Integrated TCGA and GEO analysis showed that SMAD7 is an independent prognostic factor for lung adenocarcinoma.

The lack of effective markers leads to missed optimal treatment times, resulting in poorer prognosis in most cancers. Drosophila mothers against decapentaplegic protein (SMAD) family members are important cytokines in the transforming growth factor-beta family. They jointly regulate the processes of cell growth, differentiation, and apoptosis. However, the expression of SMAD family genes in pan-cancers and their impact on prognosis have not been elucidated. Perl software and R software were used to perform expression analysis and survival curve analysis on the data collected by TCGA, GTEx, and GEO, and the potential regulatory pathways were determined through gene ontology enrichment and kyoto encyclopedia of genes and genomes enrichment analysis. It was found that SMAD7 and SMAD9 expression decreased in lung adenocarcinoma (LUAD), and their expression was positively correlated with survival time. Additionally, SMAD7 could be used as an independent prognostic factor for LUAD. In general, SMAD7 and SMAD9 can be used as prognostic markers of LUAD. Further, SMAD7 is expected to become a therapeutic target for LUAD.

Effect of astragaloside IV on cognitive dysfunction in rats with cerebrally infarcted via TGF-ß / Smad signaling pathway.

Cerebral infarction is an acute cerebrovascular disease caused by abnormal blood circulation in the brain. In the present study, we investigate the effect of astragaloside IV on cognitive dysfunction in cerebrally infarcted rats via transforming growth factor-ß (TGF-ß) / Smad signaling pathway. For this purpose, 45 rats were divided into three groups including astragaloside, model, and control. 30 of 45 healthy adult male SD rats were randomly selected to establish an acute cerebral infarction model. 15 modeled rats were enrolled as a model and astragaloside group, and another 15 rats as a blank control group. The rats in the astragaloside group were fed with astragaloside IV according to 1.08 g/kg body weight, and those in the blank group and model group were given matching normal saline. The levels of TGF-ß, Smad1, Smad3 and Smad7 of TGF-ß/Smad signaling transduction pathway at T0 (week 0), T1 (week 3) and T2 (week 6) were determined by enzyme-linked immunosorbent assay (ELISA). The modified neurological severity score (mNSS) was used to evaluate the improvement of cognitive dysfunction in rats. The mNSS of rats with cerebral infarction in the astragaloside group was lower than that in the control group and model group (P< 0.05). While the levels of TGF-ß, Smad1, Smad3 and Smad7 in the astragaloside group were higher than those in the control group and model group (P< 0.05). Astragaloside IV plays an important role in improving cognitive dysfunction in rats with cerebral infarction while affecting the levels of TGF-ß, Smad1, Smad3 and Smad7 and activating TGF-ß / Smad signaling pathway.

SMAD7 is a novel independent predictor of survival in patients with cutaneous melanoma.

Overexpression of SMAD7-a hallmark inhibitor of transforming growth factor ß (TGFß) signaling-has been documented and related with adverse prognosis in a number of epithelial malignancies, suggesting that it may be responsible for resistance to TGFß-induced growth arrest of cancer cells. The involvement of SMAD7 in development and progression of malignant melanoma is unclear, and its expression has not been characterized so far at the protein level in clinical melanoma tissue samples. We evaluated SMAD7 expression in 205 skin melanoma primary tumors by immunohistochemistry and correlated the findings with clinicopathological profiles of patients. Melanocytic SMAD7 was evidenced in 204 cases, and the expression pattern was predominantly nuclear. High expression of SMAD7 was positively associated with several features of tumor aggressiveness, for example, presence of ulceration (P < 0.001), higher tumor thickness (P < 0.001), and mitotic rate (P < 0.001), but not presence of regional or distant metastases. Moreover, high SMAD7 expression independently predicted unfavorable outcome: melanoma-specific survival (hazard ratio = 3.16, P < 0.001) and recurrence-free survival (hazard ratio = 2.88, P < 0.001). Taken together, our results underline the importance of TGFß signaling in cancer and define SMAD7 as a marker of aggressive tumor behavior and adverse clinical outcomes in melanoma patients.

