From dichotomy to diversity:deciphering the multifaceted roles of tumor-associated macrophages in cancer progression and therapy

Macrophages are innate immune cells that are ubiquitously distributed throughout the vertebrate body.Macrophages orchestrate sophisticated processes in development,homeostasis,immunity,and disease1.Macrophages residing in tumor tissues are commonly known as tumor-associated macrophages(TAMs)and promote or inhibit tumor growth depending on the activation state2.

Cell atlas of CCl_(4)-induced progressive liver fibrosis reveals stage-specific responses

Chronic liver injury leads to progressive liver fibrosis and ultimately cirrhosis,a major cause of morbidity and mortality worldwide.However,there are currently no effective anti-fibrotic therapies available,especially for latestage patients,which is partly attributed to the major knowledge gap regarding liver cell heterogeneity and cellspecific responses in different fibrosis stages.To reveal the multicellular networks regulating mammalian liver fibrosis from mild to severe phenotypes,we generated a single-nucleus transcriptomic atlas encompassing 49919nuclei corresponding to all main liver cell types at different stages of murine carbon tetrachloride(CCl_(4))-induced progressive liver fibrosis.Integrative analysis distinguished the sequential responses to injury of hepatocytes,hepatic stellate cells and endothelial cells.Moreover,we reconstructed the cell-cell interactions and gene regulatory networks implicated in these processes.These integrative analyses uncovered previously overlooked aspects of hepatocyte proliferation exhaustion and disrupted pericentral metabolic functions,dysfunction for clearance by apoptosis of activated hepatic stellate cells,accumulation of pro-fibrotic signals,and the switch from an anti-angiogenic to a pro-angiogenic program during CCl_(4)-induced progressive liver fibrosis.Our dataset thus constitutes a useful resource for understanding the molecular basis of progressive liver fibrosis using a relevant animal model.

Highly efficient generation of blastocyst-like structures from spliceosomes-repressed mouse totipotent blastomere-like cells

Mammalian embryogenesis begins with a totipotent zygote.Blastocyst-like structures can be captured by aggregated cells with extended pluripotent properties in a three-dimensional(3D)culture system.However,the efficiency of generating blastoids is low,and it remains unclear whether other reported totipotent-like stem cells retain a similar capacity.In this study,we demonstrated that spliceosomal repression-induced totipotent blastomere-like cells(TBLCs)form blastocyst-like structures within around 80%of all microwells.In addition,we generated blastoids initiating from a single TBLC.TBLC-blastoids express specific markers of constituent cell lineages of a blastocyst and resemble blastocyst in cell-lineage allocation.Moreover,singlecell RNA sequencing revealed that TBLC-blastoids share a similar transcriptional profile to natural embryos,albeit composed of fewer primitive endoderm-like cells.Furthermore,TBLC-blastoids can develop beyond the implantation stage in vitro and induce decidualization in vivo.In summary,our findings provided an alternative cell type to efficiently generate blastoids for the study of early mouse embryogenesis.

Towards a primate single-cell atlas

Biology in the 21st century is shifting substantially towards single-cell analysis.Mammalian tissues are highly heterogeneous and contain multiple cell types in different states whose tight coordination determines overall function.Bulk measurements,including RNA sequencing,provide average values,which may dilute cell-specific effects or overlook rare effects of functional importance.This greatly limits our understanding of mammalian physiology and disease.For example,the histological structures of the cortical and medullary regions of the kidney differ substantially,and their cells exhibit distinct characteristics related to environmental gradients such as oxygenation,glomerular filtrate-induced shear stress,and solute concentrations within the nephron.Furthermore,not all nephrons,mesenchymal cells,or vascular cells function in the same way,especially in the context of disease and aging.

