Biology subjects

Wu, Y.

Publications and source records attributed to Wu, Y..

At least 559 records · Page 31Linked to original sources

bioRxiv2023

Non-canonical hepatic androgen receptor mediates glucagon sensitivity in female mice through the PGC1α/ERRα/mitochondria axis

The hormone glucagon plays a crucial role in maintaining normal blood glucose levels and has recently been found to promote liver lipid catabolism in both clinical and basic research studies. However, the mechanisms by which glucagon signaling synchronizes glucose and lipid metabolism in the liver remain poorly understood. Here, we report that hepatic androgen receptor (AR) functions as a critical mediator of glucagon signaling, contributing to sexual dimorphism in hepatic glucagon sensitivity. The inhibition of AR, either through chemical or genetic means, impairs the ability of glucagon to stimulate gluconeogenesis and lipid catabolism in primary hepatocytes. Notably, female mouse hepatocytes express up to three times more AR than their male littermates. Consequently, they respond to glucagon to a much greater extent in terms of glucose production and lipid catabolism outcomes. Moreover, liver-specific AR knockout impairs the effect of glucagon in inducing blood glucose production, especially in female mice. Mechanistically, we demonstrate that hepatic AR drives a PGC1/ERR-mitochondria axis to promote lipid catabolism for liver glucose production in response to glucagon treatment. Together, our study sheds light on the role of hepatic AR in mediating glucagon activity in orchestrating glucose and lipid metabolism, particularly in female mice. These findings may help elucidate the factors responsible for sex differences in glucagon sensitivity and the development of fatty liver disease.

physiology↗

bioRxiv2023

Planar Amorphous Silicon Carbide Microelectrode Arrays for Chronic Recording in Rat Motor Cortex

Chronic implantation of intracortical microelectrode arrays (MEAs) capable of recording from individual neurons can be used for the development of brain-machine interfaces. However, these devices show reduced recording capabilities under chronic conditions due, at least in part, to the brains foreign body response. This creates a need for MEAs that can minimize the foreign body response to enable long-term recording. A potential approach to reduce the foreign body response is the use of ultrathin MEAs. Here, we fabricated ultrathin (cross-sectional area: 160 {micro}m2) amorphous silicon carbide (a-SiC) MEAs with sixteen electrode channels and implanted them into the motor cortex of seven female Sprague-Dawley rats. A-SiC was chosen as the fabrication base for its high chemical stability, good electrical insulation properties, and amenability to thin film fabrication techniques. Electrochemical analysis and neural recordings were performed weekly for 4 months. MEAs were characterized in vitro pre-implantation and in vivo using electrochemical impedance spectroscopy and cyclic voltammetry at 50 mV/s and 50,000 mV/s. Neural recordings were analyzed for single unit activity. At the end of the study, animals were sacrificed for immunohistochemistry analysis. We observed statistically significant, but small, increases in 1 and 30 kHz impedance values and 50,000 mV/s charge storage capacity over the 16-week implantation period. Slow sweep 50 mV/s CV and 1 Hz impedance did not significantly change over time. Impedance values increased from 11.6 M{Omega} to 13.5 M{Omega} at 1 Hz, 1.2 M{Omega} to 2.9 M{Omega} at 1 kHz, and 0.11 M{Omega} to 0.13 M{Omega} at 30 kHz over 16 weeks. The median charge storage capacity of the implanted electrodes at 50 mV/s were 58.1 mC/cm2 on week 1 and 55.9 mC/cm2 on week 16, and at 50,000 mV/s were 4.27 mC/cm2 on week 1 and 5.93 mC/cm2 on week 16. Devices were able to record neural activity from 92% of all active channels at the beginning of the study, At the study endpoint, a-SiC devices were still recording single-unit activity on 51% of electrochemically active electrode channels. In addition, we observed that the signal-to-noise ratio experienced a small decline of only -0.19 per week. We also classified the units as fast and slow spiking based on the trough-to-peak time. Although the overall presence of single units declined, fast and slow spiking units declined at a similar rate. Furthermore, immunohistochemistry showed minimal foreign body response to the a-SiC devices, as highlighted by statistically insignificant differences in activated glial cells between implanted brains slices and contralateral sham slices, as evidenced by GFAP staining. NeuN staining revealed the presence of neural cell bodies close to the implantation site, again statistically not different from a contralateral sham slice. These results support the use of ultrathin a-SiC MEAs for long-term implantation and use in brain-machine interfaces.

