MMPs as therapeutic targets--still a viable option?

Inhibition of matrix metalloproteinases to reduce blood brain barrier disruption and haemorrhagic transformation in ischaemic stroke: Go broad or go narrow?

Ischaemic stroke characterises impulsive cerebral-region hypoxia due to deep intracerebral arteriole blockage, often accompanied by permanent cerebral infarction and cognitive impairment. Thrombolysis with recombinant tissue plasminogen activator (rtPA) and thrombectomy remain the only guidance-approved therapies. However, emerging data draws clear links between such therapies and haemorrhage transformation, which occur when cerebral vasculature is damaged during ischaemia/reperfusion. Studies have shown that matrix metalloproteinases (MMPs) play a significant role in haemorrhage transformation, by depleting the extracellular matrix (ECM) and disrupting the blood brain barrier (BBB). Inhibitors of MMPs may be used to prevent ischaemic stroke patients from BBB disruption and haemorrhage transformation, particularly for those receiving rtPA treatment. Preclinical studies found that inhibition of MMPs with agents or in knock out mice, effectively reduced BBB disruption and infarct volume, leading to improved ischaemic stroke outcomes. At present, MMP inhibition is not an approved therapy for stroke patients. There remain concerns about timing, dosing, duration of MMP inhibition and selection of either broad spectrum or specific MMP inhibitors for stroke patients. This review aims to summarize current knowledge on MMP inhibition in ischaemic stroke and explore whether a broad spectrum or a specific MMP inhibitor should be used for ischaemic stroke patient treatment. It is crucial to inhibit MMP activities early and sufficiently to ensure BBB intact during ischaemia and reperfusion, but also to reduce side effects of MMP inhibitors to minimum. Recent advance in stroke therapy by thrombectomy could aid in such treatment with intra-arterially delivery of MMP inhibitors (and/or antioxidants).

Targeting Matrix Metalloproteinases and Their Inhibitors in Melanoma

Malignant melanoma is one of the most important dermatological neoplasms. The high mortality rate associated with this skin disease is primarily due to the occurrence of metastases, while the diagnosis and treatment of melanoma in its early stages has a favorable prognosis. Early detection is crucial because the success of treatment is directly related to the depth of cancerous growth. The family of matrix metalloproteinases (MMPs) plays a critical role in the initiation and progression of melanoma. Prominent MMPs, including MMP-1, MMP-2, MMP-3, MMP-9, MMP-13, and MMP-14, have been shown to significantly contribute to the development of melanoma. The tumor microenvironment, particularly the extracellular matrix (ECM), has emerged as a critical factor in modulating cancer progression. This review focuses on the role of matrix metalloproteinases and their inhibitors in ECM degradation and the subsequent progression of melanoma, as well as their potential as therapeutic targets.

Novel drug discovery approaches for MMP-13 inhibitors in the treatment of osteoarthritis

Recently, the key role of matrix metalloproteinase-13 (MMP-13) in a variety of diseases has attracted much attention. In the field of osteoarthritis (OA) treatment, the study of MMP-13 inhibitors has become a hotspot, and the development of selective MMP-13 inhibitors is a key direction of OA treatment strategies. This paper aims to summarize the latest research progress on MMP-13 inhibitors in drug design and delivery systems in OA treatment, in order to provide new ideas and strategies for the development of MMP-13 inhibitors. In the context of drug design, researchers have utilized innovative drug discovery strategies to developed a number of potential MMP-13 inhibitors by accurately simulating the active site and analyzing the structure of known inhibitors. With regard to delivery systems, nanotechnology has been extensively employed to enhance the targeting and bioavailability of MMP-13 inhibitors, effectively improving therapeutic efficacy through precise delivery to the lesion site. The latest research developments not only reveal the significant potential of MMP-13 inhibitors in disease treatment, but also provide new directions and challenges for future research.

MMPs as potential molecular targets in epithelial-to-mesenchymal transition driven COPD progression

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality globally and the risk of developing lung cancer is six times greater in individuals with COPD who smoke compared to those who do not smoke. Matrix metalloproteinases (MMPs) play a crucial role in the pathophysiology of respiratory diseases by promoting inflammation and tissue degradation. Furthermore, MMPs are involved in key processes like epithelial-to-mesenchymal transition (EMT), metastasis, and invasion in lung cancer. While EMT has traditionally been associated with the progression of lung cancer, recent research highlights its active involvement in individuals with COPD. Current evidence underscores its role in orchestrating airway remodeling, fostering airway fibrosis, and contributing to the potential for malignant transformation in the complex pathophysiology of COPD. The precise regulatory roles of diverse MMPs in steering EMT during COPD progression needs to be elucidated. Additionally, the less-understood aspect involves how these MMPs bi-directionally activate or regulate various EMT-associated signaling cascades during COPD progression. This review article explores recent advancements in understanding MMPs' role in EMT during COPD progression and various pharmacological approaches to target MMPs. It also delves into the limitations of current MMP inhibitors and explores novel, advanced strategies for inhibiting MMPs, potentially offering new avenues for treating respiratory diseases.

The TIMP protein family: diverse roles in pathophysiology

The tissue inhibitors of matrix metalloproteinases (TIMPs) are a family of four matrisome proteins classically defined by their roles as the primary endogenous inhibitors of metalloproteinases (MPs). Their functions however are not limited to MP inhibition, with each family member harboring numerous MP-independent biological functions that play key roles in processes such as inflammation and apoptosis. Because of these multifaceted functions, TIMPs have been cited in diverse pathophysiological contexts. Herein, we provide a comprehensive overview of the MP-dependent and -independent roles of TIMPs across a range of pathological conditions. The potential therapeutic and biomarker applications of TIMPs in these disease contexts are also considered, highlighting the biomedical promise of this complex and often misunderstood protein family.

Effects of toxin metalloproteinases from jellyfish Nemopilema nomurai nematocyst on the dermal toxicity and potential treatment of jellyfish dermatitis

Jellyfish dermatitis is a common medical problem in many countries due to the jellyfish envenomation. However, there are no specific and targeted medications for their treatment. Here we investigated the possible therapeutic effects of metalloproteinase inhibitors on the dermal toxicity of Nemopilema nomurai nematocyst venom (NnNV), a giant venomous jellyfish from China, using the jellyfish dermatitis model, focusing on inflammatory effector molecules during jellyfish envenomation. Metalloproteinase may further stimulate inflammation by promoting oxidative stress in the organism and play key roles by activating MAPK and NF-κB, in the pathogenesis of jellyfish dermatitis. And the metalloproteinase inhibitors batimastat and EDTA disodium salt may treat the Jellyfish dermatitis by inhibiting the metalloproteinase activity in NnNV. These observations suggest that the metalloproteinase components of NnNV make a considerable contribution to dermal toxicity as the inflammation effect molecular, and metalloproteinase inhibitors can be regarded as novel therapeutic medicines in jellyfish envenomation. This study contributes to understanding the mechanism of jellyfish dermatitis and suggests new targets and ideas for the treatment of jellyfish envenomation.

Engineering minimal tissue inhibitors of metalloproteinase targeting MMPs via gene shuffling and yeast surface display

Overexpression of specific matrix metalloproteinases (MMPs) has a key role in development of several diseases, such as cancer, neurological disorders, and cardiovascular diseases due to their critical role in degradation and remodeling of the extracellular matrix (ECM). Tissue inhibitors of metalloproteinases (TIMPs), a family of four in humans, are endogenous inhibitors of MMPs. TIMPs have a high level of sequence and structure homology, with a broad range of binding and inhibition to the family of MMPs. It is important to identify the key motifs of TIMPs responsible for inhibition of MMPs to develop efficient therapeutics targeting specific MMPs. We used DNA shuffling between the human TIMP family to generate a minimal TIMP hybrid library in yeast to identify the dominant minimal MMP inhibitory regions. The minimal TIMP variants screened toward MMP-3 and MMP-9 using fluorescent-activated cell sorting (FACS). Interestingly, several minimal TIMP variants selected after screening toward MMP-3cd or MMP-9cd, with lengths as short as 20 amino acids, maintained or improved binding to MMP-3 and MMP-9. The TIMP-MMP binding dissociation constant (KD ), in the nM range, and MMP inhibition constants (Ki ), in the pM range, of these minimal TIMP variants were similar to the N-terminal domain of TIMP-1 on the yeast surface and in solution indicating the potency of these minimal variants as MMP inhibitors. We further used molecular modeling simulation, and molecular docking of the minimal TIMP variants in complex with MMP-3cd to understand the binding and inhibition mechanism of these variants.