Human umbilical cord mesenchymal stem cells inhibit proliferation of hepatic stellate cells in vitro.

The effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) on the proliferation of hepatic stellate cells (HSCs) is largely unknown. The purpose of this study was to explore the mechanism of action of hUC­MSCs on the proliferation of HSCs in vitro. The upper and lower double-cell co-culture system was established between hUC­MSCs and HSCs in the experimental group. HSCs were cultured alone as a negative control group. Cell proliferation and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Cell supernatants were harvested to determine the concentration of transforming growth factor-ß1 (TGF-ß1) by ELISA. mRNA and protein of TGF-ß1, Smad3 and Smad7 in HSCs were determined by reverse transcription-polymerase chain reaction and western blotting, respectively. In the co-culture group, the proliferation of HSCs was significantly inhibited compared with the negative control group at 24 and 48 h (p<0.05). Apoptosis of HSCs in the co-culture group increased compared with that in the negative control group, which was more obvious at 48 h (p<0.05). The concentration of TGF-ß1 in the co-culture group was significantly lower than in the HSCs cultured alone (p<0.05). After HSCs were co-cultured with hUC­MSCs for 48 h, expression of TGF-ß1 and Smad3 mRNA and protein was reduced and expression of Smad7 mRNA and protein was increased compared with the negative control group (p<0.05). hUC­MSCs inhibited proliferation of HSCs, possibly through inhibiting TGF-ß1 and Smad3 expression and increasing Smad7 protein expression.

Impact of microRNA-375 and its target gene SMAD-7 polymorphism on susceptibility of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) has a high morbidity and mortality. Many studies reported that mir-375 is frequently down-regulated in many cancers including esophageal cancer, hepatocellular carcinoma, breast cancer and leukemias. AIM: Our aim was to study the expression of microRNA-375 and its target gene SMAD-7 polymorphisms (rs4939827) in CRC patients in comparison to control subjects and to correlate these results with clinical data of patients to elucidate their role in pathogenesis and early diagnosis of CRC. MATERIAL AND METHODS: The present study was conducted on 122 subjects divided into 86 patients with CRC and 36 age- and sex-matched controls. The followings were done to all subjects: full history taking, full clinical examination, complete blood picture, serum (ALT, AST), serum albumin, CEA, TLC, PLT, and creatinine. Gene expression of miRNA-375 from serum was done by real-time PCR. Gene polymorphism SNPs of SMAD7 (rs4939827) was also done in DNA extracted from blood by real-time PCR. RESULTS: As regards the polymorphism of SMAD7, we found that CC (wild) genotype has high percentage in controls compared to CRC cases (36.1% vs 15.1%). Meanwhile, the mutant and heterozygotes genotypes showed high percentage among cases compared to controls (33.7%, and 51.2% respectively) vs (22.2%, and 41.7% respectively) with no significant statistical analysis. There was a statistically significant high T-allelic frequency among cases and C-allelic frequency among controls. There was a statistically significant association between fold change in micro RNA (-375) and the susceptibility to CRC as there is down-regulation of the microRNA-375 in CRC group with fold change in 0.42±0.27. CONCLUSION: Micro RNA-375 and rs4939827 SNP in SMAD7 could be considered as potential markers for detecting and early diagnosing CRC patients.

Role of tumor-associated macrophages in the Hexim1 and TGFß/SMAD pathway, and their influence on progression of prostatic adenocarcinoma.

