AIM:To investigate the regulatory mechanism of silent information regulator 6(Sirt6)on nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway and ferroptosis in skeletal muscle aging in-duced by D-galactose(D-Gal)in mice.METHODS:A D-Gal-induced mouse aging model was established and randomly divided into control and D-Gal groups.In vitro,D-Gal-treated C2C12 mouse myoblasts were treated with ferroptosis ago-nist erastin(Era)and inhibitor ferrostatin-1(Fer-1),Sirt6 agonist MDL-800 and inhibitor OSS-128167,and Nrf2 siRNA.Mouse body weight and forelimb relative grip strength were monitored.RT-qPCR and Western blot were used to measure the expression of Sirt6,Nrf2,HO-1,P53,P21,P16,muscle ring finger protein 1,muscle atrophy F-box,solute carrier family 7 member 11,and glutathione peroxidase 4 in gastrocnemius muscle and myoblasts.Hematoxylin-eosin staining was performed to examine muscle fiber diameter.Levels of reactive oxygen species(ROS),mitochondrial ROS,mitochon-drial membrane potential,senescence-associated β-galactosidase activity,glutathione,lipid peroxidation,and Fe2? con-centration were measured in myoblasts and myotubes.Immunofluorescence staining was used to detect myosin heavy chain(MyHC)expression in myotubes.RESULTS:Mice in the D-Gal group exhibited significant reductions in body weight and forelimb grip strength(P<0.01),upregulation of aging and muscle atrophy markers,and decreased mRNA and pro-tein levels of ferroptosis markers and Sirt6(P<0.01).Additionally,gastrocnemius muscle fiber diameter significantly de-creased(P<0.01).In D-Gal-treated myoblasts and myotubes,aging and muscle atrophy markers were elevated(P<0.01),MyHC expression was reduced,and protein levels of ferroptosis-related markers,Sirt6,Nrf2,and HO-1 were de-creased(P<0.05 or P<0.01).Fer-1 pre-treatment alleviated these changes(P<0.05 or P<0.01).MDL-800 significantly improved D-Gal-induced aging and muscle atrophy in myoblasts and myotubes,while increasing the expression of ferropto-sis-related proteins(P<0.05 or P<0.01).However,the addition of Erastin abolished the beneficial effects of MDL-800(P<0.05 or P<0.01).Following Nrf2 siRNA transfection,the ability of MDL-800 to improve ferroptosis and the quality of myotube formation was significantly diminished(P<0.05 or P<0.01).CONCLUSION:Sirt6 inhibits ferroptosis in myo-blasts through the Nrf2/HO-1 signaling pathway,thereby alleviating age-related changes in myoblasts and the decline in myotube formation quality,which is beneficial for improving skeletal muscle aging.

Objective:To compare the performance of next-generation sequencing (NGS) and Sanger sequencing in investigating somatic hypermutation (SHM) status of immunoglobulin heavy chain variable region (IGHV) genes. It specifically focuses on identifying key factors contributing to discrepancies between the two methods, particularly under complex clonal backgrounds, to inform optimized strategies for clinical application.Methods:This retrospective analysis included 53 samples, comprising 43 identified as non-monoclonal and 10 as monoclonal using Sanger sequencing. All samples were further analyzed using NGS to assess IGHV SHM. The two methods were used for systematic comparison. For discordant cases, in-depth attribution analysis was conducted, considering factors, including clonal abundance quantification, differences in primer design, and interpretation criteria.Results:Among the 53 patients who underwent both Sanger and NGS testing, 36 were male and 17 were female, with a median age of 64 years (range: 33–88). Diagnoses included chronic lymphocytic leukemia (CLL) in 35 (66.0% ), diffuse large B-cell lymphoma in 9 (17.0% ), follicular lymphoma in 3 (5.7% ), mantle cell lymphoma in 3 (5.7% ), and other types in 3 (5.7% ) cases. In the 43 cases with non-monoclonal profiles using Sanger sequencing, NGS revealed 23 cases as biclonal or polyclonal, 17 as monoclonal, and 3 with no detectable clonality. The primary discrepancies between the two methods involved variations in clonality assessment, IGHV gene rearrangement types, and mutation rates. Among the 10 cases identified as monoclonal using Sanger sequencing, NGS detected biclonality and markedly different IGHV rearrangement types in 2 and 4 cases, respectively. Minor differences were observed in SHM percentage between the two methods; however, these did not substantially affect the overall determination of mutational status.Conclusion:Compared with Sanger sequencing, NGS exhibits superior performance in assessing IGHV SHM status under complex clonal conditions. It provides greater sensitivity and accuracy in detecting subclonal components and quantifying clonal proportions, thereby providing a more precise molecular basis for diagnosing and prognostically assessing lymphoid malignancies, including CLL.