New Derivatives of N-Hydroxybutanamide: Preparation, MMP Inhibition, Cytotoxicity, and Antitumor Activity

Using a novel method of N-substituted succinimide ring opening, new N-hydroxybutanamide derivatives were synthesized. These compounds were evaluated for their ability to inhibit matrix metalloproteinases (MMPs) and their cytotoxicity. The iodoaniline derivative of N1-hydroxy-N4-phenylbutanediamide showed the inhibition of MMP-2, MMP-9, and MMP-14 with an IC50 of 1-1.5 μM. All the compounds exhibited low toxicity towards carcinoma cell lines HeLa and HepG2. The iodoaniline derivative was also slightly toxic to glioma cell lines A-172 and U-251 MG. Non-cancerous FetMSC and Vero cells were found to be the least sensitive to all the compounds. In vivo studies demonstrated that the iodoaniline derivative of N1-hydroxy-N4-phenylbutanediamide had low acute toxicity. In a mouse model of B16 melanoma, this compound showed both antitumor and antimetastatic effects, with a 61.5% inhibition of tumor growth and an 88.6% inhibition of metastasis. Our findings suggest that the iodoaniline derivative of N1-hydroxy-N4-phenylbutanediamide has potential as a lead structure for the development of new MMP inhibitors. Our new synthetic approach can be a cost-effective method for the synthesis of inhibitors of metalloenzymes with promising antitumor potential.

Antibody drug conjugates beyond cytotoxic payloads

For many years, antibody drug conjugates (ADC) have teased with the promise of targeted payload delivery to diseased cells, embracing the targeting of the antibody to which a cytotoxic payload is conjugated. During the past decade this promise has started to be realised with the approval of more than a dozen ADCs for the treatment of various cancers. Of these ADCs, brentuximab vedotin really laid the foundations of a template for a successful ADC with lysosomal payload release from a cleavable dipeptide linker, measured DAR by conjugation to the Cys-Cys interchain bonds of the antibody and a cytotoxic payload. Using this ADC design model oncology has now expanded their repertoire of payloads to include non-cytotoxic compounds. These new payload classes have their origins in prior medicinal chemistry programmes aiming to design selective oral small molecule drugs. While this may not have been achieved, the resulting compounds provide excellent starting points for ADC programmes with some compounds amenable to immediate linker attachment while for others extensive SAR and structural information offer invaluable design insights. Many of these new oncology payload classes are of interest to other therapeutic areas facilitating rapid access to drug-linkers for exploration as non-oncology ADCs. Other therapeutic areas have also pursued unique payload classes with glucocorticoid receptor modulators (GRM) being the most clinically advanced in immunology. Here, ADC payloads come full circle, as oncology is now investigating GRM payloads for the treatment of cancer. This chapter aims to cover all these new ADC approaches while describing the medicinal chemistry origins of the new non-cytotoxic payloads.

Breaching the Fortress of Tumor Microenvironment to Control Cancer Metastasis

As the primary cause of death for >90% of cancers, metastasis is the fourth and final stage of cancer during which cells gain the ability to leave their primary site, invade surrounding tissues, and disseminate to distant organs [...].

Molecular Mechanisms Driven by MT4-MMP in Cancer Progression

MT4-MMP (or MMP-17) belongs to the membrane-type matrix metalloproteinases (MT-MMPs), a distinct subset of the MMP family that is anchored to the cell surface, in this case by a glycosylphosphatidylinositol (GPI) motif. Its expression in a variety of cancers is well documented. However, the molecular mechanisms by which MT4-MMP contributes to tumor development need further investigation. In this review, we aim to summarize the contribution of MT4-MMP in tumorigenesis, focusing on the molecular mechanisms triggered by the enzyme in tumor cell migration, invasiveness, and proliferation, in the tumor vasculature and microenvironment, as well as during metastasis. In particular, we highlight the putative substrates processed and signaling cascades activated by MT4-MMP that may underlie these malignancy processes and compare this with what is known about its role during embryonic development. Finally, MT4-MMP is a relevant biomarker of malignancy that can be used for monitoring cancer progression in patients as well as a potential target for future therapeutic drug development.

Noncanonical Activity of Tissue Inhibitor of Metalloproteinases 2 (TIMP2) Improves Cognition and Synapse Density in Aging

Peripheral administration of tissue inhibitor of metalloproteinases 2 (TIMP2), a protein inhibitor of matrix metalloproteinases (MMPs), has previously been shown to have beneficial effects on cognition and neurons in aged mice. Here, to better understand the potential of recombinant TIMP2 proteins, an IgG4Fc fusion protein (TIMP2-hIgG4) was developed to extend the plasma half-life of TIMP2. Following one month of administration of TIMP2 or TIMP2-hIgG4 via intraperitoneal injections, 23-month-old male C57BL/6J mice showed improved hippocampal-dependent memory in a Y-maze, increased hippocampal cfos gene expression, and increased excitatory synapse density in the CA1 and dentate gyrus (DG) of the hippocampus. Thus, fusion to hIgG4 extended the half-life of TIMP2 while retaining the beneficial cognitive and neuronal effects. Moreover, it retained its ability to cross the blood-brain barrier. To deepen the mechanistic understanding of the beneficial function of TIMP2 on neuronal activity and cognition, a TIMP2 construct lacking MMP inhibitory activity, Ala-TIMP2, was generated, which provides steric hindrance that prevents inhibition of MMPs by the TIMP2 protein while still allowing MMP binding. A comprehensive assessment of the MMP inhibitory and binding capacity of these engineered proteins is outlined. Surprisingly, MMP inhibition by TIMP2 was not essential for its beneficial effects on cognition and neuronal function. These findings both confirm previously published research, expand on the potential mechanism for the beneficial effects of TIMP2, and provide important details for a therapeutic path forward for TIMP2 recombinant proteins in aging-related cognitive decline.

Characterization of the basement membrane in kidney renal clear cell carcinoma to guide clinical therapy

Background

Renal cell carcinoma (RCC) is the most common kidney cancer in adults. According to the histological features, it could be divided into several subtypes, of which the most common one is kidney renal clear cell carcinoma (KIRC), which contributed to more than 90% of cases for RCC and usually ends with a dismal outcome. Previous studies suggested that basement membrane genes (BMGs) play a pivotal role in tumor development. However, the significance and prognostic value of BMGs in KIRC still wrap in the mist.

Methods

KIRC data were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. A prognostic risk score (PRS) model based on BMGs was established using univariate and least absolute shrinkage and selection operator (LASSO) and the Cox regression analysis was performed for prognostic prediction. The Kaplan-Meier analysis, univariate Cox regression, multivariate Cox regression, receiver operating characteristic (ROC) curves, nomogram, and calibration curves were utilized to evaluate and validate the PRS model. All KIRC cases were divided into the high-risk score (HRS) group and the low-risk score (LRS) group according to the median risk scores. In addition, single-sample gene set enrichment analysis (ssGSEA), immune analysis, tumor microenvironment (TME) analysis, principal component analysis (PCA), and half-maximal inhibitory concentration (IC50) were also applied. Expression levels of BMGs were confirmed by qRT-PCR in both human renal cancer cell lines and tissues.

