Post-transcriptional inactivation of matrix metalloproteinase-12 after focal cerebral ischemia attenuates brain damage

Bharath Chelluboina, Aditi Warhekar, Matt Dillard, Jeffrey D Klopfenstein, David M Pinson, David Z Wang, Krishna Kumar Veeravalli, Bharath Chelluboina, Aditi Warhekar, Matt Dillard, Jeffrey D Klopfenstein, David M Pinson, David Z Wang, Krishna Kumar Veeravalli

Abstract

This study highlights the possible pathological role of MMP-12 in the context of ischemic stroke. Male rats were subjected to a two-hour middle cerebral artery occlusion (MCAO) procedure. MMP-12 shRNA expressing plasmid formulation was administered to these rats twenty-four hours after reperfusion. The results showed a predominant upregulation of MMP-12 (approximately 47, 58, 143, and 265 folds on days 1, 3, 5, 7 post-ischemia, respectively) in MCAO subjected rats. MMP-12 expression was localized to neurons, oligodendrocytes and microglia, but not astrocytes. Transcriptional inactivation of MMP-12 significantly reduced the infarct size. The percent infarct size was reduced from 62.87±4.13 to 34.67±5.39 after MMP-12 knockdown compared to untreated MCAO subjected rats. Expression of myelin basic protein was increased, and activity of MMP-9 was reduced in ischemic rat brains after MMP-12 knockdown. Furthermore, a significant reduction in the extent of apoptosis was noticed after MMP-12 knockdown. TNFα expression in the ipsilateral regions of MCAO-subjected rats was reduced after MMP-12 knockdown in addition to the reduced protein expression of apoptotic molecules that are downstream to TNFα signaling. Specific knockdown of MMP-12 after focal cerebral ischemia offers neuroprotection that could be mediated via reduced MMP-9 activation and myelin degradation as well as inhibition of apoptosis.

Conflict of interest statement

The authors declare no competing financial interests.

Figures

Figure 1. Regulation of MMPs in rats…
Figure 1. Regulation of MMPs in rats after focal cerebral ischemia.
Quantitative real-time PCR data of MMPs in the ischemic brains of rats subjected to a two-hour MCAO procedure followed by various reperfusion times. Error bars indicate SD. n = 6. Values on y-axis represent fold change compared to sham controls.
Figure 2. MMP-12 protein expression in rats…
Figure 2. MMP-12 protein expression in rats subjected to focal cerebral ischemia and reperfusion.
(A) Immunoblot analysis depicting the protein expression of MMP-12 in the ipsilateral brain regions of rats subjected to ischemia and reperfusion. GAPDH was used as a loading control. Bar graph represents the quantification of MMP-12 protein expression. n = 6. R = reperfusion. *p

Figure 3. Cellular localization of MMP-12 in…

Figure 3. Cellular localization of MMP-12 in neuronal cells of rats, which were subjected to…

Figure 3. Cellular localization of MMP-12 in neuronal cells of rats, which were subjected to focal cerebral ischemia and reperfusion.
Immunofluorescence analysis showing the protein expressions of MMP-12 (green fluorescence) and NeuN/GFAP/MOG/Iba1 (red fluorescence) in the ipsilateral brain regions of rats subjected a two-hour MCAO procedure followed by seven days reperfusion. Yellow fluorescence in the merged images indicates the cellular localization of MMP-12. Nuclei were stained with DAPI. Insets in the merged images show DAPI staining. n = 6.

Figure 4. In vitro and in vivo…

Figure 4. In vitro and in vivo efficiency of plasmids expressing MMP-12 shRNA.

(A) RT-PCR…

Figure 4. In vitro and in vivo efficiency of plasmids expressing MMP-12 shRNA.
(A) RT-PCR and immunoblot analysis depicting the mRNA and protein expression, respectively, of MMP-12 after transfection of C6 rat glioma cell lines with plasmids containing an empty vector, a vector ligated with a scrambled sequence (SV-sh) and a vector ligated with MMP-12 shRNA (M-12-sh). βActin and GAPDH were used as loading controls. n = 3. Expression of MMP-12 in the ischemic brain regions of rats subjected a two-hour MCAO followed by seven days reperfusion and/or treated with SV-sh or M-12-sh. Bar graph represents the quantification of MMP-12 protein expression. n = 6. *p #p < 0.05 vs. untreated. (B) Immunofluorescence analysis depicting the protein expressions of MMP-12 (green fluorescence) in untreated and M-12-sh treated rats subjected to a two-hour MCAO procedure followed by seven days reperfusion. Nuclei were stained with DAPI. n = 6.

