Bowel inflammatory presentations on computed tomography in adult patients with severe aplastic anemia during flared inflammatory episodes

BACKGROUND Patients with severe aplastic anemia(SAA)frequently present with inflammatory episodes,and during flared inflammatory episodes,hematopoietic function is further exacerbated.The gastrointestinal tract is the most common site for infectious and inflammatory diseases,and its structural and functional features confer on it the most potent capacity to affect hematopoietic and immune functions.Computed tomography(CT)is a readily accessible approach to provide highly useful information in detecting morphological changes and guiding further work-ups.AIM To explore CT imaging presentations of gut inflammatory damage in adult SAA patients during inflammatory episodes.METHODS We retrospectively evaluated the abdominal CT imaging presentations of 17hospitalized adult patients with SAA in search of the inflammatory niche when they presented with systemic inflammatory stress and exacerbated hematopoietic function.In this descriptive manuscript,the characteristic images that suggested the presence of gastrointestinal inflammatory damage and related imaging presentations of individual patients were enumerated,analyzed and described.RESULTS All eligible patients with SAA had CT imaging abnormalities that suggested the presence of an impaired intestinal barrier and increased epithelial permeability.The inflammatory damages were concurrently present in the small intestine,the ileocecal region and the large intestines.Some readily identified imaging signs,such as bowel wall thickening with mural stratification(“water holo sign”,“fat holo sign”,intramural gas and subserosal pneumatosis)and mesenteric fat proliferation(fat stranding and“creeping fat sign”),fibrotic bowel wall thickening,“balloon sign”,rugged colonic configuration,heterogeneity in the bowel wall texture,and adhered and clustered small bowel loop(including various patterns of“abdominal cocoon”),occurred at a high incidence,which suggested that the damaged gastrointestinal tract is a common inflammatory niche responsible for the systemic inflammatory stresses and the exacerbated hematopoietic failure in patients with SAA.Particularly,the“fat holo sign”was present in 7 patients,a rugged colonic configuration was present in 10 patients,the adhesive bowel loop was present in 15 patients,and extraintestinal manifestations suggestive of tuberculosis infections were present in 5 patients.According to the imaging features,a suggestive diagnosis of Crohn’s disease was made in 5patients,ulcerative colitis in 1 patient,chronic periappendiceal abscess in 1 patient,and tuberculosis infection in 5 patients.Other patients were diagnosed with chronic enteroclolitis with acutely aggravated inflammatory damage.CONCLUSION Patients with SAA had CT imaging patterns that suggested the presence of active chronic inflammatory conditions and aggravated inflammatory damage during flared inflammatory episodes.

Leukemic transformation during anti-tuberculosis treatment in aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome:A case report and review of literature

BACKGROUND Accumulating evidence demonstrates that autoimmune hematopoietic failure and myeloid neoplasms have an intrinsic relationship with regard to clonal hematopoiesis and disease evolution.In approximately 10%-15%of patients with severe aplastic anemia(SAA),the disease phenotype is transformed into myeloid neoplasms following antithymocyte globulin plus cyclosporine-based immunosuppressive therapy.In some of these patients,myeloid neoplasms appear during or shortly after immunosuppressive therapy.Leukemic transformation in SAA patients during anti-tuberculosis treatment has not been reported.CASE SUMMARY A middle-aged Chinese female had a 6-year history of non-SAA and a 2-year history of paroxysmal nocturnal hemoglobinuria(PNH).With aggravation of systemic inflammatory symptoms,severe pancytopenia developed,and her hemoglobinuria disappeared.Laboratory findings in cytological,immunological and cytogenetic analyses of bone marrow samples met the diagnostic criteria for“SAA.”Definitive diagnosis of disseminated tuberculosis was made in the search for infectious niches.Remarkable improvement in hematological parameters was achieved within 1 mo of anti-tuberculosis treatment,and complete hematological remission was achieved within 4 mo of treatment.Frustratingly,the hematological response lasted for only 3 mo,and pancytopenia reemerged.At this time,cytological findings(increased bone marrow cellularity and an increased percentage of myeloblasts that accounted for 16.0%of all nucleated hematopoietic cells),immunological findings(increased percentage of cluster of differentiation 34+cells that accounted for 12.28%of all nucleated hematopoietic cells)and molecular biological findings(identification of somatic mutations in nucleophosmin-1 and casitas B-lineage lymphoma genes)revealed that“SAA”had transformed into acute myeloid leukemia with mutated nucleophosmin-1.The transformation process suggested that the leukemic clones were preexistent but were suppressed in the PNH and SAA stages,as development of symptomatic myeloid neoplasm through acquisition and accumulation of novel oncogenic mutations is unlikely in an interval of only 7 mo.Aggravation of inflammatory stressors due to disseminated tuberculosis likely contributed to the repression of normal and leukemic hematopoiesis,and the relief of inflammatory stressors due to anti-tuberculosis treatment contributed to penetration of neoplastic hematopoiesis.The concealed leukemic clones in the SAA and PNH stages raise the possibility of an inflammatory stress-fueled antileukemic mechanism.CONCLUSION Aggravated inflammatory stressors can repress normal and leukemic hematopoiesis,and relieved inflammatory stressors can facilitate penetration of neoplastic hematopoiesis.