Results

We established the BMGs-based prognostic model according to the following steps. Within the TCGA cohort, patients’ prognosis of the HRS group was significantly worse than that of the LRS group, which was consistent with the analysis results of the GEO cohort. PCA patterns were significantly distinct for LRS and HRS groups and pathological features of the HRS group were more malignant compared with the LRS group. Correlation analysis of the PRS model and TME features, such as immune cell scores, stromal cell scores, and ESTIMATE values, revealed a higher immune infiltration in the HRS group compared with the LRS group. The chemotherapeutic response was also evaluated in KIRC treatment. It showed that the HRS group exhibited stronger chemoresistance to chemotherapeutics like FR-180204, GSK1904529A, KIN001-102, and YM201636. The therapeutic reactivity of the other 27 chemotherapeutic agents was summarized as well. Furthermore, the FREM2 level was measured in both human kidney tissues and associated cell lines, which suggested that lower FREM2 expression prompts a severer pathology and clinical ending.

Conclusions

Our study showed that KIRC is associated with a unique BMG expression pattern. The risk scores related to the expression levels of 10 BMGs were assessed by survival status, TME, pathological features, and chemotherapeutic resistance. All results suggested that FREM2 could be a potential candidate for KIRC prognosis prediction. In this study, we established a valid model and presented new therapeutic targets for the KIRC prognosis prediction as well as the clinical treatment recommendation, and finally, facilitated precision tumor therapy for every single individual.

Nanoscale Tracking Combined with Cell-Scale Microrheology Reveals Stepwise Increases in Force Generated by Cancer Cell Protrusions

In early breast cancer progression, cancer cells invade through a nanoporous basement membrane (BM) as a first key step toward metastasis. This invasion is thought to be mediated by a combination of proteases, which biochemically degrade BM matrix, and physical forces, which mechanically open up holes in the matrix. To date, techniques that quantify cellular forces of BM invasion in 3D culture have been unavailable. Here, we developed cellular-force measurements for breast cancer cell invasion in 3D culture that combine multiple-particle tracking of force-induced BM-matrix displacements at the nanoscale, and magnetic microrheometry of localized matrix mechanics. We find that cancer-cell protrusions exert forces from picoNewtons up to nanoNewtons during invasion. Strikingly, the protrusions extension involves stepwise increases in force, in steps of 0.2 to 0.5 nN exerted from every 30 s to 6 min. Thus, this technique reveals previously unreported dynamics of force generation by invasive protrusions in cancer cells.

Hemimycale Arabica Induced Non-Cytotoxic Anti-Migratory Activity in Hepatocellular Carcinoma In Vitro

OBJECTIVE

In this work, we represented new non-cytotoxic treatments to avoid serious side effects of current used cytotoxic anticancer drugs. These treatments can compensate in finding convenient treatment for each individual case using a single agent from marine sponge Hemimycale arabica.

METHODS

The ethanol extract was partitioned by cold sequential liquid-liquid extraction to afford petroleum ether, diethyl ether, dichloromethane and ethyl acetate fractions. Chemical composition of H. arabica was performed by gas-liquid chromatography and gas chromatography-mass spectroscopy. Anticancer activity was evaluated by means of cytotoxicity, apoptosis induction, tumor cell migration inhibition and expression analysis of proliferation and migration-related genes.

RESULTS

Our results revealed that all treatments were non-cytotoxic except for dichloromethane fraction which exhibited moderate cytotoxic activity. Caspase-independent apoptosis was induced by total ethanol and dichloromethane fractions while ethyl acetate fraction induces caspase-dependent apoptosis. All treatments inhibited matrix metalloproteinase-independent migration. Petroleum ether and dichloromethane inhibited migration through the down-regulation of FGF and it could be used as anticancer therapy for VEGF-resistance patients. While ethanol inhibited tumor cell migration through down-regulation of all tested genes expression. Ether and ethyl acetate fractions exerted anti-migratory activity without affecting the tested genes. All resuls were statistically significant at p˂0.05.

CONCLUSION

Total ethanol extract is a promising non-cytotoxic anticancer agent because of its powerful apoptosis induction and capability to block tumor cell migration. Petroleum ether and ether fractions area weak non-cytotoxic anti-migratory agents. Dichloromethane could be a moderate cytotoxic anti-migratory agent induced caspase-independent apoptosis. It could be used in anticancer therapy for VEGF-resistance patients through downregulation of FGF. Ethyl acetate fraction considered a non-cytotoxic agent exerting moderate anti-migratory activity. The new sponge-derived treatments can solve different resistance problems to find a convenient treatment for each individual case using a single agent.

Selective Inhibitors of Medium-Size S1' Pocket Matrix Metalloproteinases: A Stepping Stone of Future Drug Discovery

Among various matrix metalloproteinases (MMPs), MMPs having medium-size S1' pockets are established as promising biomolecular targets for executing crucial roles in cancer, cardiovascular diseases, and neurodegenerative diseases. However, no such MMP inhibitors (MMPIs) are available to date as drug candidates despite a lot of continuous research work for more than three decades. Due to a high degree of structural resemblance among these MMPs, designing selective MMPIs is quite challenging. However, the variability and uniqueness of the S1' pockets of these MMPs make them promising targets for designing selective MMPIs. In this perspective, the overall structural aspects of medium-size S1' pocket MMPs including the unique binding patterns of enzyme-inhibitor interactions have been discussed in detail to acquire knowledge regarding selective inhibitor designing. This overall knowledge will surely be a curtain raiser for the designing of selective MMPIs as drug candidates in the future.

Matrix Metalloproteinases: From Molecular Mechanisms to Physiology, Pathophysiology, and Pharmacology

The first matrix metalloproteinase (MMP) was discovered in 1962 from the tail of a tadpole by its ability to degrade collagen. As their name suggests, matrix metalloproteinases are proteases capable of remodeling the extracellular matrix. More recently, MMPs have been demonstrated to play numerous additional biologic roles in cell signaling, immune regulation, and transcriptional control, all of which are unrelated to the degradation of the extracellular matrix. In this review, we will present milestones and major discoveries of MMP research, including various clinical trials for the use of MMP inhibitors. We will discuss the reasons behind the failures of most MMP inhibitors for the treatment of cancer and inflammatory diseases. There are still misconceptions about the pathophysiological roles of MMPs and the best strategies to inhibit their detrimental functions. This review aims to discuss MMPs in preclinical models and human pathologies. We will discuss new biochemical tools to track their proteolytic activity in vivo and ex vivo, in addition to future pharmacological alternatives to inhibit their detrimental functions in diseases. SIGNIFICANCE STATEMENT: Matrix metalloproteinases (MMPs) have been implicated in most inflammatory, autoimmune, cancers, and pathogen-mediated diseases. Initially overlooked, MMP contributions can be both beneficial and detrimental in disease progression and resolution. Thousands of MMP substrates have been suggested, and a few hundred have been validated. After more than 60 years of MMP research, there remain intriguing enigmas to solve regarding their biological functions in diseases.

Substituted Syndecan-2-Derived Mimetic Peptides Show Improved Antitumor Activity over the Parent Syndecan-2-Derived Peptide

We previously showed that a synthetic peptide (S2-P) corresponding to a portion of the human syndecan-2 (SDC2) sequence can bind to the pro-domain of matrix metalloproteinase-7 (MMP-7) to inhibit colon cancer activities. Since S2-P had a relatively weak binding affinity for the MMP-7 pro-domain, we herein modified the amino acid sequence of S2-P to improve the anticancer potential. On the basis of the interaction structure of S2-P and MMP-7, four peptides were generated by replacing amino acids near Tyr 51, which is critical for the interaction. The SDC2-mimetic peptides harboring an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-D) or with an Ala-to-Phe substitution at the N-terminal side of Tyr 51 and an Ala-to-Asp substitution at the C-terminal side of Tyr 51 (S2-FE) showed improved interaction affinities for the MMP-7 pro-domain. Compared to S2-P, S2-FE was better able to inhibit the SDC2-MMP-7 interaction, the cell surface localization of MMP-7, the gelatin degradation activity of MMP-7, and the cancer activities (cell migration, invasion, and colony-forming activity) of human HCT116 colon cancer cells in vitro. In vivo, S2-FE inhibited the primary tumor growth and lung metastasis of CT26 mouse colon cancer cells in a xenograft mouse model. Together, these data suggest that S2-FE could be useful therapeutic anticancer peptides for colon cancer.

