Tissue Function Research Articles

An Easy-to-Use Arrayed Brain–Heart Chip

Multi-organ chips are effective at emulating human tissue and organ functions and at replicating the interactions among tissues and organs. An arrayed brain–heart chip was introduced whose configuration comprises open culture chambers and closed biomimetic vascular channels distributed in a horizontal pattern, separated from each other by an endothelial barrier based on fibrin matrix. A 300 μm-high and 13.2 mm-long endothelial barrier surrounded each organoid culture chamber, thereby satisfying the material transport requirements. Numerical simulations were used to analyze the construction process of fibrin barriers in order to optimize the structural design and experimental manipulation, which exhibited a high degree of correlation with experiment results. In each interconnective unit, a cerebral organoid, a cardiac organoid, and endothelial cells were co-cultured stably for a minimum of one week. The permeability of the endothelial barrier and recirculating perfusion enabled cross talk between cerebral organoids and cardiac organoids, as well as between organoids and endothelial cells. This was corroborated by the presence of cardiac troponin I (cTnI) in the cerebral organoid culture chamber and the observation of cerebral organoid and endothelial cells invading the fibrin matrix after one week of co-culture. The arrayed chip was simple to manipulate, clearly visible under a microscope, and compatible with automated pipetting devices, and therefore had significant potential for application.

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury: state of the art and future perspectives.

"Peripheral nerve injury" refers to damage or trauma affecting nerves outside the brain and spinal cord. Peripheral nerve injury results in movements or sensation impairments, and represents a serious public health problem. Although severed peripheral nerves have been effectively joined and various therapies have been offered, recovery of sensory or motor functions remains limited, and efficacious therapies for complete repair of a nerve injury remain elusive. The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function. Mesenchymal stem cells, as large living cells responsive to the environment, secrete various factors and exosomes. The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins, microRNA, and messenger RNA derived from parent mesenchymal stem cells. Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function, offering solutions to changes associated with cell-based therapies. Despite ongoing investigations, mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage. A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation. This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury, exploring the underlying mechanisms. Subsequently, it provides an overview of the current status of mesenchymal stem cell and exosome-based therapies in clinical trials, followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes. Finally, the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes, offering potential solutions and guiding future directions.

Patient-Derived Organoids: A Game-Changer in Personalized Cancer Medicine.

Research on cancer therapies has benefited from predictive tools capable of simulating treatment response and other disease characteristics in a personalized manner, in particular three-dimensional cell culture models. Such models include tumor-derived spheroids, multicellular spheroids including organotypic multicellular spheroids, and tumor-derived organoids. Additionally, organoids can be grown from various cancer cell types, such as pluripotent stem cells and induced pluripotent stem cells, progenitor cells, and adult stem cells. Although patient-derived xenografts and genetically engineered mouse models replicate human disease in vivo, organoids are less expensive, less labor intensive, and less time-consuming, all-important aspects in high-throughput settings. Like in vivo models, organoids mimic the three-dimensional structure, cellular heterogeneity, and functions of primary tissues, with the advantage of representing the normal oxygen conditions of patient organs. In this review, we summarize the use of organoids in disease modeling, drug discovery, toxicity testing, and precision oncology. We also summarize the current clinical trials using organoids.

Signatures of Structural Disorder in the Developing Drosophila Germband Epithelium

Epithelial cells generate functional tissues in developing embryos through collective movements and shape changes. In some morphogenetic events, a tissue dramatically reorganizes its internal structure—often generating high degrees of structural disorder—to accomplish changes in tissue shape. However, the origins of structural disorder in epithelia and what roles it might play in morphogenesis are poorly understood. We study this question in the germband epithelium, which undergoes dramatic changes in internal structure as cell rearrangements drive elongation of the embryo body axis. Using two order parameters that quantify volumetric and shear disorder, we show that structural disorder increases during body axis elongation and is strongly linked with specific developmental processes. Both disorder metrics begin to increase around the onset of axis elongation, but then plateau at values that are maintained throughout the process. Notably, the disorder plateau values for volumetric disorder are similar to those for random cell packings, suggesting this may reflect a limit on tissue behavior. In mutant embryos with disrupted external stresses from the ventral furrow, both disorder metrics reach wild-type maximum disorder values with a delay, correlating with delays in cell rearrangements. In contrast, in mutants with disrupted internal stresses and cell rearrangements, volumetric disorder is reduced compared to wild type, and shear disorder depends on specific external stress patterns. Together, these findings demonstrate that internal and external stresses both contribute to epithelial tissue disorder and suggest that the maximum values of disorder in a developing tissue reflect physical or biological limits on morphogenesis. Published by the American Physical Society 2024