Objective:To compare the performance of next-generation sequencing (NGS) and Sanger sequencing in investigating somatic hypermutation (SHM) status of immunoglobulin heavy chain variable region (IGHV) genes. It specifically focuses on identifying key factors contributing to discrepancies between the two methods, particularly under complex clonal backgrounds, to inform optimized strategies for clinical application.Methods:This retrospective analysis included 53 samples, comprising 43 identified as non-monoclonal and 10 as monoclonal using Sanger sequencing. All samples were further analyzed using NGS to assess IGHV SHM. The two methods were used for systematic comparison. For discordant cases, in-depth attribution analysis was conducted, considering factors, including clonal abundance quantification, differences in primer design, and interpretation criteria.Results:Among the 53 patients who underwent both Sanger and NGS testing, 36 were male and 17 were female, with a median age of 64 years (range: 33–88). Diagnoses included chronic lymphocytic leukemia (CLL) in 35 (66.0% ), diffuse large B-cell lymphoma in 9 (17.0% ), follicular lymphoma in 3 (5.7% ), mantle cell lymphoma in 3 (5.7% ), and other types in 3 (5.7% ) cases. In the 43 cases with non-monoclonal profiles using Sanger sequencing, NGS revealed 23 cases as biclonal or polyclonal, 17 as monoclonal, and 3 with no detectable clonality. The primary discrepancies between the two methods involved variations in clonality assessment, IGHV gene rearrangement types, and mutation rates. Among the 10 cases identified as monoclonal using Sanger sequencing, NGS detected biclonality and markedly different IGHV rearrangement types in 2 and 4 cases, respectively. Minor differences were observed in SHM percentage between the two methods; however, these did not substantially affect the overall determination of mutational status.Conclusion:Compared with Sanger sequencing, NGS exhibits superior performance in assessing IGHV SHM status under complex clonal conditions. It provides greater sensitivity and accuracy in detecting subclonal components and quantifying clonal proportions, thereby providing a more precise molecular basis for diagnosing and prognostically assessing lymphoid malignancies, including CLL.