Concentration of Serum Matrix Metalloproteinase-3 in Patients With Primary Biliary Cholangitis

Background and Aims

Metalloproteinases (MMPs) are involved in many distinct processes in the liver. Matrix metalloproteinase-3 (MMP-3) plays an important role in connective tissue remodeling, degradation of collagen (types II, III, IV, IX, and X), proteoglycans, fibronectin, laminin, and elastin. In addition, MMP-3 can also activate other MMPs such as MMP-1, MMP-7, and MMP-9. Primary biliary cholangitis (PBC) is a cholestatic, autoimmune liver disease, characterized by the progressive destruction of intrahepatic bile ducts, leading to cholestasis, fibrosis, cirrhosis, and liver failure. Fibrosis is the result of an imbalance between production and degradation of the extracellular matrix surrounding hepatocytes. Our aim in the present study was to determine whether the measurement of serum MMP-3 is clinically useful for assessing ongoing liver fibrosis in patients with PBC.

Methods

The MMP-3 concentration was determined in 182 PBC patients and 80 non-PBC controls using a commercially available ELISA kit.

Results

Higher concentrations of MMP-3 were found in 61% of PBC patients. PBC subjects had greater MMP-3 levels than controls: 68.9 ± 62.6 vs 21.3 ± 7.4 ng/mL, p < 0.001 for healthy subjects; 68.9 ± 62.6 vs 22.7 ± 7.6 ng/mL, p = 0.022 for autoimmune hepatitis controls; and 68.9 ± 62.6 vs 37.2 ± 17.4 ng/mL, p = 0.002 for primary sclerosing cholangitis controls. The serum MMP-3 concentration was significantly elevated in patients with higher bilirubin concentration (107.6 ± 85.8 vs 61.6 ± 46.1 ng/mL, p < 0.001) and was correlated with the level of antimitochondrial antibodies specific for PBC. The concentration of MMP-3 in sera of PBC patients was also found to correlate with the state of liver fibrosis (OR = 4.3; p < 0.01).

Conclusions

Our study demonstrated significantly higher MMP-3 levels in PBC patients than in healthy and pathological controls. Increased MMP-3 concentrations were positively correlated with various clinical and immunological parameters, and advanced liver fibrosis. The level of MMP-3 was associated with hepatic dysfunction and could play a role in the pathophysiology of hepatic fibrosis in PBC.

Engineering of tissue inhibitor of metalloproteinases TIMP-1 for fine discrimination between closely-related stromelysins MMP-3 and MMP-10

Matrix metalloproteinases (MMPs) have long been known as key drivers in the development and progression of diseases, including cancer and neurodegenerative, cardiovascular, and many other inflammatory and degenerative diseases, making them attractive potential drug targets. Engineering selective inhibitors based upon tissue inhibitors of metalloproteinases (TIMPs), endogenous human proteins that tightly yet nonspecifically bind to the family of MMPs, represents a promising new avenue for therapeutic development. Here, we used a counter-selective screening strategy for directed evolution of yeast-displayed human TIMP-1 to obtain TIMP-1 variants highly selective for the inhibition of MMP-3 in preference over MMP-10. As MMP-3 and MMP-10 are the most similar MMPs in sequence, structure, and function, our results thus clearly demonstrate the capability for engineering full-length TIMP proteins to be highly selective MMP inhibitors. We show using protein crystal structures and models of MMP-3-selective TIMP-1 variants bound to MMP-3 and counter-target MMP-10 how structural alterations within the N-terminal and C-terminal TIMP-1 domains create new favorable and selective interactions with MMP-3 and disrupt unique interactions with MMP-10. While our MMP-3-selective inhibitors may be of interest for future investigation in diseases where this enzyme drives pathology, our platform and screening strategy can be employed for developing selective inhibitors of additional MMPs implicated as therapeutic targets in disease.

Matrix metalloproteinase-13 is fully activated by neutrophil elastase and inactivates its serpin inhibitor, alpha-1 antitrypsin: Implications for osteoarthritis

Matrix metalloproteinase-13 (MMP-13) is a uniquely important collagenase that promotes the irreversible destruction of cartilage collagen in osteoarthritis (OA). Collagenase activation is a key control point for cartilage breakdown to occur, yet our understanding of the proteinases involved in this process is limited. Neutrophil elastase (NE) is a well-described proteoglycan-degrading enzyme which is historically associated with inflammatory arthritis, but more recent evidence suggests a potential role in OA. In this study, we investigated the effect of neutrophil elastase on OA cartilage collagen destruction and collagenase activation. Neutrophil elastase induced significant collagen destruction from human OA cartilage ex vivo, in an MMP-dependent manner. In vitro, neutrophil elastase directly and robustly activated pro-MMP-13, and N-terminal sequencing identified cleavage close to the cysteine switch at 72 MKKPR, ultimately resulting in the fully active form with the neo-N terminus of 85 YNVFP. Mole-per-mole, activation was more potent than by MMP-3, a classical collagenase activator. Elastase was detectable in human OA synovial fluid and OA synovia which displayed histologically graded evidence of synovitis. Bioinformatic analyses demonstrated that, compared with other tissues, control cartilage exhibited remarkably high transcript levels of the major elastase inhibitor, (AAT) alpha-1 antitrypsin (gene name SERPINA1), but these were reduced in OA. AAT was located predominantly in superficial cartilage zones, and staining enhanced in regions of cartilage damage. Finally, active MMP-13 specifically inactivated AAT by removal of the serine proteinase cleavage/inhibition site. Taken together, this study identifies elastase as a novel activator of pro-MMP-13 that has relevance for cartilage collagen destruction in OA patients with synovitis.

Zinc-Chelating Compounds as Inhibitors of Human and Bacterial Zinc Metalloproteases

Inhibition of bacterial virulence is believed to be a new treatment option for bacterial infections. In the present study, we tested dipicolylamine (DPA), tripicolylamine (TPA), tris pyridine ethylene diamine (TPED), pyridine and thiophene derivatives as putative inhibitors of the bacterial virulence factors thermolysin (TLN), pseudolysin (PLN) and aureolysin (ALN) and the human zinc metalloproteases, matrix metalloprotease-9 (MMP-9) and matrix metalloprotease-14 (MMP-14). These compounds have nitrogen or sulfur as putative donor atoms for zinc chelation. In general, the compounds showed stronger inhibition of MMP-14 and PLN than of the other enzymes, with K_i values in the lower μM range. Except for DPA, none of the compounds showed significantly stronger inhibition of the virulence factors than of the human zinc metalloproteases. TPA and Zn230 were the only compounds that inhibited all five zinc metalloproteinases with a K_i value in the lower μM range. The thiophene compounds gave weak or no inhibition. Docking indicated that some of the compounds coordinated zinc by one oxygen atom from a hydroxyl or carbonyl group, or by oxygen atoms both from a hydroxyl group and a carbonyl group, and not by pyridine nitrogen as in DPA and TPA.

Antitumoral and Anti-inflammatory Roles of Somatostatin and Its Analogs in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and affects about 8% of cirrhotic patients, with a recurrence rate of over 50%. There are numerous therapies available for the treatment of HCC, depending on cancer staging and condition of the patient. The complexity of the treatment is also justified by the unique pathogenesis of HCC that involves intricate processes such as chronic inflammation, fibrosis, and multiple molecular carcinogenesis events. During the last three decades, multiple in vivo and in vitro experiments have used somatostatin and its analogs (SSAs) to reduce the proliferative and metastatic potential of hepatoma cells by inducing their apoptosis and reducing angiogenesis and the inflammatory component of HCC. Most experiments have proven successful, revealing several different pathways and mechanisms corresponding to the aforementioned functions. Moreover, a correlation between specific effects and expression of somatostatin receptors (SSTRs) was observed in the studied cells. Clinical trials have tested either somatostatin or an analog, alone or in combination with other drugs, to explore the potential effects on HCC patients, in various stages of the disease. While the majority of these clinical trials exhibited minor to moderate success, some other studies were inconclusive or even reported negative outcomes. A complete evaluation of the efficacy of somatostatin and SSAs is still the matter of intense debate, and, if deemed useful, these substances may play a beneficial role in the management of HCC patients.

