The histone demethylase JMJD1C regulates CPS1 expression and promotes the proliferation of paroxysmal nocturnal haemoglobinuria clones through cell metabolic reprogramming.

Paroxysmal nocturnal haemoglobinuria (PNH) is a disorder resulting from erythrocyte membrane deficiencies caused by PIG-A gene mutations. While current treatments alleviate symptoms, they fail to address the underlying cause of the disease-the pathogenic PNH clones. In this study, we found that the expression of carbamoyl phosphate synthetase 1 (CPS1) was downregulated in PNH clones, and the level of CPS1 was negatively correlated with the proportion of PNH clones. Using PIG-A knockout K562 (K562 KO) cells, we demonstrated that CPS1 knockdown increased cell proliferation and altered cell metabolism, suggesting that CPS1 participates in PNH clonal proliferation through metabolic reprogramming. Furthermore, we observed an increase in the expression levels of the histone demethylase JMJD1C in PNH clones, and JMJD1C expression was negatively correlated with CPS1 expression. Knocking down JMJD1C in K562 KO cells upregulated CPS1 and H3K36me3 expression, decreased cell proliferation and increased cell apoptosis. Chromatin immunoprecipitation analysis further demonstrated that H3K36me3 regulated CPS1 expression. Finally, we demonstrated that histone demethylase inhibitor JIB-04 can suppressed K562 KO cell proliferation and reduced the proportion of PNH clones in PNH mice. In conclusion, aberrant regulation of the JMJD1C-H3K36me3-CPS1 axis contributes to PNH clonal proliferation. Targeting JMJD1C with a specific inhibitor unveils a potential strategy for treating PNH patients.

Nucleoporin Seh1 controls murine neocortical development via transcriptional repression of p21 in neural stem cells.

Mutations or dysregulation of nucleoporins (Nups) are strongly associated with neural developmental diseases, yet the underlying mechanisms remain poorly understood. Here, we show that depletion of Nup Seh1 in radial glial progenitors results in defective neural progenitor proliferation and differentiation that ultimately manifests in impaired neurogenesis and microcephaly. This loss of stem cell proliferation is not associated with defects in the nucleocytoplasmic transport. Rather, transcriptome analysis showed that ablation of Seh1 in neural stem cells derepresses the expression of p21, and knockdown of p21 partially restored self-renewal capacity. Mechanistically, Seh1 cooperates with the NuRD transcription repressor complex at the nuclear periphery to regulate p21 expression. Together, these findings identified that Nups regulate brain development by exerting a chromatin-associated role and affecting neural stem cell proliferation.

Single-institution experience of venetoclax combined with azacitidine in newly diagnosed acute myeloid leukemia patients.

To retrospectively analyze the efficacy and safety of venetoclax combined with azacitidine (VEN + AZA) in the treatment of elderly patients with acute myeloid leukemia. The clinical data for 57 AML patients treated with the VEN + AZA regimen from December 2019 to November 2022 in the Department of Hematology, General Hospital of Tianjin Medical University, were collected. Of the 57 patients included in this study, the mean age of onset was 69.89 (±8.88) years. The median follow-up time was 8.57 months, and the median OS time was 11.50 months. The ORR, CR rate, and MRD (<0.1%) negativity rate were 87.5%, 68.8%, and 58.3%, respectively. The median OS was longer in patients who achieved CR/CRi and who were MRD-negative than in those who did not. MRD negativity was less likely to be achieved in patients aged ≥75 years and with ECOG scores of ≥3. Compared to traditional intensive chemotherapy, MRD negative was achieved more quickly with VEN + AZA regimens in patients with newly diagnosed AML. Advanced age and ECOG score were risk factors for negative MRD. The dominant adverse reactions were hematological adverse events. VEN + AZA regimens in elderly unfit patients with previously untreated newly diagnosed AML have sufficient efficacy and safety.

Partial SAA patients benefit from delayed response of IST.

