摘要: Infectious diseases have become significant events that threaten global public health and economic development. Since the 20th century, multiple outbreaks of infectious diseases have gradually deepened humanity's understanding of viral infections, prevention and treatment. Organoids possess a high degree of similarity to human physiological states and have strong self-organising capabilities. Research on infectious diseases based on organoids offers significant advantages in terms of availability, editability and diversity. In this perspective, we briefly introduce the development of organoids, focusing on historically significant infectious diseases that have caused fatal harm to human health, such as HIV, ZIKV, SARS-CoV-2 and MPXV. We further summarise relevant research on the pathogenic mechanisms of these viruses based on organoid models, host reactivity, and therapeutic strategies. Finally, we list the latest research techniques combined with organoid models, discuss the challenges faced in the development of organoids and look forward to the future prospects of organoids in vaccine and drug development.

摘要: Chromosomal abnormalities acquired during cell culture can compromise the differentiation potential of human pluripotent stem cells (hPSCs). In this work, we identified a diminished differentiation capacity to retinal progenitor cells in human embryonic stem cells (hESCs) with complex karyotypes that had in common the loss of part of chromosome 18q. Time-course gene-expression analysis during spontaneous differentiation and single-cell RNA sequencing found that these variant cell lines poorly specified into anterior neuroectoderm, and, when progressing through differentiation, they yielded poorly pigmented cells, with proliferating and pluripotent cell populations. The variant cell lines showed dysregulation of TGF beta signalling during differentiation, and chemical modulation of the TGF beta pathways showed that the basis of the improper specification was due to imbalances in the anteroposterior neuroectodermal fate commitment.

摘要: Pigs are important agricultural animals whose growth rate and meat production performance are related to muscle development. Musculoskeletal embryonic nuclear protein 1 (MUSTN1) participates in various biological processes, including myogenesis and growth in animals, but the physiological functions and mechanisms of porcine MUSTN1 on muscle development are unclear; thus, we aimed to elucidate them. We found that MUSTN1 was highly expressed in the muscles of fast-growing pigs. Functionally, MUSTN1 promoted myoblast proliferation and differentiation. MUSTN1 knockout mice exhibited reduced muscle mass and fibre cross-sectional area, decreased exercise endurance, and delayed muscle regeneration. Small muscle protein X-linked (SMPX) was identified as an interacting protein of MUSTN1, and its promotion of myogenic differentiation depended on MUSTN1. Furthermore, MUSTN1 stabilised SMPX and maintained myofiber morphology. This study suggests that MUSTN1 is a critical regulator in the control of muscle development and regeneration and is a potential target for animal genetic improvement and the treatment of human muscle disease.

摘要: Mucosal healing is critical to maintain and restore intestinal homeostasis in inflammation. Previous data provide evidence that glial cell line-derived neurotrophic factor (GDNF) restores epithelial integrity by largely undefined mechanisms. Here, we assessed the role of GDNF for mucosal healing. In dextran sodium sulphate (DSS)-induced colitis in mice application of GDNF enhanced recovery as revealed by reduced disease activity index and histological inflammation scores. In biopsy-based wounding experiments GDNF application in mice improved healing of the intestinal mucosa. GDNF-induced epithelial recovery was also evident in wound assays from intestinal organoids and Caco2 cells. These observations were accompanied by an increased number of Ki67-positive cells in vivo after GDNF treatment, which were present along elongated proliferative areas within the crypts. In addition, the intestinal stem cell marker and R-spondin receptor LGR5 was significantly upregulated following GDNF treatment in all experimental models. The effects of GDNF on cell proliferation, LGR5 and Ki67 upregulation were blocked using the RET-specific inhibitor BLU-667. Downstream of RET-phosphorylation, activation of Src kinase was involved to mediate GDNF effects. GDNF promotes intestinal wound healing by promoting cell proliferation. This is mediated by RET-dependent activation of Src kinase with consecutive LGR5 upregulation, indicating activation of the stem cell niche.