Figure 5. In vivo efficacy of plasmids…

Figure 5. In vivo efficacy of plasmids expressing MMP-12 shRNA.

(A) Representative TTC staining images…

Figure 5. In vivo efficacy of plasmids expressing MMP-12 shRNA.
(A) Representative TTC staining images of the rat coronal brain sections of sham-operated, untreated MCAO-subjected and MMP-12 shRNA (M-12sh) treated MCAO-subjected rats sacrificed seven days after reperfusion. n = 6. The white-colored areas represent the infarct regions in these sections, and the red-colored areas represent normal areas. (B) Quantification of infarct volume from TTC stained sections using image analysis software. The possible influence of edema on infarct volume was corrected by standard methods (volume of contralateral hemisphere − volume of non-ischemic ipsilateral hemisphere), with infarcted volume expressed as a percentage of the contralateral hemisphere. n = 6. Values are expressed as mean ± SEM; *p #p < 0.05 vs. untreated MCAO-subjected animals.

Figure 6. Effect of MMP-12 knockdown on…

Figure 6. Effect of MMP-12 knockdown on other possible MMP-12 substrates.

(A) Gelatin zymogram showing…

Figure 6. Effect of MMP-12 knockdown on other possible MMP-12 substrates.
(A) Gelatin zymogram showing MMP levels in sham control and ischemic brains of rats subjected to a two-hour MCAO followed by seven days reperfusion without treatment and treatment with plasmids containing a vector ligated with a scrambled sequence (SV-sh) and a vector ligated with MMP-12 shRNA (M-12-sh). Quantification of MMP-9 gelatinolytic activity. n = 6. *p #p < 0.05 vs. untreated. R = reperfusion (B) Immunoblot showing the protein expression of MBP in the ischemic brains of rats subjected to a two-hour MCAO followed by seven days reperfusion with and without treatments. GAPDH was used as a loading control. Quantification of MBP protein expression. n = 6. *p < 0.05 vs. sham; #p < 0.05 vs. untreated. (C) DAB immuno-staining depicting the protein expression of MBP in the contralateral and ipsilateral rat coronal brain sections obtained from various groups of rats. Arrows demonstrate the marked loss of MBP-immunostained axonal processes with clear structural abnormalities of rarefaction and fragmentation. Brain sections are counterstained with hematoxylin for nuclear localization. n = 6. Scale bar = 200 μm.

Figure 7. Effect of MMP-12 knockdown after…

Figure 7. Effect of MMP-12 knockdown after focal cerebral ischemia on TNFα-mediated apoptosis.

