Therapeutic prospects of mesenchymal stem/stromal cells in COVID-19 associated pulmonary diseases:From bench to bedside

The ongoing outbreak of coronavirus disease 2019(COVID-19)caused by the novel severe acute respiratory syndrome coronavirus 2 has become a sudden public emergency of international concern and seriously threatens millions of people’s life health.Two current studies have indicated a favorable role for mesenchymal stem/stromal cells(MSCs)in clinical remission of COVID-19 associated pulmonary diseases,yet the systematical elaboration of the therapeutics and underlying mechanism is far from satisfaction.In the present review,we summarize the therapeutic potential of MSCs in COVID-19 associated pulmonary diseases such as pneumonia induced acute lung injury,acute respiratory distress syndrome,and pulmonary fibrosis.Furthermore,we review the underlying mechanism of MSCs including direct-and trans-differentiation,autocrine and paracrine anti-inflammatory effects,homing,and neovascularization,as well as constitutive microenvironment.Finally,we discuss the prospects and supervision of MSC-based cytotherapy for COVID-19 management before large-scale application in clinical practice.Collectively,this review supplies overwhelming new references for understanding the landscapes of MSCs in the remission of COVID-19 associated pulmonary diseases.

Towards a blood ecosystem approach to dissect systemic diseases

Systemic diseases,in contrast to localized ailments,exert widespread effects and can impact the entire body.Examples of systemic diseases encompass autoimmune disorders,infectious diseases,metabolic disorders,and chronic conditions like cancer.These diseases often entail intricate interactions among diverse organs,tissues,and physiological systems,influenced by a myriad of factors.

Regulatory mechanisms of retinal ganglion cell death in normal tension glaucoma and potential therapies

Normal tension glaucoma(NTG)is a multifactorial optic neuropathy characterized by normal intraocular pressure,progressive retinal ganglion cell(RGC)death,and glaucomatous visual field loss.Recent studies have described the mechanisms underlying the pathogenesis of NTG.In addition to controlling intraocular pressure,neuroprotection and reduction of RGC degeneration may be beneficial therapies for NTG.In this review,we summarized the main regulatory mechanisms of RGC death in NTG,including autophagy,glutamate neurotoxicity,oxidative stress,neuroinflammation,immunity,and vasoconstriction.Autophagy can be induced by retinal hypoxia and axonal damage.In this process,ischemia can cause mutations of optineurin and activate the nuclear factor-kappa B pathway.Glutamate neurotoxicity is induced by the over-stimulation of N-methyl-D-aspartate membrane receptors by glutamate,which occurs in RGCs and induces progressive glaucomatous optic neuropathy.Oxidative stress also participates in NTG-related glaucomatous optic neuropathy.It impairs the mitochondrial and DNA function of RGCs through the apoptosis signal-regulating kinase-JUN N-terminal kinase pathway.Moreover,it increases inflammation and the immune response of RGCs.Endothelin 1 causes endothelial dysfunction and impairment of ocular blood flow,promoting vasospasm and glaucomatous optic neuropathy,as a result of NTG.In conclusion,we discussed research progress on potential options for the protection of RGCs,including TANK binding kinase 1 inhibitors regulating autophagy,N-methyl-D-aspartate receptor antagonists inhibiting glutamate toxicity,ASK1 inhibitors regulating mitochondrial function,and antioxidants inhibiting oxidative stress.In NTG,RGC death is regulated by a network of mechanisms,while various potential targets protect RGCs.Collectively,these findings provide insight into the pathogenesis of NTG and potential therapeutic strategies.