Polyphenol-mediated redox-active hydrogel with H2S gaseous-bioelectric coupling for periodontal bone healing in diabetes.

Excessive oxidative response, unbalanced immunomodulation, and impaired mesenchymal stem cell function in periodontitis in diabetes makes it a great challenge to achieve integrated periodontal tissue regeneration. Here, a polyphenol-mediated redox-active algin/gelatin hydrogel encapsulating a conductive poly(3,4-ethylenedioxythiopene)-assembled polydopamine-mediated silk microfiber network and a hydrogen sulfide sustained-release system utilizing bovine serum albumin nanoparticles is developed. This hydrogel is found to reverse the hyperglycemic inflammatory microenvironment and enhance functional tissue regeneration in diabeticperiodontitis. Polydopamine confers the hydrogel with anti-oxidative and anti-inflammatory activity. Theslow, sustained release of hydrogen sulfide from the bovine serum albumin nanoparticles recruits mesenchymal stem cells and promotes subsequent angiogenesis and osteogenesis. Moreover, poly(3,4-ethylenedioxythiopene)-assembled polydopamine-mediated silk microfiber confers the hydrogel with good conductivity, which enables it to transmit endogenous bioelectricity, promote cell arrangement, and increase the inflow of calcium ion. In addition, the synergistic effects of hydrogen sulfide gaseous-bioelectric coupling promotes bone formation by amplifying autophagy in periodontal ligament stem cells and modulating macrophage polarization via lipid metabolism regulation. This study provides innovative insights into the synergistic effects of conductivity, reactive oxygen species scavenging, and hydrogen sulfide on the periodontium in a hyperglycemic inflammatory microenvironment, offering a strategy for the design of gaseous-bioelectric biomaterials to promote functional tissue regeneration in immune-related diseases.

From fat storage to immune hubs: the emerging role of adipocytes in coordinating the immune response to infection.

Adipose tissue is a rich source of diverse cell populations, including immune cells, adipocytes and stromal cells. Interactions between these different cell types are now appreciated to be critical for maintaining tissue structure and function, by governing processes such as adipogenesis, lipolysis and differentiation of white to beige adipocytes. Interactions between these cells also drive inflammation in obesity, leading to an expansion of adipose tissue immune cells, and the secretion of proinflammatory cytokines from immune cells and from adipocytes themselves. However, in evolutionary terms, obesity is a recent phenomenon, raising the question of why adipocytes evolved to express factors that influence the immune response. Studies of various pathogens indicate that adipocytes are highly responsive to infection, altering their metabolic profiles in a way that can be used to release nutrients and fuel the immune response. In the case of infection with the extracellular parasite Trypanosoma brucei, attenuating the ability of adipocytes to sense the cytokine IL-17 results in a loss of control of the local immune response and an increased pathogen load. Intriguingly, comparisons of the adipocyte response to infection suggest that the immune responses of these cells occur in a pathogen-dependent manner, further confirming their complexity. Here, with a focus on murine adipose tissue, we discuss the emerging concept that, in addition to their canonical function, adipocytes are immune signalling hubs that integrate and disseminate signals from the immune system to generate a local environment conducive to pathogen clearance.

