Biology subjects

Hao, J.

Publications and source records attributed to Hao, J..

At least 19 recordsLinked to original sources

bioRxiv2026

Brain state locks silent memories in a trained fly connectome

Complete connectomes now exist for insect nervous systems, but whether a fixed wiring diagram can learn, and what its memories consist of, is unknown. Here, we trained a spiking model of the whole male Drosophila central nervous system, 167,106 neurons with fixed wiring, to plan moves and to remember a visual cue. Spikes write the cue into neuronal adaptation, which holds it silently until the next input reads it out. Cells that hold the trace are enriched for transcripts of a calcium-activated potassium channel in fly cell atlases. The learned readout recalls the trace only in the brain state of learning: the same trace evokes a different response at another delay, and a disease-like loss of potassium current rewrites the trace and changes how it is read. Learning in the new state is spared. Memory failure can arise from a change of state rather than a loss of storage.

neuroscience↗

bioRxiv2026

DNA-PK enforces the S/G2 checkpoint in ATM-deficient cells to limit ATR inhibitor efficacy

ATR inhibition has been proposed as a strategy for tumors under replication stress or those harboring ATM deficiency. However, anti-tumor activity is limited by DNA-PK and ATM compensation. Here, we have delineated distinct roles for DNA-PK and ATM during ATR inhibitor exposure. Both kinases are activated in a cell cycle-dependent manner at the S/G2 boundary following ATR inhibition. DNA-PK imposes the S/G2 checkpoint and promotes completion of DNA replication, whereas ATM detects persistent aberrant DNA replication structures with associated DNA damage in late S and G2/M to establish a G2/M checkpoint promoting DNA repair. In ATM-deficient cells and patient tumors, DNA-PK is activated following ATR inhibition and assumes greater versatility by not only enforcing the S/G2 checkpoint but also by detecting aberrant replication structures in S phase in place of ATM, allowing cells to tolerate ATR inhibition. Consequently, DNA-PK inhibition synergizes with ATR inhibition in ATM-deficient cells and enhances ATR inhibitor efficacy in ATM-deficient PDX models. These data support clinical evaluation of combined ATR and DNA-PK inhibition in ATM-deficient cancers.

cancer biology↗

bioRxiv2026

Engineering Upd-like to broadly restrict arbovirus infection and vector competence in mosquitoes

The global expansion of mosquito-borne viruses poses a growing threat to public health, yet the endogenous signals that activate antiviral immunity in mosquito vectors remain incompletely understood. Here, we identify Aedes aegypti Upd as an activator of JAK/STAT signaling that restricts arbovirus infection. Loss of Upd increased infection and dissemination of the flaviviruses ZIKV and DENV, as well as the alphavirus SINV, whereas blood meal inducible midgut overexpression reduced ZIKV and SINV infection. Mechanistically, Upd associated with the extracellular region of the Domeless (Dome) receptor, and Upd deficiency markedly reduced STAT phosphorylation and nuclear accumulation in the midgut. Upd expression was transiently induced in the midgut by an uninfected blood meal but remained elevated following ZIKV challenge, linking physiological responses to blood feeding with antiviral defense. In mammal mosquito transmission models, Upd overexpression reduced viral acquisition from infected hosts, whereas Upd deficiency enhanced viral dissemination and increased transmission following systemic infection. Together, these findings identify Upd as an endogenous regulator of mosquito JAK/STAT signaling and provide proof of principle that temporally targeted Upd expression can reduce arbovirus susceptibility and vector competence.