摘要: Intestinal stem cells differentiate into absorptive enterocytes, characterised by increased brush border enzymes such as intestinal alkaline phosphatase (IAP), making up the majority (95%) of the terminally differentiated cells in the villus. Loss of integrity of the intestinal epithelium plays a key role in inflammatory diseases and gastrointestinal infection. Here, we show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differentiation. Repression of endogenous miR-27a-3p leads to increased enterocyte differentiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. Mechanistically, miR-27a-3p regulates intestinal cell differentiation and proliferation at least in part through the regulation of retinoic acid receptor alpha (RXR alpha), a modulator of Wnt/beta-catenin signalling. Repression of miR-27a-3p increases the expression of RXR alpha and concomitantly, decreases the expression of active beta-catenin and cyclin D1. In contrast, overexpression of miR-27a-3p mimic decreases the expression of RXR alpha and increases the expression of active beta-catenin and cyclin D1. Moreover, overexpression of the miR-27a-3p mimic results in impaired enterocyte differentiation and increases intestinal epithelial cell proliferation. These alterations were attenuated or blocked by Wnt inhibition. Our study demonstrates an miR-27a-3p/RXR alpha/Wnt/beta-catenin pathway that is important for the maintenance of enterocyte homeostasis in the small intestine. We show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differentiation. Repression of endogenous miR-27a-3p leads to increased enterocyte differentiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. image

摘要: Aberrant activation of dermal fibroblasts during wound healing often leads to debilitating fibrotic changes in the skin, such as scleroderma and keloids. However, the underlying cellular and molecular mechanisms remain elusive. Here, we established a wound-induced skin fibrosis (WISF) mouse model in mature adult mice, characterised by excessive deposition of collagen bundles, loss of dermal adipocytes, and enrichment of DPP4+Ly6A+THY1+ hypodermal interstitial adipocyte progenitors (HI-APs) and pericytes, resembling human fibrotic skin diseases. This WISF model exhibited an age-dependent gain of fibrotic characteristics, contrasting with the wound-induced hair neogenesis observed in younger mice. Through comprehensive analyses of the WISF, we delineated a trajectory of fibroblast differentiation that originates from HI-APs. These progenitors highly expressed several extracellular matrix (ECM) genes and exhibited a TGF beta pathway signature. TGF beta was identified as the key signal to inhibit the adipogenic potential and maintain the fibrogenic potential of dermal APs. Additionally, administering a TGF beta receptor inhibitor to wound scar reduced the abundance of ECM-producing APs. Finally, analysis of human scleroderma skin tissues revealed a negative correlation between the expression of AP-, ECM-, and TGF beta pathway-related genes and PPARG. Overall, this study establishes a wound-induced skin fibrosis mouse model and demonstrates that TGF beta-mediated blockage of HI-AP differentiation is crucial for driving fibrotic pathology. Targeting HI-APs and adipogenesis may provide novel avenues for developing disease-modifying therapies for fibrotic skin diseases.

摘要: Dry eye disease (DED) is a growing public health concern affecting millions of people worldwide and causing ocular discomfort and visual disturbance. Developing its therapeutic drugs based on animal models suffer from interspecies differences and poor prediction of human trials. Here, we established long-term 3D human corneal epithelial organoids, which recapitulated the cell lineages and gene expression signature of the human corneal epithelium. Organoids can be regulated to differentiate ex vivo, but the addition of FGF10 inhibits this process. In the hyperosmolar-induced DED organoid model, the release of inflammatory factors increased, resulting in damage to the stemness of stem cells and a decrease in functional mucin 1 protein. Furthermore, we found that the organoids could mimic clinical drug treatment responses, suggesting that corneal epithelial organoids are promising candidates for establishing a drug testing platform ex vivo. In summary, we established a functional, long-term 3D human epithelial organoid that may serve as an ex vivo model for studying the functional regulation and disease modelling. The functional, long-term 3D human epithelial organoids were established from human corneal epithelium tissue, which recapitulated the cell lineages and gene expression signatures of corneal epithelium. The organoid can be induced to differentiated, and the ex vivo DED model was produced under hyperosmotic stress, providing a potential to explore the stem cell identity and keratinocyte function in DED ex vivo. Based on DED organoid model, the drug testing was performed, and organoids could precisely mimic drug treatment responses of corneal epithelium. image