Toxicity of nuclear-localized GFP in reporter mice

Various techniques using fluorescent reporter probes have been developed, such as GFP transgenic mouse lines that are used to detect spatial–temporal expression levels of genes. Although GFP expression is largely considered non-toxic, recent reports have indicated that under certain conditions GFP can display cellular toxicity. We hereby report the nuclear toxicity of H2B-GFP using a K14 specific Tet-on reporter mouse system. Using this system, GFP accumulates in the nucleus of all K14 expressing cells, such as the ocular surface epithelia and ocular adnexa. Expression of high levels of nuclear GFP during embryonic stages led to an eye open-at-birth (EOB) phenotype and abnormal ocular adnexa development and during adult and aging stages showed notable toxicity to ocular tissues. Other tissues, such as skin, also presented multiple defects associated with H2B-GFP expression. This toxicity was found to be concentration dependent, with homozygous mice presenting extremely high toxicity, while heterozygous mice presented limited toxicity. Upon induction, the accumulation of H2B-GFP in the nucleus of homozygous mice led to apoptosis within 2 weeks. This study therefore shows that although the use of nuclear GFP reporter mice is a valuable tool, at high levels, nuclear GFP can be toxic, leading to cell death and affecting tissue function.

Spatially defined microenvironment for engineering organoids

In the intricately defined spatial microenvironment, a single fertilized egg remarkably develops into a conserved and well-organized multicellular organism. This observation leads us to hypothesize that stem cells or other seed cell types have the potential to construct fully structured and functional tissues or organs, provided the spatial cues are appropriately configured. Current organoid technology, however, largely depends on spontaneous growth and self-organization, lacking systematic guided intervention. As a result, the structures replicated in vitro often emerge in a disordered and sparse manner during growth phases. Although existing organoids have made significant contributions in many aspects, such as advancing our understanding of development and pathogenesis, aiding personalized drug selection, as well as expediting drug development, their potential in creating large-scale implantable tissue or organ constructs, and constructing multicomponent microphysiological systems, together with functioning at metabolic levels remains underutilized. Recent discoveries have demonstrated that the spatial definition of growth factors not only induces directional growth and migration of organoids but also leads to the formation of assembloids with multiple regional identities. This opens new avenues for the innovative engineering of higher-order organoids. Concurrently, the spatial organization of other microenvironmental cues, such as physical stresses, mechanical loads, and material composition, has been minimally explored. This review delves into the burgeoning field of organoid engineering with a focus on potential spatial microenvironmental control. It offers insight into the molecular principles, expected outcomes, and potential applications, envisioning a future perspective in this domain.

Association of circulating adipokines with metabolic measures among people with HIV: Moderating effects of alcohol use.

People with HIV (PWH) are at increased risk for cardiometabolic comorbidities. We have reported that lifetime alcohol use among people with HIV (PWH) is associated with increased risk for metabolic syndrome. Dysfunctional adipose tissue and altered circulating adipokines mediate metabolic dysregulation. The objective of this study was to determine the associations of circulating adipokine concentration with metabolic measures, and the moderating effects of lifetime and recent alcohol use in PWH. This is a cross-sectional analysis of data from 357 PWH at their baseline visit of the longitudinal New Orleans Alcohol and HIV (NOAH) study. The concentrations of four circulating adipokines (adiponectin, leptin, resistin, and fatty acid-binding protein 4 [FABP4]) and their associations with five metabolic measures (triglycerides, cholesterol, Hemoglobin A1c, Homeostatic Model Assessment for Insulin Resistance, and metabolic syndrome) were examined. Higher circulating adiponectin was associated with increased odds of normal triglyceride, cholesterol, and Hemoglobin A1c levels. Increased leptin and FABP4 concentrations were associated with decreased odds of normal triglyceride and cholesterol levels. Increased leptin and FABP4 concentrations were associated with increased odds of insulin resistance and meeting criteria for metabolic syndrome. Increased circulating resistin concentration was associated with decreased odds of normal triglyceride levels and increased odds of meeting criteria for metabolic syndrome. Additionally, among PWH with increased lifetime alcohol use, higher adiponectin concentration was associated with decreased odds of meeting criteria for metabolic syndrome. These data suggest the interplay between adiponectin, leptin, FABP4, and resistin may contribute to metabolic stability among PWH. Moreover, lifetime, but not recent, alcohol use moderates the relationship between adipokines and metabolic measures. These data highlight the relevance of functional adipose tissue mass and associated circulating adipokine levels in maintaining metabolic homeostasis, and its moderation by lifetime alcohol consumption.

