MMP inhibition as a novel strategy for extracellular matrix preservation during whole liver decellularization.

As the only reliable treatment option for end-stage liver diseases, conventional liver transplantation confronts major supply limitations. Accordingly, the decellularization of discarded livers to produce bioscaffolds that support recellularization with progenitor/stem cells has emerged as a promising translational medicine approach. The success of this approach will substantially be determined by the extent of extracellular matrix (ECM) preservation during the decellularization process. Here, we assumed that the matrix metalloproteinase (MMP) inhibition could reduce the ECM damage during the whole liver decellularization of an animal model using a perfusion-based system. We demonstrated that the application of doxycycline as an MMP inhibitor led to significantly higher preservation of collagen, glycosaminoglycans, and hepatic growth factor (HGF) contents, as well as mechanical and structural features, including tensile strength, fiber integrity, and porosity. Notably, produced bioscaffolds were biocompatible and efficiently supported cell viability and proliferation in vitro. We also indicated that produced bioscaffolds efficiently supported HepG2 cell function upon seeding onto liver ECM discs using albumin and urea assay. Additionally, MMP inhibitor pretreated decellularized livers were more durable in contact with collagenase digestion compared to control bioscaffolds in vitro. Using zymography, we confirmed the underlying mechanism that results in these promising effects is through the inhibition of MMP2 and MMP9. Overall, we demonstrated a novel method based on MMP inhibition to ameliorate the ECM structure and composition preservation during liver decellularization as a critical step in fabricating transplantable bioengineered livers.

Expression and localization of the MMP inhibitor RECK in a rat model of COPD: its involvement in the development of COPD.

OBJECTIVE: To unravel the potential function of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) as the matrix metalloproteinase (MMP) inhibitor in the development of chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Twelve specific pathogen-free Sprague Dawley rats were randomly assigned to the control cohort (n = 6) or the COPD cohort (n = 6). COPD model was developed by tobacco smoke exposure. Functional residual capacity (FRC), static lung compliance (Cchord), ratio of forced expiratory volume in 0.1 s to forced vital capacity (FEV0.1/FVC), and peak expiratory flow (PEF) were detected by respiratory function tests. Immunohistochemistry was performed to determine the pathological changes as well as the expression and localization of RECK in pulmonary tissue. RECK expression was further quantified by real-time polymerase chain reaction (PCR) and Western blot assays. RESULTS: COPD rats had significantly reduced FEV0.1/FVC% and PEF values but increased FRC and Cchord levels, as compared to the control cohort (p < 0.05). Hematoxylin and eosin (HE) staining indicated typical COPD pathological changes, including leukocyte infiltration, airway thickening, alveoli fusion, etc., in the COPD rats. IHC indicated reduced expression of RECK in the COPD cohort, which was mainly expressed on the epithelium and partly expressed on subepithelial cells and inflammatory cells. Real-time PCR and Western blot assays further revealed the significantly lower expression of RECK in lung tissue from the COPD cohort. CONCLUSIONS: RECK is mainly expressed on airway epithelial cells. COPD rats expressed significantly lower RECK levels, indicating that RECK exhibits a protective function in the development of COPD.

Hierarchical virtual screening of the dual MMP-2/HDAC-6 inhibitors from natural products based on pharmacophore models and molecular docking.