The role of bone marrow-derived cells in the origin of liver cancer revealed by single-cell sequencing

Objective:Epithelial cancers often originate from progenitor cells,while the origin of hepatocellular carcinoma(HCC)is still controversial.HCC,one of the deadliest cancers,is closely linked with liver injuries and chronic inflammation,which trigger massive infiltration of bone marrow-derived cells(BMDCs)during liver repair.Methods:To address the possible roles of BMDCs in HCC origination,we established a diethylnitrosamine(DEN)-induced HCC model in bone marrow transplanted mice.Immunohistochemistry and frozen tissue immunofluorescence were used to verify DENinduced HCC in the pathology of the disease.The cellular origin of DEN-induced HCC was further studied by single cell sequencing,single-cell nested PCR,and immunofluorescence-fluorescence in situ hybridization.Results:Studies by using single cell sequencing and biochemical analysis revealed that HCC cells in these mice were coming from donor mice BMDCs,and not from recipient mice.Furthermore,the copy numbers of mouse orthologs of several HCC-related genes previously reported in human HCC were also altered in our mouse model.DEN-induced HCCs exhibited a similar histological phenotype and genomic profile as human HCCs.Conclusions:These results suggested that BMDCs are an important origin of HCC,which provide important clues to HCC prevention,detection,and treatments.

The effects of legumain in THP1 leukemia cells

Legumain is a C13 family cysteine protease.It plays diverse roles under both physiological and pathological conditions.The high-level expression of legumain is detected in solid tumors.Legumain promotes the proliferation and migration of tumor cells.However,the effect of legumain in blood diseases has not been established.In this report,we studied the effect of legumain on leukemia cells by overexpressing it in THP1 cells.The results demonstrated that legumain promoted cell proliferation,whereas it had little effect on cell apoptosis.Furthermore,legumain promoted the migration of THP1 cells.It was worth noting that legumain decreased the stemness of THP1 cells.Further evidence showed that legumain decreased the expression of Oct4,Sox2,Myc in THP1 cells.Our study reveals the multifaced effects of legumain in leukemia cells and broadens the knowledge of legumain in malignancies.

Myeloid neoplasm with eosinophilia and rearrangement of plateletderived growth factor receptor beta gene in children: Two case reports

BACKGROUND Myeloid neoplasm(MN)with eosinophilia and rearrangement of platelet-derived growth factor receptor beta(PDGFRB)shows a good therapeutic response to imatinib in adults.MN is rarely found in children,and the efficacy of imatinib on pediatric patients remain unclear.CASE SUMMARY We report 2 pediatric cases diagnosed with MN with eosinophilia and PDGFRB rearrangement who were treated with imatinib.Case 1 was a 1-year-old girl admitted to the hospital because of“abdominal distension with hyperleukocytosis for 3 mo”.She had leukocytosis,anemia,and eosinophilia(the absolute eosinophil count(AEC)was 8960/μL),and her fluorescence in situ hybridization(FISH)test revealed that PDGFRB rearrangement was detected in 70%of 500 interphase cells.Case 2 was a 2-year-old girl admitted to the hospital because of“recurrent fever and rashes for 1 mo”.Her blood cell count showed an AEC of 3540/μL.The FISH test revealed that PDGFRB rearrangement was detected in 71%of 500 interphase cells.Both patients were diagnosed as MN with eosinophilia and PDGFRB rearrangement.Imatinib was added into their treatment regimen.As expected,complete hematologic remission was achieved after 1 mo of treatment,and symptoms disappeared.CONCLUSION Although MN with eosinophilia and PDGFRB rearrangement usually occurs in adults,it can be found in children.The therapeutic benefits of imatinib in these 2 pediatric patients were consistent with its reported effects in adult patients.

A Homozygotic Mutation in KDSR may Cause Keratinization Disorders and Thrombocytopenia: A Case Report

Pathogenic mutations in 3-keto-dihydrosphingosine reductase(KDSR)gene are associated with keratinization disorders and impaired platelet function.However,no case with both homozygotic mutation of KDSR and hepatic hemangioendothelioma has ever been reported due to its low prevalence.Here we report a seven months old Chinese boy with a homozygotic missense mutation in KDSR and both of his parents carry a same heterozygous mutation.He was born with thick plate-like scales overlying erythrodermic skin,but the skin symptoms were resolved spontaneously over the first month of his birth.He was also diagnosed with hepatic hemangioendothelioma at birth and accepted a resection surgery at 2 months old.At birth,his platelet count was severely low(10-20×10~9/L)with recurrent skin and gingival bleeding.Meanwhile,he suffered a mild normocytic,normochromic anemia with normal iron and hematinic levels.The anemia spontaneously recovered over the first 6 months,while the platelet count keeped at a low level(4-20×10~9/L).Treatment with corticosteroids,immunoglobulin or thrombopoietin was all suboptimal.

