Molecular genetic and clinical characteristics of MEF2D-BCL9 fusion gene-positive acute B-cell lymphoblastic leukemia / 白血病·淋巴瘤

Objective:To investigate the molecular genetic and clinical characteristics of MEF2D-BCL9 fusion gene-positive acute B-cell lymphoblastic leukemia (B-ALL), and to provide the reference for the diagnosis and treatment of the disease.Methods:The medical record and experimental examination data of a 18-year-old female MEF2D-BCL9 fusion gene-positive B-ALL patient were retrospectively analyzed. The clinical manifestations and biological characteristics of MEF2D-BCL9 fusion gene-positive B-ALL were summarized.Results:This 18-year-old female patient was treated in a local hospital in December 2018 and was diagnosed as B-ALL. She achieved complete remission after chemotherapy and recurred at 6 months after the initial onset, and then she was admitted to Hebei Yanda Ludaopei Hospital in the 9 months after the initial onset.MEF2D-BCL9 fusion gene was detected through RNA-sequencing (RNA-seq) and verified by using polymerase chain reaction and Sanger sequencing. Bone marrow cell morphology was similar to mature B cells with vacuoles but without characteristic chromosome karyotype abnormalities. The patient achieved remission after VLD regimen chemotherapy, chimeric antigen receptor T-cell (CAR-T) therapy and bridged to allogeneic hematopoietic stem cell transplantation (allo-HSCT). She has maintained complete remission for 2 years at the last follow-up in February 2022.Conclusions:MEF2D-BCL9 fusion gene-positive B-ALL is characterized with high risk, early relapse and poor prognosis. These patients may benefit from CAR-T and allo-HSCT. It further emphasizes the importance of taking MEF2D-BCL9 fusion gene into the detection or identification by using RNA-seq, particularly for those newly diagnosed B-ALL patients in children and adolescents with specific bone marrow morphology.

Changes of CD4+CD25+ regulatory T cells and related regulatory factors in acute renal allograft rejection in rats / 中华肾脏病杂志

Objective To observe the level of CD4+CD25+ regulatory T cells (CD4+CD25+ Treg cells) with positive fork head transcription factor 3 (Foxp3) and changes of T-box transcription factor TBX1 (TBX1) and myocyte specific enhancer 2D (MEF2D) expression in peripheral blood of rats with acute rejection after renal transplantation,and to investigate its regulatory mechanisms by combined with renal function,plasma interleukin-10 (IL-10),interferon-γ (IFN-γ) and renal histopathological changes.Methods Rat renal transplantation model was established and divided into two groups:acute rejection group (AR group) and non-acute rejection group (non-AR group).Their renal function including serum creatinine (Scr) and blood urea nitrogen (BUN) in plasma was measured.The renal histopathology was observed by HE staining.Levels of IL-10 and IFN-γ in plasma were detected by ELISA.The proportion of CD4+CD25+ Treg cells was measured by flow cytometry.The mRNA expressions of Foxp3,TBX1 and MEF2D in CD4+CD4+Treg cells were detected by real-time PCR,and their protein expressions were tested by Western blotting.Results Compared with these in the non-AR group,the levels of BUN,Scr and IFN-γ significantly increased in AR group (all P ＜ 0.05),while IL-10 decreased (P ＜ 0.05).Renal histopathology in the acute rejection group showed glomerular hypertrophy and mesangial cell proliferation,capillary proliferation and neutrophil infiltration;renal interstitial edema and tubular necrosis,accompanied by lymphocytes,plasma cells and neutrophils infiltration.Compared with that in the non-AR group,the percentage of CD4+CD25+ Treg cells in peripheral blood was notably lowered in AR group (4.50％±0.50％ vs 5.74％±1.96％,P ＜ 0.05).The mRNA and protein expressions of Foxp3 and MEF2D were lower in AR group than those in non-AR group,while the expressions of TBX1 was elevated (all P ＜ 0.05).Conclusions In rats with acute renal allograft rejection,the percentage of CD4+CD25+ Treg cells and expressions of Foxp3,MEF2D and IL-10 decrease,while the expressions of TBX1 and IFN-γ enhance.These participate in the development of acute rejection after renal transplantation,and aggravate the renal damage.