TC10 regulates breast cancer invasion and metastasis by controlling membrane type-1 matrix metalloproteinase at invadopodia

During breast cancer metastasis, cancer cell invasion is driven by actin-rich protrusions called invadopodia, which mediate the extracellular matrix degradation required for the success of the invasive cascade. In this study, we demonstrate that TC10, a member of a Cdc42 subfamily of p21 small GTPases, regulates the membrane type 1 matrix metalloproteinase (MT1-MMP)-driven extracellular matrix degradation at invadopodia. We show that TC10 is required for the plasma membrane surface exposure of MT1-MMP at these structures. By utilizing our Förster resonance energy transfer (FRET) biosensor, we demonstrate the p190RhoGAP-dependent regulation of spatiotemporal TC10 activity at invadopodia. We identified a pathway that regulates invadopodia-associated TC10 activity and function through the activation of p190RhoGAP and the downstream interacting effector Exo70. Our findings reveal the role of a previously unknown regulator of vesicular fusion at invadopodia, TC10 GTPase, in breast cancer invasion and metastasis.

Discovery and Structure-Activity Relationships of Quinazolinone-2-carboxamide Derivatives as Novel Orally Efficacious Antimalarials

A phenotypic high-throughput screen allowed discovery of quinazolinone-2-carboxamide derivatives as a novel antimalarial scaffold. Structure-activity relationship studies led to identification of a potent inhibitor 19f, 95-fold more potent than the original hit compound, active against laboratory-resistant strains of malaria. Profiling of 19f suggested a fast in vitro killing profile. In vivo activity in a murine model of human malaria in a dose-dependent manner constitutes a concomitant benefit.

The matrix metalloproteinase inhibitor IPR-179 has antiseizure and antiepileptogenic effects

Matrix metalloproteinases (MMPs) are synthesized by neurons and glia and released into the extracellular space, where they act as modulators of neuroplasticity and neuroinflammatory agents. Development of epilepsy (epileptogenesis) is associated with increased expression of MMPs, and therefore, they may represent potential therapeutic drug targets. Using quantitative PCR (qPCR) and immunohistochemistry, we studied the expression of MMPs and their endogenous inhibitors tissue inhibitors of metalloproteinases (TIMPs) in patients with status epilepticus (SE) or temporal lobe epilepsy (TLE) and in a rat TLE model. Furthermore, we tested the MMP2/9 inhibitor IPR-179 in the rapid-kindling rat model and in the intrahippocampal kainic acid mouse model. In both human and experimental epilepsy, MMP and TIMP expression were persistently dysregulated in the hippocampus compared with in controls. IPR-179 treatment reduced seizure severity in the rapid-kindling model and reduced the number of spontaneous seizures in the kainic acid model (during and up to 7 weeks after delivery) without side effects while improving cognitive behavior. Moreover, our data suggest that IPR-179 prevented an MMP2/9-dependent switch-off normally restraining network excitability during the activity period. Since increased MMP expression is a prominent hallmark of the human epileptogenic brain and the MMP inhibitor IPR-179 exhibits antiseizure and antiepileptogenic effects in rodent epilepsy models and attenuates seizure-induced cognitive decline, it deserves further investigation in clinical trials.

Identification of Broad-Spectrum MMP Inhibitors by Virtual Screening

Matrix metalloproteinases (MMPs) are the family of proteases that are mainly responsible for degrading extracellular matrix (ECM) components. In the skin, the overexpression of MMPs as a result of ultraviolet radiation triggers an imbalance in the ECM turnover in a process called photoaging, which ultimately results in skin wrinkling and premature skin ageing. Therefore, the inhibition of different enzymes of the MMP family at a topical level could have positive implications for photoaging. Considering that the MMP catalytic region is mostly conserved across different enzymes of the MMP family, in this study we aimed to design a virtual screening (VS) workflow to identify broad-spectrum MMP inhibitors that can be used to delay the development of photoaging. Our in silico approach was validated in vitro with 20 VS hits from the Specs library that were not only structurally different from one another but also from known MMP inhibitors. In this bioactivity assay, 18 of the 20 compounds inhibit at least one of the assayed MMPs at 100 μM (with 5 of them showing around 50% inhibition in all the tested MMPs at this concentration). Finally, this VS was used to identify natural products that have the potential to act as broad-spectrum MMP inhibitors and be used as a treatment for photoaging.

Inhibitors of gelatinases (MMP-2 and MMP-9) for the management of hematological malignancies

Matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) are collectively known as gelatinases whereas MMP-2 is gelatinase-A and MMP-9 is termed as gelatinase-B. Gelatinases and other matrix metalloproteinases (MMPs) have long been associated with solid tumor invasion, metastasis and angiogenesis. However, there is paucity of data available regarding the role of gelatinases in hematological malignancies. Recent studies have shown that gelatinases activities or functions are correlated with hematological malignancies. Strategies for designing more specific gelatinase inhibitors like catalytic (CAT) domain inhibitors and hemopexin (PEX) domain inhibitors as well as signaling pathway based or gelatinase expression inhibitors had been reported against hematologic malignant cells. Several substrate based non-selective to non-substrate based relatively selective synthetic matrix metalloproteinase inhibitors (MMPIs) had been developed. Few MMPIs had reached in clinical trials during the period of 1990s-2000s. Unfortunately the anti-tumor and anti-metastatic efficacies of these MMPIs were not justified with patients having several advanced stage solid tumor cancers in any substantial number of clinical trials. Till date not a single MMPI passed phase III clinical trials designed for advanced metastatic cancers due to adverse events as well as lack of ability to show uniformity in disease prolongation. With the best of our knowledge no clinical trial study has been reported with small molecule synthetic inhibitors against hematological malignancies. This review looks at the outcome of clinical trials of MMPIs for advanced stage solid tumors. This can therefore, act as a learning experience for future development of successful gelatinase inhibitors for the management of hematological malignancies.

Inhibition of MMP2-PEX by a novel ester of dihydroxy cinnamic and linoleic acid from the seagrass Cymodocea serrulata

Matrix metalloproteinases (MMPs) are pivotal for cancer cell migration and metastasis which are generally over-expressed in such cell types. Many drugs targeting MMPs do so by binding to the conserved catalytic domains and thus exhibit poor selectivity due to domain-similarities with other proteases. We report herein the binding of a novel compound [3-(E-3,4-dihydroxycinnamaoyloxyl)-2-hydroxypropyl 9Z, 12Z-octadeca-9, 12-dienoate; Mol. wt: 516.67 Da], (C₁), isolated from a seagrass, Cymodocea serrulata to the unconserved hemopexin-like (PEX) domain of MMP2 (- 9.258 kcal/mol). MD simulations for 25 ns, suggest stable ligand-target binding. In addition, C₁ killed an ovarian cancer cell line, PA1 at IC₅₀: 5.8 μM (lesser than Doxorubicin: 8.6 µM) and formed micronuclei, apoptotic bodies and nucleoplasmic bridges whilst causing DNA laddering, S and G2/M phase dual arrests and MMP disturbance, suggesting intrinsic apoptosis. The molecule increased mRNA transcripts of BAX and BAD and down-regulated cell survival genes, Bcl-xL, Bcl-2, MMP2 and MMP9. The chemical and structural details of C₁ were deduced through FT-IR, GC-MS, ESI-MS, ¹H and ¹³C NMR [both 1D and 2D] spectra.