SESN2 Ameliorates Dihydrotestosterone-induced Human Ovarian Granulosa Cell Damage by Activating AMPK/ULK1-mediated Mitophagy.

Sestrin 2 (SESN2) has been reported to participate in the regulation of granulosa cell function in ovarian tissues. However, the role of SESN2 in polycystic ovarian syndrome (PCOS) is still incompletely understood. Here, we investigated the functional role and mechanism of SESN2 in dihydrotestosterone (DHT)-induced granulosa cells. In this study, DHT was utilized to induce PCOS cell model and the AMP-activated protein kinase (AMPK) inhibitor Compound C (CC) was utilized to inhibit the AMPK pathway. qRT-PCR was performed to detect the expression of SESN2 in HGLS cells. Cell apoptosis was evaluated by flow cytometry. Oxidative stress was detected by DCFH-DA staining, superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) kits. The expression of SESN2, cell apoptosis, oxidative stress, mitophagy and AMPK/ULK1 signaling-related proteins were measured by western blot. The results showed that SESN2 was downregulated in DHT-induced granulosa cells. Overexpression of SESN2 inhibited the DHT-induced apoptosis and oxidative stress of HGLS cells. DHT induction aggravated HGLS cell apoptosis and oxidative stress. SESN2 overexpression inhibited the DHT-induced apoptosis and oxidative stress of HGLS cells. In addition, overexpression of SESN2 activated the AMPK/ULK1 signaling pathway and promoted mitophagy. Treatment of CC reversed the regulatory effect of SESN2 on mitophagy. CC also reversed the influences of SESN2 overexpression on apoptosis and oxidative stress in DHT-induced HGLS cells. Overall, SESN2 suppressed DHT-induced apoptosis and oxidative stress in PCOS through AMPK/ULK1-mediated mitophagy.

3D Bioprinting for Engineered Tissue Constructs and Patient-Specific Models: Current Progress and Prospects in Clinical Applications.

Advancements in bioprinting technology are driving the creation of complex, functional tissue constructs for use in tissue engineering and regenerative medicine. Various methods, including extrusion, jetting, and light-based bioprinting, have their unique advantages and drawbacks. Over the years, researchers and industry leaders have made significant progress in enhancing bioprinting techniques and materials, resulting in the production of increasingly sophisticated tissue constructs. Despite this progress, challenges still need to be addressed in achieving clinically relevant, human-scale tissue constructs, presenting a hurdle to widespread clinical translation. However, with ongoing interdisciplinary research and collaboration, the field is rapidly evolving and holds promise for personalized medical interventions. Continued development and refinement of bioprinting technologies have the potential to address complex medical needs, enabling the development of functional, transplantable tissues and organs, as well as advanced in vitro tissue models.

3D bioprinting for drug development and screening: Recent trends towards personalized medicine

Personalized medicine, leveraging patient-specific genomic data, is revolutionizing treatment paradigms by enabling tailored therapies to individual needs, thus mitigating adverse effects and enhancing clinical outcomes. One innovative application in this field is the use of 3D bioprinting technology to design, develop and screen patient-customized medicines. This technology meticulously designs and develops therapeutic drugs by depositing active pharmaceutical ingredients layer by layer, culminating in a drug delivery structure optimized for the patient's unique dosage requirements. 3D bioprinting represents an emerging confluence of biological sciences and additive manufacturing, meeting the clinical demand for functional biological tissues through the integration of printing technologies, regenerative medicine principles, and advanced material science. This review provides an overview of the current state of 3D bioprinting applications and explores the transformative potential of 3D bioprinting in personalizing medicine. Moreover, the review elucidates the capabilities of 3D bioprinting in drug design, facilitating the production of complex therapeutic regimens in specific dosage forms, such as drugs with tailored dose concentrations, controlled release kinetics, and the capacity to combine multiple therapeutic regimens into a single, easy-to-administer format. This paper also addresses the challenges and obstacles faced in integrating 3D bioprinting techniques into pharmaceutical practice, ranging from technical and regulatory hurdles to scalability. Further, the efficacy of 3D bioprinting as a tool for advancing personalized medicine helps to utilize the full potential of this technology to enhance patient healthcare regimes.

