Jumonji Domain-containing Protein Research Articles

An HSF1–JMJD6–HSP feedback circuit promotes cell adaptation to proteotoxic stress

Heat Shock Factor 1 (HSF1) is best known as the master transcriptional regulator of the heat-shock response (HSR), a conserved adaptive mechanism critical for protein homeostasis (proteostasis). Combining a genome-wide RNAi library with an HSR reporter, we identified Jumonji domain-containing protein 6 (JMJD6) as an essential mediator of HSF1 activity. In follow-up studies, we found that JMJD6 is itself a noncanonical transcriptional target of HSF1 which acts as a critical regulator of proteostasis. In a positive feedback circuit, HSF1 binds and promotes JMJD6 expression, which in turn reduces heat shock protein 70 (HSP70) R469 monomethylation to disrupt HSP70-HSF1 repressive complexes resulting in enhanced HSF1 activation. Thus, JMJD6 is intricately wired into the proteostasis network where it plays a critical role in cellular adaptation to proteotoxic stress.

SKP2-mediated ubiquitination and degradation of KLF11promotes osteoarthritis via modulation ofJMJD3/NOTCH1 pathway.

Osteoarthritis (OA) is the main cause of cartilage damage and disability. This study explored the biological function of S-phase kinase-associated protein 2 (SKP2) and Kruppel-like factor 11 (KLF11) in OA progression and its underlying mechanisms. C28/I2 chondrocytes were stimulated with IL-1β to mimic OA invitro. We found that SKP2, Jumonji domain-containing protein D3 (JMJD3), and Notch receptor 1 (NOTCH1) were upregulated, while KLF11 was downregulated in IL-1β-stimulated chondrocytes. SKP2/JMJD3 silencing or KLF11 overexpression repressed apoptosis and extracellular matrix (ECM) degradation in chondrocytes. Mechanistically, SKP2 triggered the ubiquitination and degradation of KLF11 to transcriptionally activate JMJD3, which resulted in activation of NOTCH1 through inhibiting H3K27me3. What's more, the invivo study found that KLF11 overexpression delayed OA development in rats via restraining apoptosis and maintaining the balance of ECM metabolism. Taken together, ubiquitination and degradation of KLF11 regulated by SKP2 contributed to OA progression by activation of JMJD3/NOTCH1 pathway. Our findings provide promising therapeutic targets for OA.

The H3K4 demethylase JMJ1 is required for proper timing of flowering in Brachypodium distachyon.

Flowering is a key developmental transition in the plant life cycle. In temperate climates, flowering often occurs in response to the perception of seasonal cues such as changes in day-length and temperature. However, the mechanisms that have evolved to control the timing of flowering in temperate grasses are not fully understood. We identified a Brachypodium distachyon mutant whose flowering is delayed under inductive long-day conditions due to a mutation in the JMJ1 gene, which encodes a Jumonji domain-containing protein. JMJ1 is a histone demethylase that mainly demethylates H3K4me2 and H3K4me3 in vitro and in vivo. Analysis of the genome-wide distribution of H3K4me1, H3K4me2, and H3K4me3 in wild-type plants by chromatin immunoprecipitation and sequencing (ChIP-seq) combined with RNA sequencing (RNA-seq) revealed that H3K4m1 and H3K4me3 are positively associated with gene transcript levels, whereas H3K4me2 is negatively correlated with transcript levels. Furthermore, JMJ1 directly binds to the chromatin of the flowering regulator genes VRN1 and ID1 and affects their transcription by modifying their H3K4me2 and H3K4me3 levels. Genetic analyses indicated that JMJ1 promotes flowering by activating VRN1 expression. Our study reveals a role for JMJ1-mediated chromatin modification in the proper timing of flowering in B. distachyon.

JMJD3 activation contributes to renal protection and regeneration following acute kidney injury in mice.