Introduction: Severe aplastic anemia(SAA)is a severe disease characterized by immune-mediated bone marrow failure and pancytopenia. Immunosuppressive therapy (ATG plus CsA, IST) is the standard treatment for patients who are not suitable for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Some patients have a delayed response after 6 months of ATG, and unnecessary to be given secondary ATG or allo-HSCT. We attempted to distinguish patients who may get potential delayed response from those who were really not responsive to IST. Methods: We collected data from 45 SAA patients who were assessed no-response to IST at 6 months after rATG and failed to receive secondary ATG or allo-HSCT. Results: CsA plus eltrombopag (EPAG) group has an extra 75% response rate while CsA maintenance group has an extra 44% response rate at 12 months. ATG was applied within 30 days after diagnosis, ATG dosage was suffificient (ATG/lymphocyte ≥2), and absolute reticulocyte count (ARC) was ≥30×109 /L at 6 months, indicated patients could get delayed response and benefifit from CsA maintenance. Addition of EPAG could give an even better response. Otherwise, secondary ATG or allo-HSCT treatment were recommended to be given immediately. Clinical Trial Registration: https://www.chictr.org.cn/searchproj.aspx, identifier ChiCTR2300067615.

Sec13 promotes oligodendrocyte differentiation and myelin repair through autocrine pleiotrophin signaling.

Dysfunction of protein trafficking has been intensively associated with neurological diseases, including neurodegeneration, but whether and how protein transport contributes to oligodendrocyte (OL) maturation and myelin repair in white matter injury remains unclear. ER-to-Golgi trafficking of newly synthesized proteins is mediated by coat protein complex II (COPII). Here, we demonstrate that the COPII component Sec13 was essential for OL differentiation and postnatal myelination. Ablation of Sec13 in the OL lineage prevented OPC differentiation and inhibited myelination and remyelination after demyelinating injury in the central nervous system (CNS), while improving protein trafficking by tauroursodeoxycholic acid (TUDCA) or ectopic expression of COPII components accelerated myelination. COPII components were upregulated in OL lineage cells after demyelinating injury. Loss of Sec13 altered the secretome of OLs and inhibited the secretion of pleiotrophin (PTN), which was found to function as an autocrine factor to promote OL differentiation and myelin repair. These data suggest that Sec13-dependent protein transport is essential for OL differentiation and that Sec13-mediated PTN autocrine signaling is required for proper myelination and remyelination.

Real-world Data on the Efficacy and Safety of Ixazomib-based Therapy in Multiple Myeloma: A Single-center Study in China.

OBJECTIVE: To assess the short-term efficacy and safety of ixazomib in Chinese multiple myeloma (MM) patients in the real world. METHODS: Fifty-nine MM patients who received at least one cycle of ixazomib-based therapy between 1 June 2018 and 30 September 2019 were retrospectively analyzed in Tianjin Medical University General Hospital. Thirteen newly diagnosed MM (NDMM), 13 refractory/relapsed MM (RRMM) and 33 continuous therapy (27 bortezomib peripheral neuritis (PN) intolerant and six maintenance therapy) MM patients were included. The indicated overall response rate (ORR), time to overall response (TOR), and adverse events (AEs) were investigated. RESULTS: The ORR in NDMM was 76.9%, with one complete response (CR), five very good partial response (VGPR), four partial response (PR), median PFS, and TOR were 122 (66-272) days and 49 (22-108) days. The ORR in RRMM was 46.2%, with one CR, two VGPR, three PR, median PFS, and TOR were 79 (28-169) days and 59 (23-88) days. The ORR in continuous therapy MM patients was 100%, with nine stringent CR, 15 CR, six VGPR and three PR, median TOR was 75 (25-141) days. There were no significant differences regarding ORR between patients with cytogenetic high risk and standard risk in three subgroups (all P>0.05). The most frequent hematological AEs were anemia (13.6%) and thrombocytopenia (10.2%). The most common nonhematological AEs were PN (25.0%) and diarrhea (13.6%). CONCLUSION: The real-world data demonstrated that ixazomib-based therapy was generally effective and safe in the short term for MM patients.

Nucleoporin Seh1 Interacts with Olig2/Brd7 to Promote Oligodendrocyte Differentiation and Myelination.

Nucleoporins (Nups) are involved in neural development, and alterations in Nup genes are linked to human neurological diseases. However, physiological functions of specific Nups and the underlying mechanisms involved in these processes remain elusive. Here, we show that tissue-specific depletion of the nucleoporin Seh1 causes dramatic myelination defects in the CNS. Although proliferation is not altered in Seh1-deficient oligodendrocyte progenitor cells (OPCs), they fail to differentiate into mature oligodendrocytes, which impairs myelin production and remyelination after demyelinating injury. Genome-wide analyses show that Seh1 regulates a core myelinogenic regulatory network and establishes an accessible chromatin landscape. Mechanistically, Seh1 regulates OPCs differentiation by assembling Olig2 and Brd7 into a transcription complex at nuclear periphery. Together, our results reveal that Seh1 is required for oligodendrocyte differentiation and myelination by promoting assembly of an Olig2-dependent transcription complex and define a nucleoporin as a key player in the CNS.