Hematopoietic stem cell transplantation of aplastic anemia by relative with mutations and normal telomere length: A case report

BACKGROUND Immunosuppressive therapy and matched sibling donor hematopoietic stem cell transplantation(MSD-HSCT)are the preferred treatments for aplastic anemia(AA).CASE SUMMARY In this report,we describe a 43-year-old male patient with severe AA who carried BRIP1(also known as FANCJ),TINF2,and TCIRG1 mutations.Screening of the family pedigree revealed the same TINF2 mutation in his mother and older brother,with his older brother also carrying the BRIP1 variant and demonstrating normal telomere length and hematopoietic function.The patient was successfully treated with oral cyclosporine A,eltrombopag,and acetylcysteine,achieving remission 4 years after receiving MSD-HSCT from his older brother.CONCLUSION This case provides a valuable clinical reference for individuals with suspected pathogenic gene mutations,normal telomere length,and hematopoietic function,highlighting them as potential donors for patients with AA.

Construction of gene/protein interaction networks and enrichment pathway analysis for paroxysmal nocturnal hemoglobinuria and aplastic anemia

Background:To develop a protein-protein interaction network of Paroxysmal nocturnal hemoglobinuria(PNH)and Aplastic anemia(AA)based on genetic genes and to predict pathways underlying the molecular complexes in the network.Methods:In this research,the PNH and AA-related genes were screened through Online Mendelian Inheritance in Man(OMIM).The plugins and Cytoscape were used to search literature and build a protein-protein interaction network.Results:The protein-protein interaction network contains two molecular complexes that are five higher than the correlation integral values.The target genes of this study were obtained:CD59,STAT3,TERC,TNF,AKT1,C5AR1,EPO,IL6,IL10 and so on.We also found that many factors regulate biological behaviors:neutrophils,macrophages,vascular endothelial growth factor,immunoglobulin,interleukin,cytokine receptor,interleukin-6 receptor,tumor necrosis factor,and so on.This research provides a bioinformatics foundation for further explaining the mechanism of common development of both.Conclusion:This indicates that the PNH and AA is a complex process regulated by many cellular pathways and multiple genes.