bioengineering↗

bioRxiv2023

Polygonum Cillinerve polysaccharide inhibits Transmissible gastroenteritis virus by regulating microRNA-181

Transmissible gastroenteritis virus (TGEV) is an important pathogen that can cause changes in the expression profile of cell miRNA. In this study, PCP could treat piglets infected with TGEV by in vivo experiment. High-throughput sequencing technology was used to detect that 9 miRNAs were up-regulated and 17 miRNAs were down-regulated during PCP inhibition of TGEV infection in PK15 cells. Meanwhile, miR-181 was related to the target genes of key proteins of apoptosis pathway. PK15 was treated with different PCP after transfection of miR-181 mimic or inhibitor. Real-time PCR was used to detect the effect of TGEV replication, electron microscopy, TEM and Hoechst fluorescence staining were used to detect the biological function of the treated cells, and western blot (WB) was used to detect the expression of key signaling factors cyt C, caspase 9 and P53 in the apoptotic signaling pathway. The results showed that compared with the control group, 250 g/mL PCP significantly inhibited the replication of TGEV gRNA and gene N (P < 0.01). PK15 cells in PCP groups (250 and 125 g/mL) had uniform cell morphology and a small number of floating cells by microscopic, no typical virus structure was observed in 250 g/mL PCP group under TEM, and apoptosis staining showed that 250 g/mL PCP significantly reduced the number of apoptotic cells. PCP may inhibit TGEV-induced apoptosis through Caspase-dependent mitochondrial pathway after transfection of miR-181. The above results provided a theoretical basis for further research on the mechanism of PCP anti-TGEV.

pharmacology and toxicology↗

bioRxiv2023

Virome analysis provides new insights into the pathogenesis mechanism and treatment of SLE disease

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease. Many viruses have been reported to be associated with SLE, but the diversity of the virome in SLE and the mechanisms underlying the interactions between viral infection and SLE are still unclear. This study identified ten human virus species from 826 RNA-Seq samples of human blood from 688 SLE patients and 138 healthy controls. SLE patients were found to have higher positive rates of viruses than healthy controls, although the virus abundances were low and comparable in both SLE patients and healthy controls. Analysis of the antiviral interferon-stimulated genes (ISGs) in samples showed higher ISG expression levels in virus-positive samples compared to virus-negative samples, which confirmed viral infections in virus-positive samples. Further analysis of differential expression genes between virus-positive and negative SLE patients showed that several genes that were up-regulated in SLE patients were further up-regulated after viral infections, and they were mainly enriched in immune response-related biological processes, suggesting an excess immune response in SLE patients after viral infections. Finally, three marker genes of the SLE severity, namely STAT1, STAT5A, and STAT5B, showed higher expression levels in virus-positive SLE patients compared to those in virus-negative SLE patients, suggesting that viral infections may aggravate the SLE disease. Overall, the study deepens our understanding of the association between viruses and SLE and provides new insights into prevention and control of the disease.

bioinformatics↗

bioRxiv2023

Cyanobacteria newly isolated from marine volcanic seeps display rapid sinking and robust, high density growth

