TGF-beta3-induced palatogenesis requires matrix metalloproteinases

Cleft lip and palate syndromes are among the most common congenital malformations in humans. Mammalian palatogenesis is a complex process involving highly regulated interactions between epithelial and mesenchymal cells of the palate to permit correct positioning of the palatal shelves, the remodeling of the extracellular matrix (ECM), and subsequent fusion of the palatal shelves. Here we show that several matrix metalloproteinases (MMPs), including a cell membrane-associated MMP (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) were highly expressed by the medial edge epithelium (MEE). MMP-13 was expressed both in MEE and in adjacent mesenchyme, whereas gelatinase A (MMP-2) was expressed by mesenchymal cells neighboring the MEE. Transforming growth factor (TGF)-beta3-deficient mice, which suffer from clefting of the secondary palate, showed complete absence of TIMP-2 in the midline and expressed significantly lower levels of MMP-13 and slightly reduced levels of MMP-2. In concordance with these findings, MMP-13 expression was strongly induced by TGF-beta3 in palatal fibroblasts. Finally, palatal shelves from prefusion wild-type mouse embryos cultured in the presence of a synthetic inhibitor of MMPs or excess of TIMP-2 failed to fuse and MEE cells did not transdifferentiate, phenocopying the defect of the TGF-beta3-deficient mice. Our observations indicate for the first time that the proteolytic degradation of the ECM by MMPs is a necessary step for palatal fusion.     

RECK及MMP-9蛋白在皮肤鳞状细胞癌中的表达及临床病理意义（英文）

目的：观察RECK基因及基质金属蛋白酶-9（MMP-9）在皮肤鳞状细胞癌（CSCC）中的表达,探讨其与肿瘤浸润转移的关系。方法：应用免疫组化SP法检测40例CSCC组织、17例癌旁不典型增生组织及14例正常皮肤组织中RECK及MMP-9蛋白的表达。结果：①RECK在CSCC、癌旁不典型增生及正常皮肤中的表达率依次增高（30.0%、47.1%、85.7%）,组间比较差异有统计学意义（P＆lt;0.05）;MMP-9蛋白在CSCC、癌旁不典型增生及正常皮肤中的表达率依次降低（82.5%、76.4%、28.6%）,组间比较差异有统计学意义（P＆lt;0.05）②RECK及MMP-9与CSCC的组织学分级、淋巴结转移密切相关（P均＆lt;0.05）;与CSCC患者的性别、年龄无关（P均＆gt;0.05）③RECK及MMP-9在CSCC中的表达呈负相关（r=-0.475p＆lt;0.01）。结论：RECK和MMP-9与CSCC的浸润转移密切相关,RECK在CSCC中表达减少或缺失可能是通过上调MMP-9的表达从而促进CSCC的侵袭与转移。     

Site-Specific Expression of Gelatinolytic Activity during Morphogenesis of the Secondary Palate in the Mouse Embryo

Morphogenesis of the secondary palate in mammalian embryos involves two major events: first, reorientation of the two vertically oriented palatal shelves into a horizontal position above the tongue, and second, fusion of the two shelves at the midline. Genetic evidence in humans and mice indicates the involvement of matrix metalloproteinases (MMPs). As MMP expression patterns might differ from sites of activity, we used a recently developed highly sensitive in situ zymography technique to map gelatinolytic MMP activity in the developing mouse palate. At embryonic day 14.5 (E14.5), we detected strong gelatinolytic activity around the lateral epithelial folds of the nasopharyngeal cavity, which is generated as a consequence of palatal shelf elevation. Activity was concentrated in the basement membrane of the epithelial fold but extended into the adjacent mesenchyme, and increased in intensity with lateral outgrowth of the cavity at E15.5. Gelatinolytic activity at this site was not the consequence of epithelial fold formation, as it was also observed in Bmp7-deficient embryos where shelf elevation is delayed. In this case, gelatinolytic activity appeared in vertical shelves at the exact position where the epithelial fold will form during elevation. Mmp2 and Mmp14 (MT1-MMP), but not Mmp9 and Mmp13, mRNAs were expressed in the mesenchyme around the epithelial folds of the elevated palatal shelves; this was confirmed by immunostaining for MMP-2 and MT1-MMP. Weak gelatinolytic activity was also found at the midline of E14.5 palatal shelves, which increased during fusion at E15.5. Whereas MMPs have been implicated in palatal fusion before, this is the first report showing that gelatinases might contribute to tissue remodeling during early stages of palatal shelf elevation and formation of the nasopharynx.     