Primitive Neuroectodermal Tumor as the Second Malignant Neoplasm in a Long-Term Survivor Child of Acute Lymphoblastic Leukemia: A Case Report

Acute lymphoblastic leukemia(ALL)is a common pediatric cancer.The second malignant neoplasms(SMNs)in long-term survivors of pediatric ALL are relatively rare.Herein we report a 10-year-old girl who was diagnosed as primitive neuroectodermal tumor(PNET)5 years after the initial diagnosis of ALL with radiotherapy・free treatment.PNET is an exceedingly rare neoplasm in SMNs of survivors of childhood ALL.It is predisposed to be misdiagnosed and the pathogenesis is unclear.The outcome is poor.Long-term follow-up is necessary for the survival children of ALL.

NBCe1 Na+-HCO3-cotransporter ablation causes reduced apoptosis following cardiac ischemia-reperfusion injury in vivo

AIM To investigate the hypothesis that cardiomyocytespecific loss of the electrogenic NBCe1 Na^+-HCO3^- cotransporter is cardioprotective during in vivo ischemiareperfusion(IR)injury.METHODS An NBCe1 (Slc4a4 gene) conditional knockout mouse(KO)model was prepared by gene targeting.Cardiovascular performance of wildtype (WT) and cardiac-specific NBCe1 KO mice was analyzed by intraventricular pressure measurements,and changes in cardiac gene expression were determined by RNA Seq analysis.Response to in vivo IR injury was analyzed after 30 min occlusion of the left anterior descending artery followed by 3 h of reperfusion. RESULTS Loss of NBCe1 in cardiac myocytes did not impair cardiac contractility or relaxation under basal conditions or in response toβ-adrenergic stimulation,and caused only limited changes in gene expression patterns,such as those for electrical excitability.However,following ischemia and reperfusion,KO heart sections exhibited significantly fewer apoptotic nuclei than WT sections.CONCLUSION These studies indicate that cardiac-specific loss of NBCe1 does not impair cardiovascular performance,causes only minimal changes in gene expression patterns,and protects against IR injury in vivo.

Cytogenetic Characteristics of Childhood Acute Lymphoblastic Leukemia:A Study of 1541 Chinese Patients Newly Diagnosed between 2001 and 2014

Objective:Cytogenetic abnormalities have been proven to be the most valuable parameter for risk stratification of childhood acute lymphoblastic leukemia(ALL).However,studies on the prevalence of cytogenetic abnormalities and their correlation to clinical features in Chinese pediatric patients are limited,especially large-scale studies.Methods:We collected the cytogenetics and clinical data of 1541 children newly diagnosed with ALL between 2001 and 2014 in four Chinese hospitals,and retrospectively analyzed their clinical features,prognosis and risk factors associated with pediatric ALL.

Single-cell transcriptomes of peripheral blood cells indicate and elucidate severity of COVID-19

