Aging of the vasculature, which is integral to the functioning of literally all human organs, serves as a fundamental physiological basis for age-related alterations as well as a shared etiological mechanism for various chronic diseases prevalent in the elderly population. China, home to the world’s largest aging population, faces an escalating challenge in addressing the prevention and management of these age-related conditions. To meet this challenge, the Aging Biomarker Consortium of China has developed an expert consensus on biomarkers of vascular aging (VA) by synthesizing literature and insights from scientists and clinicians. This consensus provides a comprehensive assessment of biomarkers associated with VA and presents a systemic framework to classify them into three dimensions: functional, structural, and humoral. Within each dimension, the expert panel recommends the most clinically relevant VA biomarkers. For the functional domain, biomarkers reflecting vascular stiffness and endothelial function are high-lighted. The structural dimension encompasses metrics for vascular structure, microvascular structure, and distribution. Additionally, proinflammatory factors are emphasized as biomarkers with the humoral dimension. The aim of this expert consensus is to establish a foundation for assessing the extent of VA and conducting research related to VA, with the ultimate goal of improving the vascular health of the elderly in China and globally.

Stem cell-based regenerative therapies, which harness the self-renewal and differentiation properties of stem cells, have been in the spotlight due to their widespread applications in treating degenerative, aging, and other, generally intractable diseases. Therapeutically effective hematopoietic stem cells, mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells have been used in numerous basic and translational studies with exciting results. However, pre-/post-transplantation issues of poor cell survival and retention, uncontrolled differentiation, and insufficient numbers of cells engrafted into host tissues are the major challenges in stem cell-based regenerative therapies. Engineered biomaterials have adjustable biochemical and biophysical properties that significantly affect cell behaviors, such as cell engraftment, survival, migration, and differentiation outcomes, thereby enhancing the engraftment of implanted stem cells and guiding tissue regeneration. Therefore, the combination of stem cell biology with bioengineered materials is a promising strategy to improve the therapeutic outcomes of stem cell-based regenerative therapy. In this review, we summarize the advances in the modulation of behaviors of stem cells via engineered biomaterials. We then present different approaches to harnessing bioengineered materials to enhance the transplantation of stem cells. Finally, we will provide future directions in regenerative therapy using stem cells.

The skeleton is an important structural and metabolic organ in human body, while aging is the physiological basis for degenerative skeletal diseases. China has the largest aging population in the world and faces great challenges in preventing and managing diseases related to skeletal aging. To address these challenges, the Aging China Biomarkers Consortium (ABC) has reached an expert consensus on biomarkers of skeletal aging by synthesizing the literature and insights from scientists and clinicians. The consensus provides a comprehensive assessment of biomarkers associated with skeletal aging and proposes a systematic framework that categorizes biomarkers into three dimensions, namely, functional, structural, and humoral dimensions. Within each dimension, the ABC recommended clinical and evidential research-based biomarkers for physiological aging and degenerative pathologies of the skeleton. This expert consensus aims to lay the foundation for future studies to assess the prediction, diagnosis, early warning, and treatment of diseases associated with skeletal aging, with the ultimate goal of improving the skeletal health of elderly populations in China and around the world.

Adult skeletal muscle stem cells (MuSCs) are essential for muscle homeostasis and regeneration. During aging, the number of MuSCs and their regenerative capacity gradually decline but the underlying mechanisms remain elusive. Here, we identify Sugt1 (suppressor of G2 allele of SKP1 homolog), which is a chaperone for kinetochore function during mitosis and is essential for muscle regeneration by regulating MuSC proliferation. Sugt1 expression level is low in quiescent MuSCs but highly induced when the cells become activated and expand as proliferating myoblasts. Inducible inactivation of Sugt1 in MuSCs causes impaired muscle regeneration upon acute injury by impairing MuSC proliferation. Furthermore, loss of Sugt1 leads to cell cycle arrest in the G2/M phase and cellular senescence. Moreover, long-term loss of Sugt1 in MuSCs results in precocious muscle aging by inhibiting MuSC cell proliferation and promoting cellular senescence. Mechanistically, we identify a cytosolic E3 ubiquitin-ligase, Trim21 as a protein interacting partner for Sugt1 in myoblast cells. We further demonstrate that Sugt1 promotes the ubiquitination of p21 via Trim21; and Sugt1 loss causes p21 accumulation to inhibit cell cycle progression and stimulates cellular senescence. Collectively, our findings uncover that Sugt1 is an essential regulator for MuSC regenerative function during muscle regeneration and aging.

