Purification and characterization of recombinant full-length and protease domain of murine MMP-9 expressed in Drosophila S2 cells

Collagenolytic Enzymes and their Applications in Biomedicine

Nowadays, enzymatic therapy is a very promising line of treatment for many different diseases. There is a group of disorders and conditions, caused by fibrotic and scar processes and associated with the excessive accumulation of collagen that needs to be catabolized to normalize the connective tissue content. The human body normally synthesizes special extracellular enzymes, matrix metalloproteases (MMPs) by itself. These enzymes can cleave components of extracellular matrix (ECM) and different types of collagen and thus maintain the balance of the connective tissue components. MMPs are multifunctional enzymes and are involved in a variety of organism processes. However, under pathological conditions, the function of MMPs is not sufficient, and these enzymes fail to deal with disease. Thus, medical intervention is required. Enzymatic therapy is a very effective way of treating such collagen-associated conditions. It involves the application of exogenous collagenolytic enzymes that catabolize excessive collagen at the affected site and lead to the successful elimination of disease. Such collagenolytic enzymes are synthesized by many organisms: bacteria, animals (especially marine organisms), plants and fungi. The most studied and commercially available are collagenases from Clostridium histolyticum and from the pancreas of the crab Paralithodes camtschatica, due to their ability to effectively hydrolyse human collagen without affecting other tissues, and their wide pH ranges of collagenolytic activity. In the present review, we summarize not only the data concerning existing collagenase-based medications and their applications in different collagen-related diseases and conditions, but we also propose collagenases from different sources for their potential application in enzymatic therapy.

Cloning and characteristic of MMP1 gene from Hyriopsis cumingii and collagen hydrolytic activity of its recombinant protein

Matrix metalloproteinases (MMPs) play an essential role in a variety of biological processes including wound healing, inflammation, cell invasion, angiogenesis and immune defense. In this study, a putative MMP1 cDNA was cloned and characterized from Hyriopsis cumingii (designated as HcMMP1). The cDNA was 1822 bp in length and encoded a putative protein of 510 amino acids, with a predicted molecular mass of 58.28 kDa and an isoelectric point (pI) of 9.27. HcMMP1 contained all prototype MMPs family signatures, such as signal peptide, prodomain, catalytic center, hinge region, and hemopexin like domain. Quantitative real time-PCR (qRT-PCR) revealed that in mussels HcMMP1 mRNA was expressed in all tissues tested, and the transcriptional expression levels were significantly up-regulated in hepatopancreas and hemocytes after Aeromonas hydrophila, peptidoglycan stimulations and in mantle after wounding. Moreover, the recombination HcMMP1 protein, successfully expressed in Escherichia coli, was purified by affinity chromatography with the concentration of final yield at 0.3 mg/mL. The recombinase had an essentially hydrolytic activity toward rat type I collagen, mouse II and IV collagen after renaturation.

Digesting a Path Forward: The Utility of Collagenase Tumor Treatment for Improved Drug Delivery

Collagen and hyaluronan are the most abundant components of the extracellular matrix (ECM) and their overexpression in tumors is linked to increased tumor growth and metastasis. These ECM components contribute to a protective tumor microenvironment by supporting a high interstitial fluid pressure and creating a tortuous setting for the convection and diffusion of chemotherapeutic small molecules, antibodies, and nanoparticles in the tumor interstitial space. This review focuses on the research efforts to deplete extracellular collagen with collagenases to normalize the tumor microenvironment. Although collagen synthesis inhibitors are in clinical development, the use of collagenases is contentious and clinically untested in cancer patients. Pretreatment of murine tumors with collagenases increased drug uptake and diffusion 2-10-fold. This modest improvement resulted in decreased tumor growth, but the benefits of collagenase treatment are confounded by risks of toxicity from collagen breakdown in healthy tissues. In this review, we evaluate the published in vitro and in vivo benefits and limitations of collagenase treatment to improve drug delivery.

