Increased angiotensin II coupled with decreased Adra1a expression enhances cardiac hypertrophy in pregnancy-associated hypertensive mice.

Cardiac hypertrophy is a crucial risk factor for hypertensive disorders during pregnancy, but its progression during pregnancy remains unclear. We previously showed cardiac hypertrophy in a pregnancy-associated hypertensive (PAH) mouse model, in which an increase in angiotensin II (Ang II) levels was induced by human renin and human angiotensinogen, depending on pregnancy conditions. Here, to elucidate the factors involved in the progression of cardiac hypertrophy, we performed a comprehensive analysis of changes in gene expression in the hearts of PAH mice and compared them with those in control mice. We found that alpha-1A adrenergic receptor (Adra1a) mRNA levels in the heart were significantly reduced under PAH conditions, whereas the renin-angiotensin system was upregulated. Furthermore, we found that Adra1a-deficient PAH mice exhibited more severe cardiac hypertrophy than PAH mice. Our study suggests that Adra1a levels are regulated by renin-angiotensin system and that changes in Adra1a expression are involved in progressive cardiac hypertrophy in PAH mice.

Comparison of the effects of peficitinib and tofacitinib in the adjuvant-induced arthritis rat model.

We investigated and compared the pharmacologic properties of two Janus kinase (JAK) inhibitors, peficitinib and tofacitinib, in an adjuvant-induced arthritis rat model. Repeated administration of peficitinib (3 - 30 mg/kg) or tofacitinib (1 - 10 mg/kg) exhibited a dose-related and significant attenuation of arthritis score, paw swelling, pain threshold, grip strength and histopathologic injuries in the model; peficitinib 10 mg/kg and tofacitinib 3 mg/kg demonstrated comparable efficacy. Equivalent Cmax and AUC0-12h values were observed with peficitinib 10 mg/kg and tofacitinib 3 mg/kg, suggesting that the two drugs may demonstrate comparable efficacy on arthritis-associated symptoms at comparable plasma concentration levels. However, peficitinib 10 mg/kg had greater efficacy than tofacitinib 3 mg/kg on some inflammation- and bone destruction-associated parameters in the paw fluid, including the production of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), receptor activator of nuclear factor kappa-B ligand, and matrix metalloproteinase-3, which are associated with arthritis exacerbation. Peficitinib 10 mg/kg also showed significantly greater inhibitory effects than tofacitinib 3 mg/kg on loss of bone mineral density and synovial thickening score, which might be a result of the VEGF and PDGF receptor kinase inhibitory effects of peficitinib, in addition to JAK inhibition. In conclusion, both tofacitinib and peficitinib potently improved arthritis and associated symptoms in adjuvant-induced arthritis rats; moreover, owing to possible differences in the mechanism of action of the two drugs, peficitinib may have exerted its effects through JAK inhibition and additional unique off-target properties.

Peficitinib inhibits fibroblast-like synoviocyte activation and angiogenic vascular endothelial tube formation via inhibitory effects on PDGF and VEGF signaling in addition to JAK.

PURPOSE: Peficitinib and tofacitinib are known to suppress inflammation in rheumatoid arthritis (RA) by inhibiting Janus kinases (JAKs). However, these effects on tyrosine kinases other than JAKs have not yet been well investigated. We evaluated the effects of peficitinib and tofacitinib on platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) receptor tyrosine kinases (RTKs) and on the activation of fibroblast-like synoviocytes (FLSs) and endothelial cells, main pathological causes of RA. METHODS: Peficitinib and tofacitinib were tested in PDGF and VEGF RTK assays. We then used FLSs derived from RA patient (RA-FLSs) and human umbilical vein endothelial cells (HUVECs) to study the effects of peficitinib and tofacitinib on PDGF- and VEGF-induced signal transduction and on the activation of RA-FLSs and endothelial cell tube formation. FINDINGS: Peficitinib, not tofacitinib, inhibited both PDGF and VEGF RTKs in addition to JAKs in cell-free assay system. Peficitinib and tofacitinib attenuated PDGF- and VEGF-induced intracellular signal transduction pathways in RA-FLSs and HUVECs to varying degrees. Only peficitinib potently inhibited PDGF-induced secretion of interleukin-6, VEGF, and matrix metalloproteinase-3 in RA-FLSs, and endothelial cell tube formation by HUVECs. CONCLUSION: Peficitinib may improve RA through inhibition of PDGF and VEGF signal transduction, in addition to JAK inhibition.

Cooperative action of APJ and α1A-adrenergic receptor in vascular smooth muscle cells induces vasoconstriction.