Trypsinogen and chymotrypsinogen: potent anti-tumor agents

Introduction: Trypsinogen and chymotrypsinogen have been used clinically in tissue repair due to their ability to resolve inflammatory symptoms. Recently, novel evidence has supported the anti-tumourigenic potential of a mixture of trypsinogen and chymotrypsinogen.Areas covered: First, we analyze the structure of these proteases and the effects of pancreatic proteinases on tissue repair, inflammation and the immune system. Second, we summarize studies that provided evidence of the effects of pancreatic (pro)enzymes on tumor cells both in vitro and in vivo and some successful clinical applications of pancreatic (pro)enzymes. Finally, we study pancreatic (pro)enzymes potential molecular targets, such as the proteinase-activated receptors (PARs).Expert opinion: This novel therapy has been shown to have effective antitumor effects. Treatment with these (pro) enzymes sensitizes Cancer Stem Cells (CSCs) which may allow chemotherapy and radiotherapy to be more effective, which could positively affect the recovery of cancer patients.

Matrix Metalloproteinase 13 Inhibitors for Modulation of Osteoclastogenesis: Enhancement of Solubility and Stability

Matrix metalloproteinase 13 (MMP-13) activity has been correlated to breast cancer bone metastasis. It has been proposed that MMP-13 contributes to bone metastasis through the promotion of osteoclastogenesis. To explore the mechanisms of MMP-13 action, we previously described a highly efficacious and selective MMP-13 inhibitor, RF036. Unfortunately, further pursuit of RF036 as a probe of MMP-13 in vitro and in vivo activities was not practical due to the limited solubility and stability of the inhibitor. Our new study has explored replacing the RF036 backbone sulfur atom and terminal methyl group to create inhibitors with more favorable pharmacokinetic properties. One compound, designated inhibitor 3, in which the backbone sulfur and terminal methyl group of RF036 were replaced by nitrogen and oxetane, respectively, had comparable activity, selectivity, and membrane permeability to RF036, while exhibiting greatly enhanced solubility and stability. Inhibitor 3 effectively inhibited MMP-13-mediated osteoclastogenesis but spared collagenolysis, and thus represents a next-generation MMP-13 probe applicable for in vivo studies of breast cancer metastasis.

Matrix metalloproteinases in the pathogenesis of dengue viral disease: Involvement of immune system and newer therapeutic strategies

Globally, the burden due to dengue infection is increasing with a recent estimate of 96 million progressing to the disease every year. Dengue pathogenesis and the factors influencing it are not completely known. It is now widely speculated that there is an important role of matrix metalloproteinases (MMPs) in the initiation and progression of dengue pathogenesis; however, their exact roles are not fully understood. Overactivation of matrix metalloproteinases may contribute to the severity of dengue pathogenesis. Cytokines and various other mediators of inflammation interact with the vascular endothelium and matrix metalloproteinases may be one of the components among them. Extensive plasma leakage into tissue spaces may result in a shock. It is evident in the literature that MMP2 and MMP9 increase in dengue patients is correlated with the severity of the disease; however, the underlying mechanism is still unknown. Activation of innate cells and adaptive immune cells which include, B and T cells, macrophages or monocytes and dendritic cells also contribute to the dengue pathology. Newer therapeutic strategies include microRNAs, such as miR-134 (targets MMP3 and MMP1) and MicroRNA-320d, (targets MMP/TIMP proteolytic system). The use of antibodies-based therapeutics like (Andecaliximab; anti-matrix metalloproteinase-9 antibody) is also suggested against MMPs in dengue. In this review, we summarize some recent developments associated with the involvement of immune cells and their mediators associated with the matrix metalloproteinases mediated dengue pathogenesis. We highlight that, there is still very little knowledge about the MMPs in dengue pathogenesis which needs attention and extensive investigations.

Role of Matrix Metalloproteinases in Angiogenesis and Its Implications in Asthma

Asthma is a chronic airway disorder associated with aberrant inflammatory and remodeling responses. Angiogenesis and associated vascular remodeling are one of the pathological hallmarks of asthma. The mechanisms underlying angiogenesis in asthmatic airways and its clinical relevance represent a relatively nascent field in asthma when compared to other airway remodeling features. Matrix metalloproteinases (MMPs) are proteases that play an important role in both physiological and pathological conditions. In addition to facilitating extracellular matrix turnover, these proteolytic enzymes cleave bioactive molecules, thereby regulating cell signaling. MMPs have been implicated in the pathogenesis of asthma by interacting with both the airway inflammatory cells and the resident structural cells. MMPs also cover a broad range of angiogenic functions, from the degradation of the vascular basement membrane and extracellular matrix remodeling to the release of a variety of angiogenic mediators and growth factors. This review focuses on the contribution of MMPs and the regulatory role exerted by them in angiogenesis and vascular remodeling in asthma as well as addresses their potential as therapeutic targets in ameliorating angiogenesis in asthma.

A novel biocompatible formate bridged 1D-Cu(ii) coordination polymer induces apoptosis selectively in human lung adenocarcinoma (A549) cells

Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)₂]_n, (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 Å. Primarily, in vitro DNA interaction studies revealed a metallopolymer which possesses high DNA binding propensity and cleaves DNA via the oxidative pathway. We further analysed its potential on cancerous cells MCF-7, HeLa, A549, and two non-tumorigenic cells HEK293 and HBE. The selective cytotoxicity potential of PCU1 against A549 cells driven us to examine the mechanistic pathways comprehensively by carrying out various assays viz, cell cycle arrest, Annexin V-FTIC/PI assay, autophagy, intercellular localization, mitochondrial membrane potential 'MMP', antiproliferative assay, and gene expression of TGF-β and MMP-2.

In Ovo and In Silico Evaluation of the Anti-Angiogenic Potential of Syringin

INTRODUCTION

Cancer is considered as one of the deadliest human diseases today. Angiogenesis, the propagation of new blood vessels from pre-existing vasculature, is a critical step in the progression of cancer as it is essential in the growth and metastasis of tumors. Hence, suppression of angiogenesis is a promising approach in cancer therapy. Syringin, a phenylpropanoid glycoside with a molecular formula of C17H24O9, has been found to exhibit chemopreventive effects. However, its anti-angiogenic activity and the underlying mechanism of action are still unknown.

METHODS

In this work, in ovo chorioallantoic membrane (CAM) assay has been conducted to evaluate the effect of syringin on neovascularization. Additionally, reverse molecular docking studies have been performed in order to identify the probable enzyme targets in the angiogenesis pathway.

RESULTS

Treatment with syringin showed significant dose-dependent inhibition of blood vessel length and junctions in the CAM of duck eggs; the anti-angiogenic activity of syringin at 100 µM and 200 µM is comparable with 200 µM of the positive control celecoxib. The results of reverse docking studies indicate that syringin binds the strongest to dihydrofolate reductase (DHFR) and, to some extent, with transforming growth factor-beta receptor type 1 (TGF-βR1), vascular endothelial growth factor receptor 2 (VEGFR2), and matrix metalloproteinase-2 (MMP-2). Furthermore, ADMET models revealed that syringin potentially possesses excellent pharmacokinetic and toxicity profiles.

CONCLUSION

This study demonstrates the potential of syringin as an anti-angiogenic agent and elicits further investigations to establish its application in cancer suppression.

The Role of Extracellular Proteases in Tumor Progression and the Development of Innovative Metal Ion Chelators that Inhibit their Activity

The crucial role of extracellular proteases in cancer progression is well-known, especially in relation to the promotion of cell invasion through extracellular matrix remodeling. This also occurs by the ability of extracellular proteases to induce the shedding of transmembrane proteins at the plasma membrane surface or within extracellular vesicles. This process results in the regulation of key signaling pathways by the modulation of kinases, e.g., the epidermal growth factor receptor (EGFR). Considering their regulatory roles in cancer, therapeutics targeting various extracellular proteases have been discovered. These include the metal-binding agents di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) and di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), which increase c-MET degradation by multiple mechanisms. Both the direct and indirect inhibition of protease expression and activity can be achieved through metal ion depletion. Considering direct mechanisms, chelators can bind zinc(II) that plays a catalytic role in enzyme activity. In terms of indirect mechanisms, Dp44mT and DpC potently suppress the expression of the kallikrein-related peptidase-a prostate-specific antigen-in prostate cancer cells. The mechanism of this activity involves promotion of the degradation of the androgen receptor. Additional suppressive mechanisms of Dp44mT and DpC on matrix metalloproteases (MMPs) relate to their ability to up-regulate the metastasis suppressors N-myc downstream regulated gene-1 (NDRG1) and NDRG2, which down-regulate MMPs that are crucial for cancer cell invasion.