Cardiac Amyloidosis: State-of-the-Art Review in Molecular Pathology.

Amyloidosis refers to a group of diseases caused by extracellular deposits of misfolded proteins, which alter tissue function and structure, potentially affecting any organ. The term "amyloid" was introduced in the 19th century and later associated with pathological protein deposits. Amyloid fibrils, which are insoluble and resistant to degradation, originate from soluble proteins that undergo misfolding. This process can be triggered by several factors, such as aging, elevated protein concentrations, or pathogenic variants. Amyloid deposits damage organs both by disrupting tissue architecture and through direct cytotoxic effects, leading to conditions such as heart failure. Amyloidosis can be classified into acquired or inherited forms and can be systemic or localized. Diagnosing cardiac amyloidosis is complex and often requires tissue biopsies, which are supported by Congo Red dye staining. In some cases, bisphosphonate bone scans may provide a less invasive diagnostic option. In this state-of-the-art review, we focus on the most common forms of cardiac amyloidosis, from epidemiology to therapy, emphasizing the differences in molecular mechanisms and the importance of pathological diagnosis for appropriate treatment using a multidisciplinary approach.

Spatial transcriptomics of a parasitic flatworm provides a molecular map of drug targets and drug resistance genes

The spatial organization of gene expression dictates tissue functions in multicellular parasites. Here, we present the spatial transcriptome of a parasitic flatworm, the common liver fluke Fasciola hepatica. We identify gene expression profiles and marker genes for eight distinct tissues and validate the latter by in situ hybridization. To demonstrate the power of our spatial atlas, we focus on genes with substantial medical importance, including vaccine candidates (Ly6 proteins) and drug resistance genes (glutathione S-transferases, ABC transporters). Several of these genes exhibit unique expression patterns, indicating tissue-specific biological functions. Notably, the prioritization of tegumental protein kinases identifies a PKCβ, for which small-molecule targeting causes parasite death. Our comprehensive gene expression map provides unprecedented molecular insights into the organ systems of this complex parasitic organism, serving as a valuable tool for both basic and applied research.

Metformin-mediated protection against doxorubicin-induced cardiotoxicity

BackgroundA phase II clinical trial of metformin (MET) for the treatment of doxorubicin (DOX)-induced cardiotoxicity (NCT02472353) failed. ObjectivesThe aims of this study were to confirm MET-mediated protection against DOX-induced cardiotoxicity and its mechanism using H9C2 cells, and to establish a Wistar rat model of DOX-induced cardiotoxicity. Subsequently, Wistar rats were utilized to identify clinically relevant indicators for evaluating MET-mediated protection against DOX-induced cardiotoxicity, thereby facilitating early transition towards successful clinical trials. MethodsMET-mediated protection was assessed using cell viability and cytotoxicity experiments. Additionally, intramitochondrial reactive oxygen species (ROS) levels were measured using an ROS fluorescent probe (dihydroethidium) to confirm the oxidative stress mechanism. Eighteen Wistar rats were randomly allocated to the control, DOX, and DOX+MET groups; and the body weight, adverse drug reactions (ADRs), myocardial injury, cardiac function, oxidative stress, and histopathology of heart tissues were compared between groups. ResultsH9C2 cells treated with MET/Dexrazoxane demonstrated dose-dependent protection against DOX-induced cardiotoxicity. The fluorescence intensity of H9C2 cells suggested DOX-induced cardiomyocyte toxicity and MET-mediated protection against DOX-induced cardiotoxicity. In vivo experiments confirmed that a rat model of DOX-induced cardiotoxicity was successfully established, but MET-mediated protection against DOX-induced cardiotoxicity was not demonstrated. This was attributed to insufficient energy intake because of ADRs, such as vomiting. ConclusionsWe confirmed the MET-mediated protection against DOX-induced cardiomyocyte toxicity and its mechanism involving the inhibition of oxidative stress in vitro experiments. It is imperative to investigate the optimal conditions for MET-mediated protection against DOX-induced cardiotoxicity in vivo or clinical trials.