We have recently demonstrated that Jumonji domain-containing protein D3 (JMJD3), a histone demethylase of histone H3 on lysine 27 (H3K27me3), is protective against renal fibrosis, but its role in acute kidney injury (AKI) remains unexplored. Here, we report that JMJD3 activity is required for renal protection and regeneration in murine models of AKI induced by ischemia/reperfusion (I/R) and folic acid (FA). Injury to the kidney upregulated JMJD3 expression and induced expression of H3K27me3, which was coincident with renal dysfunction, renal tubular cell injury/apoptosis, and proliferation. Blocking JMJD3 activity by GSKJ4 led to worsening renal dysfunction and pathological changes by aggravating tubular epithelial cell injury and apoptosis in both murine models of AKI. JMJD3 inhibition by GSKJ4 also reduced renal tubular cell proliferation and suppressed expression of cyclin E and phosphorylation of CDK2, but increased p21 expression in the injured kidney. Furthermore, inactivation of JMJD3 enhanced I/R- or FA-induced expression of TGF-β1, vimentin, and Snail, phosphorylation of Smad3, STAT3, and NF-κB, and increased renal infiltration by F4/80 (+) macrophages. Finally, GSKJ4 treatment caused further downregulation of Klotho, BMP-7, Smad7, and E-cadherin, all of which are associated with renal protection and have anti-fibrotic effects. Therefore, these data provide strong evidence that JMJD3 activation contributes to renal tubular epithelial cell survival and regeneration after AKI.

JMJD2A mediates transcriptional activation of SFRP4 and regulates oxidative stress and mitochondrial dysfunction in heart failure.

The importance of mitochondrial dysfunction and oxidative stress has been indicated in the progression of heart failure (HF). The molecular mechanisms, however, remain to be fully elucidated. This study aimed to explore the role and underlying mechanism of secreted frizzled-related protein 4 (SFRP4) in these two events in HF. Mice with HF were developed using transverse aortic constriction, and hematoxylin-eosin staining, MASSON staining, and Terminal deoxynucleotidyl transferase (TdT)-mediated 2'-Deoxyuridine 5'- Triphosphate nick end labeling (TUNEL assays) were conducted to detect morphological damage in the myocardial tissues of mice. HL-1 mouse cardiomyocytes were induced with isoproterenol (ISO), and cell viability and apoptosis were examined using cell counting kit-8 and TUNEL assays. SFRP4 and Jumonji domain-containing protein 2A (JMJD2A) were highly expressed in myocardial tissues. Suppression of SFRP4 alleviated apoptosis and fibrosis in myocardial tissues of mice. In addition, the extent of mitochondrial dysfunction and oxidative stress in damaged myocardial tissues and HL-1 cells was mitigated by SFRP4 inhibition as well. JMJD2A catalyzed demethylation modification of the SFRP4 promoter, thus promoting SFRP4 transcription in the development of HF. JMJD2A is responsible for SFRP4 transcription activation in the failing hearts of mice. Blockade of JMJD2A or SFRP4 might be a novel therapy effective in mitigating HF progression.

Expression and significance of jumonji domain-containing protein 2B and hypoxia inducible factor-1α in non-Hodgkin lymphoma tissues in children

To investigate the expression and significance of jumonji domain-containing protein 2B (JMJD2B) and hypoxia-inducible factor-1α (HIF-1α) in non-Hodgkin's lymphoma (NHL) tissues in children. Immunohistochemistry was used to detect the expression of JMJD2B and HIF-1α in lymph node tissue specimens from 46 children with NHL (observation group) and 24 children with reactive hyperplasia (control group). The relationship between JMJD2B and HIF-1α expression with clinicopathological characteristics and prognosis in children with NHL, as well as the correlation between JMJD2B and HIF-1α expression in NHL tissues, were analyzed. The positive expression rates of JMJD2B (87% vs 21%) and HIF-1α (83% vs 42%) in the observation group were higher than those in the control group (P<0.05). The expression of JMJD2B and HIF-1α was correlated with serum lactate dehydrogenase levels and the risk of international prognostic index in children with NHL (P<0.05). The expression of JMJD2B was positively correlated with the HIF-1α expression in children with NHL (rs=0.333, P=0.024). JMJD2B and HIF-1α are upregulated in children with NHL, and they may play a synergistic role in the development of pediatric NHL. JMJD2B can serve as a novel indicator for auxiliary diagnosis, evaluation of the severity, treatment guidance, and prognosis assessment in pediatric NHL.

Targeting Esophageal Squamous Cell Carcinoma by Combining Copper Ionophore Disulfiram and JMJD3/UTX Inhibitor GSK J4.