BACKGROUND: Hexamethylene bisacetamide-inducible protein 1 (Hexim1) regulates transforming growth factor-ß (TGFß) activity and turnover of SMAD proteins in a cyclin-dependent kinase 9-dependent way. It does so specifically through inhibiting function of this enzyme and by inhibiting the transcriptional activity of positive transcription elongation factor b (P-TEFb). Tumor-associated macrophages (TAMs) play a role in the progression of prostate adenocarcinomas. We investigated the clinicopathological significance of Hexim1, TGFß, SMAD2, and SMAD7 expression in prostate adenocarcinoma cells, and assessed associations between TAMs density and these proteins. METHODS: The cases of 100 patients diagnosed with prostate acinar adenocarcinoma who had undergone radical prostatectomy were retrospectively examined. Each was reviewed for Gleason score, cancer stage, and specific histopathological features. Original slides were re-examined, and new slides were prepared and immunostained with Hexim1, TGFß, SMAD2, SMAD7 and CD68. RESULTS: Hexim1 expression was positively correlated with Gleason score, cancer stage, lymphovascular invasion, perineural invasion, extracapsular extension, and positive surgical margin. TAMs density was positively correlated with Gleason score, cancer stage, perineural invasion, extracapsular extension, and positive surgical margin. TAMs density was positively correlated with Hexim1 expression and TGFß expression. More advanced cancer stage, lymphovascular invasion, perineural invasion, and extracapsular extension were correlated with strong Hexim1 expression, strong SMAD2 expression, and mild SMAD7 expression, respectively. Strong Hexim1 expression, strong TGFß expression, and mild SMAD7 expression were associated with higher Gleason score. Strong Hexim1 expression was correlated with strong TGFß expression and mild SMAD7 expression. Strong Hexim1 expression, strong SMAD2 expression, and mild expression of SMAD7 were associated with disease progression. Strong SMAD2 expression was associated with shorter disease-free survival. CONCLUSION: The results suggest that greater TAMs density, strong Hexim1 expression, strong SMAD2 expression, and mild SMAD7 expression play important roles in the progression of prostate adenocarcinoma. Further investigation of these proteins will help facilitate the definitive prognosis of prostate adenocarcinomas. Ultimately, these proteins may be therapeutic targets for patients with prostate cancer.

Novel Smad proteins localize to IR-induced double-strand breaks: interplay between TGFß and ATM pathways.

Cellular damage from ionizing radiation (IR) is in part due to DNA damage and reactive oxygen species, which activate DNA damage response (DDR) and cytokine signaling pathways, including the ataxia telangiectasia mutated (ATM) and transforming growth factor (TGF)ß/Smad pathways. Using classic double-strand breaks (DSBs) markers, we studied the roles of Smad proteins in DDR and the crosstalk between TGFß and ATM pathways. We observed co-localization of phospho-Smad2 (pSmad2) and Smad7 with DSB repair proteins following low and high linear energy transfer (LET) radiation in human fibroblasts and epithelial cells. The decays of both foci were similar to that of γH2AX foci. Irradiation with high LET particles induced pSmad2 and Smad7 foci tracks indicating the particle trajectory through cells. pSmad2 foci were absent in S phase cells, while Smad7 foci were present in all phases of cell cycle. pSmad2 (but not Smad7) foci were completely abolished when ATM was depleted or inactivated. In contrast, a TGFß receptor 1 (TGFßR1) inhibitor abrogated Smad7, but not pSmad2 foci at DSBs sites. In summary, we suggest that Smad2 and Smad7 contribute to IR-induced DSB signaling in an ATM or TGFßR1-dependent manner, respectively.

Smad7 acts as a negative regulator of the epidermal growth factor (EGF) signaling pathway in breast cancer cells.

Although it has been suggested that smad7 blocks downstream signaling of TGF-ß, the role of smad7 in the EGF signaling pathway has not been fully elucidated. We determined the effect of smad7 on EGF-induced MMP-9 expression in SKBR3 breast cancer cells. The expression of smad7 and MMP-9 was increased by EGF or TGF-ß1, respectively, and further increased by EGF and TGF-ß1 co-treatment. EGF induced the phosphorylation of EGFR, smad3, ERK, and JNK, and MMP-9 expression was decreased by the EGFR inhibitor, AG1478. In addition, EGF-induced MMP-9 expression was inhibited by UO126 (a MEK1/2 inhibitor) or SIS3 (a smad3 inhibitor), but not by SP600125 (a JNK inhibitor). Interestingly, EGF-induced smad3 phosphorylation was completely blocked by smad7 over-expression, but not the phosphorylation of ERK and JNK. EGF- or TGF-ß1-induced MMP-9 expression was completely decreased by adenoviral-smad7 (Ad-smad7) over-expression. We also investigated the role of smad3 on EGF-induced MMP-9 expression and showed that EGF-induced MMP-9 expression was decreased by smad3 siRNA transfection, whereas EGF-induced MMP-9 expression was further increased by smad3 over-expression, as expected. This study showed that EGF-induced smad3 phosphorylation mediates the induction of MMP-9, whereas smad7 inhibits TGF-ß1 as well as the EGF signaling pathway in SKBR3 cells.