A single-cell 3D dynamic volume control system for chondrocytes.

In articular cartilage, zone-specific cellular morphology is a typical characteristic of cartilage tissue, which is related with chondrocyte function, inflammation and osteoarthritis (OA). Chondrocyte hypertrophic phenotype is a criticle physiological process which indicates a hallmark of chondrocyte terminal differentiation and bone formation. Thus, developing a in vitro cell culture system for dynamic regulation of single chondrocyte volume at a three-dimensional (3D) level is particularly necessary for understanding how physical cues of matrix microenvironment regulate chondrocyte fate and the degeneration of articular cartilage. Here, based on the soft lithography techniques, we have constructed well-defined single-cell 3D dynamic volume control system to recapitulate the physiological matrix microenvironment of single chondrocyte niche. The results of finite element analysis indicated that the stress and strain distribution in the cell culture region is homogeneous during the stretching process. Additionally, 3D dynamic volume expansion and compression of single cells in physiological or hyperphysiological can be realized in this cell culture system. Our device for single-cell 3D dynamic culture provides a microphysiological culture system for chondrocytes to explore the mechanisms of cartilage hypertrophy, as well as develops a new paradigm for functional cartilage tissue engineering and regenerative medicine.

Increased dietary protein rather than fiber supports key metabolic and intestinal tissue functions in pigs, without increasing post-weaning diarrhea.

The post-weaning period in pigs is a critical window where nutritional interventions are implemented to prevent post-weaning diarrhea (PWD) and antibiotic use. One common strategy is feeding of low protein diets immediately following weaning. This intervention may reduce protein fermentation and pathogen proliferation, therefore decreasing the incidence of post-weaning diarrhea. These effects may also be mitigated by providing dietary fiber. However, studies examining the role of protein and fiber on gastrointestinal microbiota and metabolism are complicated by the presence of other substrates, including polyphenols and antinutritional factors in complex ingredients. In this study, semi-purified diets formulated to meet nutrient requirements were fed to 40 weaned pigs (n = 10/diet) to examine the effects of high protein (HP), high fiber (HF), or both (HFHP) compared to a control (CON) diet with industry standard crude protein and fiber content. Critical alterations in host metabolism and cecal transcriptome were identified in response to the CON diet. Diets with lower protein levels (CON and HF) induced alteration in transcripts from the serine synthesis pathways and integrated stress response in cecal tissue alongside systemic increases in metabolic pathways related to lysine degradation. High protein diets did not induce increases in gastrointestinal pathogen abundance. These results challenge the practice of feeding low protein diets post-weaning, by demonstrating a detrimental effect on intestinal cell function and muscle accretion. This suggests that with careful ingredient selection, increased dietary protein post-weaning could better pig health and growth compared to a standard diet.

Selenium Attenuates Ethanol-induced Hepatocellular Injury by Regulating Ferroptosis and Apoptosis.

Ferroptosis is a newly identified type of cell death which is strongly linked to the development of several diseases. Whereas, the role of ferroptosis in the improvement of ethanol-induced hepatocytes injury by selenium has not been confirmed. In this study, an in vitro cell damage model was established using half inhibition concentration of ethanol to induce NCTC clone 1469. Cell activity, lipid peroxidation, apoptosis and the expression of markers related to ferroptosis pathway was determined. A mouse model of alcoholic liver disease (ALD) was constructed and the effectiveness of selenium and ferrostatin-1 in treating ALD in vivo was assessed by serum liver function tests, tissue staining and immunohistochemistry for ferroptosis related proteins. Pretreatment with selenomethionine and ebselen significantly improved ethanol-induced reduction in hepatocyte viability, elevated GSH levels and SOD enzyme activity, reduced MDA and iron content, while improving ethanol-induced changes in apoptosis levels and ferroptosis markers GPX4, SLC7A11, and ACSL4, with the effect of Selenomethionine being more significant. In vivo results also indicated that intervention with selenium or ferroptosis inhibitors significantly improved ethanol-induced liver tissue damage, significantly reduced serum ALT and AST levels, upregulated GPX4 and SLC7A11, but reduced ACSL4 protein levels in liver tissue. The process of ethanol damage to hepatocytes is regulated by the ferroptosis pathway. Selenium may exert a beneficial role in ethanol-induced hepatocyte injury by antagonizing oxidative stress and regulating apoptosis and ferroptosis pathways.

