Evodiamine ameliorates liver fibrosis in rats via TGF-β1/Smad signaling pathway

Liver fibrosis is considered to be a result of chronic liver pathological changes, and hepatic stellate cells (HSCs) play an important role during this process. Evodiamine, an indole alkaloid derived from Evodia rutaecarpa, exhibits pharmacological activities. This study focused on the effects of evodiamine on carbon tetrachloride (CCl₄)-induced liver fibrosis in rats and HSCs in vitro via the TGF-β1/Smad signaling pathway. A liver fibrosis rat model was established by the intraperitoneal injection of CCl₄ (3 ml/kg, 30% in olive oil). Evodiamine (15 and 25 mg/kg) was administered orally for 8 weeks. HSCs were treated with different evodiamine concentrations. The results indicated that evodiamine could improve the histopathological abnormalities in liver tissues and decrease the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), hydroxyproline, and total bilirubin (TBIL). Concentrations of IL-6, tumor necrosis factor-α (TNF-α), collagen-I (COL-I), and collagen-III (COL-III) were reduced by evodiamine. Western blotting and real-time PCR showed that protein expression of transforming growth factor-β (TGF-β1), p-Smad 2/3 (phosphorylation of Smad 2/3), and smooth muscle alpha-actin (α-SMA) as well as mRNA expression of TGF-β1 and α-SMA in liver tissues were downregulated by evodiamine. The cell proliferation, production of hydroxyproline, and the protein expression of TGF-β1, p-Smad 2/3, and α-SMA in HSCs were dose-dependently reduced by evodiamine. Collectively, evodiamine had an antifibrosis effect in CCl₄-induced liver fibrosis, and reduced HSCs proliferation and collagen metabolism in vitro. The major mechanism was downregulation of relative expression of TGF-β1, p-Smad 2/3, and α-SMA.     

Role of TGF-β/Smad signaling pathway in pulmonary fibrosis after rheumatoid arthritis in mice北大核心CSCD

Aim To investigate the role of TGF-β/Smad signaling pathway in rheumatoid arthritis (RA) - associated postinterstitial pulmonary fibrosis in mice. Methods The mouse model of RA was constructed by subcutaneous administration of complete Freund's adjuvant (CFA) and chicken II collagen (Col-II) to the tail root of mice. The blank group was given the same amount of distilled water, and the control group was given the same amount of glacial acetic acid (solvent). The degree of toe swelling (joint swelling degree and arthritis index) was monitored to evaluate the mouse modeling. The pathological changes of mouse lung tissues were observed by HE and Masson staining. The expression of TGF-β in lung tissues were observed by immunohistochemical staining. The level of hydroxyproline in lung tissues was measured by chemiluminescence method. The expressions of Smad2, Smad3 and phosphorylated p-Smad2 and phosphorylated p-Smad3 in lung tissues were detected by Western blot. Results Compared with blank group and solvent group, the joint swelling and arthritis index of model group significantly increased. Twenty-one days after administration, HE staining showed inflammatory changes in lung interstitium of the model group, Masson staining showed collagen fiber deposition and obvious fibrosis in lung interstitium of the model group, and immunohistochemical staining showed that the expression of TGF-β in cytoplasm of lung interstitial cells of the model group increased, which was brown and yellow. Meanwhile, hydroxyproline was significantly raised in lung tissue homogenate of the model group. Further WB analysis showed that compared with blank group and solvent group, the expression of p-Smad2 and pSmad3 in lung tissues of the model group was significantly up-regulated (P < 0. 05, P < 0. 01). Conclusions RA can give rise to pulmonary fibrosis, and the expressions of p-Smad2 and p-Smad3 are up-regulated, which is be pivotal in pulmonary fibrosis and RA-related post-interstitial pulmonary fibrosis. © 2023 Publication Centre of Anhui Medical University. All rights reserved.     