Cyanobacteria are photosynthetic organisms that play important roles in carbon cycling as well as promising bioproduction chassis. Here, we isolate two novel cyanobacteria, UTEX 3221 and UTEX 3222, from a unique marine environment with naturally elevated CO2. We describe complete genome sequences for both isolates and, focusing on UTEX 3222 due to its planktonic growth in liquid, characterize biotechnologically-relevant growth and biomass characteristics. UTEX 3222 outpaces other fast-growing model strains on solid medium. It can double every 2.35 hours in a liquid medium and grows to high density (>31g/L biomass dry weight) in batch culture, nearly double that of Synechococcus sp. PCC 11901, whose high-density growth was recently reported. In addition, UTEX 3222 sinks readily, settling more quickly than other fast-growing strains, suggesting improved de-watering of UTEX 3222 biomass. This settling behavior can be explained in part by larger cell volume. These traits may make UTEX 3222 a compelling choice for photosynthetic bioproduction from CO2. Overall, we find that bio-prospecting in environments with naturally elevated CO2 may uncover novel CO2-metabolizing organisms with unique characteristics.

microbiology↗

bioRxiv2023

Immune Epitopes of SARS-CoV-2 Spike Protein and Considerations for Universal Vaccine Development

Despite the success of global vaccination programs in slowing the spread of COVID-19, these efforts have been hindered by the emergence of new SARS-CoV-2 strains capable of evading prior immunity. The mutation and evolution of SARS-CoV-2 have created a demand for persistent efforts in vaccine development. SARS-CoV-2 Spike protein has been the primary target for COVID-19 vaccine development, but it is also the hotspot of mutations directly involved in host susceptibility and immune evasion. Our ability to predict emerging mutants and select conserved epitopes is critical for the development of a broadly neutralizing therapy or a universal vaccine. In this article, we review the general paradigm of immune responses to COVID-19 vaccines, highlighting the immunological epitopes of Spike protein that are likely associated with eliciting protective immunity resulting from vaccination. Specifically, we analyze the structural and evolutionary characteristics of the SARS-CoV-2 Spike protein related to immune activation and function via the toll-like receptors (TLRs), B cells, and T cells. We aim to provide a comprehensive analysis of immune epitopes of Spike protein, thereby contributing to the development of new strategies for broad neutralization or universal vaccination.

immunology↗

bioRxiv2023

A large-scale volumetric correlated light and electron microscopy study localizes Alzheimer's disease-related molecules in the hippocampus

Connectomics using volume-electron-microscopy enables mapping and analysis of neuronal networks, revealing insights into neural circuit function and dysfunction. In Alzheimers disease (AD), where amyloid-{beta} (A{beta}) and hyperphosphorylated-Tau (pTau) are implicated, connectomics offers an approach to unravel how these molecules contribute to circuit alterations by enabling the study of these molecules within the context of the complete local neuronal and glial milieu. We present a volumetric-correlated-light-and-electron microscopy (vCLEM) protocol using fluorescent nanobodies to localize A{beta} and pTau within a large-scale connectomics dataset from the hippocampus of the 3xTg AD mouse model. A key outcome of this work is a publicly accessible vCLEM dataset, featuring fluorescent labeling of A{beta} and pTau in the ultrastructural context with segmented neurons, glia, and synapses. This dataset provides a unique resource for exploring AD pathology in the context of connectomics and fosters collaborative opportunities in neurodegenerative disease research. As a proof-of-principle, we uncovered new localizations of A{beta} and pTau, including pTau-positive spine-like protrusions at the axon initial segment and changes in the number and size of synapses near A{beta} plaques. Our vCLEM approach facilitates the discovery of both molecular and structural alterations within large-scale EM data, advancing connectomics research in Alzheimers and other neurodegenerative diseases.

neuroscience↗

bioRxiv2023

Monocytes reprogrammed by 4-PBA potently contribute to the resolution of inflammation and atherosclerosis