Temporal and Spatial Expression of Hoxa-2 During Murine Palatogenesis

1. Mice homozygous for a targeted mutation of the Hoxa-2 gene are born with a bilateral cleft of the secondary palate associated with multiple head and cranial anomalies and these animals die within 24 hr of birth (Gendron-Maguire et al., 1993; Rijli et al., 1993; Mallo and Gridley, 1996). We have determined the spatial and temporal expression of the Hoxa-2 homeobox protein in the developing mouse palate at embryonic stages E12, E13, E13.5, E14, E14.5, and E15.2. Hoxa-2 is expressed in the mesenchyme and epithelial cells of the palate at E12, but is progressively restricted to the tips of the growing palatal shelves at E13.3. By the E13.5 stage of development, Hoxa-2 protein was found to be expressed throughout the palatal shelf. These observations correlate with palatal shelf orientation and Hoxa-2 protein may play a direct or indirect role in guiding the palatal shelves vertically along side the tongue, starting with the tips of the palatal shelves at E13, followed by the entire palatal shelf at E13.5.4. As development progresses to E14, the stage at which shelf elevation occurs, Hoxa-2 protein is downregulated in the palatal mesenchyme but remains in the medial edge epithelium. Expression of Hoxa-2 continues in the medial edge epithelium until the fusion of opposing palatal shelves.5. By the E15 stage of development, Hoxa-2 is downregulated in the palate and expression is localized in the nasal and oral epithelia.6. In an animal model of phenytoin-induced cleft palate, we report that Hoxa-2 mRNA and protein expression were significantly decreased, implicating a possible functional role of the Hoxa-2 gene in the development of phenytoin-induced cleft palate.7. A recent report by Barrow and Capecchi (1999), has illustrated the importance of tongue posture during palatal shelf closure in Hoxa-2 mutant mice. This along with our new findings of the expression of the Hoxa-2 protein during palatogenesis has shed some light on the putative role of this gene in palate development.     

Occurrence and temporal variation in matrix metalloproteinases and their inhibitors during murine secondary palatal morphogenesis

Extracellular matrix (ECM) molecules are known to play a pivotal role in morphogenesis of the secondary palate, and changes in their composition and distribution, not attributable to changes in synthesis, are known to occur during palatogenesis. The present study was undertaken to determine if the enzymes responsible for mediating their degradation, the matrix metalloproteinases (MMP), and their specific inhibitors, the tissue inhibitors of metalloproteinases (TIMP), are temporospatially regulated during murine palatal shelf morphogenesis. Palatal shelves were harvested at gestational days (gd) 12, 13 and 14. MMPs were identified by gelatin zymography, with and without inhibitors, and the identity of specific bands confirmed by Western blot analysis. TIMPs were identified by reverse zymography. MMP and TIMP messages were detected using RT-PCR with specific primers to MMPs 2, 3, 7, 9 and 13 and TIMPs 1 and 2. Zymography revealed bands of molecular weights corresponding to MMPs 2, 7, 9 and 13 at all ages examined; the intensity of these bands increased with developmental age. Western blot analysis established the presence of MMP-3 and its developmental variation in expression. RT-PCR demonstrated the presence of mRNA for all MMPs and TIMP at all sampling times and all but MMP-2 showed developmental variation. Whereas increases in mRNA were detected for MMPs 3, 9, and 13, MMP-7 mRNA decreased between gd 12 and 14. The results of this study demonstrate that MMPs 2, 3, 7, 9 and 13 and TIMPs 1 and 2 and their messages are present during the course of palatal shelf remodelling and that their expression is temporally regulated.     