Presence of insulin-like growth factor binding proteins correlates with tumor-promoting effects of matrix metalloproteinase 9 in breast cancer

The stroma of breast cancer can promote the disease’s progression, but whether its composition and functions are shared among different subtypes is poorly explored. We compared stromal components of a luminal [mouse mammary tumor virus (MMTV)–Neu] and a triple-negative/basal-like [C3(1)–Simian virus 40 large T antigen (Tag)] genetically engineered breast cancer mouse model. The types of cytokines and their expression levels were very different in the two models, as was the extent of innate immune cell infiltration; however, both models showed infiltration of innate immune cells that expressed matrix metalloproteinase 9 (MMP9), an extracellular protease linked to the progression of many types of cancer. By intercrossing with Mmp9 null mice, we found that the absence of MMP9 delayed tumor onset in the C3(1)-Tag model but had no effect on tumor onset in the MMTV-Neu model. We discovered that protein levels of insulin-like growth factor binding protein-1 (IGFBP-1), an MMP9 substrate, were increased in C3(1)-Tag;Mmp9^−/− compared to C3(1)-Tag;Mmp9^+/+ tumors. In contrast, IGFBP-1 protein expression was low in MMTV-Neu tumors regardless of Mmp9 status. IGFBP-1 binds and antagonizes IGFs, preventing them from activating their receptors to promote cell proliferation and survival. Tumors from C3(1)-Tag;Mmp9^−/− mice had reduced IGF-1 receptor phosphorylation, consistent with slower tumor onset. Finally, gene expression analysis of human breast tumors showed that high expression of IGFBP mRNA was strongly correlated with good prognosis but not when MMP9 mRNA was also highly expressed. In conclusion, MMP9 has different effects on breast cancer progression depending on whether IGFBPs are expressed.

Handling Metalloproteinases

Substrate cleavage by metalloproteinases involves nucleophilic attack on the scissile peptide bond by a water molecule that is polarized by a catalytic metal, usually a zinc ion, and a general base, usually the carboxyl group of a glutamic acid side chain. The zinc ion is most often complexed by imidazole nitrogens of histidine side chains. This arrangement suggests that the physiological pH optimum of most metalloproteinases is in the neutral range. In addition to their catalytic metal ion, many metalloproteinases contain additional transition metal or alkaline earth ions, which are structurally important or modulate the catalytic activity. As a consequence, these enzymes are generally sensitive to metal chelators. Moreover, the catalytic metal can be displaced by adventitious metal ions from buffers or biological fluids, which may fundamentally alter the catalytic function. Therefore, handling, purification, and assaying of metalloproteinases require specific precautions to warrant their stability.

Development of in-cell imaging assay systems for MMP-2 and MMP-9 based on trans-localizing molecular beacon proteins

A sensitive in-cell imaging MMP-2 and MMP-9 detection systems that enables direct fluorescence detection of a target protease and its inhibition inside living cells has been developed. This in-cell imaging system utilizes the concept of fluorescent molecular beacon reporter (MBR) protein comprising a masking protein, a mitochondrial targeting sequence, a protease specific cleavage sequence and a fluorescent marker sequence, green fluorescent protein (GFP). The MBR protein is designed to change its intracellular location upon cleavage by either MMP-2 or MMP-9 from cytosol to mitochondria. Full and partial MMP-2 and MMP-9 were tested for optimal expression and activity in the cell. The activity of MMP-2 and MMP-9 was approximately 65-71%. Among MMP clones, MMP-2 catalytic domain and MMP-9 clone containing pro, catalytic and hemopexin domain were most active. Both MMP-2 and MMP-9 required divalent ions Ca and Zn for its activity and MMP-9 was more active at higher Ca/Zn ratio. With the in-cell imaging assay the protease activity can be measured in cellular environment and cellular toxicity of candidate molecules can be monitored at the same time. These are great advantage when compared to other currently used in vitro biochemical assays. The in-cell imaging assay developed in this study can be modified for other MMPs and can be used in various life science and drug discovery researches including the high throughput screening and high contents screening applications.