The blood and immune system of coronavirus disease 2019(COVID-19)infected patients are dysfunctional,and numerous studies have been conducted to resolve their characteristics and pathogenic mechanisms.Nevertheless,the variations of immune responses along with disease severity have not been comprehensively documented.Here,we profiled the single-cell transcriptomes of 96,313 peripheral blood mononuclear cells(PBMCs)derived from 12 COVID-19 patients(including four moderate,four severe and four critical cases)and three healthy donors.We showed that proliferative CD8 effector T cells with declined immune functions and cytotoxicity accumulated in the critical stage.By contrast,the quantity of natural killer(NK)cells was significantly reduced,while they exhibited enhanced immune activities.Notably,a gradually attenuated responseto COVID-19 along with disease severity was observed in monocytes,in terms of cellular composition,transcriptional discrepancy and transcription factor regulatory network.Furthermore,we identified immune cell-type dependent cytokine signatures distinguishing the severity of COVID-19 patients.In addition,cell interactions between CD8 effector T/NK cells and monocytes mediated by inflammatory cytokines were enhanced in moderate and severe stages,but weakened in critical cases.Collectively,our work uncovers the cellular and molecular players underlying the disordered and heterogeneous immune responses associated with COVID-19 severity,which could provide valuable insights for the treatment of critical COVID-19 patients.

A Method of Acquiring Raman Spectrum for Blood Samples with Low Cost

Blood is composed of plasma and blood cells.Plasma contains many kinds of proteins,free DNA,inorganic salt,fat,sugar,hormones and other chemical components.The changes in these components can reflect the health status of the body.Raman spectroscopy as a vibrational spectroscopic technique could gain label-free,non-destructive biochemical information about blood samples.It has a huge potential as a clinical diagnostic tool.However,the drawbacks with the application of the technique include sample preparation,expensive substrates and long acquisition times.Our study aims to establish a method of acquiring Raman spectrum of blood samples with stability,accuracy and low cost.In this study,we investigated the different instrumental and sample preparation parameters to identify the best combination for acquiring spectrum from blood plasma.It could be the technological basis of the potential application of Raman spectroscopy in clinical diagnosis.

Reduced ABO blood group antibody titers in patients after CD19 CAR-T cell therapy

1.INTRODUCTION With rapid developments in genetic engineering,tumor immunology,and cellular engineering,chimeric antigen receptor T cell(CAR-T)cell therapy has become a novel immunotherapy for oncology and other medical fields.1 The promising results of CD19 CAR-T treating B-cell malignancies were reported.2,3 Simultaneously,there existed many adverse events,the most reported of which including B-cell aplasia,hematological toxicity,cytokine release syndrome(CRS),and immune effector-cell–associated neurotoxicity syndrome(ICANS),3,4 but there is still lack of reports demonstrating the impact of CD19 CAR-T on the ABO blood group potency of patient’s serum.

Efficacy and safety of human umbilical cord-derived mesenchymal stem cells in the treatment of refractory immune thrombocytopenia:a prospective,single arm,phase I trial

Patients with refractory immune thrombocytopenia(ITP)frequently encounter substantial bleeding risks and demonstrate limited responsiveness to existing therapies.Umbilical cord-derived mesenchymal stem cells(UC-MSCs)present a promising alternative,capitalizing on their low immunogenicity and potent immunomodulatory effects for treating diverse autoimmune disorders.This prospective phase I trial enrolled eighteen eligible patients to explore the safety and efficacy of UC-MSCs in treating refractory ITP.The research design included administering UC-MSCs at escalating doses of 0.5×10^(6)cells/kg,1.0×10^(6)cells/kg,and 2.0×10^(6)cells/kg weekly for four consecutive weeks across three cohorts during the dose-escalation phase,followed by a dose of 2.0×10^(6)cells/kg weekly for the dose-expansion phase.Adverse events,platelet counts,and changes in peripheral blood immunity were monitored and recorded throughout the administration and follow-up period.Ultimately,12(with an addition of three patients in the 2.0×10^(6)cells/kg group due to dose-limiting toxicity)and six patients were enrolled in the dose-escalation and dose-expansion phase,respectively.Thirteen patients(13/18,72.2%)experienced one or more treatment emergent adverse events.Serious adverse events occurred in four patients(4/18,22.2%),including gastrointestinal hemorrhage(2/4),profuse menstruation(1/4),and acute myocardial infarction(1/4).The response rates were 41.7%in the dose-escalation phase(5/12,two received 1.0×10^(6)cells/kg per week,and three received 2.0×10^(6)cells/kg per week)and 50.0%(3/6)in the dose-expansion phase.The overall response rate was 44.4%(8/18)among all enrolled patients.To sum up,UC-MSCs are effective and well tolerated in treating refractory ITP(ClinicalTrials.gov ID:NCT04014166).