microbiology↗

bioRxiv2026

A Distributed Architectural Code Governs DNA Repair

Repair of DNA double-strand breaks (DSBs) depends on large-scale changes in nuclear shape and genome organization. How damage signaling coordinates such remodeling remains unclear. We find that the human DNA damage response (DDR) couples interdependent, temporally ordered tubulin modifications to nuclear membrane and lipid regulation, driving nuclear reshaping (nucleomorphosis) through DSB-capturing nuclear envelope tubules (dsbNETs). Tubulin detyrosination by vasohibins 1/2 (VASH1/2) and acetylation by -tubulin acetyltransferase 1 (ATAT1) promote dsbNET formation and support both homologous recombination and non-homologous end joining. Microtubule-dependent processes also promote the phosphorylation-dependent inactivation of the membrane stress-sensing lipid regulator CTP cytidylyltransferase- (CCT), which typically restrains baseline nuclear lipid droplets (nLDs) and dsbNETs while supporting ATR signaling. Damage-induced nLD formation requires diacylglycerol acyltransferases 1/2 (DGAT1/2) and supports dsbNETs. Our findings reveal a distributed architectural code spanning interconnected cytoskeletal, membrane, and lipid regulators. This code governs nucleomorphosis and its role in DNA repair and genome stability.

molecular biology↗

bioRxiv2026

Keratinocyte FABP5 mediates saturated fat-induced MAPK/CCL20 signaling in psoriatic inflammation

Saturated fats in high-fat diets (HFDs) have been associated with increased risk and severity of psoriasis. However, the underlying cellular and molecular mechanisms remain to be further defined. Here, using a unique mouse strain with keratinocyte-specific deletion of fatty acid-binding protein 5 (FABP5) (Fabp5f/fKrt6a-Cre), we reported that keratinocyte FABP5 deletion significantly attenuated saturated HFD-exacerbated psoriatic symptoms. Immunological analyses demonstrated that FABP5 specific deletion in keratinocytes selectively reduced skin TCR {gamma} {delta} dim cell accumulation and IL-17A production. Further skin bulk-RNA and single-cell RNA sequence analyses showed a strong association of keratinocyte FABP5 with increased activation of mitogen-activated protein kinase (MAPK) pathways under saturated HFD-induced obesity. Mechanistically, saturated fatty-acids (SFAs) induce FABP5-dependent MAPK activation and CCL20 production in keratinocytes, promoting the recruitment and activation of IL-17-producing {gamma}{delta} T cells in the skin. Together, these findings suggest a previously undefined FABP5/MAPK/CCL20 signaling axis that links saturated fats to exacerbated psoriatic inflammation.

immunology↗

bioRxiv2026

Metabolic signatures of cone-dominant and cone-degenerating retinas

Cone photoreceptors are essential for daylight vision, and their degeneration has more profound visual consequences than rod loss in retinal degenerative diseases. Metabolic dysfunction is closely associated with cone degeneration, however the relatively small population of cones in mice and humans have limited our understanding of cone-specific metabolism. Here, we leveraged cone-dominant and cone-degeneration mouse models including Nrl-/-, Cnga3-/-, and high-dose Triiodothyronine (T3) treatment to investigate cone-specific metabolism and their metabolic impacts on the retinal pigment epithelium (RPE). Across models, cone-dominant retinas consistently showed lower pyruvate abundance alongside increases in glutathione, purines, pentose phosphate pathway intermediates, and one-carbon metabolites. Increases in several key amino acids were also associated with higher cone abundance, such as proline, arginine, alanine, valine, leucine, and hypotaurine. Strikingly, aminoadipate, an intermediate in lysine catabolism, was the most robustly changed metabolite in the retina, showing highly consistent increases across models. Relative cone increases were also associated with metabolic changes in the RPE/choroid. Like the retina, RPE/choroids showed consistent increases in aminoadipate, proline, and hypotaurine, as well as xanthosine and betaine, alongside decreases in uracil. Moreover, proteomic analysis of Nrl-/- mice showed decreases in many key metabolite transporters in the RPE/choroid, including carriers for glucose, lactate, aspartate, glutamate, serine, lysine, taurine, and proline. Collectively, these findings further our understanding of cone-specific metabolism and highlight potential cone-specific metabolic vulnerabilities in retinal degeneration.

biochemistry↗

bioRxiv2026

Assessing Microcirculation Impairment in Ischemic Stroke Mice Using Arteriovenous Co-fluctuation Analysis