The urokinase receptor homolog Haldisin is a novel differentiation marker of stratum granulosum in squamous epithelia

Several members of the Ly-6/uPAR (LU)-protein domain family are differentially expressed in human squamous epithelia. In some cases, they even play important roles in maintaining skin homeostasis, as exemplified by the secreted single domain member, SLURP-1, the deficiency of which is associated with the development of palmoplantar hyperkeratosis in the congenital skin disorder Mal de Meleda. In the present study, we have characterized a new member of the LU-protein domain family, which we find to be predominantly expressed in the stratum granulosum of human skin, thus resembling the expression of SLURP-1. In accordance with its expression pattern, we denote this protein product, which is encoded by the LYPD5 gene, as Haldisin (human antigen with LU-domains expressed in skin). Two of the five human glycolipid-anchored membrane proteins with multiple LU-domains characterized so far are predominantly confined to squamous epithelia (i.e., C4.4A), to stratum spinosum, and Haldisin to stratum granulosum under normal homeostatic conditions. Whether Haldisin is a prognostic biomarker for certain epithelial malignancies, like C4.4A and SLURP-1, remains to be explored.

Stabilization of the dystroglycan complex in Cajal bands of myelinating Schwann cells through plectin-mediated anchorage to vimentin filaments

Previous studies have unmasked plectin, a uniquely versatile intermediate filament-associated cytolinker protein, to be essential for skin and skeletal muscle integrity. Different sets of isoforms of the protein were found to stabilize cells mechanically, regulate cytoskeletal dynamics, and serve as a scaffolding platform for signaling molecules. Here, we investigated whether a similar scenario prevails in myelinating Schwann cells. Using isoform-specific antibodies, the two plectin variants predominantly expressed in the cytoplasmic compartment (Cajal bands) of Schwann cells were identified as plectin (P)1 and P1c. Coimmunoprecipitation and immunolocalization experiments revealed complex formation of Cajal band plectin with β-dystroglycan, the core component of the dystrophin glycoprotein complex that in Schwann cells is crucial for the compartmentalization and stabilization of the myelin sheath. To study the functional implications of Schwann cell-specific plectin-β-dystroglycan interaction, we generated conditional (Schwann cell-restricted) plectin knockout mice. Ablation of plectin in myelinating Schwann cells (SCs) was found not to affect myelin sheath formation but to abrogate the tight association of the dystroglycan complex with the intermediate filament cytoskeleton. We show that the disruption of this association leads to the destabilization of the dystroglycan complex combined with increased myelin sheath deformations observed in the peripheral nerve during ageing of the animal.

Imaging tumor-stroma interactions during chemotherapy reveals contributions of the microenvironment to resistance

Little is known about the dynamics of cancer cell death in response to therapy in the tumor microenvironment. Intravital microscopy of chemotherapy-treated mouse mammary carcinomas allowed us to follow drug distribution, cell death, and tumor-stroma interactions. We observed associations between vascular leakage and response to doxorubicin, including improved response in matrix metalloproteinase-9 null mice that had increased vascular leakage. Furthermore, we observed CCR2-dependent infiltration of myeloid cells after treatment and that Ccr2 null host mice responded better to treatment with doxorubicin or cisplatin. These data show that the microenvironment contributes critically to drug response via regulation of vascular permeability and innate immune cell infiltration. Thus, live imaging can be used to gain insights into drug responses in situ.

Drosophila melanogaster S2 cells for expression of heterologous genes: From gene cloning to bioprocess development

In the present review we discuss strategies that have been used for heterologous gene expression in Drosophila melanogaster Schneider 2 (S2) cells using plasmid vectors. Since the growth of S2 cells is not dependent on anchorage to solid substrates, these cells can be easily cultured in suspension in large volumes. The factors that most affect the growth and gene expression of S2 cells, namely cell line, cell passage, inoculum concentration, culture medium, temperature, dissolved oxygen concentration, pH, hydrodynamic forces and toxic metabolites, are discussed by comparison with other insect and mammalian cells. Gene expression, cell metabolism, culture medium formulation and parameters involved in cellular respiration are particularly emphasized. The experience of the authors with the successful expression of a biologically functional protein, the rabies virus glycoprotein (RVGP), by recombinant S2 cells is presented in the topics covered.

