ABSTRACT
BACKGROUND@#This study investigated whether xenotransplantation of human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) reduces thioacetamide (TAA)-induced mouse liver fibrosis and the underlying molecular mechanism. @*METHODS@#Recipient NOD/SCID mice were injected intraperitoneally with TAA twice weekly for 6 weeks before initial administration of WJ-MSCs. Expression of regenerative and pro-fibrogenic markers in mouse fibrotic livers were monitored post cytotherapy. A hepatic stallate cell line HSC-T6 and isolated WJ-MSCs were used for in vitro adhesion, migration and mechanistic studies. @*RESULTS@#WJ-MSCs were isolated from human umbilical cords by an explant method and characterized by flow cytometry. A single infusion of WJ-MSCs to TAA-treated mice significantly reduced collagen deposition and ameliorated liver fibrosis after 2-week therapy. In addition to enhanced expression of hepatic regenerative factor, hepatocyte growth factor, and PCNA proliferative marker, WJ-MSC therapy significantly blunted pro-fibrogenic signals, including Smad2, RhoA, ERK. Intriguingly, reduction of plasma fibronectin (pFN) in fibrotic livers was noted in MSC-treated mice. In vitro studies further demonstrated that suspending MSCs triggered pFN degradation, soluble pFN conversely retarded adhesion of suspending MSCs onto type I collagen-coated surface, whereas pFN coating enhanced WJ-MSC migration across mimicked wound bed. Moreover, pretreatment with soluble pFN and conditioned medium from MSCs with pFN strikingly attenuated the response of HSC-T6 cells to TGF-b1-stimulation in Smad2 phosphorylation and RhoA upregulation. @*CONCLUSION@#These findings suggest that cytotherapy using WJ-MSCs may modulate hepatic pFN deposition for a better regenerative niche in the fibrotic livers and may constitute a useful anti-fibrogenic intervention in chronic liver diseases.
ABSTRACT
BACKGROUND@#This study investigated whether xenotransplantation of human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) reduces thioacetamide (TAA)-induced mouse liver fibrosis and the underlying molecular mechanism. @*METHODS@#Recipient NOD/SCID mice were injected intraperitoneally with TAA twice weekly for 6 weeks before initial administration of WJ-MSCs. Expression of regenerative and pro-fibrogenic markers in mouse fibrotic livers were monitored post cytotherapy. A hepatic stallate cell line HSC-T6 and isolated WJ-MSCs were used for in vitro adhesion, migration and mechanistic studies. @*RESULTS@#WJ-MSCs were isolated from human umbilical cords by an explant method and characterized by flow cytometry. A single infusion of WJ-MSCs to TAA-treated mice significantly reduced collagen deposition and ameliorated liver fibrosis after 2-week therapy. In addition to enhanced expression of hepatic regenerative factor, hepatocyte growth factor, and PCNA proliferative marker, WJ-MSC therapy significantly blunted pro-fibrogenic signals, including Smad2, RhoA, ERK. Intriguingly, reduction of plasma fibronectin (pFN) in fibrotic livers was noted in MSC-treated mice. In vitro studies further demonstrated that suspending MSCs triggered pFN degradation, soluble pFN conversely retarded adhesion of suspending MSCs onto type I collagen-coated surface, whereas pFN coating enhanced WJ-MSC migration across mimicked wound bed. Moreover, pretreatment with soluble pFN and conditioned medium from MSCs with pFN strikingly attenuated the response of HSC-T6 cells to TGF-b1-stimulation in Smad2 phosphorylation and RhoA upregulation. @*CONCLUSION@#These findings suggest that cytotherapy using WJ-MSCs may modulate hepatic pFN deposition for a better regenerative niche in the fibrotic livers and may constitute a useful anti-fibrogenic intervention in chronic liver diseases.