Seasonal changes in immunoreactivity of activin signaling component proteins in wild ground squirrel testes.

The seasonal spermatogenesis and localization of inhibin/activin subunits (alpha, betaA, betaB) in the testes of wild ground squirrel has been previously described; however, the expression pattern of activin receptors and cytoplasmic signaling SMADs has not been detected in any seasonal breeders. The objective of this study was to investigate the abundance and cellular localization of activin signaling components in testes of the wild ground squirrel during the breeding and nonbreeding seasons. The immunolocalizations of ActRIIB (activin type II receptor B) and activin-related SMADs (phospho-SMAD2/3, SMAD4 and SMAD7) were observed by immunohistochemistry. Total proteins were extracted from testicular tissues in the breeding and nonbreeding seasons and were used for Western blotting analysis for ActRIIB and SMADs. Immunoreactivities of activin signaling components were greater in the testes of the breeding season, and then decreased to a relatively low level in the nonbreeding season. ActRIIB and related SMADs were widely spread in the active testes, while spermatogonia were the predominant cellular sites of activin signal transduction during arrested spermatogenesis. The dynamic regulation of activin type II receptor and SMADs indicated that the activin signal pathway played an important paracrine role in seasonal spermatogenesis of the wild ground squirrel. Furthermore, the distinct localizations and immunoreactivity of ActRIIB and SMADs might suggest different functions of activin in seasonal spermatogenesis.

Transforming growth factor-ß signaling pathway in Marfan's syndrome: a preliminary histopathological study.

BACKGROUND: Marfan's syndrome is an inherited disorder that affects the connective tissue. It has been proposed that mutations of FBN1 gene or of transforming growth factor (TGF)-beta type II receptor may be responsible for its pathogenesis. However, the role of TGF-beta signaling pathway in the development of Marfan's syndrome has not been comprehensively investigated. MATERIALS AND METHODS: Surgical specimens of the aorta were obtained from two female Marfan patients, and the control aortic tissue was taken from an autopsy of a healthy individual. The aortic specimens were examined with hematoxylin-eosin, Masson's trichrome, von Gieson/victoria blue-van Gieson bichrome, and immunohistochemical stainings of TGF-beta1, TGF-beta type I receptor, Smad2/3, Smad4 and Smad7. RESULTS: Hematoxylin-eosin staining demonstrated severe elastic lamellar disruption and patchy vascular smooth muscle dissolution in the aortic media of the Marfan patients. Collagen deposition, interlamilar elastic fiber fragmentation, loss or proliferation, and acid mucopolysaccharide accumulation were observed in the disarrayed aortic wall structures of Marfan patients by Masson's trichrome, victoria blue-van Gieson bichrome, and Alcian blue and periodic schiff's (AB-PAS) stainings, respectively. By immunohistochemistry, structural disruptions with enhanced TGF-beta;1 in the cytoplasm, Smad2/3 in the interstices, Smad4 in the cytoplasm, nuclei or interstices, and OOO Smad7, in the nucleus along with attenuated TGF-beta type I receptor in the aortic tissues of Marfan patients in comparison to the healthy control. CONCLUSIONS: Marfan patients may have aberrant TGF-beta signaling pathway associated with increased collagen deposition, interlamilar elastic fiber degenerative changes, and acid mucopolysaccharide accumulation. The signaling dysregulation may play an important role in the pathogenesis of this genetic disorder.

Increased expression of Smad proteins, and in particular Smad3, in oral lichen planus compared to normal oral mucosa.