Aplastic anemia and severe pancytopenia during treatment with peg-interferon,ribavirin and telaprevir for chronic hepatitis C

Telaprevir and Boceprevir are the first direct acting antivirals approved for chronic hepatitis C in combination with peg-interferon alfa and ribavirin.Pancytopenia due to myelotoxicity caused by these drugs may occur,but severe hematological abnormalities or aplastic anemia(AA) have not been described.We collected all cases of severe pancytopenia observed during triple therapy with telaprevir in four Spanish centers since approval of the drug in 2011.Among 142 cirrhotic patients receiving treatment,7 cases of severe pancytopenia(5%) were identified and three were consistent with the diagnosis of AA.Mean age was 59 years,five patients had compensated cirrhosis and two patients had severe hepatitis C recurrence after liver transplantation.Severe pancytopenia was diagnosed a median of 10 wk after the initiation of therapy.Three patients had pre-treatment hematological abnormalities related to splenomegaly.In six patients,antiviral treatment was interrupted at the onset of hematological abnormalities.Two patients died due to septic complications and one patient due to acute alveolar hemorrhage.The remaining patients recovered.Severe pancytopenia and especially AA,are not rare during triple therapy with telaprevir in patients with advanced liver disease.Close monitoring is imperative in this setting to promptly detect serious hematological disorders and to prevent further complications.

Yin and Yang of mesenchymal stem cells and aplastic anemia

Acquired aplastic anemia(AA) is a bone marrow failure syndrome characterized by peripheral cytopenias and bone marrow hypoplasia. It is ultimately fatal without treatment, most commonly from infection or hemorrhage. Current treatments focus on suppressing immune-mediated destruction of bone marrow stem cells or replacing hematopoietic stem cells(HSCs) by transplantation. Our incomplete understanding of the pathogenesis of AA has limited development of targeted treatment options. Mesenchymal stem cells(MSCs) play a vital role in HSC proliferation; they also modulate immune responses and maintain an environment supportive of hematopoiesis. Some of the observed clinical manifestations of AA can be explained by mesenchymal dysfunction. MSC infusions have been shown to be safe and may offer new approaches for the treatment of this disorder. Indeed, infusions of MSCs may help suppress auto-reactive, T-cell mediated HSC destruction and help restore an environment that supports hematopoiesis. Small pilot studies using MSCs as monotherapy or as adjuncts to HSC transplantation have been attempted as treatments for AA. Here we review the current understanding of the pathogenesis of AA and the function of MSCs, and suggest that MSCs should be a target for further research and clinical trials in this disorder.

Proliferation and Apoptosis of Bone Marrow CD4^+ T Cells in Patients with Aplastic Anemia and Impacts of the Secreted Cytokines on Hematopoietic Stem Cells from Umbilical Cord Blood

Recent studies indicate that immune-associated aplastic anemia(AA)resembles such autoimmune diseases as insulin-dependent diabetes and chronic autoimmune thyroiditis that belong to organ-specific autoimmune diseases.Many independent investigation groups have successfully isolated the pathopoiesis-associated T cell clone causing hematopoiesis failure with a CD4 phenotype from peripheral blood and bone marrow(BM)in AA patients.In the current study,BM CD4+ T cells were isolated from AA patients and healthy controls with immunomagnetic beads sorting,and proliferation capability,apoptosis features and the impacts of their secreted cytokines on hematopoiesis stem/progenitor cells were compared between them.By 3H-TdR method,CD4+ T cells in AA group presented more enhanced proliferative activity.The stimulation index in control group and AA group was 1.47±0.24,and 2.51±0.34 respectively(P<0.01).After BM CD4+ T cells were induced by high concentration of CD3 monoclonal antibody for 18 h,evident apoptosis cells could be seen under the electron microscope in both control group and AA group.Flow cytometry revealed that apoptosis rates in the early and late stages of AA group were significantly higher than in control group(P<0.01).Early-stage apoptosis rate in control and AA groups was(6.85±1.48)% and(16.98±4.40)%,and late-stage apoptosis rate in control group and AA group was(2.65±1.57)% and(7.74±0.83)%,respectively(P<0.01).The CFU-GM count in AA group and control group was(74.50±9.50)/104 cells and(124.25±19.80)/104 cells respectively under an inverted microscope(P<0.01),and the expression levels of CyclinD3 mRNA and protein in cord blood CD34+ cells were both down-regulated induced by BM CD4+ T cell culture supernatant in AA patients.These results indicate that BM CD4+ T cells of AA patients are likely in an abnormally proliferative,and activated state which can correlate intimately with AA hematopoiesis damage.BM CD4+ T cells in AA patients can secret some soluble cytokines that can inhibit proliferation of hematopoietic stem cells by suppressing the expression of Cyclin D3,resulting in hematopoiesis failure.