Ulcerative colitis (UC) is a chronic inflammatory disease of colon, which is characterized by cryptarchitectural distortion. Alternation of colonic stem cell (CoSC) contributed to the occurrence of UC, yet the regulatory mechanisms remain unclear. To investigate the dysregulation of transcriptional and post-transcriptional regulation, we performed RNA-seq, ATAC-seq, and m⁶A meRIP-seq analysis of the cultured CoSCs that were isolated from UC patients. The transcriptome analysis revealed distinct expression signatures of UC patients in mild and severe stages. We observed abnormal activation of immune and extracellular matrix-related genes in patients affected by severe UC. The chromatin accessibility at the promoter regions of these genes was also specifically increased in the severe stage. In addition, we identified that a global loss of RNA m⁶A modification in the severe stage was accompanied by higher expression of the m⁶A demethylase FTO. The aberrant activation of a large number of immune and extracellular matrix-related genes, including IL4R, HLA-DPA1, and COL6A1, was related to both the gain of chromatin accessibility and the loss of m⁶A in severe UC patients. Our finding revealed an environment-independent immune activation of CoSCs in UC and provided FTO as a potential therapeutic target.

Regulation of totipotency and naïve pluripotency is crucial for early human embryo development. However, the mechanisms of naïve pluripotency and totipotency regulation in humans, especially the signaling pathways involved in these processes, remain largely unknown. Here, using the conversion of human extended pluripotent stem cells (hEPSCs) to naïve pluripotent stem cells as a model, we performed a CRISPR/Cas9-based kinome knockout screen to analyze the effect of disrupting 763 kinases in regulating human naïve pluripotency. Further validation using small molecules revealed that the inhibition of ErbB family kinases promoted the transition of hEPSCs to human naïve pluripotent stem cells. More importantly, chemical inhibition of the ErbB family also promoted induction of totipotent signatures in human pluripotent cells under different culture conditions. Our findings provide new mechanistic insights into the regulation of naïve pluripotency and totipotency in humans.

The pathogenesis of several kidney diseases results in the eventual destruction of the renal tubular system, which can progress to end-stage renal disease. Previous studies have demonstrated the involvement of a population of SOX9-positive cells in kidney regeneration and repair process following kidney injury. However, the ability of these cells to autonomously generate kidney organoids has never been investigated. Here, we isolated SOX9⁺ kidney progenitor cells (KPCs) from both mice and humans and tested their differentiation potential in vitro. The data showed that the human SOX9⁺ KPC could self-assemble into organoids with kidney-like morphology. We also used single-cell RNA sequencing to characterize the organoid cell populations and identified four distinct types of renal tubular cells. Compared to the induced pluripotent stem cell-derived kidney organoids, KPC demonstrated more tubular differentiation potential but failed to differentiate into glomerular cells. KPC-derived organoid formation involved the expression of genes related to metanephric development and followed a similar mechanism to renal injury repair in acute kidney injury patients. Altogether, our study provided a potentially useful approach to generating kidney tubular organoids for future application.

Aging is a complex and heterogeneous process, raising important questions about how aging is differently impacted by underlying genetics and external factors. Recently, migrasomes, newly discovered organelles, have been identified to play important roles in various physiological and pathological processes by facilitating cell-to-cell communication. Thus far, their involvement in cellular senescence and aging remains largely unexplored. In this study, we aimed to investigate how migrasomes impact on cellular aging by leveraging multiple cellular senescence models, including replicatively senescent (RS), pathologically senescent and stress-induced senescent human mesenchymal stem cells (hMSCs), as well as RS human primary fibroblasts. In all cellular aging models, we detected an enhanced formation of migrasomes. Notably, migrasomes in senescent cells exhibited an accumulation of numerous aging hallmarks, such as dysfunctional mitochondria, endogenous retroviruses, and senescence-associated pro-inflammatory cytokines. Furthermore, we discovered that migrasomes derived from senescent cells can be taken up by young cells, thereby transferring aging signals and subsequently causing premature senescence phenotypes in recipient cells. Mechanistically, we found that treatment with migrasomes derived from senescent cells activated the innate immune response. Thus, our study sheds light on a pivotal role of migrasomes in mediating the contagiousness of aging.