ABSTRACT
This study investigated the regulatory role of nerve growth factor (NGF) in sirtuin 1 (SIRT1) expression in cholestatic livers. We evaluated the expression of NGF and its cognate receptors in human livers with hepatolithiasis and the effects of NGF therapy on liver injury and hepatic SIRT1 expression in a bile duct ligation (BDL) mouse model. Histopathological and molecular analyses showed that the hepatocytes of human diseased livers expressed NGF, proNGF (a precursor of NGF), TrkA and p75NTR, whereas only p75NTR was upregulated in hepatolithiasis, compared with non-hepatolithiasis livers. In the BDL model without NGF therapy, p75NTR, but not TrkA antagonism, significantly deteriorated BDL-induced liver injury. By contrast, the hepatoprotective effect of NGF was abrogated only by TrkA and not by p75NTR antagonism in animals receiving NGF therapy. Intriguingly, a positive correlation between hepatic SIRT1 and NGF expression was found in human livers. In vitro studies demonstrated that NGF upregulated SIRT1 expression in mouse livers and human Huh-7 and rodent hepatocytes. Both NGF and proNGF induced protective effects against hydrogen peroxide-induced cytotoxicity in Huh-7 cells, whereas inhibition of TrkA and p75NTR activity prevented oxidative cell death. Mechanistically, NGF, but not proNGF, upregulated SIRT1 expression in human Huh-7 and rodent hepatocytes via nuclear factor (NF)-κB activity, whereas NGF-induced phosphoinositide-3 kinase/Akt, extracellular signal–regulated kinase and NF-κB signaling and SIRT1 activity were involved in its hepatoprotective effects against oxidative injury. These findings suggest that pharmacological manipulation of the NGF/SIRT1 axis might serve as a novel approach for the treatment of cholestatic disease.
Subject(s)
Animals , Humans , Mice , Bile Ducts , Cell Death , Cholestasis , Hepatocytes , Hydrogen , In Vitro Techniques , Ligation , Liver , Nerve Growth Factor , Phosphotransferases , Rodentia , Sirtuin 1ABSTRACT
Primary intraosseous arteriovenous malformations (AVMs) are rare and have only been occasionally reported. We herein report a histologically proven case of primary intraosseous AVM in the tibia, which mimicked a fibrous tumour on radiography. This presentation carries a risk of triggering acute large haemorrhage through unnecessary biopsy. In intraosseous AVM, the magnetic resonance (MR) imaging features typical of a soft tissue AVM are absent, making diagnosis difficult. In this report, peculiar MR features in the presence of a connecting vessel between the normal deep venous system of the lower extremity and the tumour provide a clue for the early diagnosis of primary intraosseous AVM.
Subject(s)
Female , Humans , Young Adult , Arteriovenous Malformations , Diagnostic Imaging , Biopsy , Contrast Media , Chemistry , Hemorrhage , Magnetic Resonance Imaging , Pain , Radiography , Technetium , Chemistry , Tibia , Whole Body ImagingABSTRACT
<p><b>OBJECTIVE</b>To establish human bronchial epithelial cell lines over expressing oncogene and to investigate its application in detection of carcinogen-induced cell transformation.</p><p><b>METHODS</b>Mediated by retrovirus infection, human telomerase catalytic subunit, hTERT was introduced into immortal human bronchial epithelial cells (16HBE) and followed by introduction of the oncogenic allele H-Ras(V12), or c-Myc or empty vector, creating cell lines 16HBETR, 16HBETM and 16HBETV, respectively. Biological characteristics of these cell lines including morphology, proliferation, and chromosomal aberration were examined to access whether they were transformed. Soft agar experiment and nude mice subcutaneous injection were performed using pre-transformed 16HBE cells induced by known carcinogens, nickel sulfate (NiSO4) and 7, 8, -dihydrodiol-9, 10-epoxide benzo[a] pyrene (BPDE).</p><p><b>RESULTS</b>With detection of telomerase activity and Western blotting, the expression of target proteins was verified. Thus, the transgenic 16HBE cell lines were successfully established. Cells expressing oncogene H-Ras or c-Myc grew 30.3% or 10.4% faster than control cells. However, these cells failed to form colonies in soft agar or form tumor in nude mice. 16HBETR, 16HBETM cells obtained transformed phenotype at 5 wks, 11 wks, respectively after treatment with BPDE, which are 15 wks and 9 wks earlier than control cells 16HBETV (20 wks). Meanwhile, 16HBETR, 16HBETM cells obtained transformed phenotype at 11 wks, 14 wks, respectively after treatment with nickel sulfate, which are 21 wks and 18 wks earlier than control cells (32 wks).</p><p><b>CONCLUSION</b>With the advantage of shorter latency, transgenic human cell transformation models could be used in potent carcinogen screening and applied to chemical-carcinogenesis mechanism study.</p>