BackgroundChronic inflammation initiated by inflammatory monocytes underlies the pathogenesis of atherosclerosis. However, approaches that can effectively resolve chronic low-grade inflammation targeting monocytes are not readily available. The small chemical compound 4-phenylbutyric acid (4-PBA) exhibits broad anti-inflammatory effects in reducing atherosclerosis. Selective delivery of 4-PBA reprogrammed monocytes may hold novel potential in providing targeted and precision therapeutics for the treatment of atherosclerosis. MethodsSystems analyses integrating single-cell RNA-sequencing and complementary immunological approaches characterized key resolving characteristics as well as defining markers of reprogrammed monocytes trained by 4-PBA. Molecular mechanisms responsible for monocyte reprogramming was assessed by integrated biochemical and genetic approaches. The inter-cellular propagation of homeostasis resolution was evaluated by co-culture assays with donor monocytes trained by 4-PBA and recipient naive monocytes. The in vivo effects of monocyte resolution and atherosclerosis prevention by 4-PBA were assessed with the high fat diet-fed ApoE-/- mouse model with i.p. 4-PBA administration. Furthermore, the selective efficacy of 4-PBA trained monocytes were examined by i.v. transfusion of ex vivo trained monocytes by 4-PBA into recipient high fat diet-fed ApoE-/- mice. ResultsIn this study, we found that monocytes can be potently reprogrammed by 4-PBA into an immune-resolving state characterized by reduced adhesion and enhanced expression of anti-inflammatory mediator CD24. Mechanistically, 4-PBA reduced the expression of ICAM-1 via reducing peroxisome stress and attenuating SYK-mTOR signaling. Concurrently, 4-PBA enhanced the expression of resolving mediator CD24 through promoting PPAR{gamma} neddylation mediated by TOLLIP. 4-PBA trained monocytes can effectively propagate anti-inflammation activity to neighboring monocytes through CD24. Our data further demonstrated that 4-PBA trained monocytes effectively reduce atherosclerosis pathogenesis when administered in vivo. ConclusionOur study describes a robust and effective approach to generate resolving monocytes, characterizes novel mechanisms for targeted monocyte reprogramming, and offers a precision-therapeutics for atherosclerosis based on delivering reprogrammed resolving monocytes.

immunology↗

bioRxiv2023

Yes1-mediated Cul9 phosphorylation promotes the metabolic reprogramming in gastric cancer

Although Cul9 has been implicated in human carcinogenesis, its upstream regulators and roles remain unknown. Herein, we indicate that the Cul9 promoter is hypermethylated in GCs. Bioinformatics, mass spectrometry, and unbiased-kinase screen identify the tyrosine kinase Yes1 as a key regulator of Cul9. Yes1 phosphorylates Cul9 at Y1505, promoting its selective autophagy. Patient-associated mutation of Yes1 or helicobacter pylori infection induces Cul9-Y1505 phosphorylation which switches Cul9 from a tumor-suppressor to an oncogene, as evidenced by the fact that Cul9-Y1505D knockin mice are more susceptible to gastric tumorigenesis than wild-type counterparts. Metabolic profiling and ATAC sequencing reveal that Cul9-Y1505D mutant promotes pyrimidine and purine synthesis pathways in GC. DNA-demethylating drug decitabine or HG78 compound upregulates Cul9 expression and limits GC cell proliferation in a Yes1-dependent manner. The Yes1 inhibitor CH6953755 or Leflunomide and Mycophenolate mofetil (MMF) also impair the malignancy of GC with Cul9 dysregulation. Cul9 in turn binds Yes1 and disrupts Yes1 stability, establishing a feedback circuit. Collectively, our project reveals an unrecognized role of the Yes1-Cul9 loop in GC, suggesting potential therapeutic targets.