Matrix metalloproteinase (MMP-2 and MMP-9) and steroid receptor expressions in feline mammary tumors

We evaluated the presence of estrogen (ER) and progesterone (PR) receptors, and matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) enzymes in 18 feline mammary tubulopapillary carcinomas. Immunohistochemistry was performed to localize ER, PR, MMP-2 and MMP-9 in situ. Western blotting and zymographic analyses also were performed to investigate the presence and activities of MMP-2 and MMP-9 enzymes in fresh tissue homogenates. ER immune expression was detected in five samples (27.7%) and PR was positive in sixteen (88.8%) samples. Diffuse cytoplasmic staining of MMP-2 and MMP-9 in neoplastic mammary epithelial cells, stromal fibroblasts and inflammatory cell was evident. MMP-2 and MMP-9 staining was observed also in metastasizing neoplastic cells within lymphatic vessels. MMP-2 and MMP-9 enzymes and their activities in fresh tumor homogenates were demonstrated by zymography. Comparison of MMP-9 gelatinolytic bands from tumor samples and controls revealed a statistically significant difference. We demonstrated elevated MMP-9 and MMP-2 levels in tumor samples by Western blotting; analysis of protein bands revealed 1.9-to-3 fold increase in MMP-9 in tumor samples and the difference was statistically significant. Our results suggest that the expression of MMP-9 can be an important indicator for tumor progression and the possible metastatic nature of feline tubulopapillary carcinomas.     

Matrix metalloproteinase (MMP-2 and MMP-9) and steroid receptor expressions in feline mammary tumors

We evaluated the presence of estrogen (ER) and progesterone (PR) receptors, and matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) enzymes in 18 feline mammary tubulopapillary carcinomas. Immunohistochemistry was performed to localize ER, PR, MMP-2 and MMP-9 in situ. Western blotting and zymographic analyses also were performed to investigate the presence and activities of MMP-2 and MMP-9 enzymes in fresh tissue homogenates. ER immune expression was detected in five samples (27.7%) and PR was positive in sixteen (88.8%) samples. Diffuse cytoplasmic staining of MMP-2 and MMP-9 in neoplastic mammary epithelial cells, stromal fibroblasts and inflammatory cell was evident. MMP-2 and MMP-9 staining was observed also in metastasizing neoplastic cells within lymphatic vessels. MMP-2 and MMP-9 enzymes and their activities in fresh tumor homogenates were demonstrated by zymography. Comparison of MMP-9 gelatinolytic bands from tumor samples and controls revealed a statistically significant difference. We demonstrated elevated MMP-9 and MMP-2 levels in tumor samples by Western blotting; analysis of protein bands revealed 1.9-to-3 fold increase in MMP-9 in tumor samples and the difference was statistically significant. Our results suggest that the expression of MMP-9 can be an important indicator for tumor progression and the possible metastatic nature of feline tubulopapillary carcinomas.     

MMP-2、Fhit、RECK、VEGF在喉癌组织中的表达及相关性分析

目的:探讨基质金属蛋白酶-2(MMP-2)、脆性组氨酸三联体基因(Fhit)、逆转录诱导蛋白基因(RECK)、血管内皮细胞生长因子(VEGF)在喉癌组织中的表达及其相关性。方法:选取2011年1月到2016年12月在陕西省人民医院接受治疗的喉癌患者80例,收集其手术中切除的喉癌组织和癌旁组织,另收集40例喉癌组织切除外缘的正常喉粘膜组织。比较喉癌组织、癌旁组织、正常喉粘膜组织中MMP-2、Fhit、RECK、VEGF的表达,分析喉癌组织中MMP-2、Fhit、RECK、VEGF的表达与临床病理特征的关系,并分析四个指标的相关性。结果:喉癌组织中MMP-2、VEGF表达明显高于癌旁组织和正常喉粘膜组织,Fhit、RECK表达明显低于癌旁组织和正常喉粘膜组织(P0.05)。喉癌组织中MMP-2的表达与淋巴结转移、临床分期、分化程度有关(P0.05);Fhit、RECK的表达与淋巴结转移、临床分期有关(P0.05);VEGF的表达与淋巴结转移有关(P0.05)。喉癌组织中MMP-2的表达水平与Fhit、RECK呈负相关(P0.05),与VEGF呈正相关(P0.05);Fhit与RECK呈正相关(P0.05),与VEGF呈负相关(P0.05);RECK与VEGF呈负相关(P0.05)。结论:在喉癌组织中MMP-2、Fhit、RECK、VEGF均存在异常表达;其相互影响,可能共同参与了喉癌的发生、发展。     