Accurate assessment of cerebral hemodynamics impairment traditionally relies on arterial metrics, yet often overlooks venous drainage and arteriovenous dynamics, thereby limiting the evaluation of ischemia-induced microvascular dysfunction. To address this limitation, we implemented a signal-averaging framework, combined with co-fluctuation analysis, to extract predominantly arterial and venous hemodynamic signals and construct a dynamic arteriovenous co-fluctuation index that quantifies frame-by-frame coordination between arterial inflow and venous outflow activity. This time-resolved index enables spatial characterization of large-scale cortical arteriovenous coordination beyond conventional static correlation-based analyses. Comparative analyses between healthy controls and acute ischemic stroke mice demonstrated that the arteriovenous co-fluctuation index sensitively detects disruption of vascular coordination, revealing a slower state transition that occurs alongside distinct temporal abnormalities and regional heterogeneity between ischemic core and penumbral regions. These findings underscore the utility of arteriovenous coordination as a sensitive indicator of microcirculatory dysfunction, offering a practical analytical tool for assessing stroke-induced microvascular impairment.

neuroscience↗

bioRxiv2026

Radioligand therapy in combination with CAR T cells overcomes the heterogeneous immunosuppressive prostate tumor microenvironment

177Lu-PSMA-617 (PluvictoTM, Lu-177 RLT) is an FDA-approved targeted radioligand therapy (RLT) for metastatic castration-resistant prostate cancer (mCRPC), but its durability of response to this singular approach poses a challenge to the field. Chimeric antigen receptor (CAR) T cell therapy has revolutionized clinical practice for hematological malignancies, but its clinical development for solid tumors, including mCRPC, has been encumbered by antigen heterogeneity and the immunosuppressive tumor microenvironment (TME). Here, we evaluate the therapeutic combination of Lu-177 RLT and PSCA-CAR T cells to overcome these barriers. In human xenograft and mouse syngeneic prostate cancer models with homogeneous or heterogeneous antigen expression, the sequential administration of Lu-177 RLT, cyclophosphamide (Cy), and PSCA-CAR T cells improves tumor control and prolongs survival compared to monotherapies. Mechanistically, Lu-177 RLT alone or with Cy remodels the TME by promoting pro-inflammatory myeloid responses and activating endogenous T cells, while enhancing CAR T cell activation and effector function. We additionally evaluated 225Ac-PSMA-617 RLT as an emerging approach in combination with CAR T cells and observed anti-tumor responses, supporting its potential as an alternative RLT partner. These findings support RLT as an immune priming strategy to enhance CAR T cell therapy and provide a rationale for clinical translation of this combination in mCRPC. One Sentence SummaryCombining 177Lu-PSMA-617 radioligand therapy with PSCA-CAR T cells improves tumor control and survival in prostate cancer models by overcoming the antigen heterogeneity and reshaping the immunosuppressive tumor microenvironment.

cancer biology↗

bioRxiv2026

Focal radiotherapy improves CAR T cell therapy targeting prostate cancer

Chimeric antigen receptor (CAR) T cell therapy has limited efficacy against solid tumors such as prostate cancer due to the immunosuppressive tumor microenvironment (TME). Combining CAR T cells with existing therapies that remodel the TME and promote endogenous immune responses, such as radiation therapy and chemotherapies, may strengthen antitumor responses. Here, we assessed the potency of combining focal radiotherapy (RT), cyclophosphamide (Cy) preconditioning, and prostate stem cell antigen (PSCA)-CAR T cells against syngeneic prostate cancer models. Focal RT alone increased T cell and dendritic cell infiltration and activation in the irradiated tumor. Furthermore, the combination of all three therapies was critical for enhanced antitumor responses and survival across multiple subcutaneous, bone-metastatic, and multifocal disease models. This combination, in the irradiated TME and tumor-draining lymph nodes (tdLN), led to greater antigen presentation by myeloid cells and endogenous T cell activation and cytotoxicity. Our study demonstrates the potency of combining focal RT with PSCA-CAR T cells, significantly improving therapeutic responses in the irradiated tumor and contributing to a more robust systemic immune response against metastatic burden in prostate cancer.