cancer biology↗

bioRxiv2023

Epigenome erosion in Alzheimer's disease brain cells and induced neurons

Late-onset Alzheimers disease (LOAD) is typically sporadic, correlated only to advanced age, and has no clear genetic risk factors. The sporadic nature of LOAD presents a challenge to understanding its pathogenesis and mechanisms. Here, we comprehensively investigated the epigenome of LOAD primary entorhinal cortex brain tissues via single-cell multi-omics technologies, simultaneously capturing DNA methylation and 3D chromatin conformation. We identified AD-specific DNA methylation signatures and found they interact with bivalent promoters of AD differentially expressed genes. In addition, we discovered global chromosomal epigenome erosion of 3D genome structure within and across brain cell types. Furthermore, to evaluate whether these age- and disease-dependent molecular signatures could be detected in the in vitro cellular models, we derived induced neurons (iNs) converted directly from AD patients fibroblasts and found a set of conserved methylation signatures and shared molecular processes. We developed a machine-learning algorithm to identify robust and consistent methylation signatures of LOAD in vivo primary brain tissues and in vitro fibroblast-derived iNs. The results recapitulate the age- and disease-related epigenetic features in iNs and highlight the power of epigenome and chromatin conformation for identifying molecular mechanisms of neuronal aging and generating biomarkers for LOAD. HIGHLIGHTO_LIAD-specific DNA methylation signatures are identified in entorhinal cortex brain cell types C_LIO_LIThe AD differentially expressed genes linked with differentially methylated regions via loop interactions are enriched in a bivalent chromatin state C_LIO_LIChromosomal epigenome erosion of 3D genome structures occurs in LOAD brain cell types. C_LIO_LIShared and reliable methylation signatures are observed in both in vitro cellular iN models and primary brain tissues. C_LIO_LIMachine learning models identify robust and reliable methylation loci as AD biomarkers across cell types. C_LI

genomics↗

bioRxiv2023

Deep learning-based aberration compensation improves contrast and resolution in fluorescence microscopy

Optical aberrations hinder fluorescence microscopy of thick samples, reducing image signal, contrast, and resolution. Here we introduce a deep learning-based strategy for aberration compensation, improving image quality without slowing image acquisition, applying additional dose, or introducing more optics into the imaging path. Our method (i) introduces synthetic aberrations to images acquired on the shallow side of image stacks, making them resemble those acquired deeper into the volume and (ii) trains neural networks to reverse the effect of these aberrations. We use simulations and experiments to show that applying the trained de-aberration networks outperforms alternative methods, providing restoration on par with adaptive optics techniques; and subsequently apply the networks to diverse datasets captured with confocal, light-sheet, multi-photon, and super-resolution microscopy. In all cases, the improved quality of the restored data facilitates qualitative image inspection and improves downstream image quantitation, including orientational analysis of blood vessels in mouse tissue and improved membrane and nuclear segmentation in C. elegans embryos.

bioengineering↗

bioRxiv2023

Pervasive biases in proxy GWAS based on parental history of Alzheimer's disease

Almost every recent Alzheimers disease (AD) genome-wide association study (GWAS) has performed meta-analysis to combine studies with clinical diagnosis of AD with studies that use proxy phenotypes based on parental disease history. Here, we report major limitations in current GWAS-by-proxy (GWAX) practices due to uncorrected survival bias and non-random participation of parental illness survey, which cause substantial discrepancies between AD GWAS and GWAX results. We demonstrate that current AD GWAX provide highly misleading genetic correlations between AD risk and higher education which subsequently affects a variety of genetic epidemiologic applications involving AD and cognition. Our study sheds important light on the design and analysis of mid-aged biobank cohorts and underscores the need for caution when interpreting genetic association results based on proxy-reported parental disease history.

genetics↗

bioRxiv2023

Enterocytozoon hepatopenaei Proliferate in Procambarus clarkii: A Warning for Crayfish and Shrimp Aquaculture