The dual-target inhibitors tend to improve the response rate in treating tumors, comparing with the single-target inhibitors. Matrix metalloproteinase-2 (MMP-2) and histone deacetylase-6 (HDAC-6) are attractive targets for cancer therapy. In this study, the hierarchical virtual screening of dual MMP-2/HDAC-6 inhibitors from natural products is investigated. The pharmacophore model of MMP-2 inhibitors is built based on ligands, but the pharmacophore model of HDAC-6 inhibitors is built based on the experimental crystal structures of multiple receptor-ligand complexes. The reliability of these two pharmacophore models is validated subsequently. The hierarchical virtual screening, combining these two different pharmacophore models of MMP-2 and HDAC-6 inhibitors with molecular docking, is carried out to identify the dual MMP-2/HDAC-6 inhibitors from a database of natural products. The four potential dual MMP-2/HDAC-6 inhibitors of natural products, STOCK1 N-46177, STOCK1 N-52245, STOCK1 N-55477, and STOCK1 N-69706, are found. The studies of binding modes show that the screened four natural products can simultaneously well bind with the MMP-2 and HDAC-6 active sites by different kinds of interactions, to inhibit the MMP-2 and HDAC-6 activities. In addition, the ADMET properties of screened four natural products are assessed. These found dual MMP-2/HDAC-6 inhibitors of natural products could serve as the lead compounds for designing the new dual MMP-2/HDAC-6 inhibitors having higher biological activities by carrying out structural modifications and optimizations in the future studies.

Expression of TIMP-2 in HPV-16 infected oral squamous cell carcinoma in patients in Iraq

Aim: To determine the expression of tissue inhibitors of metalloproteinases (TIMP-2) in oralsquamous cell carcinoma (OSCC) and the difference in its expression level between positiveand negative HPV-16 (human papilloma virus- 16) OSCC patients. Methods: This study wasconducted on 33 biopsies obtained from patients with OSCC and 10 normal oral mucosa ascontrols. In situ hybridization (ISH) was used to investigate the presence of HPV-16, whileimmunohistochemistry (IHC) was used to estimate the expression level of TIMP-2. Results: TheTIMP-2 was expressed in 27 (81.8%) of OSCC sections with no significant difference betweenits expression level in HPV-16 positive and HPV-16 negative OSCC cases (p=0.058). TIMP-2was found to be highly expressed in OSCC sections, and the presence of HPV was not relatedto its overexpression. Conclusions: The percentage of samples that appeared to accommodatedetectable HPV-16 was high, but no significant difference was observed in relation to TIMP-2expression level. Future studies with a larger number of patients are highly recommended toaddress the possible association between TIMp-2 and OSCC positive HPV-16.

[The utility of metalloproteinases (MMPs) and their inhibitors (TIMPs) in diagnostics of gynecological malignancies]. / Przydatnosc oznaczania metaloproteinaz (MMPs) i ich inhibitorów (TIMPs) w diagnostyce nowotworów narzadu rodnego.

Metalloproteinases (MMPs) are a family of proteolytic enzymes, involved in the degradation of collagen and other extracellular matrix components. They play a very important role in many physiological processes, i.e. angiogenesis, hemostasis, cyclic changes in the endometrium, wounds healing, as well as in tumor growth and spreading. Already performed studies have shown significant increase in the expression of MMP-2 and MMP-9 in the most common gynecological cancer (cervix, endometrium, ovary) compared to normal tissue and benign lesions. In addition, the MMP-9 concentration correlated with the clinical stage and the presence of distant metastases. Moreover the level of MMP-2 was significantly associated with the degree of malignancy. MMP-7 may be helpful in the diagnosis of ovarian cancer and useful in estimating of lymph node metastasis presence in endometrial cancer. In the detection of cervical cancer it may be useful to evaluate the expression of MMP-11 and MMP-12 (absent in normal cells) and their increase according to the degree of tissue damage. The usefulness of metalloproteinases in the diagnosis of gynecological cancer still requires confirmation test. However, it appears that they will be valuable factors in diagnostic complement, especially in combination with conventional markers, i.e. CA 125, SCCAg or HE-4.

Systems pharmacology-based approach for dissecting the active ingredients and potential targets of the Chinese herbal Bufei Jianpi formula for the treatment of COPD.