The alcohol-averse drug disulfiram has been reported to have anti-tumor effects and is well suited for drug combinations. In order to identify potential drug combinations in esophageal squamous cell carcinoma (ESCC), we screened a bioactive compound library with the disulfiram copper chelation product CuET. The Jumonji domain-containing protein 3 (JMJD3) and the ubiquitously transcribed tetratricopeptide repeat protein X-linked (UTX) inhibitor GSK J4 were identified. To further understand the molecular mechanism underlying the efficient drug combination, we applied quantitative mass spectrometry to analyze the signaling pathway perturbation after drug treatment. The data revealed that the synergistic effect of GSK J4 and CuET was due to the interaction among JMJD3 and UTX, which may play important roles in maintaining endoplasmic reticulum (ER) homeostasis in tumor cells. Interestingly, our clinical data analysis showed that high expression of JMJD3 and UTX was associated with T stage and worse prognosis of ESCC patients, further supporting the importance of the above findings. In conclusion, our findings suggest that the combination of CuET and targeting JMJD3/UTX may be a safe, effective, and available treatment for ESCC.

Macrophage LMO7 deficiency facilitates inflammatory injury via metabolic-epigenetic reprogramming

Inflammatory bowel disease (IBD) is a formidable disease due to its complex pathogenesis. Macrophages, as a major immune cell population in IBD, are crucial for gut homeostasis. However, it is still unveiled how macrophages modulate IBD. Here, we found that LIM domain only 7 (LMO7) was downregulated in pro-inflammatory macrophages, and that LMO7 directly degraded 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) through K48-mediated ubiquitination in macrophages. As an enzyme that regulates glycolysis, PFKFB3 degradation led to the glycolytic process inhibition in macrophages, which in turn inhibited macrophage activation and ultimately attenuated murine colitis. Moreover, we demonstrated that PFKFB3 was required for histone demethylase Jumonji domain-containing protein 3 (JMJD3) expression, thereby inhibiting the protein level of trimethylation of histone H3 on lysine 27 (H3K27me3). Overall, our results indicated the LMO7/PFKFB3/JMJD3 axis is essential for modulating macrophage function and IBD pathogenesis. Targeting LMO7 or macrophage metabolism could potentially be an effective strategy for treating inflammatory diseases.

Design, synthesis and biological evaluation of pyrimidine base hydroxamic acid derivatives as dual JMJD3 and HDAC inhibitors

The Jumonji domain-containing protein demethylase 3 (JMJD3) and histone deacetylase (HADC) are related to various cancers and regard as antitumor targets for drug discovery. In this study, based on rational drug design strategy, we designed and synthesized a series of pyrimidine derivatives with hydroxamic acid as novel dual JMJD3 and HDAC inhibitors for synergistic cancer treatment. Compound A5b exhibited inhibitory potency against JMJD3 and HDAC1/6 simultaneously and favorable cytotoxicity against human cancer cells such as A549 and U937. Furthermore, mechanistic studies showed that A5b treatment in A549 cells increased the hypermethylation of histone H3K27 and hyperacetylation of H3K9, suppressed clonogenicity, migration and invasion of cancer cells. Besides, A5b induced apoptosis via the cleavage of caspase-7 and PARP, and G1 cell cycle arrest via upregulated p21 expression. All these results suggested that A5b was the first dual inhibitor against JMJD3 and HDAC and can be a potential compound for cancer therapy.

JMJD6 functions as an oncogene and is associated with poor prognosis in esophageal squamous cell carcinoma

BackgroundEsophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with a high prevalence and poor prognosis. It is an urgent problem to deeply understand the molecular mechanism of ESCC and develop effective diagnostic and prognostic methods.MethodsUsing tumor tissue and corresponding paracancerous samples from 141 resected ESCC patients, we assessed Jumonji domain-containing protein 6 (JMJD6) expression using Immunohistochemical (IHC) staining. Kaplan-Meier survival analysis and univariate or multivariate analysis were used to investigate the relationship between JMJD6 expression and clinicopathological features. The expression status and prognostic value of JMJD6 were analyzed by bioinformatics and enrichment analysis.ResultsThe expression of JMJD6 in ESCC samples was higher than that in the corresponding paracancerous samples, and high expression of JMJD6 was positively associated with poor prognosis of ESCC patients. In addition, bioinformatics analysis of the expression and prognosis of JMJD6 in a variety of tumors showed that high expression of JMJD6 was significantly associated with poor overall survival (OS) in ESCC patients. Enrichment analysis indicated that the high expression of genes similar to JMJD6, such as Conserved oligomeric Golgi 1(COG1), Major facilitator superfamily domain 11 (MFSD11) and Death Effector Domain Containing 2 (DEDD2), was associated with poor prognosis of ESCC, suggesting that JMJD6 might be involved in the occurrence and prognosis of ESCC.ConclusionOur study found that JMJD6 expression was significantly increased in ESCC patients and positively correlated with prognosis, indicating that targeting JMJD6 might be an attractive prognostic biomarker and provides a potential treatment strategy for ESCC.Trial registrationThe study was approved by Tangdu Hospital ethics committee (No. TDLL-202110-02).

C-Jun-mediated JMJD6 restoration enhances resistance of liver cancer to radiotherapy through the IL-4-activated ERK pathway.

Radiotherapy is widely used in the treatment of liver cancer, but the efficacy can be limited by radioresistance. In this study, we attempt to delineate the possible molecular mechanism of c-Jun-regulated Jumonji domain-containing protein 6/interleukin 4/extracellular signal-regulated kinase(JMJD6/IL-4/ERK) axis in radioresistance of liver cancer. The expression of c-Jun was quantified in liver cancer tissues and cell lines, and the results indicated that c-Jun was upregulated in liver cancer tissues and cells. We further illustrated the role of c-Jun following gain- and loss-of-function strategies in malignant phenotypes of liver cancer cells. It was established that c-Jun elevated JMJD6 expression and augmented the malignancy and aggressiveness of liver cancer cells. The in vivo effects of c-Jun on radioresistance in liver cancer were validated in nude mice, in response to IL-4 knockdown or the ERK pathway inhibitor, PD98059. In the presence of JMJD6 upregulation, the expression of IL-4 was elevated in mice with liver cancer, which enhanced the radiation resistance. Moreover, knockdown of IL-4 inactivated the ERK pathway, thereby reversing the radiation resistance caused by overexpressed JMJD6 in tumor-bearing mice. Taken together, c-Jun augments the radiation resistance in liver cancer by activating the ERK pathway through JMJD6-upregulated IL-4 transcription.

13-Cis Retinoic Acid Induces Neuronal Differentiation in Daoy (Medulloblastoma) Cells Through Epigenetic Regulation of Topoisomerase IIβ.

Medulloblastoma (MB) is a malignant tumor of the cerebellum that occurs in children and infants. Abnormal neuronal differentiation can lead to brain tumors, and topoisomerase IIβ (Top IIβ) plays an important role in neuronal differentiation. The aim of this study was to investigate the molecular mechanism of 13-cis retinoic acid (13-cis RA) promoting the expression of Top IIβ and inducing neuronal differentiation in human MB Daoy cells. The results showed that 13-cis RA inhibited the cell proliferation and induced cell cycle arrest in G0/G1 phase. The cells differentiated into a neuronal phenotype, with high expression of the neuronal marker microtubule-associated protein 2 (MAP2) and abundant Top IIβ, and obvious neurite growth. Chromatin immunoprecipitation (ChIP) assay showed that histone H3 lysine 27 tri-methylation (H3K27me3) modification in Top IIβ promoter decreased after 13-cis RA-induced cell differentiation, while jumonji domain-containing protein 3 (JMJD3) binding in Top IIβ promoter increased. These results suggest that H3K27me3 and JMJD3 can regulate the expression of Top IIβ gene, which is related to inducing neural differentiation. Our results provide new insights into understanding the regulatory mechanisms of Top IIβ during neuronal differentiation and imply the potential application of 13-cis RA in the clinical treatment of MB.