Pharyngeal pouches, which are endodermal outpockets that segment the pharyngeal arches, play a crucial role in the development of craniofacial skeletons in vertebrate embryos. Our previous study successfully identified pharyngeal pouch progenitors (PPPs) in zebrafish embryos and emphasized the significance of BMP2b signaling in their specification. However, the specific mechanism by which these progenitors originate from endodermal cells remains largely unknown. Here we found that the pharmacological activation of Wnt signaling pathway disrupts the emergence of PPPs and subsequently hinders the formation of pharyngeal pouches. Moreover, we have identified the expression of tmem88a and tmem88b (collectively known as tmem88a/b) in PPPs during the early-somite stages. Furthermore, the deficiency of tmem88a/b leads to an excessive accumulation of β-catenin in both the cytoplasm and nucleus of endodermal cells that are intended to differentiate into PPPs. Importantly, suppressing the hyperactivation of Wnt/β-catenin signaling through pharmacological treatment, the defects in PPP specification in tmem88a/b^−/− mutants are successfully rescued. In summary, our findings establish a clear connection between the specification of PPPs and the regulation of Wnt signaling mediated by Tmem88. These results underscore the pivotal role of Tmem88 in the development of pharyngeal pouches.

Cardiac aging constitutes a significant risk factor for cardiovascular diseases prevalent among the elderly population. Urgent attention is required to prioritize preventive and management strategies for age-related cardiovascular conditions to safeguard the well-being of elderly individuals. In response to this critical challenge, the Aging Biomarker Consortium (ABC) of China has formulated an expert consensus on cardiac aging biomarkers. This consensus draws upon the latest scientific literature and clinical expertise to provide a comprehensive assessment of biomarkers associated with cardiac aging. Furthermore, it presents a standardized methodology for characterizing biomarkers across three dimensions: functional, structural, and humoral. The functional dimension encompasses a broad spectrum of markers that reflect diastolic and systolic functions, sinus node pacing, neuroendocrine secretion, coronary micro-circulation, and cardiac metabolism. The structural domain emphasizes imaging markers relevant to concentric cardiac remodeling, coronary artery calcification, and epicardial fat deposition. The humoral aspect underscores various systemic (N) and heart-specific (X) markers, including endocrine hormones, cytokines, and other plasma metabolites. The ABC’s primary objective is to establish a robust foundation for assessing cardiac aging, thereby furnishing a dependable reference for clinical applications and future research endeavors. This aims to contribute significantly to the enhancement of cardiovascular health and overall well-being among elderly individuals.

Recurrent spontaneous abortion (RSA) affects 2%–5% of couples worldwide and remains a subject of debate regarding the effectiveness of lymphocyte immunotherapy (LIT) due to limited retrospective studies. We conducted a comprehensive Bayesian analysis to assess the impact of LIT on RSA. Using data from the Shenzhen Maternity and Child Healthcare Hospital (2001–2020, n = 2316), a Bayesian generalized linear model with predictive projection feature selection was employed. Our analysis revealed a significant improvement in live birth rates for RSA patients undergoing LIT. Notably, LIT had a greater impact compared to the other 85 factors considered. To mitigate research bias, we conducted a Bayesian meta-analysis combining our dataset with 19 previously reported studies (1985–2021, n = 4246). Additionally, we developed an empirical model high-lighting the four key factors, which are the LIT result, age, paternal blood type, and anticardiolipin antibody. Younger age (19–27), paternal blood type B, and a positive anticardiolipin antibody (IgM) were associated with better therapeutic outcomes in LIT for RSA. These findings aid clinicians in identifying suitable candidates for LIT and improving treatment outcomes.

3D bioprinting emerges as a critical tool in biofabricating functional 3D tissue or organ equivalents for regenerative medicine. Bioprinting techniques have been making strides in integrating automation, customization, and digitalization in coping with diverse tissue engineering scenarios. The convergence of robotic arm-based 3D bioprinting techniques, especially in situ 3D bioprinting, is a versatile toolbox in the industrial field, promising for biomedical application and clinical research. In this review, we first introduce conceptualized modalities of robotic arm-based bioprinting from a mechanical perspective, which involves configurative categories of current robot arms regarding conventional bioprinting strategies. Recent advances in robotic arm-based bioprinting in tissue engineering have been summarized in distinct tissues and organs. Ultimately, we systematically discuss relative advantages, disadvantages, challenges, and future perspectives from bench to bedside for biomedical application.

Glioma stem cells (GSCs) in the hypoxic niches contribute to tumor initiation, progression, and recurrence in glioblastoma (GBM). Metabolic pathways are altered in GSCs under hypoxia, but the mechanism underlying the altered one-carbon metabolism in GSCs by hypoxia is largely unknown. Here, we report that hypoxia induces down-regulation of DHFR as well as up-regulation of MAT2A in GBM tumorsphere cells, and confers them the ability of cell proliferation that is independent of exogenous folate. Importantly, short-term inhibition of the methionine cycle or exposure to the MAT2A inhibitor is sufficient to cripple the tumor-initiating capability of GBM tumorsphere cells. Therefore, we present a novel perspective on how hypoxia alters the pattern of one-carbon metabolism in GBM tumorsphere cells and provide evidence that restriction of methionine intake or targeting MAT2A inhibits the tumorigenicity of GBM tumorsphere cells.