摘要: Immunotherapy has brought significant advancements in the treatment of lung adenocarcinoma (LUAD), but identifying suitable candidates remains challenging. In this study, we investigated tumour cell heterogeneity using extensive single-cell data and explored the impact of different tumour cell cluster abundances on immunotherapy in the POPLAR and OAK immunotherapy cohorts. Notably, we found a significant correlation between CKS1B+ tumour cell abundance and treatment response, as well as stemness potential. Leveraging marker genes from the CKS1B+ tumour cell cluster, we employed machine learning algorithms to establish a prognostic and immunotherapeutic signature (PIS) for LUAD. In multiple cohorts, PIS outperformed 144 previously published signatures in predicting LUAD prognosis. Importantly, PIS reliably predicted genomic alterations, chemotherapy sensitivity and immunotherapy responses. Immunohistochemistry validated lower expression of immune markers in the low-PIS group, while in vitro experiments underscored the role of the key gene PSMB7 in LUAD progression. In conclusion, PIS represents a novel biomarker facilitating the selection of suitable LUAD patients for immunotherapy, ultimately improving prognosis and guiding clinical decisions. Developed a novel prognostic and immunotherapeutic signature for lung adenocarcinoma, revealing its effectiveness in predicting treatment outcomes and immunotherapy responsiveness, fundamentally advancing personalized cancer therapy. image

摘要: Osteoporosis (OP) is a common disease characterized by bone loss and bone tissue microstructure degradation. Drug treatment is a common clinical treatment that aims to increase bone mass and bone density. Tetrahedral DNA nanostructures (TDNs) are three-dimensional tetrahedral frames formed by folding four single-stranded DNA molecules, which have good biological safety and can promote bone regeneration. In this study, a mouse model of OP was established by ovariectomy (OVX) and TDN was injected into the tail vein for 8 weeks. We found that ovariectomized mice could simulate some physiological changes in OP. After treatment with TDNs, some of this destruction in mice was significantly improved, including an increase in the bone volume fraction (BV/TV) and bone trabecular number (Tb. N), decrease in bone separation (Tb. SP), reduction in the damage to the mouse cartilage layer, reduction in osteoclast lacunae in bone trabecula, and reduction in the damage to the bone dense part. We also found that the expression of ALP, beta-Catenin, Runx2, Osterix, and bone morphogenetic protein (BMP)2 significantly decreased in OVX mice but increased after TDN treatment. Therefore, this study suggests that TDNs may regulate the Wnt/beta-Catenin and BMP signalling pathways to improve the levels of some specific markers of osteogenic differentiation, such as Runx2, ALP, and Osterix, to promote osteogenesis, thus showing a therapeutic effect on OP mice.

摘要: Bone repair is intricately correlated with vascular regeneration, especially of type H vessels. Sirtuin 1 (SIRT1) expression is closely associated with endothelial function and vascular regeneration; however, the role of SIRT1 in enhancing the coupling of type H vessel formation with osteogenesis to promote bone repair needs to be investigated. A co-culture system combining human umbilical vein endothelial cells and osteoblasts was constructed, and a SIRT1 agonist was used to evaluate the effects of SIRT1 activity. The angiogenic and osteogenic capacities of the co-culture system were examined using short interfering RNA. Mouse models with bone defects in the femur or mandible were established to explore changes in type H vessel formation and bone repair following modulated SIRT1 activity. SIRT1 activation augmented the angiogenic and osteogenic capacities of the co-culture system by activating the PI3K/AKT/FOXO1 signalling pathway and did not significantly regulate osteoblast differentiation. Inhibition of the PI3K/AKT/FOXO1 pathway attenuated SIRT1-mediated effects. The SIRT1 activity in bone defects was positively correlated with the formation of type H vessels and bone repair in vivo, whereas SIRT1 inhibition substantially weakened vascular and bone formation. Thus, SIRT1 is crucial to the coupling of type H vessels with osteogenesis during bone repair.