REDH:A database of RNA editome in hematopoietic differentiation and malignancy

Background:The conversion of adenosine(A)to inosine(I)through deamination is the prevailing form of RNA editing,impacting numerous nuclear and cytoplasmic transcripts across various eukaryotic species.Millions of high-confidence RNA editing sites have been identified and integrated into various RNA databases,providing a convenient platform for the rapid identification of key drivers of cancer and potential therapeutic targets.However,the available database for integration of RNA editing in hematopoietic cells and hematopoietic malignancies is still lacking.Methods:We downloaded RNA sequencing(RNA-seq)data of 29 leukemia patients and 19 healthy donors from National Center for Biotechnology Information(NCBI)Gene Expression Omnibus(GEO)database,and RNA-seq data of 12 mouse hematopoietic cell populations obtained from our previous research were also used.We performed sequence alignment,identified RNA editing sites,and obtained characteristic editing sites related to normal hematopoietic development and abnormal editing sites associated with hematologic diseases.Results:We established a new database,"REDH",represents RNA editome in hematopoietic differentiation and malignancy.REDH is a curated database of associations between RNA editome and hematopoiesis.REDH integrates 30,796 editing sites from 12 murine adult hematopoietic cell populations and systematically characterizes more than 400,000 edited events in malignant hematopoietic samples from 48 cohorts(human).Through the Differentiation,Disease,Enrichment,and knowledge modules,each A-to-I editing site is systematically integrated,including its distribution throughout the genome,its clinical information(human sample),and functional editing sites under physiological and pathological conditions.Furthermore,REDH compares the similarities and differences of editing sites between different hematologic malignancies and healthy control.Conclusions:REDH is accessible at http://www.redhdatabase.com/.This user-friendly database would aid in understanding the mechanisms of RNA editing in hematopoietic differentiation and malignancies.It provides a set of data related to the maintenance of hematopoietic homeostasis and identifying potential therapeutic targets in malignancies.

Ivosidenib in Chinese patients with relapsed or refractory isocitrate dehydrogenase 1 mutated acute myeloid leukemia:a registry study

Ivosidenib,an isocitrate dehydrogenase 1(IDH1)inhibitor,has demonstrated clinical benefits in a pivotal study(AG120-C-001)in patients with IDH1-mutated(mIDH1)acute myeloid leukemia(AML).A registry study(CS3010-101:NCT04176393)was conducted to assess the pharmacokinetic(PK)characteristics,safety,and efficacy of ivosidenib in Chinese patients with relapsed or refractory(R/R)mIDH1 AML.Patients received ivosidenib 500 mg once daily for 28-day cycles until disease progression.Ten subjects underwent intensive PK/progressive disease(PD)assessments.All subjects had the clinical response assessed at screening,every 28 days through month 12,and then every 56 days.Between November 12,2019,and April 2,2021,30 patients were enrolled;26(86.7%)had de novo AML and 18(60.0%)were transfusion-dependent at baseline.Following single and repeated doses of ivosidenib,median time to maximum plasma concentration(T_(max))was 4.0 and 2.0 hours,respectively.The inter-individual variability of pharmacokinetic exposure was moderate to high(coefficient of variation[CV],25%–53%).No obvious accumulation was observed after repeated doses at cycle 2 day 1.Regarding the clinical response,the CR+CRh rate was 36.7%(95%confidence interval[CI]:19.9%–56.1%),the median duration of CR+CRh was 19.7 months(95%CI:2.9 months–not reached[NR]),and median duration of response(DoR)was 14.3 months(95%CI:6.4 months–NR).Consistent clinical benefits and safety of ivosidenib were consistently observed at the final data cutoff with median follow-up time 26.0 months,as compared with primary data cutoff,and the data from Chinese R/R mIDH1 AML patients were also consistent with results from pivotal study.