Modulation of bleomycin-induced oxidative stress and pulmonary fibrosis by N-acetylcysteine in rats via AMPK/SIRT1/NF-κβ

The efficacy of bleomycin (BLM) as an antineoplastic drug is limited to the development of dose and time-dependent pulmonary fibrosis. This study was intended to investigate the effect of N-acetylcysteine (NAC) on BLM-induced pulmonary fibrosis in rats. Twenty rats were randomly divided to the following four groups: Group one served as control; group two received BLM (15 mg/kg, intraperitoneal (ip)) for five consecutive days; group three received NAC (200 mg/kg, ip) for five consecutive days; and group four received NAC 1 hour before BLM for 5 days. The expression of connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), silent information regulator l (SIRT1), AMP-activated protein kinase (AMPK) were determined by qRT-PCR in lung tissues. The changes in transforming growth factor-beta1 (TGF-β1), tumour necrosis factor-α (TNF-α), interleukin-β1 (IL-β1) and nuclear factor kappa-β (NF-κβ) in serum were measured by ELISA. The tissue antioxidant status was determined biochemically. BLM administration caused pulmonary fibrosis as evidenced by increased levels of inflammatory mediators (TGF-β1, TNF-α, IL-β1 and NF-κβ) in serum (P < .05), elevated lipid peroxidation and nitric oxide and depleted endogenous antioxidants in lung tissue (P < .05). The expression levels of SIRT1 and AMPK were significantly decreased (P < .05), while the expression levels of CTGF and PDGF were increased significantly in the BLM group as compared to the control group (P < .05). These alterations were normalized by NAC intervention. NAC markedly attenuated the lung histopathological changes and reduced collagen deposition. These results suggest that NAC exerted an ameliorative effect against BLM-induced oxidative damage and pulmonary fibrosis via SIRT1/ AMPK/ NF-κβ pathways.     

S-allyl-l-cysteine attenuates bleomycin-induced pulmonary fibrosis and inflammation via AKT/NF-κB signaling pathway in mice

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease characterized by inflammation, multifocal fibrotic lesions and excessive collagen deposition with limited therapies. As a major bioactive compound in garlic, S-allyl-l-cysteine (SAC) is a neuroprotective drug candidate to prevent cognitive decline, however, its anti-pulmonary fibrotic activity remains unknown. Here, we investigated whether SAC could attenuate bleomycin (BLM)-induced pulmonary fibrosis and inflammation in mice. Our results showed that SAC dose-dependently reduced the infiltration of inflammatory cells, pulmonary lesions and collagen deposition in BLM treated mice with downregulated mRNA expression levels of fibrotic genes including alpha smooth muscle actin (α-SMA), fibronectin, collagen I and collagen III as well as the protein level of α-SMA. In addition, SAC could also reduce the mRNA expression of inflammatory mediators such as TNF-α and iNOS. Furthermore, higher phosphorylation of AKT and NF-κB p65 in IPF patient samples and murine samples was verified by immunohistochemistry while SAC could decrease the phosphorylation level of AKT and NF-κB p65 in mice stimulated with BLM. These findings, for the first time, indicate that SAC might mediate AKT/NF-κB signaling pathway to inhibit BLM-induced pulmonary fibrosis and support the potential role of SAC as an anti-pulmonary fibrosis agent.     

Puerarin alleviates vincristine-induced neuropathic pain and neuroinflammation via inhibition of nuclear factor-κB and activation of the TGF-β/Smad pathway in rats

Chemotherapy-induced neuropathic pain harms the quality of life patients. Vincristine is an often used chemotherapeutic drug that evokes neuralgia via inflammation. Puerarin (Pue) extracted from Puerariae Lobatae Radix has analgesic and anti-inflammatory effects; however, its possible effect and mechanism in vincristine (Vin)-induced neuropathic pain has not been investigated. The present research aimed to explore whether Pue could relieve chemotherapy-evoked neuropathic pain and the underlying mechanism actions. Rat neuropathic pain was established by intraperitoneal injection of vincristine. Pue was orally administered in two dose levels (25 or 50 mg/kg/d) for three weeks. The paw withdrawal latency and paw withdrawal threshold were performed to evaluate the pain behaviors. Inflammatory cytokines in the spinal cord and dorsal root ganglion were measured by ELISA kits. qRT-PCR, western blot, and immunofluorescence staining were employed to measure the level and expression feature of inflammatory cytokines. Our findings showed that Pue improved hyperalgesia and allodynia. Treatment with Pue restored the levels of tumor necrosis factor-α (TNF-α), and IL-1β and increased the levels of transforming growth factor-β (TGF-β), and interleukin-10 (IL-10). On the molecular level, treatment with Pue down-regulated the protein levels of IL-1β, and NF-κBp65 and up-regulated the protein levels of TGF-β, p-Smad2, and p-Smad3 (TGF-β/Smad) in the spinal cord and DRG. Immunofluorescence staining further demonstrated that Pue decreased the NF-κBp65 protein. Our findings imply that Pue relieved chemotherapy-induced neuropathic pain might be attributable to the suppression of inflammation cytokines. The anti-inflammation action of Pue might be associated with the activation of the TGF-β/Smad pathway, a novel mechanism exploring its prophylactic effect in vincristine-induced neuropathic pain.     