Excellent response of severe aplastic anemia to treatment of gut inflammation: A case report and review of the literature

BACKGROUND Cumulative evidence suggests that the aberrant immune responses in acquired aplastic anemia(AA) are sustained by active chronic infections in genetically susceptible individuals. Recently, the constant source to trigger and sustain the pathophysiology has been proposed to come from the altered gut microbiota and chronic intestinal inflammation. In this case, our serendipitous finding provides convincing evidence that the persistently dysregulated autoimmunity may be generated, at least in a significant proposition of AA patients, by the altered gut microbiota and compromised intestinal epithelium.CASE SUMMARY A 30-year-old Chinese male patient with refractory severe AA experienced a 3-month-long febrile episode, and his fever was refractory to many kinds of injected broad-spectrum antibiotics. When presenting with abdominal cramps, he was prescribed oral mannitol and gentamycin to get rid of the gut infection. This treatment resulted in a quick resolution of the fever. Unanticipatedly, it also produced an excellent hematological response. He had undergone three episodes of recurrence within the one-year treatment, with each recurrence occurring 7-8 wk from the gastrointestinal inflammation eliminating preparations. However,subsequent treatments were able to produce subsequent remissions and consecutive treatments were successful in achieving durative hematological improvements, strongly indicating an etiological association between chronic gut inflammation and the development of AA. Interestingly, comorbid diseases superimposed on this patient(namely, psychiatric disorders, hypertension,insulin resistance, and renal dysfunction) were ameliorated together with the hematological improvements.CONCLUSION Chronic gut inflammation may be responsible for AA pathogenesis. The comorbidities and AA may share a common etiological association.

Trichosporon asahii ankle cavity effusion infection in a patient with severe aplastic anemia

Rationale:Trichosporon,an anamorphic fungus,proliferates under high humidity,causing serious opportunistic infections collectively called trichosporonosis.Among the Trichosporon species causing trichosporonosis are Trichosporon(T.)asahii,T.asteroides,T.cutaneum etc.Patient concerns:A 38-year-old Chinese male with severe aplastic anemia was admitted due to multiple joints pain,poor appetite,and right ankle swelling.One year earlier he had undergone allogeneic hematopoietic stem cell transplantation.Diagnosis:T.asahii infection and severe aplastic anemia.Interventions:Combined treatment of amphotericin B liposomes(55 mg/24 h)and voriconazole(200 mg/12 h)for 8 days.Outcomes:The symptoms of the patient’s ankle were relieved and effusion cultures showed no T.asahii.Lessons:To the best of our knowledge,T.asahii ankle cavity effusion infections are rare.Trichosporon infections may be attributed to risk factors such as improper long-term use of antimicrobials for an underlying disease(e.g.,anemia,hypoalbuminemia).Attention should be paid to prevent and control Trichosporon infections in order to avoid comorbidities.

The therapeutic efficiency of ursodeoxycholic acid on Gilbert syndrome complicated by aplastic anemia: a series of case reports

Objective:To reduce the potential risk in aplastic anemia patients complicated with Gilbert syndrome,and find an effective treatment for the unconjugated hyperbilirubinemia.Material and Methods:The mutation of UGT1A1 gene was identified first via sequencing in patients with Gilbert syndrome complicated by aplastic anemia.Before the treatment for aplastic anemia,bilirubin and phenobarbitone tests were conducted.Patients were then treated for their primary disease and given ursodeoxycholic acid(UDCA)either with or without phenobarbitone.Results:The clinical practice of UDCA,which can alleviate increased bilirubin levels,did not affect the key treatments for aplastic anemia.Conclusions:These results indicate that Gilbert syndrome should be addressed when treating aplastic anemia.Furthermore,abnormal bilirubin levels can be controlled effectively by the UDCA treatment.