Expression of Matrix Metalloproteinases and Their Tissue Inhibitors in Peripheral Blood Leukocytes and Plasma of Children with Nonalcoholic Fatty Liver Disease

Gene expression profiles of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) were evaluated in peripheral blood leukocytes of children with nonalcoholic fatty liver disease (NAFLD). Gene expression patterns were correlated with their plasma protein counterparts, systemic parameters of liver injury, and selected markers of inflammation. The MMP-2, MMP-9, MMP-12, MMP-14, TIMP-1, TIMP-2, TGF-β, and IL-6 transcripts levels were tested by the real-time PCR. Plasma concentrations of MMP-9, TIMP-1, MMP-9/TIMP-1 ratio, MMP-2/TIMP-2 ratio, sCD14, leptin, resistin, IL-1 beta, and IL-6 and serum markers of liver injury were estimated by ELISA. The MMP-9, TIMP-2 expression levels, plasma amounts of MMP-9, TIMP-1, and the MMP-9/TIMP-1 ratio were increased in children with NAFLD. Concentrations of AST, ALT, GGT, and leptin were elevated in serum patients with NAFLD, while concentration of other inflammatory or liver injury markers was unchanged. The MMP-2 and MMP-9 levels correlated with serum liver injury parameters (ALT and GGT concentrations, respectively); there were no other correlations between MMP/TIMP gene expression profiles, their plasma counterparts, and serum inflammatory markers. Association of MMP-2 and MMP-9 expression with serum liver injury parameters (ALT, GGT) may suggest leukocyte engagement in the early stages of NAFLD development which possibly precedes subsequent systemic inflammatory responses.

In-silico strategies for identification of potent inhibitor for MMP-1 to prevent metastasis of breast cancer

Matrix Metalloproteinase-1 (MMP-1) has been often upregulated in advanced breast cancers, known to participate in ECM degradation, migration, invasion, thus leading to metastasis. Due to these effects, the condition is often reported to inversely correlate with survival in advanced breast cancers. In the present study, in-silico method was adopted based on selective non zinc binding inhibitors of MMP-1. ADME properties were predicted for PASS filtered compounds and docking calculations were performed using Glide XP and IFD protocols of Schrodinger program. We identified six ligands as potent inhibitors and validated by observing structures and the interactions of MMP-1. The identified hits were validated using molecular dynamics simulation studies. Electronic structure analysis was performed for two top hit compounds myricetin and quercetin using density function theory (DFT) at B3LYP/6-31**G level to understand their molecular reactivity. Finally, one compound myricetin has emerged as the structurally stable compound with -7.801 kcal/mol and reasonable pose inside the binding site. Molecular dynamics results indicated that myricetin forms a stable interaction with the key amino acid residues such as Glu209, Glu219, Tyr240 and Pro238. In addition, it did not form any binding with the catalytic zinc at its active site. The interaction pattern of myricetin at its substrate binding site exhibited to be potent MMP-1 inhibitor. DFT study also showed that it has more potent inhibitory effect and solubility. These factors altogether show that myricetin could be considered as the best among the compounds evaluated in inhibiting MMP-1 thereby preventing metastasis of breast cancer. Communicated by Ramaswamy H. Sarma.

Targeting the Tumor Microenvironment in Neuroblastoma: Recent Advances and Future Directions

Neuroblastoma (NB) is the most common pediatric tumor malignancy that originates from the neural crest and accounts for more than 15% of all the childhood deaths from cancer. The neuroblastoma cancer research has long been focused on the role of MYCN oncogene amplification and the contribution of other genetic alterations in the progression of this malignancy. However, it is now widely accepted that, not only tumor cells, but the components of tumor microenvironment (TME), including extracellular matrix, stromal cells and immune cells, also contribute to tumor progression in neuroblastoma. The complexity of different components of tumor stroma and their resemblance with surrounding normal tissues pose huge challenges for therapies targeting tumor microenvironment in NB. Hence, the detailed understanding of the composition of the TME of NB is crucial to improve existing and future potential immunotherapeutic approaches against this childhood cancer. In this review article, I will discuss different components of the TME of NB and the recent advances in the strategies, which are used to target the tumor microenvironment in neuroblastoma.

The Physical Microenvironment of Tumors: Characterization and Clinical Impact

The tumor microenvironment plays a critical role in tumorigenesis and metastasis. As tightly controlled extracellular matrix homeostasis is lost during tumor progression, a dysregulated extracellular matrix can significantly alter cellular phenotype and drive malignancy. Altered physical properties of the tumor microenvironment alter cancer cell behavior, limit delivery and efficacy of therapies, and correlate with tumorigenesis and patient prognosis. The physical features of the extracellular matrix during tumor progression have been characterized; however, a wide range of methods have been used between studies and cancer types resulting in a large range of reported values. Here, we discuss the significant mechanical and structural properties of the tumor microenvironment, summarizing their reported values and clinical impact across cancer type and grade. We attempt to integrate the values in the literature to identify sources of reported differences and commonalities to better understand how aberrant extracellular matrix dynamics contribute to cancer progression. An intimate understanding of altered matrix properties during malignant transformation will be crucial in effectively detecting, monitoring, and treating cancer.

High Throughput strategies Aimed at Closing the GAP in Our Knowledge of Rho GTPase Signaling

Since their discovery, Rho GTPases have emerged as key regulators of cytoskeletal dynamics. In humans, there are 20 Rho GTPases and more than 150 regulators that belong to the RhoGEF, RhoGAP, and RhoGDI families. Throughout development, Rho GTPases choregraph a plethora of cellular processes essential for cellular migration, cell–cell junctions, and cell polarity assembly. Rho GTPases are also significant mediators of cancer cell invasion. Nevertheless, to date only a few molecules from these intricate signaling networks have been studied in depth, which has prevented appreciation for the full scope of Rho GTPases’ biological functions. Given the large complexity involved, system level studies are required to fully grasp the extent of their biological roles and regulation. Recently, several groups have tackled this challenge by using proteomic approaches to map the full repertoire of Rho GTPases and Rho regulators protein interactions. These studies have provided in-depth understanding of Rho regulators specificity and have contributed to expand Rho GTPases’ effector portfolio. Additionally, new roles for understudied family members were unraveled using high throughput screening strategies using cell culture models and mouse embryos. In this review, we highlight theses latest large-scale efforts, and we discuss the emerging opportunities that may lead to the next wave of discoveries.

Challenges in Matrix Metalloproteinases Inhibition

Matrix metalloproteinases are enzymes that degrade the extracellular matrix. They have different substrates but similar structural organization. Matrix metalloproteinases are involved in many physiological and pathological processes and there is a need to develop inhibitors for these enzymes in order to modulate the degradation of the extracellular matrix (ECM). There exist two classes of inhibitors: endogenous and synthetics. The development of synthetic inhibitors remains a great challenge due to the low selectivity and specificity, side effects in clinical trials, and instability. An extensive review of currently reported synthetic inhibitors and description of their properties is presented.

Ali R, Abd. Hamid R, Chang SK, Rahman MH, Zainal Z, Khaza’ai H. Temporal changes in the cell population and wound healing-related gene expression in deep partial-thickness burn wound model

Background

Burns are injuries that lie on the skin or other organic tissues caused by exposures to the heat, electricity, chemicals or ionizing radiation. The present study was carried out to record temporal changes in the cell population and wound healing-related gene expression in rats with deep partial-thickness burn.

Methods

Burn wound was induced on the dorsal part of Sprague-Dawley rats using temperature-regulated 20-mm wide aluminum head heating device. Animals were then sacrificed on days three, seven, 11, 14 and 21 post-burn, respectively. Half of the wounded skin tissues were dissected and fixed in buffered neutral formalin for Hematoxylin & Eosin (H&E) staining, and the other half were cut off and stored in − 20 °C for real-time PCR analyses.