Synthesis, Characterization, and Antitumor Mechanism Investigation of Ruthenium(II)/Rhenium(I)-Daminozide Conjugates

Daminozide, a plant growth regulator, is an effective inhibitor of the Jumonji domain-containing protein (JMJD) histone demethylase. Herein, four ruthenium(II)/rhenium(I)-daminozide conjugates, with molecular formulas [Ru(N-N)2bpy(4-CH2OH-4′-CH2O-daminozide)](PF6)2 (Ru-1/Ru-2) (N-N = 1,10-phenanthroline (phen, in Ru-1) and 4,7-diphenyl-1,10-phenanthroline (DIP, in Ru-2)) and Re(N-N)(CO)3(PyCH2O-daminozide) (Re-1/Re-2) (Py = pyridine, N-N = phen (in Re-1) and DIP (in Re-2)), were synthesized and characterized. Among these complexes, Ru-2 and Re-2 exhibited higher cytotoxicity against tumor cells than cisplatin. Upregulation of H3K9Me3 expression level was found in human cervical cancer cells (HeLa) treated with Ru-2 and Re-2, indicating that these two complexes can inhibit the activity of JMJD histone demethylase. Further investigation revealed that Re-2 can selectively accumulate in the mitochondria of HeLa cells. Both Ru-2 and Re-2 can cause mitochondrial damage, induce apoptosis, and inhibit cell migration and colony formation of HeLa cells. Overall, these complexes exhibit multiple anticancer functions, including inhibiting JMJD, inducing apoptosis, and inhibiting cell invasion, making them promising candidates for anticancer drugs.

Role of Jumonji domain-containing protein D3 and its inhibitor GSK-J4 in Hashimoto's thyroiditis.

Hashimoto's thyroiditis (HT) is an autoimmune illness caused by a combination of genetic, epigenetic, and environmental factors. The pathogenesis of HT is not fully elucidated, especially in epigenetics. The epigenetic regulator Jumonji domain-containing protein D3 (JMJD3) has been extensively investigated in immunological disorders. This study has been performed to explore the roles and potential mechanisms of JMJD3 in HT. Thyroid samples from patients and healthy subjects were collected. We first analyzed the expression of JMJD3 and chemokines in the thyroid gland using real-time PCR and immunohistochemistry. In vitro, the apoptosis effect of the JMJD3-specific inhibitor GSK-J4 on the thyroid epithelial cell line Nthy-ori 3-1 was evaluated using FITC Annexin V Detection kit. Reverse transcription-polymerase chain reaction and Western blotting were applied to examine the inhibitory effect of GSK-J4 on the inflammation of thyrocytes. In the thyroid tissue of HT patients, JMJD3 messenger RNA and protein levels were substantially greater than in controls (P < 0.05). Chemokines C-X-C motif chemokine ligand 10 (CXCL10) and C-C motif chemokine ligand 2 (CCL2) were elevated in HT patients, and thyroid cells with stimulation of tumor necrosis factor α (TNF-α). GSK-J4 could suppress TNF-α-induced synthesis of chemokines CXCL10 and CCL2 and prohibit thyrocyte apoptosis. Our results shed light on the potential role of JMJD3 in HT and indicate that JMJD3 may become a novel therapeutic target in HT treatment and prevention.

Jumonji domain-containing protein RIOX2 is overexpressed and associated with worse survival outcomes in prostate cancers.

Histone demethylase RIOX2 was cloned as a c-Myc downstream gene involved in cell proliferation and has been implicated as an oncogenic factor in multiple tumor types. Its expression profiles and correlation with disease progression in prostate cancers are unknown. Transcriptomic profiles of Jumanji domain-containing protein genes were assessed using multiple public expression datasets generated from RNA-seq and cDNA microarray assays. RIOX2 protein expression was assessed using an immunohistochemistry approach on a tissue section array from benign and malignant prostate tissues. Gene expression profiles were analyzed using the bioinformatics software R package. Western blot assay examined androgen stimulation on RIOX2 protein expression in LNCaP cells. Among 35 Jumanji domain-containing protein genes, 12 genes were significantly upregulated in prostate cancers compared to benign compartments. COX regression analysis identified that the ribosomal oxygenase 2 (RIOX2) gene was the only one significantly associated with disease-specific survival outcomes in prostate cancer patients. RIOX2 upregulation was confirmed at the protein levels using immunohistochemical assays on prostate cancer tissue sections. Meanwhile, RIOX2 upregulation was associated with clinicopathological features, including late-stage diseases, adverse Gleason scores, TP53 gene mutation, and disease-free status. In castration-resistant prostate cancers (CRPC), RIOX2 expression was positively correlated with AR signaling index but negatively correlated with the neuroendocrinal progression index. However, androgen treatment had no significant stimulatory effect on RIOX2 expression, indicating a parallel but not a causative effect of androgen signaling on RIOX2 gene expression. Further analysis discovered that RIOX2 expression was tightly correlated with its promoter hypomethylation and MYC gene expression, consistent with the notion that RIOX2 was a c-Myc target gene. The Jumanji domain-containing protein RIOX2 was significantly overexpressed in prostate cancer, possibly due to c-Myc upregulation. RIOX2 upregulation was identified as an independent prognostic factor for disease-specific survival.