(A) Immunofluorescence…

Figure 7. Effect of MMP-12 knockdown after focal cerebral ischemia on TNFα-mediated apoptosis.
(A) Immunofluorescence analysis showing the protein expressions of MMP-12 (green fluorescence) and TNFα (red fluorescence) in the ischemic core and the penumbra of rats subjected a two-hour MCAO procedure followed by seven days reperfusion with and without treatments. Nuclei were stained with DAPI (blue fluorescence). Yellow fluorescence in the merged images indicates the colocalization of MMP-12 and TNFα. n = 6. Scale bar = 100 μm. (B) TUNEL assay on the paraffin-embedded coronal brain sections of rats subjected to a two-hour MCAO procedure followed by seven days reperfusion with and without treatments. TUNEL-positive cells were quantified in the ipsilateral regions of rat brain that consisted of the ischemic core and the penumbra. n = 6. Values are expressed as mean ± SEM. *p #p < 0.05 vs. untreated.
All figures (7)
Figure 3. Cellular localization of MMP-12 in…
Figure 3. Cellular localization of MMP-12 in neuronal cells of rats, which were subjected to focal cerebral ischemia and reperfusion.
Immunofluorescence analysis showing the protein expressions of MMP-12 (green fluorescence) and NeuN/GFAP/MOG/Iba1 (red fluorescence) in the ipsilateral brain regions of rats subjected a two-hour MCAO procedure followed by seven days reperfusion. Yellow fluorescence in the merged images indicates the cellular localization of MMP-12. Nuclei were stained with DAPI. Insets in the merged images show DAPI staining. n = 6.
Figure 4. In vitro and in vivo…
Figure 4. In vitro and in vivo efficiency of plasmids expressing MMP-12 shRNA.
(A) RT-PCR and immunoblot analysis depicting the mRNA and protein expression, respectively, of MMP-12 after transfection of C6 rat glioma cell lines with plasmids containing an empty vector, a vector ligated with a scrambled sequence (SV-sh) and a vector ligated with MMP-12 shRNA (M-12-sh). βActin and GAPDH were used as loading controls. n = 3. Expression of MMP-12 in the ischemic brain regions of rats subjected a two-hour MCAO followed by seven days reperfusion and/or treated with SV-sh or M-12-sh. Bar graph represents the quantification of MMP-12 protein expression. n = 6. *p #p < 0.05 vs. untreated. (B) Immunofluorescence analysis depicting the protein expressions of MMP-12 (green fluorescence) in untreated and M-12-sh treated rats subjected to a two-hour MCAO procedure followed by seven days reperfusion. Nuclei were stained with DAPI. n = 6.
Figure 5. In vivo efficacy of plasmids…
Figure 5. In vivo efficacy of plasmids expressing MMP-12 shRNA.
(A) Representative TTC staining images of the rat coronal brain sections of sham-operated, untreated MCAO-subjected and MMP-12 shRNA (M-12sh) treated MCAO-subjected rats sacrificed seven days after reperfusion. n = 6. The white-colored areas represent the infarct regions in these sections, and the red-colored areas represent normal areas. (B) Quantification of infarct volume from TTC stained sections using image analysis software. The possible influence of edema on infarct volume was corrected by standard methods (volume of contralateral hemisphere − volume of non-ischemic ipsilateral hemisphere), with infarcted volume expressed as a percentage of the contralateral hemisphere. n = 6. Values are expressed as mean ± SEM; *p #p < 0.05 vs. untreated MCAO-subjected animals.
Figure 6. Effect of MMP-12 knockdown on…
Figure 6. Effect of MMP-12 knockdown on other possible MMP-12 substrates.
(A) Gelatin zymogram showing MMP levels in sham control and ischemic brains of rats subjected to a two-hour MCAO followed by seven days reperfusion without treatment and treatment with plasmids containing a vector ligated with a scrambled sequence (SV-sh) and a vector ligated with MMP-12 shRNA (M-12-sh). Quantification of MMP-9 gelatinolytic activity. n = 6. *p #p < 0.05 vs. untreated. R = reperfusion (B) Immunoblot showing the protein expression of MBP in the ischemic brains of rats subjected to a two-hour MCAO followed by seven days reperfusion with and without treatments. GAPDH was used as a loading control. Quantification of MBP protein expression. n = 6. *p < 0.05 vs. sham; #p < 0.05 vs. untreated. (C) DAB immuno-staining depicting the protein expression of MBP in the contralateral and ipsilateral rat coronal brain sections obtained from various groups of rats. Arrows demonstrate the marked loss of MBP-immunostained axonal processes with clear structural abnormalities of rarefaction and fragmentation. Brain sections are counterstained with hematoxylin for nuclear localization. n = 6. Scale bar = 200 μm.
Figure 7. Effect of MMP-12 knockdown after…
Figure 7. Effect of MMP-12 knockdown after focal cerebral ischemia on TNFα-mediated apoptosis.
(A) Immunofluorescence analysis showing the protein expressions of MMP-12 (green fluorescence) and TNFα (red fluorescence) in the ischemic core and the penumbra of rats subjected a two-hour MCAO procedure followed by seven days reperfusion with and without treatments. Nuclei were stained with DAPI (blue fluorescence). Yellow fluorescence in the merged images indicates the colocalization of MMP-12 and TNFα. n = 6. Scale bar = 100 μm. (B) TUNEL assay on the paraffin-embedded coronal brain sections of rats subjected to a two-hour MCAO procedure followed by seven days reperfusion with and without treatments. TUNEL-positive cells were quantified in the ipsilateral regions of rat brain that consisted of the ischemic core and the penumbra. n = 6. Values are expressed as mean ± SEM. *p #p < 0.05 vs. untreated.