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa which the World Health Organisation (WHO) considers a premalignant condition. One step in malignant development is so called epithelial mesenchymal transition (EMT), a process whereby epithelial cells acquire mesenchymal characteristics. EMT occurs during embryogenesis and wound healing but also in some human diseases such as cancer and fibrosis. A factor known to induce EMT is transforming growth factor-ß (TGF-ß), which uses the Smad proteins as mediators for its signalling. TGF-ß is also often over-expressed in squamous cell carcinoma of the head and neck (SCCHN). METHODS: In the present study we mapped expression of Smad proteins in OLP lesions by immunohistochemistry, and compared to expression in normal and sensitive oral mucosa. The latter group of patients had developed SCCHN after shorter or longer periods of diffuse oral symptoms. The aim was to see if there were any signs of EMT related changes in the OLP lesions, as judged by changes in the TGF-ß pathway. CONCLUSION: Changes in the TGF-ß pathway related to EMT are seen in the very earliest stages of oral malignancy and become more severe as lesions progress.

Expression of SMAD proteins, TGF-beta/activin signaling mediators, in human thyroid tissues.

OBJECTIVE: To investigate the expression of SMAD proteins in human thyroid tissues since the inactivation of TGF-beta/activin signaling components is reported in several types of cancer. Phosphorylated SMAD 2 and SMAD3 (pSMAD2/3) associated with the SMAD4 induce the signal transduction generated by TGF-beta and activin, while SMAD7 inhibits this intracellular signaling. Although TGF-beta and activin exert antiproliferative roles in thyroid follicular cells, thyroid tumors express high levels of these proteins. MATERIALS AND METHODS: The protein expression of SMADs was evaluated in multinodular goiter, follicular adenoma, papillary and follicular carcinomas by immunohistochemistry. RESULTS: The expression of pSMAD2/3, SMAD4 and SMAD7 was observed in both benign and malignant thyroid tumors. Although pSMAD2/3, SMAD4 and SMAD7 exhibited high cytoplasmic staining in carcinomas, the nuclear staining of pSMAD2/3 was not different between benign and malignant lesions. CONCLUSIONS: The finding of SMADs expression in thyroid cells and the presence of pSMAD2/3 and SMAD4 proteins in the nucleus of tumor cells indicates propagation of TGF-beta/activin signaling. However, the high expression of the inhibitory SMAD7, mostly in malignant tumors, could contribute to the attenuation of the SMADs antiproliferative signaling in thyroid carcinomas.

Trps1 haploinsufficiency promotes renal fibrosis by increasing Arkadia expression.

Mutations in TRPS1 cause tricho-rhino-pharyngeal syndrome (TRPS). Trps1 is essential for nephron development, acting downstream of Bmp7. Because Bmp7 counteracts epithelial-to-mesenchymal transition (EMT) and reverses chronic renal injury, we examined the function of Trps1 in renal fibrosis. Immunohistochemistry revealed Trps1 expression in proximal tubular epithelial cells of mice. Unilateral ureteral obstruction reduced mRNA and protein expression of Trps1 in wild-type and heterozygous Trps1-knockout (Trps1(+/-)) mice. Trps1 haploinsufficiency promoted tubulointerstitial fibrosis via increased phosphorylation of Smad3 and decreased Smad7 protein. In primary culture, Trps1 deficiency promoted TGF-beta1-mediated EMT in proximal tubule cells. Trps1(+/-)-derived cells had higher levels of phosphorylated Smad3, and TGF-beta1 induced a time-dependent decrease in Smad7 protein in wild-type and Trps1(+/-) kidneys. In addition, compared with wild-type cells, Trps1(+/-) cells had double the amount of the E3 ubiquitin ligase Arkadia, and TGF-beta1 induced further Arkadia expression. Furthermore, knockdown of Arkadia inhibited TGF-beta1-induced EMT in Trps1(+/-) cells. Collectively, these data suggest that Trps1 haploinsufficiency enhances TGF-beta1-induced EMT and tubulointerstitial fibrosis by modulating the amount of Smad7 through Arkadia/ubiquitin-mediated degradation.

Prevention of stricture development after corrosive esophageal burn with a modified esophageal stent in dogs.