Results

The number of adipose cells was found to be maximal on the 3rd day post-burn, and it gradually decreased over time and completely disappeared on day 11 post-burn. The maximum number of neutrophils were found to be on the 3rd and 14th day post-burn, while the maximum number of myofibroblasts were found on the 11th day post-burn. The number of lymphocytes did not change too much during the whole healing process. At the gene expression level, the expression pattern of inflammation-related genes including IL-6, TNF-α and iNOS were similar, which was found to be increased from day 3 to day 11 and decreased thereafter. Angiogenesis related genes including both VEGF-A and TGF-β1 showed a same expression pattern, both of which were slightly increased from day 3 to day 14 and smoothly decreased on day 21 post-burn. Matrix re-modeling related genes including MMP-2, TIMP-2 and Collagen-1 changed over time synchronously, where they all persistently increased from day 3 till day 14, then slightly declined on day 21 post-burn.

Conclusion

The present study revealed the changes in the cell population and expression profile of wound healing-related genes in deep partial-thickness burn, which could provide a cellular and genomic basis for the future research of burn injuries.

Selective inhibition of matrix metalloproteinase 10 (MMP10) with a single-domain antibody

Since their discovery, the matrix metalloproteinase (MMP) family proteases have been considered as therapeutic targets in numerous diseases and disorders. Unfortunately, clinical trials with MMP inhibitors have failed to yield any clinical benefits of these inhibitors. These failures were largely due to a lack of MMP-selective agents; accordingly, it has become important to identify a platform with which high selectivity can be achieved. To this end, we propose using MMP-targeting antibodies that can achieve high specificity in interactions with their targets. Using a scaffold of single-domain antibodies, here we raised a panel of MMP10-selective antibodies through immunization of llamas, a member of the camelid family, whose members generate conventional heavy/light-chain antibodies and also smaller antibodies lacking light-chain and CH1 domains. We report the generation of a highly selective and tightly binding MMP10 inhibitor (K_i < 2 nm). Using bio-layer interferometry-based binding assays, we found that this antibody interacts with the MMP10 active site. Activity assays demonstrated that the antibody selectively inhibits MMP10 over its closest relative, MMP3. The ability of a single-domain antibody to discriminate between the most conserved MMP pair via an active site-directed mechanism of inhibition reported here supports the potential of this antibody as a broadly applicable scaffold for the development of selective, tightly binding MMP inhibitors.

Medicinal Effect, In Silico Bioactivity Prediction, and Pharmaceutical Formulation of Ageratum conyzoides L.: A Review

Goat weed (Ageratum conyzoides L.), or bandotan in Indonesia, is an herbaceous plant that broadly grows up in both subtropical as well as tropical areas. This herb contains many phytoconstituents which have many benefits in different aspects. The essential oil contains phytochemicals such as phenol, phenolic ester, and coumarin, whereas many compounds can been identified in the whole part such as terpenoid, steroid, chromene, pyrrolizidine alkaloid, and flavonoid. Empirically, this herb has been used as an antihemorrhagic, antiseptic, antileprosy, and wound-healing agent. This article reviews the potency of the herb in medication according to the chemical substances being deposited, which are collected from numerous studies, followed by its in silico bioactivity prediction as well as its pharmaceutical dosage form formulation.

The Evolution of Animal Models in Wound Healing Research: 1993-2017

Significance: Wound healing is a complex and dynamic series of events influenced by a variety of intrinsic and extrinsic factors. Problematic wounds, particularly chronic wounds and pathologic scars, remain clinically significant burdens. Modeling physiologic and aberrant wound repair processes using in vitro or in vivo models have contributed to Advances in Wound Care (AWC); however, the fidelity of each model used, particularly with respect to its species-specific limitations, must be taken into account for extrapolation to human patients. Twenty-five years of wound healing models published in Wound Repair and Regeneration (1993-2017) and AWC (2012-2017) were collected and analyzed to determine trends in species utilization and models used. Recent Advances: In 25 years, 1,521 original research articles utilizing one or more wound models were published (total of 1,665 models). Although 20 different species were used over the course of 25 years, 5 species were most commonly utilized: human, mouse, rat, pig, and rabbit. In vivo modeling was used most frequently, followed by in vitro, ex vivo, and in silico modeling of wound healing processes. Critical Issues: A comparison of articles from 1993 to 1997 and 2013 to 2017 periods showed notable differences in model and species usage. Experiments utilizing mouse and human models increased, while the usage of pig models remained constant, rabbit and rat models declined in the more recent time period examined compared to the time period two decades before. Future Directions: This analysis shows notable changes in types of models and species used over time which may be attributed to new knowledge, techniques, technology, and/or reagents. Explorations into mechanisms of limb regeneration and wound healing of noncutaneous tissues have also contributed to a shift in modeling over time. Changes within the journals (i.e., page expansion and increased rejection rates), research funding, and model expense may also influence the observed shifts.

The Versatile Role of Matrix Metalloproteinase for the Diverse Results of Fibrosis Treatment

Fibrosis is a type of chronic organ failure, resulting in the excessive secretion of extracellular matrix (ECM). ECM protects wound tissue from infection and additional injury, and is gradually degraded during wound healing. For some unknown reasons, myofibroblasts (the cells that secrete ECM) do not undergo apoptosis; this is associated with the continuous secretion of ECM and reduced ECM degradation even during de novo tissue formation. Thus, matrix metalloproteinases (MMPs) are considered to be a potential target of fibrosis treatment because they are the main groups of ECM-degrading enzymes. However, MMPs participate not only in ECM degradation but also in the development of various biological processes that show the potential to treat diseases such as stroke, cardiovascular diseases, and arthritis. Therefore, treatment involving the targeting of MMPs might impede typical functions. Here, we evaluated the links between these MMP functions and possible detrimental effects of fibrosis treatment, and also considered possible approaches for further applications.

Pyridine-Containing Macrocycles Display MMP-2/9 Inhibitory Activity and Distinct Effects on Migration and Invasion of 2D and 3D Breast Cancer Models

The role of metalloproteinases (MMPs) on the migration and invasion of cancer cells has been correlated with tumor aggressiveness, namely with the up-regulation of MMP-2 and 9. Herein, two pyridine-containing macrocyclic compounds, [15]pyN5 and [16]pyN5, were synthesized, chemically characterized and evaluated as potential MMP inhibitors for breast cancer therapy using 3D and 2D cellular models. [15]pyN5 and [16]pyN5 (5-20 µM) showed a marked inhibition of MMPs activity (100% at concentrations ≥ 7.5 μM) when compared to ARP-100, a known MMP inhibitor. The inhibitory activity of [15]pyN5 and [16]pyN5 was further supported through in silico docking studies using Goldscore and ChemPLP scoring functions. Moreover, although no significant differences were observed in the invasion studies in the presence of all MMPs inhibitors, cell migration was significantly inhibited by both pyridine-containing macrocycles at concentrations above 5 μM in 2D cells (p < 0.05). In spheroids, the same effect was observed, but only with [16]pyN5 at 20 μM and ARP-100 at 40 μM. Overall, [15]pyN5 and [16]pyN5 led to impaired breast cancer cell migration and revealed to be potential inhibitors of MMPs 2 and 9.

Mechanism and Inhibition of Matrix Metalloproteinases

Matrix metalloproteinases hydrolyze proteins and glycoproteins forming the extracellular matrix, cytokines and growth factors released in the extracellular space, and membrane-bound receptors on the outer cell membrane. The pathological relevance of MMPs has prompted the structural and functional characterization of these enzymes and the development of synthetic inhibitors as possible drug candidates. Recent studies have provided a better understanding of the substrate preference of the different members of the family, and structural data on the mechanism by which these enzymes hydrolyze the substrates. Here, we report the recent advancements in the understanding of the mechanism of collagenolysis and elastolysis, and we discuss the perspectives of new therapeutic strategies for targeting MMPs.