Transcriptome Analysis Reveals the Early Development in Subcutaneous Adipose Tissue of Laiwu Piglets.

Adipose tissue plays an important role in pig production efficiency. Studies have shown that postnatal development has a vital impact on adipose tissue; however, the mechanisms behind pig adipose tissue early-life programming remain unknown. In this study, we analyzed the transcriptomes of the subcutaneous adipose tissue (SAT) of 1-day and 21-day old Laiwu piglets. The results showed that the SAT of Laiwu piglets significantly increased from 1-day to 21-day, and transcriptome analysis showed that there were 2352 and 2596 differentially expressed genes (DEGs) between 1-day and 21-day SAT in male and female piglets, respectively. Expression of genes in glycolysis, gluconeogenesis, and glycogen metabolism such as pyruvate kinase M1/2 (PKM), phosphoenolpyruvate carboxy kinase 1 (PCK1) and amylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase (AGL) were significantly different between 1-day and 21-day SAT. Genes in lipid uptake, synthesis and lipolysis such as lipase E (LIPE), acetyl-CoA carboxylase alpha (ACACA), Stearoyl-CoA desaturase (SCD), and 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) were also differentially expressed. Functional analysis showed enrichment of DEGs in transcriptional regulation, protein metabolism and cellular signal transduction. The protein-protein interaction (PPI) networks of these DEGs were analyzed and potential hub genes in these pathways were identified, such as transcriptional factors forkhead box O4 (FOXO4), CCAAT enhancer binding protein beta (CEBPB) and CCAAT enhancer binding protein delta (CEBPD), signal kinases BUB1 mitotic checkpoint serine/threonine kinase (BUB1) and cyclin-dependent kinase 1 (CDK1), and proteostasis-related factors ubiquitin conjugating enzyme E2 C (UBE2C) and cathepsin D (CTSD). Moreover, we further analyzed the transcriptomes of SAT between genders and the results showed that there were 54 and 72 DEGs in 1-day and 21-day old SAT, respectively. Genes such as KDM5D and KDM6C showed gender-specific expression in 1-day and 21-day SAT. These results showed the significant changes in SAT between 1-day and 21-day in male and female Laiwu pigs, which would provide information to comprehensively understand the programming of adipose tissue early development and to regulate adipose tissue function.

Adipose tissue responds to stress-induced immunosuppression affecting immune response partially by miR-145-5p/S1PR1 pathway

Stress-induced immunosuppression (SIIS) is one of the most common problems in intensive poultry production, which can cause immunized chickens to still develop diseases and bring huge losses to production. Recently, adipose tissue, as an immunomodulatory organ, has become a hot topic of attention. However, the function and mechanism of adipose tissue involved in SIIS and its influence on the immune response are still unclear. In this study, we dynamically analyzed the correlations between the T cells migration and change of sphingosine-1-phosphate receptor 1(S1PR1) gene in adipose tissue using chicken models with different immune states, and further explored the regulatory mechanisms and application. The results showed that SIIS could significantly change the expressions of lymphocytes migration related S1PR1 gene, and SIIS could inhibit the Newcastle disease virus (NDV) immune response partially by affecting the migration and proliferation of TCRα+ T cells in adipose tissue. Moreover, the miR-145-5p/S1PR1 pathway was a potential key mechanism to regulate T cells migration in adipose tissue, and circulating miR-145-5p had potential value as a molecular marker. This research can provide innovative reference for in-depth studying the immunoregulatory function and mechanism of adipose tissue.