BACKGROUND: The Chinese herbal Bufei Jianpi formula (BJF) provides an effective treatment option for chronic obstructive pulmonary disease (COPD). However, the systems-level mechanism underlying the clinical effects of BJF on COPD remains unknown. METHODS: In this study, a systems pharmacology model based on absorption filtering, network targeting, and systems analyses was applied specifically to clarify the active compounds and therapeutic mechanisms of BJF. Then, a rat model of cigarette smoke- and bacterial infection-induced COPD was used to investigate the therapeutic mechanisms of BJF on COPD and its comorbidity. RESULTS: The pharmacological system successfully identified 145 bioactive ingredients from BJF and revealed 175 potential targets. There was a significant target overlap between the herbal constituents of BJF. These results suggested that each herb of BJF connected with similar multitargets, indicating potential synergistic effects among them. The integrated target-disease network showed that BJF probably was efficient for the treatment of not only respiratory tract diseases but also other diseases, such as nervous system and cardiovascular diseases. The possible mechanisms of action of BJF were related to activation of inflammatory response, immune responses, and matrix metalloproteinases, among others. Furthermore, we demonstrated that BJF treatment could effectively prevent COPD and its comorbidities, such as ventricular hypertrophy, by inhibition of inflammatory cytokine production, matrix metalloproteinases expression, and other cytokine production in vivo. CONCLUSION: This study using the systems pharmacology method, in combination with in vivo experiments, helped us successfully dissect the molecular mechanism of BJF for the treatment of COPD and predict the potential targets of the multicomponent BJF, which provides a new approach to illustrate the synergetic mechanism of the complex prescription and discover more effective drugs against COPD.

Aplicação de modelagem molecular e de formalismo do CAMD (Computer-Aided Molecular Design) na elucidação do mecanismo de ação de inibidores de metalopropteinases de matriz / Molecular modeling methods and computer-aided molecular design (CAMD) formalisms for elucidating the mechanism of action of matrix metalloproteinases inhibitors

As metaloproteinases de matriz (MMP) são enzimas superexpressas em quase todos os tumores humanos, sendo que os subtipos MMP-2 e MMP-9 têm sido associados ao potencial metastático e prognóstico desfavorável em neoplasias malignas como, por exemplo, melanoma metastático e glioma. Compostos capazes de inibir a atividade destas enzimas podem representar potenciais agentes terapêuticos. O composto 4-nerolidilcatecol (4-NC), isolado de plantas do gênero Pothomorphe, apresentou resultados promissores para o tratamento do melanoma e glioma e foi capaz de atuar em várias etapas bioquímicas importantes envolvidas na progressão dessas patologias, inclusive inibindo MMP-2 e MMP-9. No entanto, o mecanismo de ação do 4-NC não está completamente elucidado. O presente estudo envolveu a aplicação de métodos de modelagem molecular e de formalismos do planejamento de novas moléculas auxiliado por computador, CAMD (Computer-Aided Molecular Design) a fim de explorar a interação entre esta molécula e as enzimas MMP-2 e MMP-9, além de planejar novos inibidores para estes alvos. Análise exploratória de dados, que compreende a análise de agrupamentos hierárquicos e de componentes principais. foi desenvolvida para um conjunto de hidroxamatos (N=64) descritos como inibidores de MMP-2 e MMP-9, a fim de identificar as propriedades moleculares que mais influenciavam o processo de discriminação dos compostos. As propriedades termodinâmicas, eletrônicas e estéricas foram importantes para descrever os compostos mais ativos no conjunto de dados da MMP-2. Para a MMP-9, o coeficiente de distribuição (ClogD) em pH 1,5 foi relevante no processo de discriminação do conjunto. A presença de substituintes volumosos na porção R3 parece ser crucial para o conjunto de inibidores investigados. Esta região está envolvida em interações moleculares com a cavidade S1 de ambas as enzimas, mas há um limite de volume a ser considerado para estes substituintes. O formalismo QSAR-4D independente do receptor (IR) foi aplicado ao mesmo conjunto de dados e permitiu estabelecer o mapeamento do farmacóforo, além de explorar diferentes alinhamentos para a obtenção da hipótese de conformação bioativa prevista pelo melhor modelo de QSAR. OS modelos QSAR apresentaram boa capacidade de previsão, auxiliaram na proposição de novos inibidores e estimaram a atividade do 4-NC. Com o melhor modelo QSAR para MMP-9 (N=64), a atividade prevista para o 4-NC foi classificada na faixa dos inibidores com atividade moderada. Entretanto, o melhor modelo QSAR obtido para MMP-2 (N=38) não foi capaz de prever, de forma adequada, a atividade de compostos com arcabouço químico diferente daqueles utilizados na construção dos modelos. Estudos de ancoramento molecular foram desenvolvidos para investigar a orientação do 4-NC no sitio catalítico das duas enzimas e as interações que poderiam ser estabelecidas nestes complexos. Duas conformações favoráveis foram encontradas. Simulações computacionais de dinâmica molecular foram desenvolvidas com os complexos mais promissores selecionados nos estudos de ancoramento, a fim de obter informações mais detalhadas e de maior confiabilidade. sobre suas interações intermoleculares. O 4-NC tende a se orientar no sítio de forma a acomodar sua cadeia lateral no bolso S1 adjacente ao sítio catalítico em ambas as enzimas. Ensaios de zimografia também foram realizados com o objetivo de elucidar possíveis contribuições da cadeia lateral e do núcleo catecólico do 4-NC na atividade inibitória frente às enzimas em estudo. O núcleo catecólico parece ser o responsável por sua atividade, pois o composto 1,2dimetoxibenzeno, que possui as hidroxilas bloqueadas por grupos metil, não foi capaz de exercer atividade inibitória significante frente à MMP-2 e MMP-9. Estudos de voltametria reforçaram a hipótese de que o 4-NC tem a capacidade de quelar os íons zinco presentes no tampão de incubação