A New Immunosuppressive Therapy for Very Severe Aplastic Anemia in Children with Autoantibodies

Objective At present,a number of very severe aplastic anemia(VSAA)patients cannot receive hematopoietic stem cell transplantation(HSCT)or standard immunosuppressive therapy(IST)due to the high cost of therapy,shortage of sibling donors,and lack of resources to support the HSCT.In addition,some VSAA patients with autoantibodies have no life-threatening infections or bleeding at the time of initial diagnosis.Considering the disease condition,economics and other factors,the present study designed a new and relatively mild treatment strategy:cyclosporine A plus pulsed high-dose prednisone(CsA+HDP).Methods The present study retrospectively analyzed 11 VSAA patients,who were treated with CsA+HDP in our hospital from August 2017 to August 2019.Results The median follow-up time for these patients was 24.9 months.The overall response rate was 54.5%(6/11)at six months after the initiation of IST and 81.8%(9/11)at deadline.Five patients achieved complete remission and four patients met the criteria for partial response at the last follow-up.The median time to response for responders was 110 days.Three patients underwent HSCT due to the poor effect of CsA+HDP or to find a suitable transplant donor.Recurrence and clonal evolution were not found in any of these patients.The estimated 3-year overall survival rate and 3-year failure-free survival rate were 100.0%and 72.7%,respectively.In addition,the results revealed that the cyclosporine-prednisone-associated toxicity was mild and well-tolerated by most patients.Conclusion The novel CsA+HDP regimen has good therapeutic effect and safety for VSAA patients with autoantibodies,who have no serious life-threatening infections or bleeding at the time of initial diagnosis.

Acquired aplastic anemia:Is bystander insult to autologous hematopoiesis driven by immune surveillance against malignant cells?

We previously reported a serendipitous finding from a patient with refractory severe aplastic anemia who had gotten an unexpected hematological response to treatment with gut-cleansing preparations(GCPs).This patient experienced three recurrences over the ensuing one year of intermittent GCP treatments,with each recurrence occurring 7-8 wk from a GCP.After his third recurrence,he was prescribed successive treatment with rifampicin,berberine,and monthly administered GCP for 4 mo,and he developed an erythroid proliferative neoplasma and an overwhelming enteropathy,and eventually died of septic shock.Laboratory investigations had validated the resolution of myelosuppression and the appearance of malignant clonal hematopoiesis.From the treatment process and laboratory investigations,it is reasonably inferred that the engagement of gut inflammation is critically required in sustaining the overall pathophysiology of acquired aplastic anemia probably by creating a chronic inflammatory state.Incorporation of rifampicin,berberine,and monthly GCP into cyclosporine can enhance the immunosuppressive effect.In a subgroup of acquired aplastic anemia patients whose pathogenesis is associated with genotoxic exposure,the suppressed normal hematopoiesis may result from the bystander insult that is mediated by the soluble inflammatory cytokines generated in response to the immunogenic products of damaged hematopoietic cells in the context of chronic inflammatory state and may offer a protective antineoplastic mechanism against malignant proliferation.

What is responsible for acute myocardial infarction in combination with aplastic anemia? A case report and literature review

BACKGROUND Aplastic anemia(AA)complicated with myocardial infarction(MI)is rare and associated with poor prognosis.Here,we present a case of AA with recurrent acute MI(AMI)in a patient treated with cyclosporine A(CsA)and stanozolol.In this patient,we suspect the long-term use of medication linked to platelets hyperfunction.CASE SUMMARY In 2017,a 45-year-old man was rushed to the emergency department of China-Japan Union Hospital due to precordial pain for 5 h.Based on his symptoms,medical history,blood tests,and findings from coronary angiography(CAG),the patient was diagnosed with acute anterior wall,ST-segment elevated MI,Killip II grade,AA,and dyslipidemia.In 2021,the patient was readmitted to the hospital for 2 h due to chest pain.Because the patient’s platelet count was 30×109/L and he had severe thrombocytopenia,we performed CAG following platelet transfusion.Optical coherence tomography revealed lipid plaque and thrombus mass in his right coronary artery.The antithrombotic approach was adjusted to employ only anticoagulants(factor Xa inhibitors)and adenosine diphosphate inhibitors(clopidogrel)after assessing the risk of bleeding/thrombotic events.Long-term follow-up revealed that the patient had made a good recovery.CONCLUSION Patients with AA should be closely monitored for the risk of thrombosis and cardiovascularevents, particularly when taking stanozolol or CsA for an extended period of time.