NK cells suppress CD8+ T cell immunity via NKG2D in severe aplastic anemia.

The roles of natural killer (NK) cells in shaping the immune system had raised wide interests. Here we intended to explore the regulatory functions of NK cells on CD8+ T cells in severe aplastic anemia (SAA) using human participants and lymphocyte infusion-induced bone marrow failure (BMF) mouse model. In SAA patients, NK cells had over-expressions of NKG2D and NKp46, under-expression of NKG2A and enhanced cytotoxicity. NK cells limited autologous CD8+ T cell immunity in an effector/target ratio manner. The suppression was dependent on the existence of NKG2D. We also observed upregulated MICA expression on activated CD8+ T cells, which were susceptible to NK cell mediated lysis in SAA. Animal model concurred with the data from patients. Infusion of NK cells suppressed the proliferation of CD8+ T cells and decreased IFN-γ production. In conclusion, NK cells served NKG2D-dependent immunoregulatory roles by attenuating autologous CD8+ T cell response in SAA.

The shortening telomere length of T lymphocytes maybe associated with hyper­function in servere aplastic anemia.

Severe aplastic anemia (SAA) is a primary disorder of severe bone marrow failure characterizing with extreme pancytopenia and a profound diminution of bone marrow progenitor cells, which is associated with T cell hyper­function. Abnormal telomere shortening of bone marrow mononuclear cell has been reported in AA, which may lead to genomic instability, and result in cell senescence or apoptosis. Notably, certain studies identfieid that lymphocytes of shortening telomere length have undergone apoptosis escape in autoimmune diseases. In order to investigate the association between telomere lengths and function of T lymphocytes in SAA, the relative telomere lengths (RTLs) of different subtypes of T lymphocytes were investigated by flow­fluorescent in situ hybridization in 30 patients with SAA and 25 healthy controls. Then the levels of expression of cluster of differentiation 28 (CD28), CD158 and CD70 were measured, which represent the function of T lymphocytes. The apoptosis rate and the cell cycle progression of CD8+T lymphocytes, and the level of secretion interferon­Î³ and tumor necrosis factor­α were also measured. Finally, the correlation between telomere length and these functional events of CD8+T lymphocytes was analyzed in patients with SAA. The results showed that RTLs of CD8+T lymphocytes in SAA were significantly shorter compared with those in controls. Furthermore, in patients with SAA, CD8+T lymphocytes are associated with T cell hyper­function, which is related to the RTL. Thus, the shorter RTLs of CD8+T lymphocytes in SAA may be associated with hyper­function of these cells, which contribute to the pathogenesis of SAA.

Iron overload may promote alteration of NK cells and hematopoietic stem/progenitor cells by JNK and P38 pathway in myelodysplastic syndromes.

The objective of the study was to examine levels of intracellular iron, reactive oxygen species (ROS) and the expression of JNK and p38MAPK in NK cells and hematopoietic stem/progenitor cells (HSPCs) in MDS patients, and explore potential mechanisms by which iron overload (IOL) promotes MDS progression. Thirty-four cases of MDS and six cases of AML transformed from MDS (MDS/AML) were included. HSPCs and NK cells were isolated by magnetic absorption cell sorting. We used flow cytometry to detect the levels of ROS and intracellular JNK and P38 in NK cells and HSPCs. Total RNA and protein were extracted from NK cells and CD34+ cells to examine the expression of JNK and p38MAPK using RT-PCR and Western blotting. Intracellular iron concentration was detected. Data were analyzed by SPSS 21 statistical software. Intracellular iron concentration and ROS were increased in both NK cells and HSPCs in MDS patients with iron overload (P < 0.05). MDS patients with iron overload had higher JNK expression and lower p38 expression in NK cells, and higher p38 expression in HSPCs compared with non-iron overload group. IOL may cause alterations in NK cells and HSPCs through the JNK and p38 pathways, and play a role in the transformation to AML from MDS.