Development of a novel virus-like particle-based vaccine for preventing tick-borne encephalitis virus infection

Tick-borne encephalitis virus(TBEV)is an important tick-borne pathogen that poses as a serious public health concern.The coverage and immunogenicity of the currently available vaccines against TBEV are relatively low;therefore,it is crucial to develop novel and effective vaccines against TBEV.The present study describes a novel strategy for the assembly of virus-like particles(VLPs)by co-expressing the structural(core/prM/E)and non-structural(NS2B/NS3Pro)proteins of TBEV.The efficacy of the VLPs was subsequently evaluated in C57BL/6 mice,and the resultant IgG serum could neutralize both Far-Eastern and European subtypes of TBEV.These findings indicated that the VLP-based vaccine elicited the production of cross-subtype reactive antibodies.The VLPs provided protection to mice lacking the type I interferon receptor(IFNAR^(-/-))against lethal TBEV challenge,with undetectable viral load in brain and intestinal tissues.Furthermore,the group that received the VLP vaccine did not exhibit significant pathological changes and the inflammatory factors were significantly suppressed compared to the control group.Immunization with the VLP vaccine induced the production of multiple-cytokine-producing antiviral CD4+T cells in vivo,including TNF-α^(+),IL-2^(+),and IFN-γ^(+)T cells.Altogether,the findings suggest that noninfectious VLPs can serve as a potentially safe and effective vaccine candidate against diverse subtypes of TBEV.

Spatially resolved expression landscape and generegulatory network of human gastric corpus epithelium

Molecular knowledge of human gastric corpus epithelium remains incomplete.Here,by integrated analyses using single-cell RNA sequencing(scRNA-seq),spatial transcriptomics,and single-cell assay for transposase accessible chromatin sequencing(scATAC-seq)techniques,we uncovered the spatially resolved expression landscape and gene-regulatory network of human gastric corpus epithelium.Specifically,we identified a stem/progenitor cell population in the isthmus of human gastric corpus,where EGF and WNT signaling pathways were activated.Meanwhile,LGR4,but not LGR5,was responsible for the activation of WNT signaling pathway.Importantly,FABP5 and NME1 were identified and validated as crucial for both normal gastric stem/progenitor cells and gastric cancer cells.Finally,we explored the epigenetic regulation of critical genes for gastric corpus epithelium at chromatin state level,and identified several important cell-type-specific transcription factors.In summary,our work provides novel insights to systematically understand the cellular diversity and homeostasis of human gastric corpus epithelium in vivo.

Generation of pigs with humanized type Ⅱ collagen by precise human COL2A1 gene knock-in

Osteoarthritis(OA)is the most common chronic disease,characterized by progressive cartilage breakdown,subchondral bone sclerosis,and aberrant bone outgrowth(Yucesoy et al.,2015;Hussain et al.,2016).OA is one of the leading causes of cartilage damage.Patients with severe cartilage damage require transplantation of articular cartilage to improve their quality of life.Type Ⅱ collagen is a major component of articular cartilage and intervertebral discs and plays an important role in the structure and strength of connective tissues that support muscles and joints(Byers,1994).

Biomarkers of aging

Aging biomarkers are a combination of biological parameters to(i)assess age-related changes,(ii)track the physiological aging process,and(iii)predict the transition into a pathological status.Although a broad spectrum of aging biomarkers has been developed,their potential uses and limitations remain poorly characterized.An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research:How old are we?Why do we get old?And how can we age slower?This review aims to address this need.Here,we summarize our current knowledge of biomarkers developed for cellular,organ,and organismal levels of aging,comprising six pillars:physiological characteristics,medical imaging,histological features,cellular alterations,molecular changes,and secretory factors.To fulfill all these requisites,we propose that aging biomarkers should qualify for being specific,systemic,and clinically relevant.

SARS-CoV-2 immunity in animal models

The COVID-19 pandemic,which was caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),has become a worldwide health crisis due to its transmissibility.SARS-CoV-2 infection results in severe respiratory illness and can lead to significant complications in affected individuals.These complications encompass symptoms such as coughing,respiratory distress,fever,infectious shock,acute respiratory distress syndrome(ARDS),and even multiple-organ failure.Animal models serve as crucial tools for investigating pathogenic mechanisms,immune responses,immune escape mechanisms,antiviral drug development,and vaccines against SARS-CoV-2.Currently,various animal models for SARS-CoV-2 infection,such as nonhuman primates(NHPs),ferrets,hamsters,and many different mouse models,have been developed.Each model possesses distinctive features and applications.In this review,we elucidate the immune response elicited by SARS-CoV-2 infection in patients and provide an overview of the characteristics of various animal models mainly used for SARS-CoV-2 infection,as well as the corresponding immune responses and applications of these models.A comparative analysis of transcriptomic alterations in the lungs from different animal models revealed that the K18-hACE2 and mouse-adapted virus mouse models exhibited the highest similarity with the deceased COVID-19 patients.Finally,we highlighted the current gaps in related research between animal model studies and clinical investigations,underscoring lingering scientific questions that demand further clarification.