Epstein–Barr-virus-associated hepatitis with aplastic anemia: A case report

BACKGROUND Hepatitis-associated aplastic anemia(HAAA) is a rare condition. Patients with HAAA usually present with acute hepatitis, jaundice and significantly increased transaminase. After 1–2 mo, hepatitis gradually improves, but progressive hemocytopenia, bone marrow hematopoietic failure, and severe or extremely severe aplastic anemia are manifest. Most cases of HAAA are fulminant and usually lethal if left untreated. The literature on Epstein–Barr virus(EBV)-associated HAAA is sparse.CASE SUMMARY We report a 30-year-old man who was admitted to our hospital because of pale yellow urine and skin with a simultaneous decrease in peripheral blood ternary cells. We made a diagnosis of EBV-associated HAAA. The treatment strategy for this patient included eltrombopag, an immunosuppressive regimen of rabbit antihuman thymocyte immunoglobulin, cyclosporine, and supportive care. The patient was discharged in normal physical condition after five months. A hemogram performed on follow-up revealed that he had achieved a complete response.CONCLUSION Eltrombopag plus anti-thymocyte globubin and cyclosporine may be a therapeutic option for EBV-associated HAAA.Larger studies are warranted to confirm.

再生障碍性贪血(Aplastic anemia, AA)的治疗

治疗原则早期治疗,联合及交替用药;长期治疗、坚持不懈;根据类型、用不方法。治疗方案推荐方案1—8。其中1—6用于慢性AA,7—8用于急性、重型及单纯红系AA。

Progress on the role and mechanism of autophagy in aplastic anemia

Aplastic anemia is a kind of disease mainly manifested by bone marrow failure.Autophagy is very important for cells to adjust the changes and maintain the balance of themselves.Patients with AA suffer from defects in autophagy function,and the level of autophagy is closely related to the pathogenesis of AA.Autophagy may influence the proliferation and differentiation of HSC and their functional,hematopoietic microenvironmental and immune response,thereby mediating the occurrence and development of AA.This review will summarize the role of HSC,hematopoietic microenvironment and immune response in the pathogenesis of AA,and further elaborated the application of autophagy in regulating T cell subsets and the autophagy function of Treg cells in the treatment of AA.

Effects of Angelica Polysaccharide on telomere length in mice with benzene-induced aplastic anemia

Objective:To investigate the changes in telomere length and the level of burst-forming units-erythrocyte(BFU-Es)and colony-forming unit-erythrocytes(CFU-Es)in mice with benzene-induced aplastic anemia(AA),and follow-up the therapeutic effects of Angelica Polysaccharide(AP).Methods:Male BALB/c mice(n=120)were randomly divided into three groups(1,2,3):normal control(n=24),AA control(n=48),and treated AA(n=48),respectively.Mice in Group 2 received benzene inhalation for 2.5 months and 1 ml distilled water p.o.per day for 2 weeks after the establishment of AA models.Similar procedure was applied to the mice in Group 3 and AP was given for 2 weeks after the establishment of AA models.Real-time polymerase chain reaction was used to survey relative telomere length measurement of the bone marrow cells.A BFU-Es and CFU-Es survey was done to follow-up the therapeutic effects of AP.Results:Compared with normal control,significant reductions of RBC,WBC,and platelet counts were found in peripheral blood of AA mice.After treatment with AP,counts of BFU-Es and CFU-Es were restored up to 66.8%and 77.25%,respectively,and length of telomere was restored up to 76.34%,of the normal levels.The telomere length in treated AA group was higher than the control AA group.Conclusion:The AP can protect the telomere length and differentiation of hemopoietic stem/progenitor cells,accelerate the recovery of BFU-Es and CFU-Es of AA mice,and then improve the bone marrow failure.