Cancer Biology↗

bioRxiv2026

Anthocyanin-associated cellular programs underlying terroir variation in Cabernet Sauvignon grape berry revealed by SEED-based deconvolution

Plant tissues consist of diverse cell populations that collectively contribute to development, metabolism, environmental responses, and phenotype formation. Although single-cell and single-nucleus RNA sequencing have greatly advanced the study of plant cellular heterogeneity, their application to large sample cohorts remains limited by cost, technical complexity, tissue dissociation constraints, and throughput. In contrast, bulk RNA-seq datasets have accumulated extensively across plant species, tissues, developmental stages, and environmental conditions, yet the celltype-level information embedded in these datasets remains difficult to resolve because plant-oriented deconvolution frameworks are still lacking. Existing deconvolution methods have largely been developed in mammalian systems and have not been systematically optimized for plant transcriptomic features, leaving their applicability under plant-specific constraints unclear. Here, we present SEED, an adaptive deconvolution framework optimized for plant transcriptomic data. SEED integrates candidate reference-template construction with seven deconvolution strategies and automatically identifies an optimal combination for a given dataset. In grapevine simulated benchmarking, SEED showed its clearest advantage under low-replication conditions and remained broadly competitive, rather than uniformly dominant, when larger pseudo-bulk sample sizes were evaluated. SEED further performed robustly in public Arabidopsis thaliana and Nicotiana tabacum datasets. Finally, we applied SEED to bulk RNA-seq data generated in this study from Vitis vinifera cv. Cabernet Sauvignon berries collected from Yinchuan and Yantai, identifying terroir-associated cell subtypes and coordinated celltype interaction patterns. Together, these results establish SEED as a practical framework for plant transcriptome deconvolution and provide a new tool for dissecting cellular heterogeneity associated with environmental adaptation and phenotype formation in plants.

bioinformatics↗

bioRxiv2026

FABP4 Couples Lipid Metabolism to PD-L1 Stabilization in Immunosuppressive Macrophages

Metabolic dysregulation in obesity reshapes immune function, but how lipid signals drive immune suppression remains unclear. Here, we identify a FABP4-PD-L1 axis that links lipid metabolism to immune checkpoint regulation in monocytes and macrophages. Single-cell transcriptomics revealed a distinct FABP4high immunosuppressive macrophage subset enriched under high-fat diet (HFD) conditions, characterized by impaired antigen presentation and elevated PD-L1 expression. Mechanistically, palmitic acid (PA) induces FABP4 and promotes PD-L1 palmitoylation, leading to its stabilization on the cell surface independent of transcriptional regulation. FABP4 is essential for this process, which enables PD-L1 surface stabilization, immunosuppression and mammary tumor progression. In humans, a conserved CD14intCD16 monocyte population exhibits elevated FABP4-PD-L1 signaling and correlates with obesity and invasive breast cancer. These findings establish PD-L1 as a metabolically regulated protein and reveal a mechanism by which lipid excess drives immune evasion, suggesting that targeting FABP4 may enhance responses to immune checkpoint blockade. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/717546v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1fe3f2corg.highwire.dtl.DTLVardef@e587a7org.highwire.dtl.DTLVardef@12d0f75org.highwire.dtl.DTLVardef@151f916_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIFABP4 defines a lipid-responsive, immunosuppressive monocyte/macrophage subset C_LIO_LIFABP4 links lipid sensing to PD-L1 expression in macrophages C_LIO_LIFABP4 enables palmitic acid-dependent PD-L1 palmitoylation and stabilization C_LIO_LIFABP4-PD-L1 signaling correlates with obesity and invasive breast cancer in humans C_LI

immunology↗

bioRxiv2026

Decoding Immunomodulatory Hydrogels for Arthritis: Comparative Insights from Predictive Machine Learning and Large Language Models

Hydrogels are increasingly recognized as promising therapeutics for arthritic joints, extending their traditional role as mechanical lubricants to modulators of joint immunity. However, the rational design of these materials remains challenging, with progress largely driven by empirical experimentation. To address this, we curated a comprehensive database of 220 hydrogel formulations from 317 published studies and applied an interpretable machine learning (ML) framework to uncover the relationships between hydrogel design parameters and the arthritis severity score. Using a Random Forest algorithm, our model achieved an external validation accuracy of 0.67 in predicting effective hydrogel therapies for arthritis. Analysis revealed a clear hierarchy of design principles: the choice of functional agent, base polymer, and elastic modulus were the most influential predictors of therapeutic efficacy, with composite agents, protein-based polymers, and softer hydrogels most strongly associated with positive therapeutic outcomes. Mechanistic investigations further demonstrated that successful hydrogels promote an anti-inflammatory M2 macrophage phenotype. Benchmarking against classical statistical methods and a large language model framework showed that our ML approach provided more robust, nuanced insights into complex feature interactions. This data-driven framework offers a generalizable blueprint for the rational design of next-generation immunomodulatory hydrogels, paving the way for more effective arthritis therapies.