Targeting Myocyte-specific Enhancer Factor 2D Contributes to the Suppression of Cardiac Hypertrophic Growth by MiR-92b-3p in Cardiomyocytes / 中山大学学报(医学科学版)

[Objective]To investigate the role and the potential target of miR-92b-3p in angiotensin Ⅱ(Ang-Ⅱ)-induced mouse cardiac hypertrophy.[Methods]Ang-Ⅱ-induced cardiac hypertrophy models were established in adult C57BL/6 mice. AgomiR-92b-3p,the cholesterol-modified miR-92b-3p mimic,was delivered to increase the level of miR-92b-3p in mouse myocar?dium via tail vein injection. In the present study,three groups of mice were used in the animal experiment as follows,the agomiR-negative control(agomiR-NC)+saline group,the agomiR-NC+Ang-Ⅱgroup and the agomiR-92b-3p+Ang-Ⅱgroup. A cell model of cardiac hypertrophy was also established in Ang-Ⅱ-induced neonatal mouse cardiomyocytes in this study Luciferase activity was assayed after transfection using a luciferase reporter assay system. The expression of Myocyte-specific enhancer factor 2D( MEF2D) and hypertrophy-related genes atrial natriuretic peptide (ANP),cardiac muscle α-actin (ACTA1) and β-myosin heavy chain (MHC)at mRNA and protein levels in Ang-Ⅱ-induced hypertrophic myocardium and cardiomyocytes were detected by qRT-PCR and Western blot,respectively.[Results]The expression of ANP,ACTA1,β-MHC were markedly increased in Ang-Ⅱ-induced hypertrophic myocardium and cardiomyocytes. Dual luciferase reporter assay revealed that MEF2D is a potential target gene of miR-92b-3p. And miR-92b-3p can reduce the expression of MEF2D at the post-transcriptional level. Functionally,miR-92b-3p mimic, consistent with MEF2D siRNA,inhibited cell size increase and protein expression of ANP,ACTA1 andβ-MHC in Ang-II-treated mouse cardiomyocytes.[Conclusions]MEF2D is a novel target of miR-92b-3p,a target gene of miR-92b-3,which mediates the ef?fect of miR-92b-3p on attenuating cardiomyocyte hypertrophy.

MEF2C mediates inhibitory effect of microRNA-214 on cardiomyocyte hypertrophy / 中国病理生理杂志

AIM:To investigate the effect of microRNA-214 ( miR-214) on cardiomyocyte hypertrophy and the expression of the potential target genes .METHODS:A cell model of hypertrophy was established based on angiotensin-Ⅱ( Ang-Ⅱ)-induced neonatal mouse ventricular cardiomyocytes ( NMVCs) .Dual luciferase reporter assay was performed to verify the interaction between miR-214 and the 3’ UTR of MEF2C.The expression of MEF2C and hypertrophy-related genes at mRNA and protein levels was determined by RT-qPCR and Western blot , respectively .RESULTS:The expression of ANP, ACTA1,β-MHC and miR-214 was markedly increased in Ang-Ⅱ-induced hypertrophic cardiomyocytes .Dual lu-ciferase reporter assay revealed that miR-214 interacted with the 3’ UTR of MEF2C, and miR-214 was verified to inhibit MEF2C expression at the transcriptional level .The protein expression of MEF2C was markedly increased in the hypertro-phic cardiomyocytes .Moreover, miR-214 mimic, in parallel to MEF2C siRNA, inhibited the expression of hypertrophy-re-lated genes in Ang-Ⅱ-induced NMVCs.CONCLUSION:MEF2C is a target gene of miR-214, which mediates the effect of miR-214 on attenuating cardiomyocyte hypertrophy .

Molecular cloning and in silico analysis of the duck (Anas platyrhynchos) MEF2A gene cDNA and its expression profile in muscle tissues during fetal development

The role of myogenic enhancer transcription factor 2a (MEF2A) in avian muscle during fetal development is unknown. In this work, we cloned the duck MEF2A cDNA sequence (GenBank accession no. HM460752) and examined its developmental expression profiles in cardiac muscle, non-vascular smooth muscle and skeletal muscle. Duck MEF2A cDNA comprised 1479 bp encoding 492 amino acid residues. In silico analysis showed that MEF2A contained MADS (MCM1, AGAMOUS, DEFICIENS and SRF -serum response factor), MEF2 and mitogen-activated protein kinase (MAPK) transcription domains with high homology to related proteins in other species. Modified sites in these domains were conserved among species and several variants were found. Quantitative PCR showed that MEF2A was expressed in all three muscles at each developmental stage examined, with the expression in smooth muscle being higher than in the other muscles. These results indicate that the conserved domains of duck MEF2A, including the MADS and MEF2 domains, are important for MEF2A transcription factor function. The expression of MEF2A in duck smooth muscle and cardiac muscle suggests that MEF2A plays a role in these two tissues.