OBJECTIVE: We sought to test the feasibility and technical ease of a newly designed nitinol-based modified esophageal stent and its effects on preventing postcaustic stricture in mongrel dogs and to try to explain the result at the molecular level. METHODS: Twenty-four dogs were included in this controlled study. Stenosis index (wall thickness/intraluminal diameter), pathologic features, hydroxyproline quantities, esophageal compliance, and biomechanics were compared between the injured but unstented and stented dogs. Transforming growth factor beta1, Sma/Mad (Smad)3, and Smad7 mRNA expression and protein levels in esophageal tissue were detected by means of reverse transcriptase-polymerase chain reaction and Western blotting, respectively. RESULTS: The modified esophageal stent was able to be placed and retrieved successfully and conveniently and was not only intact but there was also no macroscopic esophageal mucosal injury after the stent removal 4 months later. In comparison with the injured but unstented group, esophageal compliance, biomechanics, and the stenosis index were significantly better in the stented group. Histopathologic study revealed that collagen bundles were thinner and its orientation tended toward a regular and parallel pattern. Transforming growth factor beta1 and Smad3 mRNA expression and protein levels increased and Smad7 mRNA expression and protein levels decreased significantly in esophageal tissue in the stented group. These variables showed no statistically significant difference 2 months after stent removal. CONCLUSIONS: The modified esophageal stent might be a promising stent in preventing stricture formation after corrosive esophageal burns clinically.

Coculture of osteoclast precursors with rheumatoid synovial fibroblasts induces osteoclastogenesis via transforming growth factor beta-mediated down-regulation of osteoprotegerin.

OBJECTIVE: The mechanisms of osteoclast maturation and the role of rheumatoid arthritis (RA) synovial fibroblasts in the control of osteoclastogenesis remain unclear. The purpose of this study was to determine the humoral factors that influence osteoclast differentiation resulting from mutual interactions between osteoclast progenitor cells and synovial fibroblasts. METHODS: The cloned mouse macrophage cell line RAW 264.7 or isolated human CD14+ monocytes were cocultured with RA or osteoarthritis (OA) synovial fibroblasts in the presence of RANKL. Osteoclasts were visualized by staining for tartrate-resistant acid phosphatase (TRAP), and their functions were evaluated by bone resorption assay. Transforming growth factor beta (TGFbeta) and osteoprotegerin (OPG) levels were measured by enzyme-linked immunosorbent assay. Expression of pSmad2 and Smad7 was analyzed by Western blotting. RESULTS: RANKL-mediated osteoclast formation was observed in cocultures of RAW cells with RA synovial cells, but not with OA synovial cells. This formation was inhibited by TGFbeta receptor kinase inhibitor or neutralizing TGFbeta antibody. Human CD14+ monocytes showed the same results with RAW 264.7, and bone resorption activity was consistent with osteoclast formation. RA synovial fibroblasts produced TGFbeta in response to cell-cell contact with RAW cells in a RANKL-dependent manner. TGFbeta reduced OPG production by RA synovial fibroblasts, but dose-dependently increased OPG secretion in OA synovial fibroblasts. TGFbeta decreased the expression of pSmad2 and increased the expression of Smad7 in RA synovial fibroblasts, but not OA synovial fibroblasts. CONCLUSION: Suppression of OPG production by down-regulation of TGFbeta/Smad2 signaling may contribute to RANKL-mediated osteoclastogenesis from RA synovial fibroblasts.

Prevention of colonic fibrosis by Boswellia and Scutellaria extracts in rats with colitis induced by 2,4,5-trinitrobenzene sulphonic acid.