Matrix metalloproteinases (MMP) enzymes are overexpressed in almost all human tumors, and MMP-2 and MMP-9 subtypes have been associated with metastatic potential and poor prognosis in malignant tumors, such as metastatic melanoma and glioma. Compounds capable of inhibiting the activity of theses enzymes would be considered as potential therapeutic agents. The 4-nerolidylcatechol compound (4-NC), isolated from plants of genus Pothomorphe, has showed promising results in the treatment of melanoma and glioma, and was able to act in several important biochemical steps involved in the progression of these diseases, as well as inhibiting MMP-2 and MMP-9. However, the 4-NC mechanism of action is not completely understood. This study has involved the application of molecular modeling methods and formalisms of computer-aided molecular design (CAMD) in order to explore the interaction between 4-NC and MMP-2/MMP-9, and to design new inhibitors for these targets. Exploratory data analysis, which comprises hierarchical cluster analysis and principal components analysis, was performed to a set of hydroxamates (N=64). previously reported as MMP-2 and MMP-9 inhibitors, in order lo identify the molecular properties that is most critical for the discrimination process regarding the investigated compounds. The thermodynamic, electronic, and steric properties were: quite important to describe the highly active compounds in the data set of MMP-2, whereas the apparent partition coefficient (ClogD) at pH 1.5 was the property more relevant for MMP-9 data set. The presence of bulky substituents on the R3 moiety seems to be crucial for this set of inhibitors due to the molecular interaction with the S1 subsite of both enzymes. However, there is a limit regarding the substituents volume in this region. Receptor independent (RI) 4D-QSAR analysis was applied lo the same data set and it was possible to establish the pharmacophore mapping, besides to explore different alignments in order to generate the hypothesized bioactive conformation through the best QSAR model. The QSAR models have presented good predictability, assisted in proposing new inhibitors, and estimated the activity of 4-NC. Regarding the best QSAR model for MMP-9 (N=64), the 4-NC predicted activity was classified in the range of the moderate active inhibitors. The best QSAR model obtained for MMP-2 (N=38), however was not able to properly predict the activity for compounds with different chemical scaffold from those used to build up the QSAR model. Molecular docking studies have been developed to investigate the 4-NC binding mode into the catalytic site of the two enzymes and the interactions that could be established in those complexes. The results have shown two favorable conformers regarding the MMP inhibition. Molecular dynamics computational simulation were combined to molecular docking studies in order to obtain more detailed and reliable information regarding the intermolecular interactions of each complex. The 4-NC molecule tends to accommodate the side chain in the S1 pocket adjacent to the catalytic site in both enzymes. Experimental zymography assays were also performed to elucidate the possible contribution of the side chain and the catechol core in the 4-NC inhibitory activity against the MMP-2 and MMP-9 enzymes. The catechol core seems to be responsible for its activity, since the 1,2 dimethoxybenzene compound, which has the hydroxyl blocked by a methyl group, was not able to exert any significant inhibition on enzymes. Voltametric assays confirmed the hypothesis that 4-NC chelates zinc ions present in the incubation buffer