References

    1. Banerjee S., Williamson D., Habib N., Gordon M. & Chataway J. Human stem cell therapy in ischaemic stroke: a review. Age Ageing 40, 7–13 (2011).
    1. del Zoppo G. J. tPA: a neuron buster, too? Nat. Med. 4, 148–150 (1998).
    1. Hacke W. et al. Thrombolysis in acute ischemic stroke: controlled trials and clinical experience. Neurology 53, S3–14 (1999).
    1. Wang X. et al. Lipoprotein receptor-mediated induction of matrix metalloproteinase by tissue plasminogen activator. Nat. Med. 9, 1313–1317 (2003).
    1. Gasche Y. et al. Early appearance of activated matrix metalloproteinase-9 after focal cerebral ischemia in mice: a possible role in blood-brain barrier dysfunction. J. Cereb. Blood Flow Metab. 19, 1020–1028 (1999).
    1. Heo J. H. et al. Matrix metalloproteinases increase very early during experimental focal cerebral ischemia. J. Cereb. Blood Flow Metab. 19, 624–633 (1999).
    1. Mun-Bryce S. & Rosenberg G. A. Matrix metalloproteinases in cerebrovascular disease. J. Cereb. Blood Flow Metab. 18, 1163–1172 (1998).
    1. Asahi M. et al. Effects of matrix metalloproteinase-9 gene knock-out on the proteolysis of blood-brain barrier and white matter components after cerebral ischemia. J. Neurosci. 21, 7724–7732 (2001).
    1. Lo E. H., Dalkara T. & Moskowitz M. A. Mechanisms, challenges and opportunities in stroke. Nat. Rev. Neurosci. 4, 399–415 (2003).
    1. Lo E. H., Broderick J. P. & Moskowitz M. A. tPA and proteolysis in the neurovascular unit. Stroke 35, 354–356 (2004).
    1. Pfefferkorn T. & Rosenberg G. A. Closure of the blood-brain barrier by matrix metalloproteinase inhibition reduces rtPA-mediated mortality in cerebral ischemia with delayed reperfusion. Stroke 34, 2025–2030 (2003).
    1. Lee S. R. & Lo E. H. Induction of caspase-mediated cell death by matrix metalloproteinases in cerebral endothelial cells after hypoxia-reoxygenation. J. Cereb. Blood Flow Metab. 24, 720–727 (2004).
    1. Gu Z. et al. A highly specific inhibitor of matrix metalloproteinase-9 rescues laminin from proteolysis and neurons from apoptosis in transient focal cerebral ischemia. J. Neurosci. 25, 6401–6408 (2005).
    1. Matsumoto S. et al. Expression and localization of matrix metalloproteinase-12 in the aorta of cholesterol-fed rabbits: relationship to lesion development. Am. J. Pathol. 153, 109–119 (1998).
    1. Chandler S., Cossins J., Lury J. & Wells G. Macrophage metalloelastase degrades matrix and myelin proteins and processes a tumour necrosis factor-alpha fusion protein. Biochem. Biophys. Res. Commun. 228, 421–429 (1996).
    1. Belaaouaj A. A., Li A., Wun T. C., Welgus H. G. & Shapiro S. D. Matrix metalloproteinases cleave tissue factor pathway inhibitor. Effects on coagulation. J. Biol. Chem. 275, 27123–27128 (2000).
    1. Dong Z., Kumar R., Yang X. & Fidler I. J. Macrophage-derived metalloelastase is responsible for the generation of angiostatin in Lewis lung carcinoma. Cell 88, 801–810 (1997).
    1. Cornelius L. A. et al. Matrix metalloproteinases generate angiostatin: effects on neovascularization. J. Immunol. 161, 6845–6852 (1998).
    1. Dwivedi A. & George S. MMP-12 is important for VSMC proliferation and migration: role of B-catenin signalling. Vascul Pharmacol 45, e129 (2006).
    1. Wells J. E. et al. Matrix metalloproteinase (MMP)-12 expression has a negative impact on sensorimotor function following intracerebral haemorrhage in mice. Eur. J. Neurosci. 21, 187–196 (2005).
    1. Svedin P., Hagberg H. & Mallard C. Expression of MMP-12 after neonatal hypoxic-ischemic brain injury in mice. Dev. Neurosci. 31, 427–436 (2009).
