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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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Patterns of SPARC expression during liver fibrogenesis.(A–F) Representative images taken from SPARC+/+ mice liver sections stained for SPARC (B, E; red) and SMA (A; green) or vWF (D; green) and merge of both images (C, F). (G–L). Representative images taken from 10 weeks TAA-treated SPARC+/+ mice liver sections (n  = 4–6) stained for SPARC (H, K; red) and SMA (G; green) or vWF (J; green). Co-localization of SPARC and SMA (I) or SPARC and vWF (L). (M–R) Representative images taken from 7 days BDL SPARC+/+ mice liver stained for SPARC (N, Q; red) and SMA (M; green) or vWF (P; green). Arrows: co-expression of the two markers; dotted arrows: autofluorescence due to hepatic ceroid-laden macrophages. Original magnification 400X (A–F) or 1000X (G–R).
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pone-0054962-g002: Patterns of SPARC expression during liver fibrogenesis.(A–F) Representative images taken from SPARC+/+ mice liver sections stained for SPARC (B, E; red) and SMA (A; green) or vWF (D; green) and merge of both images (C, F). (G–L). Representative images taken from 10 weeks TAA-treated SPARC+/+ mice liver sections (n  = 4–6) stained for SPARC (H, K; red) and SMA (G; green) or vWF (J; green). Co-localization of SPARC and SMA (I) or SPARC and vWF (L). (M–R) Representative images taken from 7 days BDL SPARC+/+ mice liver stained for SPARC (N, Q; red) and SMA (M; green) or vWF (P; green). Arrows: co-expression of the two markers; dotted arrows: autofluorescence due to hepatic ceroid-laden macrophages. Original magnification 400X (A–F) or 1000X (G–R).

Mentions: We next asked whether or not SPARC expression could be similarly induced in different in vivo models developed in SPARC+/+ mice. To address whether SPARC expression levels may change during liver fibrogenesis, samples were processed for qPCR studies. SPARC was found to be induced after 2 weeks of TAA treatment and its expression levels remained similar after 10 weeks of treatment, as well as in mice subjected to BDL (Figure 1B). While in non-treated animals SPARC expression was undetectable (Figure 2 B and E), after 10 weeks of TAA treatment, SPARC was additionally expressed in fibrous septae as well as in parenchymal areas, surrounding sinusoids (Figure 2H and K). SPARC was found to be expressed by α-SMA+ myofibroblast cells, mainly within fibrous septae (Figure 2G–I). In addition, SPARC was also found to be expressed by vWF+ endothelial cells (Figure 2J–and L). A similar expression pattern was observed in the liver of mice subjected to BDL. SPARC was expressed by α-SMA+ myofibroblast cells mainly in the portal areas, but most of the expression was observed in endothelial cells (Figure 2M–R). From these results we can conclude that SPARC is overexpressed in the liver of cirrhotic patients and of mice exposed to different stimuli inducing 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)

Patterns of SPARC expression during liver fibrogenesis.(A–F) Representative images taken from SPARC+/+ mice liver sections stained for SPARC (B, E; red) and SMA (A; green) or vWF (D; green) and merge of both images (C, F). (G–L). Representative images taken from 10 weeks TAA-treated SPARC+/+ mice liver sections (n  = 4–6) stained for SPARC (H, K; red) and SMA (G; green) or vWF (J; green). Co-localization of SPARC and SMA (I) or SPARC and vWF (L). (M–R) Representative images taken from 7 days BDL SPARC+/+ mice liver stained for SPARC (N, Q; red) and SMA (M; green) or vWF (P; green). Arrows: co-expression of the two markers; dotted arrows: autofluorescence due to hepatic ceroid-laden macrophages. Original magnification 400X (A–F) or 1000X (G–R).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3569438&req=5

pone-0054962-g002: Patterns of SPARC expression during liver fibrogenesis.(A–F) Representative images taken from SPARC+/+ mice liver sections stained for SPARC (B, E; red) and SMA (A; green) or vWF (D; green) and merge of both images (C, F). (G–L). Representative images taken from 10 weeks TAA-treated SPARC+/+ mice liver sections (n  = 4–6) stained for SPARC (H, K; red) and SMA (G; green) or vWF (J; green). Co-localization of SPARC and SMA (I) or SPARC and vWF (L). (M–R) Representative images taken from 7 days BDL SPARC+/+ mice liver stained for SPARC (N, Q; red) and SMA (M; green) or vWF (P; green). Arrows: co-expression of the two markers; dotted arrows: autofluorescence due to hepatic ceroid-laden macrophages. Original magnification 400X (A–F) or 1000X (G–R).
Mentions: We next asked whether or not SPARC expression could be similarly induced in different in vivo models developed in SPARC+/+ mice. To address whether SPARC expression levels may change during liver fibrogenesis, samples were processed for qPCR studies. SPARC was found to be induced after 2 weeks of TAA treatment and its expression levels remained similar after 10 weeks of treatment, as well as in mice subjected to BDL (Figure 1B). While in non-treated animals SPARC expression was undetectable (Figure 2 B and E), after 10 weeks of TAA treatment, SPARC was additionally expressed in fibrous septae as well as in parenchymal areas, surrounding sinusoids (Figure 2H and K). SPARC was found to be expressed by α-SMA+ myofibroblast cells, mainly within fibrous septae (Figure 2G–I). In addition, SPARC was also found to be expressed by vWF+ endothelial cells (Figure 2J–and L). A similar expression pattern was observed in the liver of mice subjected to BDL. SPARC was expressed by α-SMA+ myofibroblast cells mainly in the portal areas, but most of the expression was observed in endothelial cells (Figure 2M–R). From these results we can conclude that SPARC is overexpressed in the liver of cirrhotic patients and of mice exposed to different stimuli inducing 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