Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Itabashi-Ku, Tokyo 173-8610, Japan
Prof. Noboru Fukuda
Division of Nephrology, Hypertension and Endocrinology, Department of Internal Medicine, Nihon University School of Medicine, Itabashi-Ku, Tokyo 173-8610, Japan
We have demonstrated that mesenchymal cells from spontaneously hypertensive rats genetically express complement 3 (C3). Mature tubular epithelial cells can undergo epithelial-to-mesenchymal transition (EMT) that is linked to the pathogenesis of renal fibrosis and injury. In this study, we investigated the contribution of C3 in EMT and in the renal renin-angiotensin (RA) systems associated with hypertension. C3a induced EMT in mouse TCMK-1 epithelial cells, which displayed increased expression of renin and Krüppel-like factor 5 (KLF5) and nuclear localization of liver X receptor α (LXRα). C3 and renin were strongly stained in the degenerated nephrotubulus and colocalized with LXRα and prorenin receptor in unilateral ureteral obstruction (UUO) kidneys from wild-type mice. In C3-deficient mice, hydronephrus and EMT were suppressed, with no expression of renin and C3. After UUO, systolic blood pressure was increased in wild-type but not C3-deficient mice. In wild-type mice, intrarenal angiotensin II (ANG II) levels were markedly higher in UUO kidneys than normal kidneys and decreased with aliskiren. There were no increases in intrarenal ANG II levels after UUO in C3-deficient mice. Thus C3 induces EMT and dedifferentiation of epithelial cells, which produce renin through induction of LXRα. These data indicate for the first time that C3 may be a primary factor to activate the renal RA systems to induce hypertension.
Complement activation contributes to tissue injury in various forms of glomerulopathy and is characterized by deposition of complement components, which accelerates the progression of chronic renal damage. We recently reported that complement 3 (C3), a critical component of the complement system, is associated with the synthetic phenotype of vascular smooth muscle cells. It is possible that C3 stimulates mesangial cells to assume the synthetic phenotype to, in turn, induce glomerular injury and sclerosis. We investigated the role of C3 in the growth and phenotype of mesangial cells. Cultured human mesangial cells (HMCs) expressed C3 mRNA and protein, and levels were increased in response to IFN‐γ and TNF‐α. HMCs also expressed C3a receptor mRNA and protein. Exogenous C3a stimulated DNA synthesis in HMCs in a dose‐dependent manner. C3a decreased expression h‐caldesmon mRNA, a marker of the contractile phenotype, and increased the expression of osteopontin, matrix Gla, and collagen type1 α1 (collagen IV) mRNAs, which are markers of the synthetic phenotype. C3a decreased expression of α‐smooth muscle actin in HMCs. Small interfering RNA (siRNA) targeting C3 reduced the DNA synthesis and proliferation of HMCs, increased expression of h‐caldesmon mRNA, and decreased expression of osteopontin, matrix Gla, and collagen IV mRNAs in HMCs. These results indicate that C3 causes HMCs to convert to the synthetic phenotype and stimulates growth of mesangial cells, suggesting that C3 may play an important role in phenotypic regulation of mesangial cells in renal diseases. J. Cell. Physiol. 213: 495–501, 2007.
We report a preclinical study of a pyrrole-imidazole (PI) polyamide that targets the human transforming growth factor (hTGF)-β1 gene as a novel transcriptional gene silencer in a common marmoset primate model. We designed and then synthesized PI polyamides to target the hTGF-β1 promoter. We examined effects of seven PI polyamides (GB1101-1107) on the expression of hTGF-β1 mRNA stimulated with phorbol 12-myristate 13-acetate (PMA) in human vascular smooth muscle cells. GB1101, GB1105 and GB1106 significantly inhibited hTGF-β1 mRNA expression. We examined GB1101 as a PI polyamide to hTGF-β1 for hypertrophic scars in marmosets in vivo. Injection of GB1101 completely inhibited hypertrophic scar formation at 35 days post-incision and inhibited cellular infiltration, TGF-β1 and vimentin staining, and epidermal thickness. Mismatch polyamide did not affect hypertrophic scarring or histological changes. Epidermis was significantly thinner with GB1101 than with water and mismatch PI polyamides. We developed the PI polyamides for practical ointment medicines for the treatment of hypertrophic scars. FITC-labeled GB1101 with solbase most efficiently distributed in the nuclei of epidermal keratinocytes, completely suppressed hypertropic scarring at 42 days after incision, and considerably inhibited epidermal thickness and vimentin-positive fibroblasts. PI polyamides targeting hTGF-β1 promoter with solbase ointment will be practical medicines for treating hypertrophic scars after surgical operations and skin burns.