AIM:To investigate the regulatory mechanism of silent information regulator 6(Sirt6)on nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway and ferroptosis in skeletal muscle aging in-duced by D-galactose(D-Gal)in mice.METHODS:A D-Gal-induced mouse aging model was established and randomly divided into control and D-Gal groups.In vitro,D-Gal-treated C2C12 mouse myoblasts were treated with ferroptosis ago-nist erastin(Era)and inhibitor ferrostatin-1(Fer-1),Sirt6 agonist MDL-800 and inhibitor OSS-128167,and Nrf2 siRNA.Mouse body weight and forelimb relative grip strength were monitored.RT-qPCR and Western blot were used to measure the expression of Sirt6,Nrf2,HO-1,P53,P21,P16,muscle ring finger protein 1,muscle atrophy F-box,solute carrier family 7 member 11,and glutathione peroxidase 4 in gastrocnemius muscle and myoblasts.Hematoxylin-eosin staining was performed to examine muscle fiber diameter.Levels of reactive oxygen species(ROS),mitochondrial ROS,mitochon-drial membrane potential,senescence-associated β-galactosidase activity,glutathione,lipid peroxidation,and Fe2? con-centration were measured in myoblasts and myotubes.Immunofluorescence staining was used to detect myosin heavy chain(MyHC)expression in myotubes.RESULTS:Mice in the D-Gal group exhibited significant reductions in body weight and forelimb grip strength(P<0.01),upregulation of aging and muscle atrophy markers,and decreased mRNA and pro-tein levels of ferroptosis markers and Sirt6(P<0.01).Additionally,gastrocnemius muscle fiber diameter significantly de-creased(P<0.01).In D-Gal-treated myoblasts and myotubes,aging and muscle atrophy markers were elevated(P<0.01),MyHC expression was reduced,and protein levels of ferroptosis-related markers,Sirt6,Nrf2,and HO-1 were de-creased(P<0.05 or P<0.01).Fer-1 pre-treatment alleviated these changes(P<0.05 or P<0.01).MDL-800 significantly improved D-Gal-induced aging and muscle atrophy in myoblasts and myotubes,while increasing the expression of ferropto-sis-related proteins(P<0.05 or P<0.01).However,the addition of Erastin abolished the beneficial effects of MDL-800(P<0.05 or P<0.01).Following Nrf2 siRNA transfection,the ability of MDL-800 to improve ferroptosis and the quality of myotube formation was significantly diminished(P<0.05 or P<0.01).CONCLUSION:Sirt6 inhibits ferroptosis in myo-blasts through the Nrf2/HO-1 signaling pathway,thereby alleviating age-related changes in myoblasts and the decline in myotube formation quality,which is beneficial for improving skeletal muscle aging.

Due to the successful application of all-trans retinoic acid (ATRA) and arsenic, the treatment of acute promyelocytic leukemia (APL) with PML::RARA fusion gene has achieved great success. However, some patients are presented with APL phenotype in cellular morphology, immunophenotype, and gene expression profile, while PML::RARA is negative, which is known as atypical APL (aAPL). In aAPL patients, more than 20 fusion genes related to retinoic acid receptors have been reported. It has been discovered that all evaluable patients with RARG fusion genes and approximately half of those with rare RARA fusion genes are resistant to ATRA, however, the molecular mechanisms of this resistance remain poorly studied. Combining with the reports in the 65th American Society of Hematology Annual Meeting, this paper reports great progresses of the key pathogenesis of aAPL and ATRA resistance mechanisms.

The seat of human intelligence is the human cerebral cortex, which is responsible for our exceptional cognitive abilities. Identifying principles that lead to the development of the large-sized human cerebral cortex will shed light on what makes the human brain and species so special. The remarkable increase in the number of human cortical pyramidal neurons and the size of the human cerebral cortex is mainly because human cortical radial glial cells, primary neural stem cells in the cortex, generate cortical pyramidal neurons for more than 130 days, whereas the same process takes only about 7 days in mice. The molecular mechanisms underlying this difference are largely unknown. Here, we found that bone morphogenic protein 7 (BMP7) is expressed by increasing the number of cortical radial glial cells during mammalian evolution (mouse, ferret, monkey, and human). BMP7 expression in cortical radial glial cells promotes neurogenesis, inhibits gliogenesis, and thereby increases the length of the neurogenic period, whereas Sonic Hedgehog (SHH) signaling promotes cortical gliogenesis. We demonstrate that BMP7 signaling and SHH signaling mutually inhibit each other through regulation of GLI3 repressor formation. We propose that BMP7 drives the evolutionary expansion of the mammalian cortex by increasing the length of the neurogenic period.
Animals ; Mice ; Humans ; Ependymoglial Cells/metabolism* ; Hedgehog Proteins/metabolism* ; Ferrets/metabolism* ; Cerebral Cortex ; Neurogenesis ; Mammals/metabolism* ; Neuroglia/metabolism* ; Bone Morphogenetic Protein 7/metabolism*