Loss of Lkb1 impairs Treg function and stability to aggravate graft-versus-host disease after bone marrow transplantation

Accumulating evidence suggests that a reduction in the number of Foxp3^(+) regulatory T cells(Tregs)contributes to the pathogenesis of acute graft-versus-host disease(aGVHD),which is a major adverse complication that can occur after allogeneic hematopoietic stem cell transplantation(allo-HSCT).However,the precise features and mechanism underlying the defects in Tregs remain largely unknown.In this study,we demonstrated that Tregs were more dramatically decreased in bone marrow compared with those in peripheral blood from aGVHD patients and that bone marrow Treg defects were negatively associated with hematopoietic reconstitution.Tregs from aGVHD patients exhibited multiple defects,including the instability of Foxp3 expression,especially in response to IL-12,impaired suppressor function,decreased migratory capacity,and increased apoptosis.Transcriptional profiling revealed the downregulation of Lkb1,a previously identified critical regulator of murine Treg identity and metabolism,and murine Lkb1-regulated genes in Tregs from aGVHD patients.Foxp3 expression in human Tregs could be decreased and increased by the knockdown and overexpression of the Lkb1 gene,respectively.Furthermore,a loss-of-function assay in an aGVHD murine model confirmed that Lkb1 deficiency could impair Tregs and aggravate disease severity.These findings reveal that Lkb1 downregulation contributes to multiple defects in Tregs in human aGVHD and highlight the Lkb1-related pathways that could serve as therapeutic targets that may potentially be manipulated to mitigate aGVHD.

Understanding the“SMART”features of hematopoietic stem cells and beyond

Since the huge success of bone marrow transplantation technology in clinical practice,hematopoietic stem cells(HSCs)have become the gold standard for defining the properties of adult stem cells(ASCs).Here,we describe the“self-renewal,multilineage differentiation,apoptosis,rest,and trafficking”or“SMART”model,which has been developed based on data derived from studies of HSCs as the most well-characterized stem cell type.Given the potential therapeutic applications of ASCs,we delineate the key characteristics of HSCs using this model and speculate on the physiological relevance of stem cells identified in other tissues.Great strides are being made in understanding the biology of ASCs,and efforts are now underway to develop safe and effective ASC-based therapies in this emerging area.

DDIT4 mediates the proliferation-promotive effect of IL-34 in human monocytic leukemia cells

Interleukin 34(IL-34)is a cytokine that shares the receptor with colony-stimulating factor 1(CSF-1).IL-34 is involved in a broad range of pathologic processes including cancer.We previously demonstrated that IL-34 promoted the proliferation and colony formation of human acute monocytic leukemia(AMoL)cells.However,the mechanism has not been elucidated.Here,by analyzing the gene profiles of Molm13 and THP1 cells overexpressing IL-34(Molm13-IL-34 and THP1-IL-34),upregulation of the DNA damageinducible transcript 4(DDIT4)was detected in both series.Knockdown of DDIT4 effectively inhibited the proliferation,promoted apoptosis and colony formation in Molm13-IL-34 and THP1-IL-34 cells.Our results suggest that DDIT4 mediates the proliferationpromotive effect of IL-34 whereas does not mediate the promotive effect of IL-34 on colony formation in AMoL cells.

Macrophages in leukemia microenvironment

Macrophages,the important component of tissue microenvironment,play important roles in both physiological and pathological processes,including tumor and leukemia.Tumor-associated macrophages are involved in tumor proliferation,angiogenesis,invasion,metastasis,and chemotherapy resistance.In leukemia,macrophages are educated by leukemia microenvironment to obtain specific activated phenotype and participate in leukemia progression.Recent studies have shown that accumulation of macrophages in leukemia patients or mouse model is correlated with poor prognosis.Hence,increasing attentions have been paid to study the characteristics of them and to develop novel therapeutic strategies targeting macrophages against leukemia.In this article,we summarize recent development of macrophages in leukemia microenvironment.