bioengineering↗

bioRxiv2026

FluNexus: a versatile web platform for antigenic prediction and visualization of influenza A viruses

Influenza A viruses continuously undergo antigenic evolution to escape host immunity induced by previous infections or vaccinations, consequently causing seasonal epidemics and occasional pandemics. Antigenic prediction and visualization of influenza A viruses are crucial for precise vaccine strain selection and robust pandemic preparedness. However, a user-friendly online platform for these capabilities remains notably absent, despite widespread demand. Here, we present FluNexus (https://flunexus.com), the first-of-its-kind, one-stop-shop web platform designed to facilitate the prediction and visualization of the antigenic change in emerging variants. FluNexus features a data preprocessing module for hemagglutinin subunit 1 (HA1) and hemagglutination inhibition (HI) data across three major public health threat subtypes (H1, H3 and H5). Meanwhile, FluNexus provides an interactive interface for online antigenic prediction and offers practical guidance for researchers. Most notably, FluNexus offers the visualization of influenza A virus antigenic evolution, providing intuitive insights into its antigenic dynamics. Specially, FluNexus proposes a novel manifold-based method for positioning antigens and antisera, generating accurate antigenic cartographies even with sparse HI data. By alleviating the programming burden on biologists, FluNexus supports more informed decision-making in vaccine strain selection and strengthens surveillance and pandemic preparedness. HighlightsO_LIFluNexus features a data preprocessing module for HA1 and HI data spanning the H1, H3, and H5 subtypes. C_LIO_LIFluNexus facilitates online antigenic prediction utilizing ten state-of-the-art antigenic prediction tools, and offers practical guidance based on a comparative evaluation of their performance. C_LIO_LIFluNexus provides a visualization module for mapping antigenic evolution of influenza A viruses, incorporating a novel manifold-based method for antigenic cartography. C_LI

bioinformatics↗

bioRxiv2026

Targeting Circulating FABP4 Ameliorates Obesity-Associated Hepatic Steatosis

Obesity is a major driver of hepatic steatosis, yet the molecular link between excess adiposity and hepatocellular lipid accumulation remains incompletely defined. Here, we identify circulating fatty acid-binding protein 4 (FABP4) as a key mediator of adipocyte-hepatocyte lipid crosstalk in obesity. Analyses of human liver specimens and mouse models reveal aberrant accumulation of FABP4 protein--but not transcript--in hepatocytes during steatosis, indicating an extrinsic source. Genetic deletion of FABP4, specifically in adipocytes, protects against high fat diet-induced hepatic steatosis without altering obesity or systemic lipid levels. Mechanistically, circulating FABP4 directly binds to hepatocytes, facilitating free fatty acid uptake. Furthermore, we developed a high-affinity humanized monoclonal antibody that selectively neutralizes circulating FABP4, blocks hepatocyte binding, suppresses fatty acid uptake, and markedly attenuates hepatic steatosis in multiple obese mouse models. These findings establish circulating FABP4 as a pathogenic lipid chaperone and a promising therapeutic target for obesity-associated hepatic steatosis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=180 SRC="FIGDIR/small/701451v1_ufig1.gif" ALT="Figure 1"> View larger version (61K): org.highwire.dtl.DTLVardef@5b91d5org.highwire.dtl.DTLVardef@1c34892org.highwire.dtl.DTLVardef@1d17ea9org.highwire.dtl.DTLVardef@d2b43c_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIHepatocytic accumulation of extrinsic FABP4 links adiposity to liver lipid deposition. C_LIO_LISpecific deletion of FABP4 in adipocytes prevents hepatic steatosis without affecting systemic lipid levels or obesity. C_LIO_LICirculating FABP4 derived from adipocytes directly binds hepatocytes to facilitate free fatty acid transfer. C_LIO_LIBlocking circulating FABP4 with a high-affinity anti-FABP4 monoclonal antibody inhibits hepatocyte lipid uptake and attenuates steatosis in multiple obese mouse models. C_LI