Objective:To summarize the clinical features associated with respiratory syncytial virus (RSV) infection in patients following the hematopoietic stem cell transplant (HSCT) and exploring the risk factors for death.Methods:Patients who had RSV infection after undergoing HSCT from October 2023 to January 2024 in the hematology department of Peking University People’s Hospital were enrolled in the study. The clinical characteristics of the participating patients were summarized. The clinical characteristics of the surviving and the dying patients were compared, and the risk factors of death were analyzed by binary logistic regression.Results:Among the 43 RSV-positive HSCT patients, 20 (46.5%) were hypoxemic, six (14.0%) were admitted to the ICU for further treatment, four (9.3%) required tracheal intubation assisted ventilation, and seven patients (16.3%) died. A comparison of the clinical features of the surviving patients and the deceased patients demonstrated that the deceased patients had a lower PLT when infected with RSV [74.5 (8.0-348.0) ×10 9/L vs 15.0 (10.0-62.0) ×10 9/L, P=0.003], a higher incidence of simultaneous bacterial infections (85.7% vs 41.7%, P=0.046), and a higher rate of hematological recurrence (71.4% vs 13.9%, P=0.004). Hematological recurrence ( OR=15.500, 95% CI 2.336-102.848, P=0.005), influenza A viral infection ( OR=14.000, 95% CI 1.064-184.182, P=0.045), and low PLT at the time of RSV infection ( OR=0.945, 95% CI 0.894-0.999, P=0.048) were the factors associated with death following HSCT. Conclusion:Patients infected with RSV after undergoing HSCT have a poor prognosis, and active prevention and treatment of RSV in the autumn and winter requires urgent attention.

FLT3 internal tandem duplication (ITD) mutations are common in acute myeloid leukemia and show an important significance in guiding prognostic stratification and targeted therapy. With the widespread application of high-throughput sequencing technology and the increased ability to analyze mutation sequences, it has been found that more than half of FLT3-ITD mutations are not just tandem duplications but are also accompanied by some complex situations such as the addition of non-template sequences. Recent studies have revealed the sequence characteristics, mutagenesis mechanisms and related clinical prognostic significance of FLT3 length mutations (FLT3-LM). FLT3-LM with added non-template sequences is formed by abnormally activated terminal deoxynucleotidyl transferase. These patients show different treatment responses and prognosis when treated with chemotherapy, targeted therapy, and allogeneic hematopoietic stem cell transplantation, which provides a new perspective to understand FLT3-LM mutations more accurately and provides proposals for FLT3-LM typing based on the mutagenesis mechanism. The new typing rules can better reflect the differences in biological characteristics of the disease and more accurately guide the prognostic stratification and development of individualized treatment for patients with FLT3-LM mutations.

Whether Fanconi anemia (FA) heterozygotes are predisposed to bone marrow failure and hematologic neoplasm is a crucial but unsettled issue in cancer prevention and family consulting. We retrospectively analyzed rare possibly significant variations (PSVs) in the five most obligated FA genes, BRCA2, FANCA, FANCC, FANCD2, and FANCG, in 788 patients with aplastic anemia (AA) and hematologic malignancy. Sixty-eight variants were identified in 66 patients (8.38%). FANCA was the most frequently mutated gene (n = 29), followed by BRCA2 (n = 20). Compared with that of the ExAC East Asian dataset, the overall frequency of rare PSVs was higher in our cohort (P = 0.016). BRCA2 PSVs showed higher frequency in acute lymphocytic leukemia (P = 0.038), and FANCA PSVs were significantly enriched in AA and AML subgroups (P = 0.020; P = 0.008). FA-PSV-positive MDS/AML patients had a higher tumor mutation burden, higher rate of cytogenetic abnormalities, less epigenetic regulation, and fewer spliceosome gene mutations than those of FA-PSV-negative MDS/AML patients (P = 0.024, P = 0.029, P = 0.024, and P = 0.013). The overall PSV enrichment in our cohort suggests that heterozygous mutations of FA genes contribute to hematopoietic failure and leukemogenesis.
Anemia, Aplastic/genetics* ; Epigenesis, Genetic ; Fanconi Anemia/genetics* ; Germ Cells ; Hematologic Neoplasms/genetics* ; Humans ; Leukemia, Myeloid, Acute/genetics* ; Retrospective Studies