BACKGROUND: Currently, no effective preventive measures or medical therapies are available for intestinal fibrosis and, thus, surgery remains the only available strategy in the management of fibrostenotic enteropathies, especially Crohn's disease. The aim of this study was to evaluate the efficacy of a combined therapy of anti-inflammatory Boswellia and antifibrotic Scutellaria extracts on the development of colonic fibrosis in rats. MATERIALS AND METHODS: Chronic colonic inflammation-associated fibrosis was induced in rats by intracolonic administration of 2,4,5-trinitrobenzene sulphonic acid (TNBS). Sixty-four healthy male Sprague-Dawley rats were assigned to five groups: 8 controls, 14 TNBS, 14 TNBS orally treated with Boswellia extracts (50 mg kg(-1) day(-1)), 14 TNBS orally treated with Scutellaria extracts (150 mg kg(-1) day(-1)), and 14 TNBS orally treated with both Boswellia (50 mg kg(-1) day(-1)) and Scutellaria extracts (150 mg kg(-1) day(-1)). The colon was removed after 21 days of treatment and assessed by macroscopic, histological, morphometric and immunohistochemical analyses. For immunohistochemical analysis, alpha-smooth muscle actin (alpha-SMA), collagen types I-III, connective tissue growth factor (CTGF), transforming growth factor-beta1 (TGF-beta1), Smad3, Smad7 and CD3 antibodies were used. RESULTS: Combined oral administration of Boswellia and Scutellaria significantly improved the course and macroscopic findings of TNBS-induced chronic colitis assessed by disease activity index, colon weight, length, adhesions, strictures, dilatation, thickness, oedema, ulcerations and extension of damage. The histological severity of the colonic fibrosis was also notably improved by the treatment and associated with a significant reduction in the colonic expression of alpha-SMA, collagen I-III, CTGF, TGF-beta1, Smad3, and Smad7. CONCLUSIONS: These data demonstrate that the prophylactic administration of anti-inflammatory Boswellia and antifibrotic Scutellaria extracts is effective in preventing colonic fibrosis in TNBS-induced colitis. Their antifibrotic mechanism of action seems to be mediated by the inhibition of TGF-beta1/Smad3 pathway.

Effects of Smads and BMPs induced by Ga-Al-As laser irradiation on calcification ability of human dental pulp cells.

We investigated the effects of Ga-Al-As laser irradiation on the mineralization ability of human dental pulp (HDP) cells and on Smads and bone morphogenetic protein (BMP) production as one mechanism for the transmission of laser photochemical energy to cells. HDP cells in vitro were irradiated once with a Ga-Al-As laser at 1.0 W for 500 s, and calcified nodule formation was assessed by Alizarin red S staining. The laser irradiation was greater in the laser-irradiated group than in the non-irradiated group. Both calcium production and alkaline phosphatase (ALP) activity were higher after laser irradiation. Expression of mRNAs for Smad1, Smad7, BMPs, ALP, and osteocalcin was greater after laser irradiation, whereas expression of Smad6 mRNA was inhibited. Production of BMP-2 and BMP-4 in conditioned medium was also higher after laser irradiation. These results suggest that Smads and BMPs play important roles in ALP activity and calcification upon laser irradiation of HDP cells.

Reduced MMP-2 activity contributes to cardiac fibrosis in experimental diabetic cardiomyopathy.

OBJECTIVE: To evaluate the regulation of matrix metalloproteinase (MMP)-2 in diabetic cardiomyopathy. METHODS: Left ventricle (LV) function was determined by a micro-tip catheter in streptozotocin (STZ)-induced diabetic rats, 2 or 6 weeks (w) after STZ-application. LV total collagen, collagen type I and III content were immunohistologically analyzed and quantified by digital image analysis. LV collagen type I, III and MMP-2 mRNA expression was quantified by real-time RT-PCR. LV pro- and active MMP-2 levels were analyzed by zymography; Smad 7, membrane type (MT)1-MMP and tissue inhibitor metalloproteinase (TIMP)-2 protein levels by Western Blot. RESULTS: STZ-induced diabetes was associated with a time-dependent impairment of LV diastolic and systolic function. This was paralleled by a time-dependent increase in LV total collagen content, despite reduced LV collagen type I and III mRNA levels, indicating a role of post-transcriptional/post-translational changes of extracellular matrix regulation. Six weeks (w) after STZ-injection, MMP-2 mRNA expression and pro-MMP-2 levels were 2.7-fold (P < 0.005) and 1.3-fold (P < 0.05) reduced versus controls, respectively, whereas active MMP-2 was decreased to undetectable levels 6 w post-STZ. Concomitantly, Smad 7 and TIMP-2 protein levels were 1.3-fold (P < 0.05) and 10-fold (P < 0.005) increased in diabetics versus controls, respectively, whereas the 45 kDa form of MT1-MMP was undetectable in diabetics. CONCLUSION: Under STZ-diabetic conditions, cardiac fibrosis is associated with a dysregulation in extracellular matrix degradation. This condition is featured by reduced MMP-2 activity, concomitant with increased Smad 7 and TIMP-2 and decreased MT1-MMP protein expression, which differs from mechanisms involved in dilated and ischemic heart disease.