乳酸化修饰参与调控DNA损伤修复和癌细胞化疗敏感性

The phenomenon in which cells prefer glycolysis to oxidative phosphorylation with increased lactate production is known as the Warburg effect and is found prevalent in cancer cells and pluripotent stem cells [1]. In addition to being an intermediate metabolite of glycolysis, lactate has been reported as a signal involved in multiple important biological processes, such as innate immunity [2], the cell cycle [3], hippocampal neurogenesis [4].

Experimental models for cancer brain metastasis

Brain metastases are a leading cause of cancer-related mortality.However,progress in their treatment has been limited over the past decade,due to an incomplete understanding of the underlying biological mechanisms.Employing accurate in vitro and in vivo models to recapitulate the complexities of brain metastasis offers the most promising approach to unravel the intricate cellular and physiological processes involved.Here,we present a comprehensive review of the currently accessible models for studying brain metastasis.We introduce a diverse array of in vitro and in vivo models,including cultured cells using the Transwell system,organoids,microfluidic models,syngeneic models,xenograft models,and genetically engineered models.We have also provided a concise summary of the merits and limitations inherent to each model while identifying the optimal contexts for their effective utilization.This review serves as a comprehensive resource,aiding researchers in making well-informed decisions regarding model selection that align with specific research questions.

Identification of mecciRNAs and their roles in the mitochondrial entry of proteins

Mammalian mitochondria have small genomes encoding very limited numbers of proteins.Over one thousand proteins and noncoding RNAs encoded by the nuclear genome must be imported from the cytosol into the mitochondria.Here,we report the identification of hundreds of circular RNAs(mecciRNAs)encoded by the mitochondrial genome.We provide both in vitro and in vivo evidence to show that mecciRNAs facilitate the mitochondrial entry of nuclear-encoded proteins by serving as molecular chaperones in the folding of imported proteins.Known components involved in mitochondrial protein and RNA importation,such as TOM40 and PNPASE,interact with mecciRNAs and regulate protein entry.The expression of mecciRNAs is regulated,and these transcripts are critical for the adaption of mitochondria to physiological conditions and diseases such as stresses and cancers by modulating mitochondrial protein importation.mecciRNAs and their associated physiological roles add categories and functions to the known eukaryotic circular RNAs and shed novel light on the communication between mitochondria and the nucleus.

Identification of a Novel Compound Heterozygous Mutation in OTOG in a Chinese Family with Severe Hearing Impairment

Objectives:Hearing loss is a worldwide disease.In 50%of the patients,hearing loss is caused by genetic problems associated with GJB2,MTRNR1,SLC26A4,and other genes.Considering the recent development and cost reduction of whole-exome sequencing,it is possible to filter out the normal genes and find which among the more novel genes contributed to the loss of hearing.Methods:After prescreening all individuals for GJB2,MTRNR1 and SLC26A4 mutations,whole-exome sequencing was performed in the proband,and the pathogenic variant was confirmed via Sanger sequencing.Results:The compound-heterozygous variant namely c.8076G>C:p.E2692D and c.6362T>C:p.V2121A in OTOG was identified as a candidate gene of a consanguineous Kazakh family.Conclusion:This is the first reported case of severe deafness caused by an OTOG compound-heterozygous variant in the world and the first case of deafness caused by an OTOG variant in China.This discovery identified the important contribution of OTOG toward deafness and expanded the spectrum of variants responsible for human hearing loss.