The pacific whiteleg shrimp (Litopenaeus vannamei) and the crayfish (Procambarus clarkii) are the most productive aquatic animals in the world. The prevalence of the microsporidium Enterocytozoon hepatopenaei (EHP), an intracellular spore-forming unicellular parasite which leading retarded growth of L. vannamei, has caused severe economic losses in most shrimp farming country. In this study, we found that the wild P. clarkii, living in shrimp ponds with EHP outbreak, excreted white faeces after temporary laboratory culture. The hepatopancreas (HP) of symptomatic crayfish exhibited a lighter color and severely atrophied. H&E-stain showed tissue lesions in both hepatopancreas and intestine, and clustered microsporidian spores were filled in the cytoplasm of the cells. PCR using EHPptp2 and two microsporidian-universal primers sets demonstrated the existence of EHP in the hepatopancreas, intestine and the white feces of P. clarkii. The EHP loads of 103-104 copies of EHPptp2/50 ng HPgDNA were detected by qPCR. Developing stages and mature spores of EHP were observed in hepatopancreas of P. clarkii through indirect-immunofluorescence assay (IFA) and transmission electron microscopy (TEM). Considering the large-scale cultivation of L. vannamei and P. clarkii, overlap farming areas between these two species as well as the ability of crayfish to crawl on land and water, our finding indicates the potential role of P. clarkii in the transmission of EHP, and it is an early warning for crayfish and shrimp farming.

microbiology↗

bioRxiv2023

ZHX2 alleviates vascular remodeling and smooth muscle cell proliferation by transcriptional regulation of GADD45G

ObjectiveThis study explores the role of ZHX2 in vascular remodeling, specifically focusing on its effects on VSMC proliferation, migration, and neointima formation following vascular injury. Methods and Results: Data from both human atherosclerotic samples and a mouse carotid injury model indicated a decrease in ZHX2 levels. In vivo, ZHX2 overexpression reduced neointima formation in mice subjected to carotid artery ligation. In vitro, ZHX2 inhibited the proliferation and migration of primary VSMCs. Conversely, specific knockout of ZHX2 in SMCs in vivo or knockdown of ZHX2 in primary VSMCs had opposite effects. RNA- seq analysis revealed that ZHX2 overexpression significantly affected the expression of cell cycle-related genes. Using Chromatin Immunoprecipitation Sequencing (ChIP-seq) and luciferase reporter assays, we demonstrated that ZHX2 plays a crucial role in the transcriptional regulation of GADD45G, identifying GADD45G as the downstream target responsible for ZHX2-mediated effects. Conclusions: ZHX2 emerges as a key player in pathological vascular remodeling, suppressing VSMC proliferation and migration through its regulatory impact on GADD45G transcription and cell cycle-related gene expression.

molecular biology↗

bioRxiv2023

Parkinsonism Sac domain mutation in Synaptojanin-1 affects ciliary properties in iPSC-derived dopaminergic neurons

Synaptojanin-1 (SJ1) is a major neuronal-enriched PI(4,5)P2 4- and 5-phosphatase implicated in the shedding of endocytic factors during endocytosis. A mutation (R258Q) that impairs selectively its 4-phosphatase activity causes Parkinsonism in humans and neurological defects in mice (SJ1RQKI mice). Studies of these mice showed, besides an abnormal assembly state of endocytic factors at synapses, the presence of dystrophic nerve terminals selectively in a subset of nigro-striatal dopamine (DA)-ergic axons, suggesting a special lability of DA neurons to the impairment of SJ1 function. Here we have further investigated the impact of SJ1 on DA neurons using iPSC-derived SJ1 KO and SJ1RQKI DA neurons and their isogenic controls. In addition to the expected enhanced clustering of endocytic factors in nerve terminals, we observed in both SJ1 mutant neuronal lines increased cilia length. Further analysis of cilia of SJ1RQDA neurons revealed abnormal accumulation of the Ca2+ channel Cav1.3 and of ubiquitin chains, suggesting an impaired clearing of proteins from cilia which may result from an endocytic defect at the ciliary base, where a focal concentration of SJ1 was observed. We suggest that SJ1 may contribute to the control of ciliary protein dynamics in DA neurons, with implications on cilia-mediated signaling.

neuroscience↗

bioRxiv2023

Integrating large-scale meta-GWAS and PigGTEx resources to decipher the genetic basis of complex traits in pig.