pathology↗

bioRxiv2026

An Asynchronous Production Line of Meiotic Prophase I in the Mouse Fetal Ovary

The initiation of meiosis in the mammalian female germline has long been described as a synchronous event, occurring within a narrow developmental window. Here, we challenge this paradigm through a systematic, quantitative analysis of meiotic entry and progression in the mouse fetal ovary. Using dynamic expression profiling of key regulators Stra8, Sycp1, and Sycp3 alongside proliferation markers, we demonstrate that germ cells enter meiosis asynchronously and continuously between embryonic days E12.5 and E16.5. During this extended period, mitotic proliferation persists, indicating that germ cells are progressively recruited into the meiotic pathway rather than halting division simultaneously. Homologous chromosome synapsis, marked by Sycp1/Sycp3 co-localization, initiates at E14.5 and is completed prenatally by E18.5. Integrating these data into a continuous-time Markov chain model, we derive a "meiotic clock" that predicts fixed temporal intervals from meiotic entry to synapsis completion ([~]72 hours) and to meiotic arrest ([~]91 hours), regardless of entry time. This model provides a predictive framework for germ cell development and establishes that female meiotic initiation is a prolonged, asynchronous production line rather than a synchronized transition, reshaping our understanding of oogenesis and its regulatory logic. TEASERThe initiation of female meiosis in mice is redefined as an asynchronous, continuous production line from E12.5 to E16.5, supported by a predictive "meiotic clock" model with fixed temporal intervals for synapsis and arrest.

developmental biology↗

bioRxiv2025

Ultrafast CTCF dynamics control cohesin barrier function

Genomes are organized into chromatin loops through cohesin-mediated extrusion, with CTCF acting as a polar boundary element. As cohesin approaches CTCF at kilobase-per-second speeds, it must rapidly choose whether to stall or bypass. How CTCF encodes this probabilistic decision within a brief encounter window has remained unclear. Here we show that CTCF governs this probabilistic outcome by rapidly sampling a dynamic ensemble of conformations generated by spontaneous rearrangements of its DNA-binding zinc fingers. This ensemble is tuned by DNA sequence, CpG methylation, nearby nucleosomes, and the cohesin regulator PDS5A before cohesin engagement. Upon cohesin binding, PDS5A enhances loop-anchor mechanical stability, reinforcing orientation-dependent boundaries. These findings establish conformational ensemble tuning, rather than static occupancy, as a regulatory principle linking base pair-scale motions to megabase-scale genome organization. One sentence summaryChromatin boundary function is governed not by CTCF occupancy alone, but by a tunable ensemble of DNA-bound conformations that probabilistically gates cohesin capture.

biophysics↗

bioRxiv2025

Genome-wide CRISPR screen reveals PEX11B as a host restriction factor against ORFV through membrane fluidity regulation

Host-pathogen interactions are shaped by cellular restriction factors that direct antiviral defenses. We built the first ovine genome-wide CRISPR knockout library in sheep testis (OA3.Ts) cells, targeting all protein-coding genes. Using this platform, we identified PEX11B, a peroxisomal membrane regulatory protein, as a strong restriction factor against orf virus (ORFV) infection. Removing PEX11B increased viral susceptibility and triggered severe cytopathic effects with membrane fusion and syncytia formation. Mechanistic studies showed that PEX11B knockout harmed peroxisomal integrity and disrupted lipid metabolism. This led to greater plasma membrane fluidity, creating a proviral environment that allowed more viral entry and replication. These results reveal a new antiviral function for PEX11B in blocking viral infection and underscore the importance of peroxisomal regulation in host-virus interactions.

microbiology↗

bioRxiv2025

Skeletal Muscle Regeneration is Accelerated Following Injection of Time Release Ion Matrix in Injured Mice