    1. Romanic A. M., White R. F., Arleth A. J., Ohlstein E. H. & Barone F. C. Matrix metalloproteinase expression increases after cerebral focal ischemia in rats: inhibition of matrix metalloproteinase-9 reduces infarct size. Stroke 29, 1020–1030 (1998).
    1. Montaner J. et al. Matrix metalloproteinase expression after human cardioembolic stroke: temporal profile and relation to neurological impairment. Stroke 32, 1759–1766 (2001).
    1. Svedin P., Hagberg H., Savman K., Zhu C. & Mallard C. Matrix metalloproteinase-9 gene knock-out protects the immature brain after cerebral hypoxia-ischemia. J. Neurosci. 27, 1511–1518 (2007).
    1. Hu Q. et al. Therapeutic application of gene silencing MMP-9 in a middle cerebral artery occlusion-induced focal ischemia rat model. Exp. Neurol. 216, 35–46 (2009).
    1. Bonoiu A. et al. MMP-9 gene silencing by a quantum dot-siRNA nanoplex delivery to maintain the integrity of the blood brain barrier. Brain Res. 1282, 142–155 (2009).
    1. Hu Q. et al. Lentivirus-mediated transfer of MMP-9 shRNA provides neuroprotection following focal ischemic brain injury in rats. Brain Res. 1367, 347–359 (2011).
    1. Mahajan S. D. et al. Suppression of MMP-9 expression in brain microvascular endothelial cells (BMVEC) using a gold nanorod (GNR)-siRNA nanoplex. Immunol. Invest 41, 337–355 (2012).
    1. Power C. et al. Intracerebral hemorrhage induces macrophage activation and matrix metalloproteinases. Ann. Neurol. 53, 731–742 (2003).
    1. Wasserman J. K., Zhu X. & Schlichter L. C. Evolution of the inflammatory response in the brain following intracerebral hemorrhage and effects of delayed minocycline treatment. Brain Res. 1180, 140–154 (2007).
    1. Gronski T. J. Jr et al. Hydrolysis of a broad spectrum of extracellular matrix proteins by human macrophage elastase. J. Biol. Chem. 272, 12189–12194 (1997).
    1. Liu Y. et al. Matrix metalloproteinase-12 contributes to neuroinflammation in the aged brain. Neurobiol. Aging 34, 1231–1239 (2013).
    1. Yong V. W., Power C., Forsyth P. & Edwards D. R. Metalloproteinases in biology and pathology of the nervous system. Nat. Rev. Neurosci. 2, 502–511 (2001).
    1. Churg A. et al. Acute cigarette smoke-induced connective tissue breakdown requires both neutrophils and macrophage metalloelastase in mice. Am. J. Respir. Cell Mol. Biol. 27, 368–374 (2002).
    1. Larsen P. H. & Yong V. W. The expression of matrix metalloproteinase-12 by oligodendrocytes regulates their maturation and morphological differentiation. J. Neurosci. 24, 7597–7603 (2004).
    1. Larsen P. H., DaSilva A. G., Conant K. & Yong V. W. Myelin formation during development of the CNS is delayed in matrix metalloproteinase-9 and -12 null mice. J. Neurosci. 26, 2207–2214 (2006).
    1. Vos C. M., van Haastert E. S., de Groot C. J., van der Valk P. & de Vries H. E. Matrix metalloproteinase-12 is expressed in phagocytotic macrophages in active multiple sclerosis lesions. J. Neuroimmunol. 138, 106–114 (2003).
    1. Ulrich R. et al. MMP-12, MMP-3, and TIMP-1 are markedly upregulated in chronic demyelinating theiler murine encephalomyelitis. J. Neuropathol. Exp. Neurol. 65, 783–793 (2006).
    1. Lanone S. et al. Overlapping and enzyme-specific contributions of matrix metalloproteinases-9 and -12 in IL-13-induced inflammation and remodeling. J. Clin. Invest 110, 463–474 (2002).
    1. Chelluboina B., Klopfenstein J. D., Gujrati M., Rao J. S. & Veeravalli K. K. Temporal regulation of apoptotic and anti-apoptotic molecules after middle cerebral artery occlusion followed by reperfusion. Mol. Neurobiol. 49, 50–65 (2014).
    1. Veeravalli K. K. et al. Human umbilical cord blood stem cells upregulate matrix metalloproteinase-2 in rats after spinal cord injury. Neurobiol. Dis. 36, 200–212 (2009).

Source: PubMed

3
Subskrybuj