EGCG对人结肠癌HT-29细胞凋亡的影响以及对MMP-2,RECK的调节作用

目的：观察表没食子儿茶素没食子酸酯（Epigallaocatechin-3-gallate,EGCG）对人结肠癌HT-29细胞增殖和凋亡的影响,并探讨其对MMP-2,RECK的调节作用。方法：体外培养人结肠癌HT-29细胞,MTT比色法检测EGCG对HT-29细胞的生长抑制作用;Histone/DNA ELISA检测细胞凋亡;FITC标记Annexin-V/PI双染流式细胞术分析凋亡细胞百分率;Western Blot和RT-PCR方法检测EGCG对MMP-2,RECK蛋白和mRNA表达的影响。结果：EGCG呈浓度和时间依赖性抑制HT-29细胞的增殖,并且增加HT-29细胞Histone/DNA碎片的渗漏;EGCG诱导HT-29细胞凋亡百分率增高;EGCG抑制MMP-2蛋白和mRNA的表达,促进RECK蛋白和mRNA的表达。结论：EGCG抑制人结肠癌HT-29细胞的增殖,促进其凋亡,并且呈浓度和时间依赖性;其作用机制可能与其下调MMP-2蛋白和mRNA的表达、上调RECK蛋白和mRNA的表达有关。     

The expression of TGF-β3 for epithelial-mesenchyme transdifferentiated MEE in palatogenesis

The fate of the palatal medial edge epithelial (MEE) cells undergoes programming cell death, migration, and epithelial-mesenchymal transdifferentiation (EMT) coincident with the process of palatal fusion and disappearance of MEE. Mesenchymal cells in the palate have both cranial neural crest (CNC) and non-CNC origins. The objectives of this study were to identify the populations of palatal mesenchymal cells using β-galactosidase (β-gal) and DiI cell lineage markers, and to determine whether MEE-derived cells continued to express transforming growth factor-β3 (TGF-β3) and transforming growth factor-β type III receptor (TβR-III), which were specific for MEE. A model has been developed using Wnt1 tissue specific expression of Cre-recombinase to activate β-gal solely in the CNC. The expressions of TGF-β3 and TβR-III in MEE were temporally correlated with critical events in palatogenesis. Three cell populations could be distinguished in the palatal mesenchymal CNC-derived, non-CNC derived and MEE-derived. After fusion, β-gal (−) and DiI (+) mesenchymal cells continued to express TGF-β3, however TβR-III was expressed only in the epithelial MEE, as well as keratin expression. In addition, we performed laser capture microdissection to identify mRNA expression of isolated DiI (+) MEE cells. Both epithelial and transdifferentiated MEE have expressed TGF-β3, however, TβR-III was only expressed in epithelium. Extracellular matrix, especially MMP13 has been expressed coincident with fused stage which can be strongly associated with TGF-β3. These results demonstrate that combining a heritable marker and a cell lineage dye can distinguish different populations of mesenchymal cells in the developing palate. Furthermore, TGF-β3 and MMP13 could be strongly associated with EMT in palatogenesis.     

HPV16 oncoproteins induce MMPs/RECK-TIMP-2 imbalance in primary keratinocytes: possible implications in cervical carcinogenesis

Cervical cancer is the third most common cancer in women worldwide. Persistent infection with high-risk HPV types, principally HPV16 and 18 is the main risk factor for the development of this malignancy. However, the onset of invasive tumor occurs many years after initial exposure in a minority of infected women. This suggests that other factors beyond viral infection are necessary for tumor establishment and progression. Tumor progression is characterized by an increase in secretion and activation of matrix metalloproteinases (MMPs) produced by either the tumor cells themselves or tumor-associated fibroblasts or macrophages. Increased MMPs expression, including MMP-2, MMP-9 and MT1-MMP, has been observed during cervical carcinoma progression. These proteins have been associated with degradation of ECM components, tumor invasion, metastasis and recurrence. However, few studies have evaluated the interplay between HPV infection and the expression and activity of MMPs and their regulators in cervical cancer. We analyzed the effect of HPV16 oncoproteins on the expression and activity of MMP-2, MMP-9, MT1-MMP, and their inhibitors TIMP-2 and RECK in cultures of human keratinocytes. We observed that E7 expression is associated with increased pro-MMP-9 activity in the epithelial component of organotypic cultures, while E6 and E7 oncoproteins co-expression down-regulates RECK and TIMP-2 levels in organotypic and monolayers cultures. Finally, a study conducted in human cervical tissues showed a decrease in RECK expression levels in precancer and cancer lesions. Our results indicate that HPV oncoproteins promote MMPs/RECK-TIMP-2 imbalance which may be involved in HPV-associated lesions outcome.     