S-Allylmercaptocysteine attenuates Bleomycin-induced pulmonary fibrosis in mice via suppressing TGF-β1/Smad and oxidative stress pathways

Pulmonary fibrosis (PF) is a disease characterized by diffusing alveolar inflammation and alveolar structural disorders that ultimately lead to pulmonary interstitial fibrosis. S-allylmercaptocysteine (SAMC) as a water-soluble organosulfur garlic derivative exhibits efficient anti-inflammatory and anti-oxidative activities. In this study, we attempted to explore the function of SAMC in inhibiting bleomycin (BLM)-induced pulmonary fibrosis in mice. 0.035 U/g of BLM was intraperitoneally injected into mice twice per week for 4 weeks to induce fibrosis. SAMC (25 and 50 mg/kg) and N-acetylcysteine (NAC, 600 mg/kg) were given to mice for 28 days. The results indicate that SAMC could significantly ameliorate the pathological structure, and decrease inflammatory cell infiltration and pro-inflammatory cytokines in bronchoalveolar lavage fluid (BALF) in BLM-induced pulmonary fibrosis mice. SAMC showed an anti-fibrosis effect by increasing anti-oxidants like HO-1, GSH and SOD as well as decreasing hydroxyproline (HYP) in BLM-induced mice. Mechanistic studies suggested that SAMC alleviated oxidative stress probably by impacting the Nox4/Nrf2 pathways, and played an anti-fibrosis role with decreasing the expression of α-SMA, collagen III, collagen I by suppressing the TGF-β1/Smad pathway. These findings indicate that SAMC may be partially responsible for the therapeutic effect on PF patients.     

Epithelial–mesenchymal transition involved in pulmonary fibrosis induced by multi-walled carbon nanotubes via TGF-beta/Smad signaling pathway

Multi-walled carbon nanotubes (MWCNT) are a typical nanomaterial with a wide spectrum of commercial applications. Inhalation exposure to MWCNT has been linked with lung fibrosis and mesothelioma-like lesions commonly seen with asbestos. In this study, we examined the pulmonary fibrosis response to different length of MWCNT including short MWCNT (S-MWCNT, length = 350–700 nm) and long MWCNT (L-MWCNT, length = 5–15 μm) and investigated whether the epithelial–mesenchymal transition (EMT) occurred during MWCNT-induced pulmonary fibrosis. C57Bl/6J male mice were intratracheally instilled with S-MWCNT or L-WCNT by a single dose of 60 μg per mouse, and the progress of pulmonary fibrosis was evaluated at 7, 28 and 56 days post-exposure. The in vivo data showed that only L-MWCNT increased collagen deposition and pulmonary fibrosis significantly, and approximately 20% of pro-surfactant protein-C positive epithelial cells transdifferentiated to fibroblasts at 56 days, suggesting the occurrence of EMT. In order to understand the mechanism, we used human pulmonary epithelial cell line A549 to investigate the role of TGF-β/p-Smad2 signaling pathway in EMT. Our results showed that L-MWCNT downregulated E-cadherin and upregulated α-smooth muscle actin (α-SMA) protein expression in A549 cells. Taken together, both in vivo and in vitro study demonstrated that respiratory exposure to MWCNT induced length dependent pulmonary fibrosis and epithelial-derived fibroblasts via TGF-β/Smad pathway.     

Synergistic protection of Schizandrin B and Glycyrrhizic acid against bleomycin-induced pulmonary fibrosis by inhibiting TGF-β1/Smad2 pathways and overexpression of NOX4