Sterile alpha and Toll/interleukin 1 receptor motif-containing protein 1 (SARM1) is regarded as a key protein and a central executor of the self-destruction of injured axons. To identify novel molecular players and understand the mechanisms regulating SARM1 function, we investigated the interactome of SARM1 by proximity labeling and proteomic profiling. Among the SARM1-associated proteins, we uncovered that overexpression (OE) of ubiquitin-specific peptidase 13 (USP13) delayed injury-induced axon degeneration. OE of an enzyme-dead USP13 failed to protect injured axons, indicating that the deubiquitinase activity of USP13 was required for its axonal protective effect. Further investigation revealed that USP13 deubiquitinated SARM1, which increased the inhibitory interaction between the N-terminal armadillo repeat motif (ARM) and C-terminal Toll/interleukin-1 receptor (TIR) domains of the SARM1 protein, thereby suppressing SARM1 activation in axon injury. Collectively, these findings suggest that increase of USP13 activity enhances the self-inhibition of SARM1, which may provide a strategy to mitigate axon degeneration in injury and disease.

DNA double-strand breaks (DSBs) induced by gene-editing tools are primarily repaired through non-homologous end joining (NHEJ) or homology-directed repair (HDR) using synthetic DNA templates. However, error-prone NHEJ may result in unexpected indels at the targeted site. For most genetic disorders, precise HDR correction using exogenous homologous sequence is ideal. But, the therapeutic application of HDR might be especially challenging given the requirement for the codelivery of exogenous DNA templates with toxicity into cells, and the low efficiency of HDR could also limit its clinical application. In this study, we efficiently repair pathogenic mutations in HBB coding regions of hematopoietic stem cells (HSCs) using CRISPR/Cas9-mediated gene conversion (CRISPR/GC) using the paralog gene HBD as the internal template. After transplantation, these edited HSCs successfully repopulate the hematopoietic system and generate erythroid cells with significantly reduced thalassemia propensity. Moreover, a range of pathogenic gene mutations causing β-thalassemia in HBB coding regions were effectively converted to normal wild-type sequences without exogenous DNA templates using CRISPR/GC. This highlights the promising potential of CRISPR/GC, independent of synthetic DNA templates, for genetic disease gene therapy.

Synaptic vesicle (SV) exocytosis is orchestrated by protein machineries consisting of the SNARE complex, Ca²⁺ sensors, and their partners. Secretagogin (SCGN) is a Ca²⁺-binding protein involved in multiple forms of vesicle secretion. Although SCGN is implicated in multiple neurological disorders, its role in SV exocytosis in neurons remains unknown. Here, using knockout and knockdown techniques, we report that SCGN could regulate the asynchronous and spontaneous forms of excitatory but not inhibitory SV exocytosis in mouse hippocampal neurons. Furthermore, SCGN functioned in glutamate release via directly interacting with Doc2α, a high-affinity Ca²⁺ sensor specific for asynchronous and spontaneous SV exocytosis. Conversely, the interaction with SCGN is also required for Doc2α to execute its Ca²⁺ sensor function in SV release. Together, our study revealed that SCGN plays an important role in asynchronous and spontaneous glutamate release through its interaction with Doc2α.

Vitamin C is used to treat anaemia; however, the mechanism through which vitamin C promotes erythroid differentiation is not comprehensively understood. The in vitro erythroid differentiation induction system can reveal the differentiation mechanism and provide erythrocytes for clinical transfusion and anaemia treatment. This process can be promoted by adding small-molecule compounds. In this study, we added L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate (AA2P), a derivative of vitamin C, to an erythroid differentiation system induced from umbilical cord blood haematopoietic stem and progenitor cells in vitro and detected its effect on erythroid differentiation using single-cell transcription sequencing technology combined with non-targeted metabolism detection. AA2P increased the proportion of late basophilic erythroblasts, upregulating the expression of erythroid-related regulatory molecules GATA1, KLF1, ALAS2, and the globins HBG and HBB. CA1 is a target gene of AA2P, and CA1 knockdown affected the expression of globin-related genes. AA2P also increased glycolysis and decreased oxidative phosphorylation to facilitate terminal erythroid differentiation and enhanced the proliferation of early erythroid progenitors by altering the cell cycle. These results provide a reliable basis for using vitamin C to improve the efficiency of erythropoiesis in vitro and for the clinical treatment of anaemia.