Myocyte-specific enhancer binding factor 2C (MEF2C) expression in the dentate gyrus during development and after pilocarpine-induced status epilepticus: a preliminary report / Realce miócito específico ligado a expressão do fator 2C (MEF2C) no giro denteado durante o desenvolvimento e após uso de pilocarpina induzindo status epilepticus: estudo preliminar

OBJECTIVE: As axon outgrowth and dentate granule cell neurogenesis are hallmarks of hippocampal development and are also the two morphologic changes in the structure of the dentate gyrus after status epilepticus (SE), we hypothesized that molecules involved in normal development may also play a role during epileptogenesis. METHOD: Using in situ hybridization, we have characterized mRNA expression of myocyte-specific enhancer binding factor 2C (MEF2C) in the dentate gyrus during development (P0, P3, P7, P14 and P28) and at multiple time points following pilocarpine-induced SE (3, 7, 14, 28 days after SE). RESULTS: It was demonstrated that MEF2C is up-regulated during development (P0, P3, P7, P14 and P28) and in the adult rat dentate gyrus following SE (3, 7, 14, 28 days after SE). CONCLUSIONS: The molecules controlling cell-fate decisions in the developing dentate gyrus are also operative during epileptogenesis.

OBJETIVO: Como o crescimento axonal e a neurogênese do giro denteado são características intrínsecas do hipocampo durante o processo de desenvolvimento, e também são duas alterações morfológicas na estrutura do giro denteado após o status epilepticus (SE), nós hipotetizamos que as moléculas envolvidas no processo normal do desenvolvimento hipocampal também podem participar do processo de epileptogênese. MÉTODO: Utilizando hibridização in situ, caracterizamos a expressão do RNAm do fator de transcrição myocyte-specific enhancer binding factor 2C (MEF2C) no giro denteado durante o desenvolvimento (P0, P3, P7, P14 e P28) e em diferentes períodos após o SE (3, 7, 14, 28 dias após SE). RESULTADOS: Foi demonstrado um aumento da expressão de MEF2C no giro denteado durante o desenvolvimento e no giro denteado de animais adultos após o SE. CONCLUSÃO: As moléculas que controlam o destino celular durante o processo de desenvolvimento também estão operativas durante o processo de epileptogênese.

P38/caspase-3 mediated MEF2C pathway and its significance in the injuries of hippocampal CA1 region of rats following ischemia/reperfusion / 基础医学与临床

Objective To investigate the level of MEF2C phosphorylation (activation) and protein expression, and to further clarify the possible mechanism following ischemia-reperfusion in hippocampal CA1 region of rat. MethodsBrain ischemia was induced by four-vessel occlusion in SD rats. Protein level was determined by Western blotting. Results MEF2C was significantly activated with a peak at 6 h of reperfusion, but its protein expression decreased in late phase of reperfusion (3～5 d). The elevation of activated (17 ku) and the inactivated forms (32 ku) of caspase-3 proteases were remarkable during 1～5 d of reperfusion. In addition, Ac-DEVD-CHO, a specific inhibitor of caspase-3, up-regulated MEF2C protein level of 3 d reperfusion. SB202190 (an inhibitor of P38), but not ERK5-antisense oligonucleotides, not only inhibited MEF2C activation of 6 h reperfusion but also apparently prevented the increase of caspase-3 activation caused by 3 d reperfusion. Conclusion P38/caspase-3 mediated MEF2C pathway may function in the injuries of hippocampal CA1 region of rats following ischemia/reperfusion.

Cloning and Analyzing The Promoter of PPAR? / 生物化学与生物物理进展

Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear hormone receptors belonging to the steroid receptor superfamily. Three PPAR isoforms, PPAR?, PPAR? (also known as PPAR?) and PPAR? have been found in the mouse. They can activate expression of many genes, including those involved in lipidmetabolism. PPAR? is ubiquitously expressed, but the level of expression differs markedly between different cell types. PPAR? is expressed in skeletal muscle at 10- and 50-fold higher levels compared with PPAR? and PPAR?, respectively. A role for PPAR? in skeletal muscle is to increase the genes expression with relation to oxidative metabolism. In order to determine the molecular mechanisms governing PPAR? gene expression in muscle, a 2 kb 5′ flanking region was cloned and analyzed. The DNA fragment is able to transcribe GFP in COS7 cells. Dual luciferase assay is used to quantify promoter activity. Deletion analysis of the 2 kb PPAR? promoter fragment in COS7 and NIH 3T3 cells shows that the proximal promoter sequence, nt -197 to +120, confers basal transcriptional activity of the mouse PPAR? gene. Computational analysis of putative cis-acting elements located within the ～2.0 kb mouse PPAR? 5′-flanking sequence was performed using the TRANSFAC database and MatInspector software and 4 potential MEF2A binding sites were found. And there is a potential binding site sharing 100% identity with positive element of MEF2A in the proximal promoter (nt -261). Co-transfection experiments of the PPAR? promoter reporter and pMEF2A expression plasmid (pMEF2A) showed that MEF2A significantly enhanced transcription activity of PPAR? promoter in NIH 3T3. Moreover, the enhancive effect depended on the concentration of plasmid pMEF2A transfected into cells. The results suggested that MEF2A may enhance transcription activity of the PPAR promoter in muscle cells.