Understanding the molecular and cellular mechanisms that underlie complex traits in pigs is crucial for enhancing their genetic improvement program and unleashing their substantial potentials in human biomedicine research. Here, we conducted a meta-GWAS analysis for 232 complex traits with 28.3 million imputed whole-genome sequence variants in 70,328 individuals from 14 pig breeds. We identified a total of 6,878 genomic regions associated with 139 complex traits. By integrating with the Pig Genotype-Tissue Expression (PigGTEx) resource, we systemically explored the biological context and regulatory circuits through which these trait-associated variants act and finally prioritized 16,664 variant-gene-tissue-trait circuits. For instance, rs344053754 regulates the expression of UGT2B31 in the liver by affecting the activity of regulatory elements and ultimately influences litter weight at weaning. Furthermore, we investigated the conservation of genetic and regulatory mechanisms underlying 136 human traits and 232 pig traits. Overall, our multi-breed meta-GWAS in pigs provides invaluable resources and novel insights for understanding the regulatory and evolutionary mechanisms of complex traits in both pigs and humans.

genetics↗

bioRxiv2023

SmartEM: machine-learning guided electron microscopy

Connectomics provides nanometer-resolution, synapse-level maps of neural circuits to understand brain activity and behavior. However, few researchers have access to the high-throughput electron microscopes necessary to generate enough data for whole brain or even whole circuit reconstruction. To date, machine-learning methods have been used after the collection of images by electron microscopy (EM) to accelerate and improve neuronal segmentation, synapse reconstruction and other data analysis. With the computational improvements in processing EM images, acquiring EM images has now become the rate-limiting step in automated connectomics. Here, in order to speed up EM imaging, we integrate machine-learning into real-time image acquisition in a single-beam scanning electron microscope. This SmartEM approach allows an electron microscope to perform intelligent, data-aware imaging of specimens. SmartEM saves time by allocating the proper imaging time for each region of interest - first scanning all pixels rapidly, then rescanning more slowly only the small subareas where a higher quality signal is required. We demonstrate that SmartEM achieves up to a ~7-fold acceleration of image acquisition time for connectomic samples using a commercial single-beam SEM in samples from nematodes, mice and human brain. We apply this fast imaging method to reconstruct a portion of mouse cerebral cortex with an accuracy comparable to traditional electron microscopy.

neuroscience↗

bioRxiv2023

Intraoperative Bioprinting of Human Adipose-derived Stem cells and Extra-cellular Matrix Induces Hair Follicle-Like Downgrowths and Adipose Tissue Formation during Full-thickness Craniomaxillofacial Skin Reconstruction

Craniomaxillofacial (CMF) reconstruction is a challenging clinical dilemma. It often necessitates skin replacement in the form of autologous graft or flap surgery, which differ from one another based on hypodermal/dermal content. Unfortunately, both approaches are plagued by scarring, poor cosmesis, inadequate restoration of native anatomy and hair, alopecia, donor site morbidity, and potential for failure. Therefore, new reconstructive approaches are warranted, and tissue engineered skin represents an exciting alternative. In this study, we demonstrated the reconstruction of CMF full-thickness skin defects using intraoperative bioprinting (IOB), which enabled the repair of defects via direct bioprinting of multiple layers of skin on immunodeficient rats in a surgical setting. Using a newly formulated patient-sourced allogenic bioink consisting of both human adipose-derived extracellular matrix (adECM) and stem cells (ADSCs), skin loss was reconstructed by precise deposition of the hypodermal and dermal components under three different sets of animal studies. adECM, even at a very low concentration such as 2% or less, has shown to be bioprintable via droplet-based bioprinting and exhibited de novo adipogenic capabilities both in vitro and in vivo. Our findings demonstrate that the combinatorial delivery of adECM and ADSCs facilitated the reconstruction of three full-thickness skin defects, accomplishing near-complete wound closure within two weeks. More importantly, both hypodermal adipogenesis and downgrowth of hair follicle-like structures were achieved in this two-week time frame. Our approach illustrates the translational potential of using human-derived materials and IOB technologies for full-thickness skin loss.

bioengineering↗