Effect of ginsenoside Rg1 on hematopoietic stem cells in treating aplastic anemia in mice via MAPK pathway

BACKGROUND Aplastic anemia(AA)presents a significant clinical challenge as a life-threatening condition due to failure to produce essential blood cells,with the current the-rapeutic options being notably limited.AIM To assess the therapeutic potential of ginsenoside Rg1 on AA,specifically its protective effects,while elucidating the mechanism at play.METHODS We employed a model of myelosuppression induced by cyclophosphamide(CTX)in C57 mice,followed by administration of ginsenoside Rg1 over 13 d.The invest-igation included examining the bone marrow,thymus and spleen for pathological changes via hematoxylin-eosin staining.Moreover,orbital blood of mice was collected for blood routine examinations.Flow cytometry was employed to identify the impact of ginsenoside Rg1 on cell apoptosis and cycle in the bone marrow of AA mice.Additionally,the study further evaluated cytokine levels with enzyme-linked immunosorbent assay and analyzed the expression of key proteins in the MAPK signaling pathway via western blot.RESULTS Administration of CTX led to significant damage to the bone marrow’s structural integrity and a reduction in hematopoietic cells,establishing a model of AA.Ginsenoside Rg1 successfully reversed hematopoietic dysfunction in AA mice.In comparison to the AA group,ginsenoside Rg1 provided relief by reducing the induction of cell apoptosis and inflammation factors caused by CTX.Furthermore,it helped alleviate the blockade in the cell cycle.Treatment with ginsenoside Rg1 significantly alleviated myelosuppression in mice by inhibiting the MAPK signaling pathway.CONCLUSION This study suggested that ginsenoside Rg1 addresses AA by alleviating myelosuppression,primarily through modulating the MAPK signaling pathway,which paves the way for a novel therapeutic strategy in treating AA,highlighting the potential of ginsenoside Rg1 as a beneficial intervention.

Repair of dysfunctional bone marrow endothelial cells alleviates aplastic anemia

Aplastic anemia(AA)is a life-threatening disease characterized by bone marrow(BM)failure and pancytopenia.As an important component of the BM microenvironment,endothelial cells(ECs)play a crucial role in supporting hematopoiesis and regulating immunity.However,whether impaired BM ECs are involved in the occurrence of AA and whether repairing BM ECs could improve hematopoiesis and immune status in AA remain unknown.In this study,a classical AA mouse model and VE-cadherin blocking antibody that could antagonize the function of ECs were used to validate the role of BM ECs in the occurrence of AA.Nacetyl-L-cysteine(NAC,a reactive oxygen species scavenger)or exogenous EC infusion was administered to AA mice.Furthermore,the frequency and functions of BM ECs from AA patients and healthy donors were evaluated.BM ECs from AA patients were treated with NAC in vitro,and then the functions of BM ECs were evaluated.We found that BM ECs were significantly decreased and damaged in AA mice.Hematopoietic failure and immune imbalance became more severe when the function of BM ECs was antagonized,whereas NAC or EC infusion improved hematopoietic and immunological status by repairing BM ECs in AA mice.Consistently,BM ECs in AA patients were decreased and dysfunctional.Furthermore,dysfunctional BM ECs in AA patients led to their impaired ability to support hematopoiesis and dysregulate T cell differentiation toward proinflammatory phenotypes,which could be repaired by NAC in vitro.The reactive oxygen species pathway was activated,and hematopoiesis-and immune-related signaling pathways were enriched in BM ECs of AA patients.In conclusion,our data indicate that dysfunctional BM ECs with impaired hematopoiesis-supporting and immunomodulatory abilities are involved in the occurrence of AA,suggesting that repairing dysfunctional BM ECs may be a potential therapeutic approach for AA patients.