiblast of the blastocyst and offer possibilities to explore how lineage integrity is maintained. Here, we discover that Polycomb repressive complex 2 (PRC2) restricts an intrinsic capacity of naive pluripotent stem cells to give rise to trophectoderm. Through quantitative epigenome profiling, we find that broad histone H3 lysine 27 trimethylation (H3K27me3) hypermethylation is a common feature of naive pluripotency across species. We define a previously unappreciated, naive-specific set of bivalent promoters, featuring PRC2-mediated H3K27me3 concomitant with H3K4me3. Naive bivalency maintains key trophectoderm transcription factors in a transcriptionally poised state that is resolved to an active state upon depletion of H3K27me3 via inhibition of the enzymatic subunits of PRC2, EZH1/2. Conversely, primed human embryonic stem cells cannot be driven towards trophectoderm development via PRC2 inhibition. While naive and primed hESCs share the majority of bivalent promoters, PRC2 contributes to the repression of largely non-overlapping subsets of these promoters in each state, hence H3K27me3-mediated repression provides a highly adaptive mechanism to restrict lineage potential during early human development.

developmental biology↗

bioRxiv2021

Transient late gestation prenatal hypoxic insult results in functional deficits but not gross neuroanatomic deficits in mice

Intrauterine hypoxia is a common cause of brain injury in children resulting in a broad spectrum of long-term neurodevelopmental sequela, including life-long disabilities that can occur even in the absence of severe neuroanatomic damage. Postnatal hypoxia-ischemia rodent models are commonly used to understand the effects of ischemia and transient hypoxia on the developing brain. Postnatal models, however, have some limitations. First, they do not test the impact of placental pathologies on outcomes from hypoxia. Second, they primarily recapitulate severe injury because they provoke substantial cell death, which is not seen in children with mild hypoxic injury. Lastly, they do not model preterm hypoxic injury. Prenatal models of hypoxia in mice may allow us to address some of these limitations to expand our understanding of developmental brain injury. The published rodent models of prenatal hypoxia employ multiple days of hypoxic exposure or complicated surgical procedures, making these models challenging to perform consistently in mice. Furthermore, large animal models suggest that transient prenatal hypoxia without ischemia is sufficient to lead to significant functional impairment to the developing brain. However, these large animal studies are resource-intensive and not readily amenable to mechanistic molecular studies. Therefore, here we characterized the effect of late gestation (embryonic day 17.5) transient prenatal hypoxia (5% inspired oxygen) on long-term anatomical and neurodevelopmental outcomes in mice. Late gestation transient prenatal hypoxia increased hypoxia-inducible factor 1 alpha protein levels (a marker of hypoxic exposure) in the fetal brain. Hypoxia exposure predisposed animals to decreased weight at postnatal day 2, which normalized by day 8. However, hypoxia did not affect gestational age at birth, litter size at birth, or pup survival. No differences in fetal brain cell death or long-term gray or white matter changes resulted from hypoxia. Animals exposed to prenatal hypoxia did have several long-term functional consequences, including sex-dichotomous changes. Hypoxia exposure was associated with a decreased seizure threshold and abnormalities in hindlimb strength and repetitive behaviors in males and females. Males exposed to hypoxia had increased anxiety-related deficits, whereas females had deficits in social interaction. Neither sex developed any motor or visual learning deficits. This study demonstrates that late gestation transient prenatal hypoxia in mice is a simple, clinically relevant paradigm for studying putative environmental and genetic modulators of the long-term effects of hypoxia on the developing brain.

animal behavior and cognition↗

bioRxiv2021

Age-related Cellular and Microstructural Changes in the Rotator Cuff Enthesis

Rotator cuff injuries increase with age. The enthesis is the most frequent site of rotator cuff injury and degeneration. Understanding age-related changes of the enthesis are essential to determine the mechanism of rotator cuff injuries, degeneration, and to guide mechanistically driven therapies. In this study, we explored age-related cellular changes of the rotator cuff enthesis in young, mature, and aged rats. Here we found that the aged enthesis is typified by an increased mineralized zone and decreased non-mineralized zone. Proliferation, migration, and colony forming potential of rotator cuff derived cells (RCECs) was attenuated with aging. The tenogenic and chondrogenic potential were significantly reduced, while the osteogenic potential increased in aged RCECs. The adipogenic potential increased in RCECs with age. This study explores the cellular differences found between young, mature, and aged rotator cuff enthesis cells and provides a basis for further delineation of mechanisms and potential therapeutics for rotator cuff injuries.

cell biology↗