Role of Transforming Growth Factor-β1 in the Process of Fibrosis of Denervated Skeletal Muscle

In order to investigate the biological function of transforming growth factor-β1（TGF-β1） during fibrosis in denervated skeletal muscle,we recruited sciatic nerve injury model of SD rats in which denervated gastrocnemius was isolated for analysis.At different time points after operation,denervated muscle was examined by several methods.Masson trichrome staining showed morphological changes of denervated skeletal muscle.Quantitative RT-PCR detected the rapid increase of TGF-β1 expression at mRNA level after nerve injury.It was found that a peak of TGF-β1 mRNA expression appeared one week post-operation.The expression of collagen Ⅰ（COL Ⅰ） mRNA was up-regulated in the nerve injury model as well,and reached highest level two weeks post-injury.Immunoblot revealed similar expression pattern of TGF-β1 and COL Ⅰ in denervated muscles at protein level.In addition,we found that the area of the gastrocnemius muscle fiber was decreased gradually along with increased interstitital fibrosis.Interestingly,this pathological change could be prevented,at least partly,by local injection of TGF-β1 antibodies,which could be contributed to the reduced production of COL Ⅰ by inhibiting function of TGF-β1.Taken together,in this study,we demonstrated that the expression of TGF-β1 was increased significantly in denervated skeletal muscle,which might play a crucial role during muscle fibrosis after nerve transection.

Fibrosis of the Quadriceps Muscles Secondary to Sickle Cell Disease: A Case Report

The musculo-skeletal system is commonly affected in sickle cell disease, manifesting itself as bone infarction, femoral head osteonecrosis, osteomyelitis, myonecrosis, myofibrosis and fascitis. Myositis and fasciitis are observed during a vaso-occlusive crisis in 4% of patients. Pain and swelling of bilateral proximal groups of muscles of upper and lower limbs are common presenting complaints due to prolonged sickling crises [1]. We report a case of 30-year old known HbSS patient with bilateral knee stiffness of two months duration, with associated swelling and warmth of both thighs. No preceding history of trauma. He was said to suffer at least two sickling crises in a month with the last one occurring one week prior to presentation. X-ray of the thigh showed no calcification in muscle groups. He was commenced on flexion-extension exercises.

Investigation of the Distribution and Changes of VLDLR Subtype in Fibrotic Cardiac Muscles

Very low-density lipoprotein receptor (VLDLR) is the major receptor with which cells can uptake the triacylglycerol from blood. It is divided into two subtypes according to presence of O- linked sugar domain located in the VLDLR receptor immediately outside of the membrane. Type Ⅰ VLDLR contains the O-link domain, while type Ⅱhas no such domain. The type ⅠVLDLR are mainly found on the surface of human myocardial cells. The result of our quantitative polymerase chain reaction on the normal and fibrotic cardiac muscles showed that both subtypes and expression level of VLDLR on the myocardial cell surface did not vary significantly between the normal and the fibrotic cardiac muscles despite the presence of malfunction due to fibrosis. This finding suggests that fibrosis doesn't exert significant influence on the subtype and the expression of VLDLR on the sur- face of myocardial cells. Such inconsistence with the changes found in other fibrotic tissues is awaiting further studies.

Antifibrotic effect of aloe vera in viral infection-induced hepatic periportal fibrosis

AIM:To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver fibrosis.METHODS:Aloe vera high molecular weight fractions(AHM) were processed by patented hyper-dry system in combination of freeze-dry technique with microwave and far infrared-ray radiation.Fifteen healthy volunteers as the control group and 40 patients were included.The patients were randomly subdivided into two equal groups:the conventional group was treated with placebo(starch),and AHM group was treated with 0.15 gm/d AHM,both for 12 consecutive weeks.The patients were investigated before and after treatment.Serum activity of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),hyaluronic acid(HA),transforming growth factor-β(TGF-β) and matrixmetalloproteinase-2(MMP-2) were determined.The reduced glutathione(GSH) and malondialdehyde(MDA) levels in liver were assayed and the expression of hepatic α-smooth muscle actin(α-SMA) was identified by immunohistochemistry.RESULTS:At the start of the study,the hematoxylin and eosin staining revealed fibro-proliferated bile ductules,thick fibrous septa and dense inflammatory cellular infiltration in the patients before treatment.The use of AHM for 12 wk significantly ameliorated the fibrosis,inhibited the inflammation,and resulted in minimal infiltration and minimal fibrosis compared to the conventional group.The enzyme activities of the liver(ALT,AST and ALP) were attenuated after treatment in both groups,and the decrease in the AHM group was more significant as compared with the conventional group.Similar to the AST,the MDA levels were significantly higher before treatment,and were attenuated after treatment in both groups.In contrast,the hepatic glutathione content in the patients were decreased significantly in the AHM group compared to the controls.The serum levels of the fibrosis markers(HA,TGF-β and MMP-2) were also reduced significantly after treatment.The expression of α-SMA was modified in patients before and after treatment as compared with the normal controls.In the conventional group,there was only thin and incomplete parenchymal α-SMA positive septum joining the thickened centrilobular veins,while in the AHM group,few α-SMA positive cells were present in sinusoid and lobule after treatment.CONCLUSION:Oral supplementation with AHM could be helpful in alleviating the fibrosis and inflammation of hepatic fibrosis patients.

