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Lack of the matricellular protein SPARC (secreted protein, acidic and rich in cysteine) attenuates liver fibrogenesis in mice.

Atorrasagasti C, Peixoto E, Aquino JB, Kippes N, Malvicini M, Alaniz L, Garcia M, Piccioni F, Fiore EJ, Bayo J, Bataller R, Guruceaga E, Corrales F, Podhajcer O, Mazzolini G - PLoS ONE (2013)

Bottom Line: Consistently, collagen deposits and mRNA expression levels were decreased in SPARC(-/-) mice when compared to SPARC(+/+) mice; in addition, MMP-2 expression was increased in SPARC(-/-) mice.A reduction in the number of activated myofibroblasts was observed.Overall our data suggest that SPARC plays a significant role in liver fibrogenesis.

View Article: PubMed Central - PubMed

Affiliation: Gene Therapy Laboratory, School of Medicine, Austral University, Derqui-Pilar, Buenos Aires, Argentina.

ABSTRACT

Introduction: Secreted Protein, Acidic and Rich in Cysteine (SPARC) is a matricellular protein involved in many biological processes and found over-expressed in cirrhotic livers. By mean of a genetic approach we herein provide evidence from different in vivo liver disease models suggesting a profibrogenic role for SPARC.

Methods: Two in vivo models of liver fibrosis, based on TAA administration and bile duct ligation, were developed on SPARC wild-type (SPARC(+/+)) and knock-out (SPARC(-/-)) mice. Hepatic SPARC expression was analyzed by qPCR. Fibrosis was assessed by Sirius Red staining, and the maturation state of collagen fibers was analyzed using polarized light. Necroinflammatory activity was evaluated by applying the Knodell score and liver inflammatory infiltration was characterized by immunohistochemistry. Hepatic stellate cell activation was assessed by α-SMA immunohistochemistry. In addition, pro-fibrogenic genes and inflammatory cytokines were measured by qPCR and/or ELISA. Liver gene expression profile was analyzed in SPARC(-/-) and SPARC(+/+) mice using Affymetrix Mouse Gene ST 1.0 array.

Results: SPARC expression was found induced in fibrotic livers of mouse and human. SPARC(-/-) mice showed a reduction in the degree of inflammation, mainly CD4+ cells, and fibrosis. Consistently, collagen deposits and mRNA expression levels were decreased in SPARC(-/-) mice when compared to SPARC(+/+) mice; in addition, MMP-2 expression was increased in SPARC(-/-) mice. A reduction in the number of activated myofibroblasts was observed. Moreover, TGF-β1 expression levels were down-regulated in the liver as well as in the serum of TAA-treated knock-out animals. Ingenuity Pathway Analysis (IPA) analysis suggested several gene networks which might involve protective mechanisms of SPARC deficiency against liver fibrogenesis and a better established machinery to repair DNA and detoxify from external chemical stimuli.

Conclusions: Overall our data suggest that SPARC plays a significant role in liver fibrogenesis. Interventions to inhibit SPARC expression are suggested as promising approaches for liver fibrosis treatment.

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Induction of SPARC mRNA expression during liver fibrogenesis.(A) Quantitative data showing differences in SPARC mRNA expression levels in human cirrhotic (Pt#1 to Pt#5) with fibrosis degree F4 and non-cirrhotic liver samples as measured by qPCR. *p<0.05, **p<0.01 compared with healthy liver samples. Mann-Whitney test. (B) qPCR analyses of liver samples from TAA and BDL mice. Complementary DNA was synthesized and was subjected to qPCR for the expression of SPARC transcripts. The relative amount of the PCR product (AU, arbitrary units) amplified from control liver samples was set at 1. *p<0.05 versus control (−TAA), **p<0.01 versus control (−BDL), Mann-Whitney test.
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pone-0054962-g001: Induction of SPARC mRNA expression during liver fibrogenesis.(A) Quantitative data showing differences in SPARC mRNA expression levels in human cirrhotic (Pt#1 to Pt#5) with fibrosis degree F4 and non-cirrhotic liver samples as measured by qPCR. *p<0.05, **p<0.01 compared with healthy liver samples. Mann-Whitney test. (B) qPCR analyses of liver samples from TAA and BDL mice. Complementary DNA was synthesized and was subjected to qPCR for the expression of SPARC transcripts. The relative amount of the PCR product (AU, arbitrary units) amplified from control liver samples was set at 1. *p<0.05 versus control (−TAA), **p<0.01 versus control (−BDL), Mann-Whitney test.

Mentions: We first investigated whether SPARC expression levels may be upregulated in the liver of cirrhotic patients. To address this issue, liver biopsies taken from cirrhotic and non-cirrhotic patients were processed for qPCR studies. A significant upregulation in SPARC expression levels was observed in cirrhotic samples when compared to non-fibrotic ones (Figure 1A). These data suggest a possible role for SPARC in liver fibrogenesis.