Effect of psychological stress on the structure of the temporomandibular joint and the expression of MMP-3 and TIMP-3 in the cartilage in rats.

Our aim was to observe the effects of psychological stress on the structure of the temporomandibular joint (TMJ), and to evaluate the expression of matrix metallopeptidase-3 (MMP-3) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in condylar chondrocytes in rats. The rats were divided into 3 groups of 12 according to the duration of psychological stress: 3 weeks or 6 weeks, and 6 weeks of recovery. A fourth group of 12 rats was used as controls. Each rat was evaluated by the open-field test and the weight measured. The results confirmed psychological stress in 24 of the 36 rats (67%). The tissues of the TMJ were stained with haematoxylin and eosin and pathological changes were studied under a light microscope. MMP-3 and TIMP-3 expression was investigated using the SP kit. The experimental groups showed thinning of articular cartilage, shedding of collagen fibres, cracks in the articular discs, and other structural changes that were aggravated with time, from three weeks to six weeks. The 6-week recovery group showed an improvement in these changes, which indicated the initiation of joint repair. The MMP-3 expression rate correlated with the degree of joint lesion, while the TIMP-3 rate showed an opposite trend and was highest in the 6-week recovery group. Our findings clearly indicate that psychological stress may play an important part in the development of TMJ diseases in rats; further studies should be made to extrapolate the results to other models before clinical use.

Peri-implant versus periodontal wound healing.

AIM: Peri-implant gingival healing following one-stage implant placement was investigated and compared to periodontal healing. METHODS: Healing at surgical sites [implant (I) and adjacent teeth (T+)] was compared to non-operated tooth (T-) in non-smokers receiving one-stage implant. Periodontal Indices (PI, GI) were recorded at surgery and up to 12 weeks post-operatively. Peri-implant (PICF) and gingival crevicular fluids (GCF) were analysed for cytokines, collagenases and inhibitors. Data were analysed by linear mixed model regression analysis and repeated measures anova. RESULTS: Forty patients (22 females; 21-74 years old) completed the study. Surgical site GI, increased at week 1, decreased significantly during early healing (weeks 1-3; p = 0.0003) and continually decreased during late healing (weeks 6-12) for I (p < 0.01). PICF volume decreased threefold by week 12 (p = 0.0003). IL-6, IL-8, MIP-1ß and TIMP-1 levels significantly increased at surgical sites at week one, significantly decreasing thereafter (p < 0.016). Week one IL-6, IL-8 and MIP-1ß levels were ~threefold higher and TIMP-1 levels 63% higher, at I compared to T+ (p = 0.001). CONCLUSION: Peri-implant gingival healing, as determined by crevicular fluid molecular composition, differs from periodontal healing. The observed differences suggest that peri-implant tissues, compared to periodontal tissues, represent a higher pro-inflammatory state.

On-line screening of matrix metalloproteinase inhibitors by capillary electrophoresis coupled to ESI mass spectrometry.