IntroductionSkeletal muscle injury remains a significant cause of disability with limited treatment options. Here we report accelerated skeletal muscle regeneration following injection of an inorganic biomaterial alone, cobalt oxide time-release ion matrix (CoO-TRIM). MethodsThe tibialis anterior (TA) muscle of adult C57BL/6J mice was injured with 70 {micro}L of barium chloride, with uninjured limbs serving as contralateral controls. Following the acute inflammatory phase (3 days post injury, dpi), mice were randomly separated into three groups: untreated controls, 70 {micro}l sterile saline injection alone (vehicle control) or 70 {micro}l CoO-TRIM (5 {micro}g/{micro}l) and evaluated at 8- and 14 dpi. Results14 dpi, injured TA muscles receiving a single injection of CoO-TRIM exhibited greater recovery of maximal force production (means {+/-} SEM: Healthy; TRIM, 31.8 {+/-} 0.6 N/cm3; Untreated, 31.7 {+/-} 0.8 N/cm3; Saline, 31.6 {+/-} 0.8 N/cm3, Injured; TRIM, 31.8 {+/-} 0.8 N/cm3; Untreated, 26.1 {+/-} 1.1 N/cm3, P= <0.01 vs. TRIM Injured; Saline, 26.0 {+/-} 1.3 N/cm3, P= <0.01 vs. TRIM Injured), increased fiber size (Healthy; TRIM, 2466 {+/-} 128 {micro}m2 vs. Untreated, 2351 {+/-} 131 {micro}m2; vs. Saline, 2460 {+/-} 129 {micro}m2, Injured; TRIM, 2179 {+/-} 63 {micro}m2 vs. Untreated, 1525 {+/-} 52 {micro}m2, P= <0.01; vs. Saline, 1470 {+/-} 99 {micro}m2, P= <0.01), and accelerated muscle regeneration (TRIM, 32.7 {+/-} 6.8 eMyHC+ fibers/mm2 vs. Untreated, 91.8 {+/-} 11.8 eMyHC+ fibers/mm2, P= <0.01; vs. Saline, 94.0 {+/-} 9.6 eMyHC+ fibers/mm2, P= <0.01). Vascular endothelial growth factor was elevated 14 dpi (TRIM, 17.3 {+/-} 2.9 pg/mg vs. Untreated, 10.3 {+/-} 1.1 pg/mg, P= 0.04; Saline, 5.5 {+/-} 1.2 pg/mg, P= <0.01), with increased muscle microvascular area (TRIM, 119.9 {+/-} 4.2 {micro}m2/fiber vs. Untreated, 94.9 {+/-} 4.2 {micro}m2/fiber, P= <0.01; Saline, 91.3 {+/-} 4.0 {micro}m2/fiber, P= <0.01) following CoO-TRIM treatment. There were early increases in inflammatory responses 8 dpi in injured TA muscles receiving CoO-TRIM (IL-6; TRIM, 29.1 {+/-} 8.2 pg/ml vs. Untreated, 12.4 {+/-} 1.5 pg/ml, P= 0.02; Saline, 11.7 {+/-} 0.8 pg/mg, P= 0.01), with early resolution of degenerative inflammatory cytokines and elevated regenerative cytokines 14 dpi (IL-10; SEM: TRIM, 2.4 {+/-} 0.1 pg/ml vs. Untreated, 2.1 {+/-} 0.1 pg/ml, P= 0.25; Saline, 2.0 {+/-} 0.1 pg/ml, P= 0.04). No differences were observed in healthy contralateral limbs following treatment with CoO-TRIM compared to healthy control mice at 8- and 14 dpi. DiscussionThis work suggests CoO-TRIM enhances muscle regeneration following injury, possibly through an immune cell-mediated mechanism. Statement of Clinical RelevanceThis is the first report of an injected, inorganic biomaterial alone to accelerate regeneration of injured skeletal muscle with no observed effects on healthy muscle. These findings suggest enhancements to skeletal muscle regeneration following CoO-TRIM treatment may be immune cell mediated with an increased local inflammatory response and subsequent improvements to muscle microvasculature and myogenic regulatory factors.

physiology↗