Lack of the matricellular protein SPARC (secreted protein, acidic and rich in cysteine) attenuates liver fibrogenesis in mice.

Atorrasagasti C, Peixoto E, Aquino JB, Kippes N, Malvicini M, Alaniz L, Garcia M, Piccioni F, Fiore EJ, Bayo J, Bataller R, Guruceaga E, Corrales F, Podhajcer O, Mazzolini G - PLoS ONE (2013)

Induction of SPARC mRNA expression during liver fibrogenesis.(A) Quantitative data showing differences in SPARC mRNA expression levels in human cirrhotic (Pt#1 to Pt#5) with fibrosis degree F4 and non-cirrhotic liver samples as measured by qPCR. *p<0.05, **p<0.01 compared with healthy liver samples. Mann-Whitney test. (B) qPCR analyses of liver samples from TAA and BDL mice. Complementary DNA was synthesized and was subjected to qPCR for the expression of SPARC transcripts. The relative amount of the PCR product (AU, arbitrary units) amplified from control liver samples was set at 1. *p<0.05 versus control (−TAA), **p<0.01 versus control (−BDL), Mann-Whitney test.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3569438&req=5

pone-0054962-g001: Induction of SPARC mRNA expression during liver fibrogenesis.(A) Quantitative data showing differences in SPARC mRNA expression levels in human cirrhotic (Pt#1 to Pt#5) with fibrosis degree F4 and non-cirrhotic liver samples as measured by qPCR. *p<0.05, **p<0.01 compared with healthy liver samples. Mann-Whitney test. (B) qPCR analyses of liver samples from TAA and BDL mice. Complementary DNA was synthesized and was subjected to qPCR for the expression of SPARC transcripts. The relative amount of the PCR product (AU, arbitrary units) amplified from control liver samples was set at 1. *p<0.05 versus control (−TAA), **p<0.01 versus control (−BDL), Mann-Whitney test.
Mentions: We first investigated whether SPARC expression levels may be upregulated in the liver of cirrhotic patients. To address this issue, liver biopsies taken from cirrhotic and non-cirrhotic patients were processed for qPCR studies. A significant upregulation in SPARC expression levels was observed in cirrhotic samples when compared to non-fibrotic ones (Figure 1A). These data suggest a possible role for SPARC in liver fibrogenesis.

Bottom Line: Consistently, collagen deposits and mRNA expression levels were decreased in SPARC(-/-) mice when compared to SPARC(+/+) mice; in addition, MMP-2 expression was increased in SPARC(-/-) mice.A reduction in the number of activated myofibroblasts was observed.Overall our data suggest that SPARC plays a significant role in liver fibrogenesis.

View Article: PubMed Central - PubMed

Affiliation: Gene Therapy Laboratory, School of Medicine, Austral University, Derqui-Pilar, Buenos Aires, Argentina.

ABSTRACT

Introduction: Secreted Protein, Acidic and Rich in Cysteine (SPARC) is a matricellular protein involved in many biological processes and found over-expressed in cirrhotic livers. By mean of a genetic approach we herein provide evidence from different in vivo liver disease models suggesting a profibrogenic role for SPARC.

Methods: Two in vivo models of liver fibrosis, based on TAA administration and bile duct ligation, were developed on SPARC wild-type (SPARC(+/+)) and knock-out (SPARC(-/-)) mice. Hepatic SPARC expression was analyzed by qPCR. Fibrosis was assessed by Sirius Red staining, and the maturation state of collagen fibers was analyzed using polarized light. Necroinflammatory activity was evaluated by applying the Knodell score and liver inflammatory infiltration was characterized by immunohistochemistry. Hepatic stellate cell activation was assessed by α-SMA immunohistochemistry. In addition, pro-fibrogenic genes and inflammatory cytokines were measured by qPCR and/or ELISA. Liver gene expression profile was analyzed in SPARC(-/-) and SPARC(+/+) mice using Affymetrix Mouse Gene ST 1.0 array.

Results: SPARC expression was found induced in fibrotic livers of mouse and human. SPARC(-/-) mice showed a reduction in the degree of inflammation, mainly CD4+ cells, and fibrosis. Consistently, collagen deposits and mRNA expression levels were decreased in SPARC(-/-) mice when compared to SPARC(+/+) mice; in addition, MMP-2 expression was increased in SPARC(-/-) mice. A reduction in the number of activated myofibroblasts was observed. Moreover, TGF-β1 expression levels were down-regulated in the liver as well as in the serum of TAA-treated knock-out animals. Ingenuity Pathway Analysis (IPA) analysis suggested several gene networks which might involve protective mechanisms of SPARC deficiency against liver fibrogenesis and a better established machinery to repair DNA and detoxify from external chemical stimuli.

Conclusions: Overall our data suggest that SPARC plays a significant role in liver fibrogenesis. Interventions to inhibit SPARC expression are suggested as promising approaches for liver fibrosis treatment.

Show MeSH
Related in: MedlinePlus