Pulmonary fibrosis, a progressive and lethal lung disease, is a major therapeutic challenge for which new therapeutic strategies are warranted. Schisandrin B (Sch B) and Glycyrrhizic acid (GA) are the principal active ingredients of Schisandra chinensis and Glycyrrhiza glabra respectively, which have been reported to protect against lung injures. The present study was aimed at exploring the combinatorial therapeutic effects on bleomycin-induced pulmonary fibrosis. Lung fibrotic injuries were induced in mice by a single intratracheal instillation of 5 mg/kg bleomycin (BLM). Then, these mice were administered with Sch B (100 mg/kg) or/and GA (75 mg/kg) for 28 days. BLM-triggered structure distortion, collagen overproduction, excessive inflammatory infiltration, pro-inflammatory cytokine release, and oxidative stress damages in lung tissues were attenuated to a higher degree by combinatorial treatment than by treatment of the individual agents. The expression of TGF-β1 and the phosphorylation of its downstream target, Smad2 were enhanced by BLM, but weakened by Sch B or/and GA. Furthermore, the significant overexpression of NADPH oxidase 4 (NOX4) was observed in BLM-induced pulmonary fibrosis, which was inhibited by Sch B or/and GA. Our study reveals that the synergistic protection by Sch B and GA against BLM-induced pulmonary fibrosis is correlated to its anti-inflammatory, anti-oxidative and anti-fibrotic properties, involving inhibition of TGF-β1/Smad2 signaling pathways and overexpression of NOX4.     

Houttuynia cordata inhibits lipopolysaccharide-induced rapid pulmonary fibrosis by up-regulating IFN-γ and inhibiting the TGF-β1/Smad pathway

This study aimed to explore the effect and mechanism of H. cordata vapor extract on acute lung injury (ALI) and rapid pulmonary fibrosis (RPF). We applied the volatile extract of HC to an RPF rat model and analyzed the effect on ALI and RPF using hematoxylin-eosin (H&E) staining, routine blood tests, a cell count of bronchoalveolar lavage fluid (BALF), lactate dehydrogenase (LDH) content, van Gieson (VG) staining, hydroxyproline (Hyp) content and the dry/wet weight ratio. The expression of IFN-γ/STAT(1), IL-4/STAT(6) and TGF-β(1)/Smads was analyzed using ELISA, immunohistochemistry and western blotting methods. The active ingredients of the HC vapor extract were analyzed using a gas chromatograph-mass spectrometer (GC-MS), and the effects of the active ingredients of HC on the viability of NIH/3T3 and RAW264.7 cells were detected using an MTT assay. The active ingredients of the HC vapor extract included 4-terpineol, α-terpineol, l-bornyl acetate and methyl-n-nonyl ketone. The results of the lung H&E staining, Hyp content, dry/wet weight ratio and VG staining suggested that the HC vapor extract repaired lung injury and reduced RPF in a dose-dependent manner and up-regulated IFN-γ and inhibited the TGF-β1/Smad pathway in vivo. In vitro, it could inhibit the viability of RAW264.7 and NIH/3T3 cells. It also dose-dependently inhibited the expression of TGF-β1 and enhanced the expression of IFN-γ in NIH/3T3. The HC vapor extract inhibited LPS-induced RPF by up-regulating IFN-γ and inhibiting the TGF-β1/Smad pathway.     

The role of TGF-β1/Smad3 signaling pathway and oxidative stress in the inhibition of osteoblast mineralization by copper chloride

To explore the relationship of oxidative stress and TGF-β 1/Smad3 pathway in the inhibition of osteoblast mineralization by copper chloride (CuCl₂), the osteoblasts were treated with CuCl₂ (0, 50 μM, 100 μM, 150 μM CuCl₂ 5H₂O) for 24 h. We found that Cu impaired the osteoblast structure, inhibited the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, alkaline phosphatase (ALP) content, mRNA expression of collagen I (COL-I), osteocalcin (OCN), insulin-like growth factor I (IGF-I), bone morphogenetic protein-2 (BMP-2), transforming growth factor β1 (TGF-β1) and core-binding factor α1 (Cbfα1), promoted the reactive oxygen species (ROS) production, inactivated the TGF-β1/Smad3 pathway. It indicates that the inactivated TGF-β1/Smad3 pathway leads to osteoblast impairment by CuCl₂. It will contribute to clarify the influence of CuCl₂ on the osteoblast mineralization.     