Effects of Acupotomy on Immobilization-Induced Gastrocnemius Contracture and Fibrosis in Rats via Wnt/β-Catenin Signaling

Objective To determine whether acupotomy ameliorates immobilization-induced muscle contracture and fibrosis via Wnt/β-catenin signaling pathway.Methods Thirty Wistar rats were randomly divided into 5 groups(n=6)by a random number table,including control,immobilization,passive stretching,acupotomy,and acupotomy 3 weeks(3-w)groups.The rat model of gastrocnemius contracture was established by immobilizing the right hind limb in plantar flexion for 4 weeks.Rats in the passive stretching group received passive stretching at gastrocnemius,a daily series of 10 repetitions for 30 s each at 30-s intervals for 10 consecutive days.Rats in the acupotomy and acupotomy 3-w groups received acupotomy once and combined with passive stretching at gastrocnemius a daily series of 10 repetitions for 30 s each at 30-s intervals for 10 consecutive days.Additionally,rats in the acupotomy 3-w group were allowed to walk freely for 3 weeks after 10-day therapy.After treatment,range of motion(ROM),gait analysis[i.e.,paw area,stance/swing and maximum ratio of paw area to paw area duration(Max dA/dT)],gastrocnemius wet weight and the ratio of muscle wet weight to body weight(MWW/BW)were tested.Gastrocnemius morphometric and muscle fiber cross-sectional area(CSA)were assessed by hematoxylin-eosin staining.Fibrosis-related mRNA expressions(i.e.,Wnt 1,β-catenin,axin-2,α-smooth muscle actin,fibronectin,and types I and III collagen)were measured using real-time quantitative polymerase chain reactions.Wnt 1,β-catenin and fibronectin concentrations were measured by enzyme-linked immunosorbent assay.Types I and III collagen in the perimysium and endomysium were analyzed using immunofluorescence.Results Compared with the control group,ROM,gait function,muscle weight,MWW/BW and CSA were significantly decreased in the immobilization group(all P<0.01),while protein levels of types I and III collagen,Wnt 1,β-catenin,fibronectin and mRNA levels of fibrosis-related genes were obviously increased(all P<0.01).Treatment with passive stretching or acupotomy restored ROM and gait function and increased muscle wet weight,MWW/BW and CSA(all P<0.05),while protein expression levels of Wnt 1,β-catenin,fibronectin,types I and III collagen and mRNA levels of fibrosis-related genes were remarkably declined compared with the immobilization group(all P<0.05).Compared with passive stretching group,ROM,gait function,MWW was remarkably restored(all P<0.05),and mRNA levels of fibrosis-related genes as well as protein expression levels of Wnt 1,β-catenin,fibronectin,types I and III collagen in the acupotomy group were obviously decreased(all P<0.05).Compared with the acupotomy group,ROM,paw area,Max dA/dT,and MWW were restored(all P<0.05),and mRNA levels of fibrosis-related genes along with protein levels of Wnt 1,β-catenin,fibronectin,types I and III collagen in the acupotomy 3-w group were decreased(P<0.05).Conclusion Improvements in motor function,muscle contractures,and muscle fibrosis induced by acupotomy correlates with the inhibition of Wnt/β-catenin signaling pathway.

Smoothelin,a new marker to determine the origin of liver fibrogenic cells

AIM: To explore this hypothesis that smooth muscle cells may be capable of acquiring a myofibroblastic phenotype, we have studied the expression of smoothelin in fibrotic conditions.