Concomitant lack of MMP9 and uPA disturbs physiological tissue remodeling

Urokinase-type plasminogen activator (uPA) and matrix metalloproteinase-9 (MMP9, gelatinase B) have separately been recognized to play important roles in various tissue remodeling processes. In this study, we demonstrate that deficiency for MMP9 in combination with ablation of either uPA- or tissue-type plasminogen activator (tPA)-catalyzed plasminogen activation is critical to accomplish normal gestation in mice. Gestation was also affected by simultaneous lack of MMP9 and the uPA receptor (uPAR). Interestingly, uPA-deficiency additionally exacerbated the effect of MMP9-deficiency on bone growth and an additive effect caused by combined lack in MMP9 and uPA was observed during healing of cutaneous wounds. By comparison, MMP9-deficiency combined with absence of either tPA or uPAR resulted in no significant effect on wound healing, indicating that the role of uPA during wound healing is independent of uPAR, when MMP9 is absent. Notably, compensatory upregulation of uPA activity was seen in wounds from MMP9-deficient mice. Taken together, these studies reveal essential functional dependency between MMP9 and uPA during gestation and tissue repair.

Proteolytic action of kallikrein-related peptidase 7 produces unique active matrix metalloproteinase-9 lacking the C-terminal hemopexin domains

The gelatinases, matrix metalloproteinase (MMP)-9 and -2, are produced as latent, inactive enzymes that can be proteolytically activated by a number of proteases. In many normal and pathological conditions, where the expression of MMPs is deregulated, changes in the expression of other proteases have also been reported. Human kallikrein-related peptidase 7 (KLK7), a chymotryptic-like serine protease, is overexpressed in many different types of neoplastic conditions, which have also been shown to express high levels of both MMP-9 and -2. Since the activation of MMPs by KLK7 has never been examined, we sought to determine whether KLK7 can activate these MMPs. To test this hypothesis KLK7 was incubated with the recombinant MMPs and the products of the reaction were analyzed for their activity. Incubation of proMMP-9 with KLK7 resulted in the production of a novel truncated, active MMP-9 lacking the C-terminal hemopexin domains. In contrast, KLK7 degraded, but did not activate, proMMP-2. The novel activation of proMMP-9 by KLK7 was further confirmed using conditioned medium prepared from an MMP-9-expressing cell line, MDA-MMP-9. Our results clearly establish that KLK7 activates proMMP-9 to produce a novel truncated, active MMP-9 product not generated by other proteases. These findings suggest that KLK7 may play an important role in the activation of MMP-9 in tumors that express high levels of both these proteases and the resulting truncated MMP may possess altered substrate specificities compared with full-length MMP-9 activated by other proteases.

MMP9 is protective against lethal inflammatory mass lesions in the mouse colon

The family of matrix metalloproteinases (MMPs) is responsible for extracellular matrix degradation during physiological and pathophysiological tissue remodeling processes such as embryogenesis, tissue repair and cancer progression. Despite these important roles of MMPs, inhibition or ablation of individual members of the MMP family in animal models have been shown to have little effect. It has been speculated that this results from a functional overlap between individual MMPs and (as-yet-unclassified) functional overlaps between MMPs and other protease systems. We here present genetic data showing that concomitant ablation of MMP9 (gelatinase B) and the serine protease plasmin results in lethal inflammatory mass lesions in the colon. These lesions possessed several histological attributes that are characteristic of mucosal prolapse seen in humans, and they were found to be associated with splenomegaly, enlarged mesenteric lymph nodes, decreased thymus size and altered populations of circulating immune cells. A time-course study provided evidence that the massive lymphoid hyperplasia and reactive changes were secondary to discrete fibrinous lesions also observed in mice only deficient for plasminogen (Plg), the zymogen for plasmin. These data demonstrate a non-appreciated vital protective role for MMP9 in the absence of Plg.