Adipose-derived stem cells ameliorate renal interstitial fibrosis through inhibition of EMT and inflammatory response via TGF-β1 signaling pathway

Adipose-derived stem cells (ADSCs) have been successfully used to treat acute kidney injury or acute renal failure. However, the effect of ADSCs on treating renal interstitial fibrosis remains unknown. Here, we assessed the therapeutic efficacy of ADSCs on renal interstitial fibrosis induced by unilateral ureter obstruction (UUO) and explored the potential mechanisms. After 7 days of UUO, rats were injected with ADSCs (5 × 10⁶) or vehicle via tail vein. We found that ADSCs administration significantly ameliorated renal interstitial fibrosis, the occurrence of epithelial-mesenchymal transition (EMT) and inflammatory response. Furthermore, ADSCs administration could inhibit the activation of transforming growth factor-β1 (TGF-β1) signaling pathway, which might play a crucial role in renal interstitial fibrosis of the UUO model rats. These results suggested that ADSCs treatment attenuates renal interstitial fibrosis possibly through inhibition of EMT and inflammatory response via TGF-β1 signaling pathway. Therefore, ADSCs may be an effective therapeutic strategy for the treatment of renal interstitial fibrosis.     

Senegenin exerts anti-depression effect in mice induced by chronic un-predictable mild stress via inhibition of NF-κB regulating NLRP3 signal pathway

Depressive disorder is a kind of affective disturbance disease. Emerging evidence has suggested that inflammation may contribute to the pathologic process of depressive disorder. Senegenin (SEN), a major bioactive constituent in Polygala tenuifolia Willd, has much bioactivity including anti-inflammatory and neuroprotection effects. However, the mechanism of its anti-depressant effect in mice remains unknown. This study aimed to explore the anti-depressant effects of SEN on behavioral changes and inflammatory responses in mice induced by chronic un-predictable mild stress (CUMS). SEN treatment remarkably ameliorated CUMS-induced behavioral abnormalities, such as improving locomotor activity, decreasing immobility time in Tail suspension test (TST) and Forced swimming test (FST), and increasing sucrose intake in Sucrose preference test (SPT). Additionally, SEN improve protein levels of Brain-derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3) expression.In response to stress, p65 was activated to promote production of pro-IL-1β, and then cleaved to mature IL-1β by NOD-like receptor protein 3 (NLRP3) inflammasome pathway in hippocampus of CUMS mice. After SEN treatment, protein activation related to NLRP3 inflammasome pathway was down-regulated, which inhibited IL-1β secretion. These results demonstrate that SEN plays an important role in treatment CUMS-induced depression in mice, possibly via suppression of pathway activation associated with NLRP3 inflammasome.     

Ganoderic acid hinders renal fibrosis via suppressing TGF-β/Smad and MAPK signaling pathways

OBJECTIVE To investigatethe anti-renal fibrotic effect of Ganoderic acid(GA) and the related mechanisms in vivo and in vitro. METHODS We investigated whether GA could hinder renal fibrosis and the related mechanisms in a unilateral ureteral obstruction(UUO) mouse model and TGF-β1-stimulated HK-2 cells model. The C57 mice were randomly devided into sham group, sham with GA administration group, UUO group and UUO with GA treatment group. After UUO surgery,the mice were treated with GA(3.125, 12.5 and 50 mg·kg~(-1) per day, ip) for 14 d. Then the mice were sacrificed for collecting blood and kidneys. The kidney functions were revealed by blood urea nitrogen and serum creatinine.The fibrosis and tubules injury levels were detected by Masson staining and HE staining. The epithelial-mesenchymal transition(EMT) level was detected by Western blotting and immunohistochemical staining. The changes of related signaling pathways and underlying mechanisms were demonstrated by Western blotting. The cell model was adopted to identify the potent inhibitor of renal fibrosis. RESULTS After 14 d treatment, GA dosedependently attenuated UUO-induced tubular injury and renal fibrosis; GA(50 mg·kg~(-1)) significantly ameliorated renal disfunction during fibrosis progression. We further revealed that GA treatment significantly decreased the expression of mesenchymal cell markers alpha-smooth muscle actin(α-SMA) and vimentin, and up-regulated E-cadherin expression in the kidney, suggesting the suppression of tubular EMT. Further study showed that GA downregulated both TGF-β/Smad and MAPK(ERK,JNK, P38) signaling pathways both in vivo and in vitro.GA-A, a GA monomer, was identified as a potent inhibitor on renal fibrosis in TGF-β1-stimulated HK-2 cell model.CONCLUSION GA inhibits renal interstitial fibrosis induced by UUO, mostly by suppressing EMT progression and inhibiting TGF-β/Smad and MAPK signaling pathways. In conclusion, our results suggest that GA and its purified monomer GA-A might be developed as a potential therapeutic agent in the treatment of renal fibrosis.     