Double knock-in pig models with elements of binary Tet-On and phiC31 integrase systems for controllable and switchable gene expression

Inducible expression systems are indispensable for precise regulation and in-depth analysis of biological process.Binary Tet-On system has been widely employed to regulate transgenic expression by doxycycline.Previous pig models with tetracycline regulatory elements were generated through random integration.This process often resulted in uncertain expression and unpredictable phenotypes,thus hindering their applications.Here,by precise knock-in of binary Tet-On 3G elements into Rosa26 and Hipp11 locus,respectively,a double knock-in reporter pig model was generated.We characterized excellent properties of this system for controllable transgenic expression both in vitro and in vivo.Two att P sites were arranged to flank the td Tomato to switch reporter gene.Single or multiple gene replacement was efficiently and faithfully achieved in fetal fibroblasts and nuclear transfer embryos.To display the flexible application of this system,we generated a pig strain with Dox-inducing h KRASexpression through phiC31 integrase-mediated cassette exchange.After eight months of Dox administration,squamous cell carcinoma developed in the nose,mouth,and scrotum,which indicated this pig strain could serve as an ideal large animal model to study tumorigenesis.Overall,the established pig models with controllable and switchable transgene expression system will provide a facilitating platform for transgenic and biomedical research.

Generation of rat blood vasculature and hematopoietic cells in rat-mouse chimeras by blastocyst complementation

Interspecies chimera through blastocyst complementation could be an alternative approach to create human organs in animals by using human pluripotent stem cells.A mismatch of the major histocompatibility complex of vascular endothelial cells between the human and host animal will cause graft rejection in the transplanted organs.Therefore,to achieve a transplantable organ in animals without rejection,creation of vascular endothelial cells derived from humans within the organ is necessary.In this study,to explore whether donor xeno-pluripotent stem cells can compensate for blood vasculature in host animals,we generated rat-mouse chimeras by injection of rat embryonic stem cells(rESCs)into mouse blastocysts with deficiency of Flk-1 protein,which is associated with endothelial and hematopoietic cell development.We found that rESCs could differentiate into vascular endothelial and hematopoietic cells in the rat-mouse chimeras.The whole yolk sac(YS)of Flk-1^EGFP/ECFP rat-mouse chimera was full of rat blood vasculature.Rat genes related to vascular endothelial cells,arteries,and veins,blood vessels formation process,as well as hematopoietic cells,were highly expressed in the YS.Our results suggested that rat vascular endothelial cells could undergo proliferation,migration,and self-assembly to form blood vasculature and that hematopoietic cells could differentiate into B cells,T cells,and myeloid cells in rat-mouse chimeras,which was able to rescue early embryonic lethality caused by Flk-1 deficiency in mouse.

Role of Long Non-coding RNAs in Reprogramming to Induced Pluripotency

The generation of induced pluripotent stem cells through somatic cell reprogramming requires a global reorganization of cellular functions.This reorganization occurs in a multi-phased manner and involves a gradual revision of both the epigenome and transcriptome.Recent studies have shown that the large-scale transcriptional changes observed during reprogramming also apply to long noncoding RNAs(lncR NAs),a type of traditionally neglected RNA species that are increasingly viewed as critical regulators of cellular function.Deeper understanding of lncR NAs in reprogramming may not only help to improve this process but also have implications for studying cell plasticity in other contexts,such as development,aging,and cancer.In this review,we summarize the current progress made in profiling and analyzing the role of lncR NAs in various phases of somatic cell reprogramming,with emphasis on the re-establishment of the pluripotency gene network and X chromosome reactivation.