Capillary electrophoresis (CE) with the use of mass spectrometry (MS) has been considered as a unique tool for microscale enzyme assay and inhibitor screening. In this study, matrix metalloproteinase-9 (MMP-9) was selected as target enzyme due to its important role in tumor invasion and metastasis. In order to define the optimal MS parameters, a two level half fraction factorial experimental design was performed. A background electrolyte consisting of 20mM ammonium acetate (pH 6.8) and a sheath liquid of water-methanol (50:50, v/v) containing 0.05% formic acid at a flow rate of 4µl/min were selected. This system was operated in the positive ion mode with a detection-limit of 10nM for the MMP reaction product and provided 60 folds enhancement of sensitivity by using selected reaction monitoring detection compared with MS full scan mode, which significantly increased the detectability of the system and therefore reduced the enzyme reaction time in both off-line and in-line mode. Both electrophoretically mediated microanalysis and pressure mediated microanalysis combined with MS detection were investigated for MMP inhibitor screening. Good repeatability (RSD of peak area and migration time were lower than 5.0%) and linearity (R(2)>0.996) were obtained for both in-capillary approaches. Several tetracycline antibiotics and natural products were selected to test the system. The results indicated an agreement on the ranking of inhibitory potency for both in-capillary approaches.

Doxycycline-loaded ß-tricalcium phosphate release following EDTA root surface etching improved the clinical outcomes in chronic periodontitis: an in vivo study.

BACKGROUND: The main objective of the present study is to quantify doxycycline (DOX) release from ß-tricalcium phosphate (ß-TCP) after EDTA root surface treatment. METHODS: Thirty systemically healthy patients with ≥1 paired contralateral interproximal intrabony defect ≥4 mm deep along with an interproximal probing depth ≥6 mm and clinical attachment level ≥4 mm were randomized into two groups. Group 1 (G1) consisted of sites treated with open flap debridement followed by placement of DOX blended with ß-TCP (DOX-ß-TCP), whereas group 2 (G2) sites were treated with flap surgery followed by the placement of DOX blended with ß-TCP after EDTA etching of the exposed root surfaces (DOX-ß-TCP + EDTA). Samples of gingival crevicular fluid (GCF) were obtained 1, 3, 7, 14, and 21 days after surgery. Quantitative measurements of DOX were taken with high-performance liquid chromatography. Clinical evaluation and follow-up for 6 months were performed. RESULTS: At 21 days, the DOX-ß-TCP + EDTA-treated group showed a 194.7 µg/mL value. The DOX-ß-TCP + EDTA-treated group retained more DOX during the periods of 3, 7, 10, 14, and 21 days than the DOX-ß-TCP-treated group. Six months after therapy, DOX-ß-TCP + EDTA-treated sites showed more significant clinical improvements compared to DOX-ß-TCP-treated sites (P ≤ 0.05). CONCLUSIONS: EDTA root surface etching enhances DOX availability in the GCF following its release from ß-TCP as a drug carrier.

Comparison of gene expression of tissue inhibitor of matrix metalloproteinase-1 between continuous and intermittent distraction osteogenesis: a quantitative study on rabbits.

BACKGROUND: Distraction osteogenesis is a controlled surgical procedure that initiates a regenerative process and uses mechanical strain to enhance the biological responses of the injured tissues to create new bone. To explore the effect of high-frequency mechanical traction on the expression of tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), we compared the gene expression of TIMP-1 between continuous and intermittent distraction osteogenesis using a rabbit model of mandibular lengthening. MATERIALS AND METHODS: Forty adult New Zealand white rabbits were randomly assigned to the intermittent and continuous distraction groups. A unilateral mandibular osteotomy was performed and a custom-designed manual-driven or auto-driven distractor was bridged over the osteotomy segments. Animals were sacrificed at day-6, day-10, day-14 and day-21 after osteotomy. Samples were examined with real-time polymerase chain reaction (PCR). RESULTS: Real-time PCR examination showed significantly higher mRNA levels of TIMP-1 under continuous distraction than that under intermittent distraction at day-6 and day-10. No significant differences were found at day-14 and day-21. CONCLUSION: High-frequency traction provides a good mechanical environment for accelerating bone formation by up-regulating TIMP-1.