JMJD3 Is Required for Acute Pancreatitis and Pancreatitis-Associated Lung Injury.

Acute pancreatitis (AP) can be complicated by inflammatory disorders of remote organs, such as lung injury, in which Jumonji domain-containing protein 3 (JMJD3) plays a vital role in proinflammatory responses. Currently, we found that JMJD3 expression was upregulated in the pancreas and lung in an AP male mouse model, which was also confirmed in AP patients. Further experiments revealed that the upregulation of JMJD3 and proinflammatory effects were possibly exerted by mitochondrial DNA (mtDNA) or oxidized-mtDNA from tissue injury caused by AP. The release of mtDNA and oxidized-mtDNA contributed to the infiltration of inflammatory monocytes in lung injury through the stimulator of IFN genes (STING)/TLR9-NF-κB-JMJD3-TNF-α pathway. The inhibition of JMJD3 or utilization of Jmjd3-cKO mice significantly alleviated pulmonary inflammation induced by AP. Blocking mtDNA oxidation or knocking down the TLR9/STING pathway effectively alleviated inflammation. Therefore, inhibition of JMJD3 or STING/TLR9 pathway blockage might be a potential therapeutic strategy to treat AP and the associated lung injury.

The Histone H3K27 Demethylase REF6 Is a Positive Regulator of Light-Initiated Seed Germination in Arabidopsis.

Seed germination is the first step in initiating a new life cycle in seed plants. Light is a major environmental factor affecting seed germination. Phytochrome B (phyB) is the primary photoreceptor promoting germination during the initial phase of imbibition. Post-translational histone methylation occurring at both lysine and arginine residues plays a crucial role in transcriptional regulation in plants. However, the role of histone lysine demethylation in light-initiated seed germination is not yet reported. Here, we identified that Relative of Early Flowering 6 (REF6)/Jumonji Domain-containing Protein 12 (JMJ12), a histone H3 lysine 27 (H3K27) demethylase, acts as a positive regulator of light-initiated seed germination. The loss of function of REF6 in Arabidopsis inhibits phyB-dependent seed germination. Genome-wide RNA-sequencing analysis revealed that REF6 regulates about half of the light-responsive transcriptome in imbibed seeds, including genes related to multiple hormonal signaling pathways and cellular processes. Phenotypic analyses indicated that REF6 not only regulates seed germination through GA (gibberellin) and ABA (abscisic acid) processes but also depends on the auxin signaling pathway. Furthermore, REF6 directly binds to and decreases the histone H3K27me3 levels of auxin-signaling- and cell-wall-loosening-related genes, leading to the activated expression of these genes in imbibed seeds. Taken together, our study identifies REF6 as the first histone lysine demethylase required for light-initiated seed germination. Our work also reveals the important role of REF6-mediated histone H3K27 demethylation in transcriptional reprogramming in the light-initiated seed germination process.

JMJD3 is Involved in Intracranial Aneurysm Development by Regulating DLX2 Expression through H3K27me3 Modification.