The apelin receptor (APJ), a receptor for apelin and elabela/apela, induces vasodilation and vasoconstriction in blood vessels. However, the prolonged effects of increased APJ-mediated signalling, involving vasoconstriction, in smooth muscle cells have not been fully characterized. Here, we investigated the vasoactive effects of APJ gain of function under the control of the smooth muscle actin (SMA) gene promoter in mice. Transgenic overexpression of APJ (SMA-APJ) conferred sensitivity to blood pressure and vascular contraction induced by apelin administration in vivo. Interestingly, ex vivo experiments showed that apelin markedly increased the vasoconstriction of isolated aorta induced by noradrenaline (NA), an agonist for α- and ß-adrenergic receptors, or phenylephrine, a specific agonist for α1-adrenergic receptor (α1-AR). In addition, intracellular calcium influx was augmented by apelin with NA in HEK293T cells expressing APJ and α1A-AR. To examine the cooperative action of APJ and α1A-AR in the regulation of vasoconstriction, we developed α1A-AR deficient mice using a genome-editing technique, and then established SMA-APJ/α1A-AR-KO mice. In the latter mouse line, aortic vasoconstriction induced by a specific agonist for α1A-AR, A-61603, were significantly less than in SMA-APJ mice. These results suggest that the APJ-enhanced response requires α1A-AR to contract vessels coordinately.

The N-terminal sequence of murine PRMT5 variant 2 is required for Hsp70 interaction and CHIP ligase-mediated degradation.

Protein arginine methyltransferase PRMT5 synthesizes the symmetric dimethylarginine in nuclear and cytoplasmic proteins such as histone H2A, H4 and several non-histone proteins that are required for a variety of biological processes. Currently, two splice variants (v1 and v2) of murine PRMT5 have been deposited in the NCBI sequence database, in which PRMT5-v1 and -v2 contain different 33 and 16 amino acids at the N-terminal sequences, respectively. Here we showed that murine PRMT5-v1 is stable, but PRMT5-v2 is constantly degraded through both the ubiquitin proteasome system (UPS) and the autophagic-lysosomal pathway (ALP) in an N-terminal sequence-dependent manner. Furthermore, inhibition of UPS and ALP elevated the stability of PRMT5-v2 that made it localized in the nucleus and the cytoplasm. In addition, PRMT5-v2 exhibited the enzyme activity to catalyze histone H2A and H4 methylation. Notably, we found that the heat shock protein (Hsp) 70 specially recognizes the N-terminal sequence of PRMT5-v2 and the carboxyl terminus of Hsp70-interacting protein (CHIP) is required for poly-ubiquitination and the degradation of PRMT5-v2. These results suggest that Hsp70/CHIP chaperone-mediated protein degradation system is crucial in the regulation of PRMT5-v2 turnover, which has the potential to balance the symmetrical arginine dimethylation in cells.

KDM5D-mediated H3K4 demethylation is required for sexually dimorphic gene expression in mouse embryonic fibroblasts.

Males and females share the same genetic code, but gene expression profile often displays differences between two sexes. Mouse embryonic fibroblasts (MEFs) have been used to experiment as a useful tool to test gene function. They have also been characterized by gender-based differences in expressed genes such as Y-linked Sry or X-linked Hprt. However, there is no report on sex differences in global gene expression. Here, using the next-generation RNA sequencing, we compared the comprehensive transcriptome of MEFs derived from two sexes. In comparison with the female group, the male group up-regulated 27 differentially expressed genes (DEGs), in which a male-specific histone demethylase KDM5D gene is included, and 7 DEGs were down-regulated. Based on the results by searching the ENCODE analysis, it was shown that the expression of 15 genes identified is potentially regulated by the methylation of H3K4me1 or H3K4me3. Interestingly, we demonstrated that both of H3K4 methylation are induced by knocking down KDM5D, which causes changes in patterns of eight DEGs found in male MEFs. Collectively, these data not only suggest an importance of KDM5D-mediated demethylation of H3K4 involved in the sexually dimorphic gene expression in male MEFs, but also may provide information regarding sex-dependent changes in gene expression when MEFs are used for experiments.

Angiotensin II accelerates mammary gland development independently of high blood pressure in pregnancy-associated hypertensive mice.

Angiotensin II (AngII) is a vasopressor hormone that has critical roles in maintenance of normal blood pressure and pathogenesis of cardiovascular diseases. We previously generated pregnancy-associated hypertensive (PAH) mice by mating female human angiotensinogen transgenic mice with male human renin transgenic mice. PAH mice exhibit hypertension in late pregnancy by overproducing AngII. A recent study demonstrated that angiotensin II type I (AT1) receptor is expressed in mammary epithelial cells and its signaling is critical for mammary gland involution after weaning. However, the role of AngII-AT1 receptor signaling in the development of mammary gland during pregnancy remains unclear. In this study, to investigate the role of AngII-AT1 receptor signaling in mammary gland development during pregnancy, we analyzed the mammary gland of PAH mice. Histological and gene expression analyses revealed that lobuloalveolar development was accelerated with increased milk protein production and lipid accumulation in the mammary gland of PAH mice. Furthermore, AT1 receptor blocker treatment suppressed acceleration of mammary gland development in PAH mice, while the treatment of hydralazine, another antihypertensive drug, did not. These data suggest that AngII-AT1 receptor-induced signaling accelerates mammary gland development during pregnancy through hypertension-independent mechanism.