1 December 2018 in American Journal of Physiology-Renal Physiology
We previously showed that complement 3 (C3) is highly expressed in mesenchymal tissues in spontaneously hypertensive rats (SHR). We targeted C3 gene by zinc-finger nuclease (ZFN) gene-editing technology and investigated blood pressure and phenotype in SHR. Blood pressure was measured by tail-cuff and telemetry methods. Histology and expression of liver X receptor α (LXRα), renin, Krüppel-like factor 5 (KLF5), and E-cadherin were evaluated in kidneys. Mesangial cells (MCs) were removed from glomeruli from three strains, and we evaluated the phenotype in vitro. SHR showed the salt-sensitive hypertension that was abolished in C3 knockout (KO) SHR. Proliferation of MCs from SHR was higher than that from Wistar-Kyoto (WKY) rats and showed a synthetic phenotype. Renal injury scores were higher in SHR than in WKY rats and C3 KO SHR. Expression of E-cadherin was lower, and expression of renin was higher in the nephrotubulus from SHR than WKY rats and C3 KO SHR. Expression of C3 α-chain protein and α-smooth muscle actin protein was significantly higher in renal medulla from SHR than from WKY rats. Expression of angiotensinogen, LXRα, renin, and KLF5 mRNA was increased in kidney from SHR compared with C3 KO SHR. Intrarenal angiotensin II levels were significantly higher in kidney from SHR than WKY rats and C3 KO SHR. Urinary epinephrine and norepinephrine excretions were significantly higher in SHR than in WKY rats and C3 KO SHR. These findings showed that increased C3 induces salt-sensitive hypertension with increases in urinary catecholamine excretion and intrarenal activation of the renin-angiotensin system by the dedifferentiation of mesenchymal tissues in kidney from SHR.
Abstract —The effects of angiotensin II (Ang II) on the expression and characteristics of transforming growth factor-β (TGF-β) receptors on vascular smooth muscle cells (VSMC) from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were investigated. TGF-β–induced stimulation of DNA synthesis by VSMC from WKY rats was abolished with Ang II, whereas basal and TGF-β–stimulated DNA synthesis by VSMC from SHR was increased with Ang II. Ang II stimulated DNA synthesis by VSMC from WKY rats in the presence but not in the absence of neutralizing antibody to TGF-β 1 . Antibody to TGF-β 1 enhanced the stimulatory effect of Ang II on DNA synthesis by VSMC from SHR. Ang II increased the specific binding of TGF-β to VSMC from WKY rats by increasing both the expression of the lower-affinity of TGF-β receptors as well as the total number of TGF-β binding sites. In contrast, VSMC from SHR showed a higher affinity and number of TGF-β receptors in the absence of Ang II than did cells from WKY rats, and these parameters were not affected by Ang II. Ang II increased the expression of TGF-β type I receptor mRNA in VSMC from WKY rats but had no effect of TGF-β receptor type I or II mRNA in VSMC from SHR, which predominantly express the type II receptor. These results indicate that an increase in the expression of the TGF-β type I receptor by Ang II may facilitate the ability of endogenous TGF-β to counteract the stimulatory effect of Ang II on growth in VSMC from WKY rats, whereas endogenous TGF-β induced by Ang II cannot counteract the growth-promoting action of Ang II in VSMC from SHR. The abnormal regulation of TGF-β receptors by Ang II may be associated with the exaggerated growth of VSMC from SHR.