Intracranial aneurysms are dilatations in the arteries that supply blood to the brain. Rupture of an intracranial aneurysm leads to a subarachnoid hemorrhage, which is fatal in about 50% of the cases. Microarray-based mRNA expression studies provide unbiased information about molecular mechanisms of intracranial aneurysm and the foundation for functional studies. In this study, by using a Gene Expression Omnibus (GEO) dataset, we identified distal-less homeobox 2 (DLX2) as a significantly upregulated gene in intracranial aneurysms and set to dissect its functional role and upstream mechanism. Here, we found that DLX2 expression was elevated in intracranial aneurysm patients. Silencing of DLX2 suppressed the proliferative capacity of human aortic vascular smooth muscle cells (HA-VSMC) and promoted their apoptosis. Moreover, loss of DLX2 promoted collagen I and collagen III and inhibited the levels of MMP2/9 and pro-inflammatory factors. Additionally, jumonji domain-containing protein 3 demethylase (JMJD3) promoted DLX2 expression by inhibiting H3K27me3 modification. Depletion of JMJD3 exerted the same function as DLX2 in vitro and in vivo, whereas overexpression of DLX2 in the presence of JMJD3 knockdown led to accentuated intracranial aneurysm progression and enhanced HA-VSMC survival. We conclude that JMJD3 promotes DLX2 expression through inhibition of H3K27me3 modification, thereby promoting intracranial aneurysm formation.

H3K27 tri-demethylase JMJD3 inhibits macrophage apoptosis by promoting ADORA2A in lipopolysaccharide-induced acute lung injury

Acute lung injury (ALI) is a common critical disease, which is characterized by an uncontrolled, acute inflammatory response, diffuse lung damage and ultimately directly deteriorates into acute respiratory distress syndrome. The number of pro-inflammatory macrophages is related to the severity of ALI. Up-regulation of lipopolysaccharide (LPS)-activated macrophage apoptosis can reduce the pro-inflammatory reactions. Jumonji domain-containing protein D3 (JMJD3)-mediated histone 3 lysine 27 trimethylation (H3K27me3) demethylation may promote the pro-inflammatory response of macrophages under LPS stimulation. However, the mechanism of JMJD3 affecting macrophage apoptosis is still not clear. To explore this gap in knowledge, the ALI mice model with intratracheal administration of LPS and RAW264.7 cells with LPS stimulation were used as in vivo and in vitro experiments. The expression of JMJD3 and H3K27me3 and their cellular localization were analysed in lung tissue. Apoptosis was evaluated using TUNEL staining and flow cytometry. Expression of H3K27me3, ADORA2A and C/EBPβ were compared among different treatments and chromatin immunoprecipitation was performed to investigate the regulatory relationship. Our study showed that JMJD3 expression was upregulated in LPS-induced ALI mice and RAW264.7 cells. JMJD3-indued H3K27me3 demethylation inhibited caspase-3 cleavage by upregulating ADORA2A to decrease LPS-stimulated macrophage apoptosis and promoted the inflammatory reaction. This H3K27me3 demethylation also increased C/EBPβ expression, which may enhance ADORA2A expression further. Besides, inhibiting ADORA2A can also promote LPS-limited macrophage apoptosis. Moreover, the inhibition of JMJD3 in vivo and in vitro relieved the inhibition of macrophage apoptosis thus leading to the resolution of the inflammation. JMJD3 might inhibit macrophage apoptosis by promoting ADORA2A expression in LPS-induced ALI.

Histone demethylase MaJMJ15 is involved in the regulation of postharvest banana fruit ripening

Histone methylation plays important roles in plant development. However, the role of histone methylation in fruit ripening remains unclear. Here, a total of 16 Jumonji domain-containing proteins (JMJs) were identified from banana genome. During fruit ripening, expression of MaJMJ15 was significantly upregulated. Exogenous ethylene accelerated the upregulation whereas 1-methylcyclopropene delayed the process, suggesting that MaJMJ15 positively regulates banana fruit ripening. MaJMJ15 is an H3K27me3 site-specific demethylase. Transient overexpression of MaJMJ15 promoted banana fruit ripening. Moreover, the global H3K27me3 was decreased by MaJMJ15. Furthermore, MaJMJ15 directly targeted several key ripening-related genes (RRGs) in banana including NAC transcription factor 1/2 (MaNAC1/2), 1-aminocyclopropane-1-carboxylate synthase 1 (MaACS1), 1-aminocyclopropane-1-carboxylate oxidase 1 (MaACO1) and expansin 2 (MaEXP2), removed H3K27me3 from their chromatin, and activated their expression. Our data suggest that MaJMJ15 is an H3K27me3 demethylase, which is involved in the regulation of banana fruit ripening by activating expression of key RRGs via removal of H3K27me3.