Binding of amelogenin to MMP-9 and their co-expression in developing mouse teeth

Amelogenin is the most abundant matrix protein in enamel. Proper amelogenin processing by proteinases is necessary for its biological functions during amelogenesis. Matrix metalloproteinase 9 (MMP-9) is responsible for the turnover of matrix components. The relationship between MMP-9 and amelogenin during tooth development remains unknown. We tested the hypothesis that MMP-9 binds to amelogenin and they are co-expressed in ameloblasts during amelogenesis. We evaluated the distribution of both proteins in the mouse teeth using immunohistochemistry and confocal microscopy. At postnatal day 2, the spatial distribution of amelogenin and MMP-9 was co-localized in preameloblasts, secretory ameloblasts, enamel matrix and odontoblasts. At the late stages of mouse tooth development, expression patterns of amelogenin and MMP-9 were similar to that seen in postnatal day 2. Their co-expression was further confirmed by RT-PCR, Western blot and enzymatic zymography analyses in enamel organ epithelial and odontoblast-like cells. Immunoprecipitation assay revealed that MMP-9 binds to amelogenin. The MMP-9 cleavage sites in amelogenin proteins across species were found using bio-informative software program. Analyses of these data suggest that MMP-9 may be involved in controlling amelogenin processing and enamel formation.     

Cooperation of two ADAMTS metalloproteases in closure of the mouse palate identifies a requirement for versican proteolysis in regulating palatal mesenchyme proliferation

We have identified a role for two evolutionarily related, secreted metalloproteases of the ADAMTS family, ADAMTS20 and ADAMTS9, in palatogenesis. Adamts20 mutations cause the mouse white-spotting mutant belted (bt), whereas Adamts9 is essential for survival beyond 7.5 days gestation (E7.5). Functional overlap of Adamts9 with Adamts20 was identified using Adamts9(+/-);bt/bt mice, which have a fully penetrant cleft palate. Palate closure was delayed, although eventually completed, in both Adamts9(+/-);bt/+ and bt/bt mice, demonstrating cooperation of these genes. Adamts20 is expressed in palatal mesenchyme, whereas Adamts9 is expressed exclusively in palate microvascular endothelium. Palatal shelves isolated from Adamts9(+/-);bt/bt mice fused in culture, suggesting an intact epithelial TGFβ3 signaling pathway. Cleft palate resulted from a temporally specific delay in palatal shelf elevation and growth towards the midline. Mesenchyme of Adamts9(+/-);bt/bt palatal shelves had reduced cell proliferation, a lower cell density and decreased processing of versican (VCAN), an extracellular matrix (ECM) proteoglycan and ADAMTS9/20 substrate, from E13.5 to E14.5. Vcan haploinsufficiency led to greater penetrance of cleft palate in bt mice, with a similar defect in palatal shelf extension as Adamts9(+/-);bt/bt mice. Cell density was normal in bt/bt;Vcan(hdf)(/+) mice, consistent with reduced total intact versican in ECM, but impaired proliferation persisted in palate mesenchyme, suggesting that ADAMTS-cleaved versican is required for cell proliferation. These findings support a model in which cooperative versican proteolysis by ADAMTS9 in vascular endothelium and by ADAMTS20 in palate mesenchyme drives palatal shelf sculpting and extension.     

Molecular cloning and expression of gelatinases (MMP-2 and MMP-9) in the pufferfish Takifugu rubripes

To determine the metabolism location of the extra-cellular matrix proteins in fugu (Takifugu rubripes), we cloned the cDNAs of the fugu gelatinases, matrix metalloproteinase-2 (MMP-2) and MMP-9, and examined their expressions in various adult tissues using a quantitative real-time PCR. The expression profiles of fugu gelatinases were different among tissues. FgMMP-9 mRNA was abundant in tissues that contain blood cells abundantly where fgMMP-2 mRNA was little expressed. We also examined the expression of these genes in fugu embryos during development using a whole mount in situ hybridization. Fugu MMP-2 mRNA was expressed in the pharyngeal area and mesenchyme in embryos at 80 hours post fertilization (hpf). While fugu MMP-9 mRNA was expressed in the vent at 140 hpf and the caudal end of the fin fold at 172 hpf. Although fugu MMP-2 mRNA was expressed in the pectoral fin bud at 120 hpf, fugu MMP-9 mRNA did not appear in this tissue until 10 days post fertilization (dpf). These data show expression profiles differ between the fugu gelatinases and suggest expressions of these genes are controlled at the matrix protein degradation site in fugu embryos during development.     