Transforming growth factor beta and wound healing in human cholesteatoma.

OBJECTIVE: Cholesteatoma is a nonmalignant, destructive lesion of the temporal bone that gradually expands and causes complications by the erosion of the adjacent bony structures. The consequences can be as severe as facial paralysis and intracranial complications. Until now, surgery has been the only treatment of choice. The pathogenesis of cholesteatoma remains controversial. Current concepts postulate that cholesteatoma may be a wound-healing process, although formal proof is lacking as of yet. Several reports provide evidence for the involvement of transforming growth factor (TGF)beta in both normal and abnormal wound healing. STUDY DESIGN: The expression of TGFbeta, the activated form of its intracellular effector, phosphorylated-Sma-Mad (pSmad)2, its natural inhibitor, Smad7, and target gene extra domain A-positive fibronectin (EDA-FN) were examined. METHODS: Quantitative immunohistochemical analysis was performed using an image analysis system. RESULTS: In 12 cholesteatoma and control samples, protein expressions showed consistent relationships among TGFbeta, nuclear pSmad2, and Smad7. We found concordant expressions of TGFbeta and nuclear pSmad2 in cholesteatoma epithelium and its control. Epithelial Smad7 expression was significantly reduced in cholesteatoma when compared with control epithelium (P = .04). In cholesteatoma extracellular matrix (ECM), a significantly increased TGFbeta, and nuclear pSmad2 was demonstrated (P < .01). Smad7 expression in the ECM was comparable in cholesteatoma and its control. EDA-FN deposition in cholesteatoma ECM was excessive, whereas EDA-FN expression was absent in controls. CONCLUSION: Our results confirm reports of in vitro experiments and support the concept that cholesteatoma behaves as a chronic wound healing process.

Levels of Smad7 regulate Smad and mitogen activated kinases (MAPKs) signaling and controls erythroid and megakaryocytic differentiation of erythroleukemia cells.

Smad and MAPK signaling cascades are involved in erythroid and megakaryocytic differentiation. The inhibitory Smad for TGF-beta/activin signaling, Smad7, may directly or indirectly affect these signaling pathways. By modulating Smad7 expression, we attempted to delineate the relevance of Smad7 during erythro-megakaryocytic (E/M) differentiation of human erythroleukemia cells. Smad7 transcripts were detected at low levels in different erythroleukemia cell lines (TF-1, HEL and K562). Reduction of expression of endogenous Smad7 by RNA interference enhanced erythroid differentiation of K562 cells in response to physiological doses of activin-A/TGF-beta1. Stable over-expression of Smad7 in K562 cells (K562/7) prevented activation of Smad2/3 and MAPK (ERK1/2, p38 and JNK1/2) proteins by activin-A/TGF-beta1 and subsequent induction of erythroid differentiation. High levels of Smad7 also interfered with hydroxyurea- and butyrate-, but not hemin-induced erythroid differentiation. Interestingly, K562/7 cells were found to harbor a significant proportion (about 35%) of large ploy nucleated cells compared to fewer than 12% in control cells. K562/7 cells treated with phorbol 12-myristate 13-acetate (PMA), showed a great shift in ploidy towards high ploidy classes (> or =8N) accompanied with an increase in the expression of the maturation marker CD42b. We showed here that: (a) low levels of endogenous Smad7 in erythroleukemia cells are physiologically relevant, and (b) high levels of Smad7 interferes with TGF-beta/activin-induced Smad/MAPK signaling and erythro-differentiation and promotes megakaryocytic differentiation, possibly by blocking autocrine TGF-beta.