Mitochondria as multifaceted regulators of ferroptosis

Mitochondria are well known to be“energy factories”of the cell as they provide intracellular ATP via oxidative phosphorylation.Interestingly,they also function as a“cellular suicidal weapon store”by acting as a key mediator of various forms of regulated cell death,including apoptosis,pyroptosis,necroptosis,and ferroptosis.Ferroptosis,distinct from the other types of regulated cell death,is characterized by iron-dependent lipid peroxidation and subsequent plasma membrane rupture.Growing evidence suggests that an impaired ferroptotic response is implicated in various diseases and pathological conditions,and this impaired response is associated with dramatic changes in mitochondrial morphology and function.Mitochondria are the center of iron metabolism and energy production,leading to altered lipid peroxidation sensitivity.Although a growing number of studies have explored the inextricable link between mitochondria and ferroptosis,the role of this organelle in regulating ferroptosis remains unclear.Here,we review recent advances in our understanding of the role of mitochondria in ferroptosis and summarize the characteristics of this novel iron-based cellular suicide weapon and its arsenal.We also discuss the importance of ferroptosis in pathophysiology,including the need for further understanding of the relationship between mitochondria and ferroptosis to identify combinatorial targets that are essential for the development of successful drug discovery.

Gli1 promotes epithelial-mesenchymal transition and metastasis of non-small cell lung carcinoma by regulating snail transcriptional activity and stability

Metastasis is crucial for the mortality of non-small cell lung carcinoma(NSCLC) patients.The epithelial-mesenchymal transition(EMT) plays a critical role in regulating tumor metastasis.Glioma-associated oncogene 1(Gli1) is aberrantly active in a series of tumor tissues. However, the molecular regulatory relationships between Gli1 and NSCLC metastasis have not yet been identified. Herein,we reported Gli1 promoted NSCLC metastasis. High Gli1 expression was associated with poor survival of NSCLC patients. Ectopic expression of Gli1 in low metastatic A549 and NCI-H460 cells enhanced their migration, invasion abilities and facilitated EMT process, whereas knock-down of Gli1 in high metastatic NCI-H1299 and NCI-H1703 cells showed an opposite effect. Notably, Gli1 overexpression accelerated the lung and liver metastasis of NSCLC in the intravenously injected metastasis model. Further research showed that Gli1 positively regulated Snail expression by binding to its promoter and enhancing its protein stability, thereby facilitating the migration, invasion and EMT of NSCLC. In addition, administration of GANT-61, a Gli1 inhibitor, obviously suppressed the metastasis of NSCLC. Collectively, our study reveals that Gli1 is a critical regulator for NSCLC metastasis and suggests that targeting Gli1 is a prospective therapy strategy for metastatic NSCLC.

Regeneration of immunocompetent B lymphopoiesis from pluripotent stem cells guided by transcription factors

Regeneration of functional B lymphopoiesis from pluripotent stem cells(PSCs)is challenging,and reliable methods have not been developed.Here,we unveiled the guiding role of three essential factors,Lhx2,Hoxa9,and Runx1,the simultaneous expression of which preferentially drives B lineage fate commitment and in vivo B lymphopoiesis using PSCs as a cell source.In the presence of Lhx2,Hoxa9,and Runx1 expression,PSC-derived induced hematopoietic progenitors(iHPCs)immediately gave rise to pro/pre-B cells in recipient bone marrow,which were able to further differentiate into entire B cell lineages,including innate B-1a,B-1b,and marginal zone B cells,as well as adaptive follicular B cells.In particular,the regenerative B cells produced adaptive humoral immune responses,sustained antigen-specific antibody production,and formed immune memory in response to antigen challenges.The regenerative B cells showed natural B cell development patterns of immunoglobulin chain switching and hypermutation via cross-talk with host T follicular helper cells,which eventually formed T cell-dependent humoral responses.This study exhibits de novo evidence that B lymphopoiesis can be regenerated from PSCs via an HSC-independent approach,which provides insights into treating B cell-related deficiencies using PSCs as an unlimited cell resource.

Organelle remodeling during the acquisition and loss of pluripotency

Pluripotent stem cells hold tremendous promise for regenerative medicine.The mechanisms underlying the acquisition and loss of pluripotency have been revealed at multiple levels.Subcellular mechanisms such as metabolic and organelle remodeling are emerging as critical for pluripotent cell fate transitions.Understanding the rules and roles of organelle remodeling will not only provide important insights into pluripotency regulation,but also help improving application in regenerative medicine.In this review,we summarize recent discoveries in organelle remodeling during the acquisition and loss of pluripotency and discuss how membrane lipids orchestrate organelle remodeling and drive nuclear gene expression.