Studies on Differentiation of Cardiac Myoblast Induced by Co-culture with Isolated Neonatal Rat Cardiac Myocytes / 대한해부학회지

Cellular cardiomyoplasty has recently emerged as a potential new treatment of ischemic heart disease. Combining cellular cardiomyoplasty with gene therapy using myogenic transcription factor might facilitate myocardial regeneration. In this study, we engineered H9c2, L6 using plasmid vector to overexpress the transcription factor MEF2c, Nkx2.5 involved in cardiomyogenesis. We investigated 1) formation of intercellular junction in mono-culture and co-culture with cardiomyocyte for functional and structural synchronous contraction after transplantation, 2) differentiation into cardiomyocyte, 3) resistance to hypoxic condition. Each cell overexpressing MEF2 and Nkx2.5 was generated by gene transfection and clonal selection. CO-culture was performed that each cell line added over cultured cardiomyocyte. H9c2-MEF2c and H9c2-Nkx2.5 became long, spindle shape like cardiomyocyte. Troponin T, cardiac specific marker, was found spot-like pattern in H9c2-Nkx2.5. However, co-culture with cardiomyocyte did not induce differentiation all kinds of cells into cardiomyocyte. Connexin43, which is gap junction marker was increased in H9c2-MEF2c, H9c2-Nkx2.5, L6-MEF2c and L6-Nkx2.5. Especially, co-culture with cardiomyocyte resulted in elevation of connexin43 levels more than monoculture. Ultrastructurally, formations of gap junction and desmosome were found apparently in L6-Nkx2.5. Long-standing, strong, regular and more frequent contraction were observed in cardiomyocyte co-cultured with H9c2-MEF2c, H9c2-Nkx2.5, L6-MEF2c, L6-Nkx2.5, respectively. Neverthless, any cell did not have active contraction itself, but passive movement except cardiomyocyte. H9c2-MEF2c, L6-MEF2c and L6-Nkx2.5 had resistance to hypoxia compared with other groups. These results suggested that co-culture and overexpressions of MEF2c and Nkx2.5 induced differentiation into cardiomyocyte and played an important role on intercellular junction formation and hypoxic resistance. This would be a promising source of cellular cardiomyoplasty. Therefore, much more research would be essential for clinical application of cellular cardiomyoplasty and this study would be a basic source for further study of MEF2c and Nkx2.5 in cellular cardiomyoplasty.

Human Cytomegalovirus Immediate-Early 2Prote in Transactivates c-jun Promoter Through ATF and MEF2 Site / 감염

BACKGROUND: Human cytomegalovirus (HCMV) has the ability to activate the expression of many viral and cellular genes. The c-jun proto-oncogene has known to be induced at immediate early time of HCMV infection, however, the mechanism of up-regulation of the gene was not known. We found HCMV immediate-early (IE) 2 expression transactivate the c-jun promoter in human embryonal lung cell (HEL). METHODS: The c-jun promoter region between -117 and -59 contains binding sites for the transcription factors Sp1, CAAT, AP-1 like (ATF/CREB), and MEF2. We tried to map the sequences in the c-jun promoter responsible for activation of the promoter by HCMV IE2 expression. Transient expression assays were performed using various reporter plasmids containing the c-jun promoter-regulatory region linked to the luciferase gene and a plasmid expressing HCMV IE2 gene. RESULTS: Deletional and point mutational analysis showed that ATF, MEF2, and another down stream elements were involved in the up-regulation of c-jun promoter. Gel mobility shift assay showed that there are several factors in HEL cell nuclear extracts that specifically bind to these sites and in vitro translated IE2 could not move or supershift the specific bands. CONCLUSION: This study delineate the mechanism of c-jun up-regulation in HCMV infection and would give the clue for the possible contribution of HCMV in tumorigenesis.

Mapping of Phorbol Ester and Calcium Ionophore - Responsive Sequence Element in the c - jun Promoter in Activated T Cells / 대한면역학회지

No abstract available.