Effect of TGF-β/Smad signaling pathway on lung myofibroblast differentiation

AIM: Myofibroblasts play important roles in the pathogenesis of lung fibrosis. Transforming growth factor (TGF)-beta 1 has been widely recognized as a key fibrogenic cytokine. The major signaling pathway of (TGF)-beta(1) is through cytoplasmic Smad proteins. Our study investigated the role of individual (TGF)-beta(1)/Smad signal proteins in mediating alpha-smooth muscle actin (alpha-SMA) gene expression, which is a well-known key marker of myofibroblast differentiation. METHODS: We transiently cotransfected alpha-SMA promoter-luciferase fusion plasmid (p895-Luc) and Smad expression plasmids and measured Luc activity in (TGF)-beta(1)-treated human fetal lung fibroblasts. We induced Smad3 knockout mice lung fibrosis by bleomycin. alpha-SMA protein expression was assessed by Western blotting. Collagen protein was analyzed by measuring hydroxyprolin. Myofibroblast morphology was assessed by immunohistochemistry. RESULTS: We found that the overexpression of Smad3, not Smad2 markedly increased (TGF)-beta(1)-induced alpha-SMA promoter activity and alpha-SMA protein expression in vitro, whereas the overexpression of dominant negative mutant Smad3 and Smad7 repressed (TGF)-beta(1)-induced alpha-SMA gene expression. Compared to wild-type mice, Smad3 knockout mice showed attenuated lung fibrosis after bleomycin treatment, manifested by lower collagen production and myofibroblast differentiation. CONCLUSION: Our study suggested (TGF)-beta(1)/Smad3 is a major pathway which regulated the myofibroblast differentiation. This result indicates a potential significance for future attempts of attenuating the progression of human lung fibrosis by the inhibition of the Smad3 cascade.     

CCM111 prevents hepatic fibrosis via cooperative inhibition of TGF-β, Wnt and STAT3 signaling pathways

CCM111 is an aqueous extract of Antrodia cinnamomea (AC) that has exhibited anti-liver fibrosis functions. However, the detailed mechanisms of AC action against liver fibrosis have not been elucidated yet. The present research showed that CCM111 significantly lowered the levels of the hepatic enzyme markers glutamate oxaloacetate transaminase (GOT) and glutamic pyruvic transaminase (GPT), prevented liver damage and collagen deposition, and downregulated TGF-β/Smad signaling in a dose-dependent manner compared with CCl₄ treatment alone. CCM111 markedly inhibited TGF-β, Wnt and STAT3 signaling pathway-regulated downstream genes in the liver by next-generation sequencing. The antifibrotic mechanisms of CCM111 were further demonstrated in HSC-T6 cells. Our data demonstrated for the first time that CCM111 can protect against CCl₄-induced liver fibrosis by the cooperative inhibition of TGF-β-, Wnt- and STAT3-dependent proinflammatory and profibrotic mediators, suggesting that CCM111 might be a candidate for preventing and treating chronic fibrotic liver diseases.     

Effect of efonidipine on TGF-β1-induced cardiac fibrosis through Smad2-dependent pathway in rat cardiac fibroblasts

Transforming growth factor beta-1 (TGF-β1) plays a critical role in progression of cardiac fibrosis, which may involve intracellular calcium change. We examined effects of efonidipine, a dual T-type and L-type calcium channel blocker (CCB), on TGF-β1-induced fibrotic changes in neonatal rat cardiac fibroblast. T-type and L-type calcium channel mRNAs were highly expressed in cultured cardiac fibroblasts. TGF-β1 (5 ng/mL) significantly increased Smad2 phosphorylation and [(3)H]-leucine incorporation, which were attenuated by pretreatment with efonidipine (10 μM). Neither R(-)efonidipine (10 μM), selective T-type CCB, nor nifedipine (10 μM), selective L-type CCB, efficaciously inhibited both TGF-β1-induced Smad2 phosphorylation and [(3)H]-leucine incorporation. However, both were markedly attenuated by combination of R(-)efonidipine and nifedipine, EDTA, or calcium-free medium. Pretreatment with Smad2 siRNA significantly attenuated [(3)H]-leucine incorporation induced by TGF-β1. These data suggest that efonidipine elicits inhibitory effects on TGF-β1- and Smad2-dependent protein synthesis through both T-type and L-type calcium channel-blocking actions in cardiac fibroblasts.