Zinc-chelation contributes to the anti-angiogenic effect of ellagic acid on inhibiting MMP-2 activity, cell migration and tube formation

Background

Ellagic acid (EA), a dietary polyphenolic compound, has been demonstrated to exert anti-angiogenic effect but the detailed mechanism is not yet fully understood. The aim of this study was to investigate whether the zinc chelating activity of EA contributed to its anti-angiogenic effect.

Methods and Principal Findings

The matrix metalloproteinases-2 (MMP-2) activity, a zinc-required reaction, was directly inhibited by EA as examined by gelatin zymography, which was reversed dose-dependently by adding zinc chloride. In addition, EA was demonstrated to inhibit the secretion of MMP-2 from human umbilical vein endothelial cells (HUVECs) as analyzed by Western blot method, which was also reversed by the addition of zinc chloride. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), known to down-regulate the MMP-2 activity, was induced by EA at both the mRNA and protein levels which was correlated well with the inhibition of MMP-2 activity. Interestingly, zinc chloride could also abolish the increase of EA-induced RECK expression. The anti-angiogenic effect of EA was further confirmed to inhibit matrix-induced tube formation of endothelial cells. The migration of endothelial cells as analyzed by transwell filter assay was suppressed markedly by EA dose-dependently as well. Zinc chloride could reverse these two effects of EA also in a dose-dependent manner. Since magnesium chloride or calcium chloride could not reverse the inhibitory effect of EA, zinc was found to be involved in tube formation and migration of vascular endothelial cells.

Conclusions/Significance

Together these results demonstrated that the zinc chelation of EA is involved in its anti-angiogenic effects by inhibiting MMP-2 activity, tube formation and cell migration of vascular endothelial cells. The role of zinc was confirmed to be important in the process of angiogenesis.     

Potential signal pathway of all-trans retinoic acid for MMP-2 and MMP-9 expression in injury podocyte induced by adriamycin

Abstract

All-trans-retinoic acid (ATRA) can regulate some specific genes expression in various tissue and cells via nuclear retinoic acid receptors (RARs), including three subtypes: retinoic acid receptor-alpha (RAR-α), retinoic acid receptor-beta (RAR-β) and retinoic acid receptor-gamma (RAR-γ). Podocyte injury plays a pivotal role in the progression of glomerulosclerosis (GS). This study was performed to study the potential signal pathway of ATRA in the expression of matrix metalloproteinases-2 (MMP-2) and matrix metalloproteinases-9 (MMP-9) in injury podocyte. Cells were divided into three groups: group of negative control (NC), group of injury podocyte induced by adriamycin (ADR) (AI) and group of ADR inducing podocyte injury model treated with ATRA (AA). The cells morphology changes were detected using microscope and scanning electron microscopy. MMP-2 and MMP-9 enzymic activity was detected using the gelatin zymography method. Protein and mRNA expressions of MMP-2, MMP-9, RAR-α, RAR-β and RAR-γ were measured by western-blot and real-time RT-PCR. Enzymatic activity of MMP-2 and MMP-9 in group AA was significantly enhanced compared to AI group after ATRA-treated 24?h (p?<?0.05). The protein and mRNA expressions of MMP-2/MMP-9 in group AA were significantly increased than those in group AI at both 12 and 24?h time points (p?<?0.05). Compared to group AI, RAR-α and RAR-γ protein/mRNA expressions of group AA were significantly increased at both 12 and 24?h time points (p?<?0.05). There was no difference for the expression of RAR-β between group AI and group AA (p?>?0.05). RAR-α protein level was positively correlated with MMP-2 or MMP-9 protein expression (p?<?0.05), and RAR-γ protein level was also positively correlated with MMP-2 or MMP-9 protein expression (p?<?0.05). In conclusion, ATRA may increase expression of MMP-2 and MMP-9 by the potential signal pathway of RAR-α and RAR-γ in injury podocyte induced by adriamycin, but not RAR-β.