Extracellular Metalloprotease Research Articles

The Quinazoline Otaplimastat (SP-8203) Reduces the Hemorrhagic Transformation and Mortality Aggravated after Delayed rtPA-Induced Thrombolysis in Cerebral Ischemia.

Acute ischemic stroke is the leading cause of morbidity and mortality worldwide. Recombinant tissue plasminogen activator (rtPA) is the only agent clinically approved by FDA for patients with acute ischemic stroke. However, delayed treatment of rtPA (e.g., more than 3 h after stroke onset) exacerbates ischemic brain damage by causing intracerebral hemorrhage and increasing neurotoxicity. In the present study, we investigated whether the neuroprotant otaplimastat reduced delayed rtPA treatment-evoked neurotoxicity in male Sprague Dawley rats subjected to embolic middle cerebral artery occlusion (eMCAO). Otaplimastat reduced cerebral infarct size and edema and improved neurobehavioral deficits. In particular, otaplimastat markedly reduced intracerebral hemorrhagic transformation and mortality triggered by delayed rtPA treatment, consequently extending the therapeutic time window of rtPA. We further found that ischemia-evoked extracellular matrix metalloproteases (MMPs) expression was closely correlated with cerebral hemorrhagic transformation and brain damage. In ischemic conditions, delayed rtPA treatment further increased brain injury via synergistic expression of MMPs in vascular endothelial cells. In oxygen-glucose-deprived endothelial cells, otaplimastat suppressed the activity rather than protein expression of MMPs by restoring the level of tissue inhibitor of metalloproteinase (TIMP) suppressed in ischemia, and consequently reduced vascular permeation. This paper shows that otaplimastat under clinical trials is a new drug which can inhibit stroke on its own and extend the therapeutic time window of rtPA, especially when administered in combination with rtPA.

Purification and Characterization of an Extracellular Alkaline Solvent-stable Metalloprotease Secreted from Newly Isolated Bacillus sp. DEM05: Optimization of Protease Production.

Background: Proteases play an important role in food, leather, detergent, and medical technologies.Objectives: In the current study, an alkaliphilic solvent-stable thermotolerant metalloprotease was isolated from Bacillus sp. DEM05.Material and Methods: For culture optimization, carbon, and nitrogen sources as well as incubation temperature, pH, and time were examined.Results: Herein the highest outcome for bacterial growth and protease production was obtained after 72 h incubation (pH 7) at 37 °C. DEM05 protease was successfully purified and the specific activity of the protease was 1075 U.mg-1. The purity of the enzyme was verified by SDS-PAGE electrophoresis as a single band of 30 kDa. The optimal activity of the enzyme was at pH 10 and 50 °C. H2O2, SDS, Triton X-100, Zn2+, Co2+, and Cu2+ could increase the protease activity. EDTA inhibited the protease activity, revealed that it can be classified as a metalloprotease. The enzyme was compatible with the water-miscible and water-immiscible organic solvents and proteolyzed several substrates, implying the wide substrate specificity.Conclusions: The results brought convincing evidence that DEM05 protease could be recruited as a novel prevailing protease that can be earmarked on industrial and medical technologies.

Survival prediction based on the gene expression associated with cancer morphology and microenvironment in primary central nervous system lymphoma.

Dysregulation of cell morphology and cell-cell interaction results in cancer cell growth, migration, invasion, and metastasis. Besides, a balance between the extracellular matrix (ECM) and matrix metalloprotease (MMP) is required for cancer cell morphology and angiogenesis. Here, we determined gene signatures associated with the morphology and microenvironment of primary central nervous system lymphoma (PCNSL) to enable prognosis prediction. Next-generation sequencing (NGS) on 31 PCNSL samples revealed gene signatures as follows: ACTA2, ACTR10, CAPG, CORO1C, KRT17, and PALLD in cytoskeleton, CDH5, CLSTN1, ITGA10, ITGAX, ITGB7, ITGA8, FAT4, ITGAE, CDH10, ITGAM, ITGB6, and CDH18 in adhesion, COL8A2, FBN1, LAMB3, and LAMA2 in ECM, ADAM22, ADAM28, MMP11, and MMP24 in MMP. Prognosis prediction formulas with the gene expression values and the Cox regression model clearly divided survival curves of the subgroups in each status. Furthermore, collagen genes contributed to gene network formation in glasso, suggesting that the ECM balance controls the PCNSL microenvironment. Finally, the comprehensive balance of morphology and microenvironment enabled prognosis prediction by a combinatorial expression of 8 representative genes, including KRT17, CDH10, CDH18, COL8A2, ADAM22, ADAM28, MMP11, and MMP24. Besides, these genes could also diagnose PCNSL cell types with MTX resistances in vitro. These results would not only facilitate the understanding of biology of PCNSL but also consider targeting pathways for anti-cancer treatment in personalized precision medicine in PCNSL.

Purification and characterization of thermoactive serratiopeptidase from Serratia marcescens AD-W2

Serratiopeptidase is a proteolytic enzyme extensively used as an anti-inflammatory and analgesic drug. Present work reports a thermoactive serratiopeptidase from Serratia marcescens AD-W2, a soil isolate from the North-Western Himalayan region of India. The extracellular metalloprotease has been purified by a simple two-step procedure resulting in a specific activity of 20,492 Units/mg protein with 5.28-fold purification. The molecular mass of the metalloprotease, as determined by SDS-PAGE was ~ 51 kDa. The purified serratiopeptidase presented optimum activity at pH 9.0, temperature 50 °C and stability in wide pH and temperature range. Critical temperature of 50 °C confirmed the thermoactivity of the purified serratiopeptidase. The kinetic studies of the purified serratiopeptidase revealed Vmax and Km of 57,256 Units/mL and 1.57 mg/mL, respectively, for casein. The purified serratiopeptidase from S. marcescens AD-W2 was found to be 100% identical to serralysin from Serratia marcescens ATCC 21074/E-15. The catalytic domain comprising of Zn coordinated with three histidine residues (His192, His196, His202), along with glutamate (Glu193) and tyrosine (Tyr232) residues, further confirmed that the purified protein is identical to serralysin.

Phosphonate as a Stable Zinc-Binding Group for "Pathoblocker" Inhibitors of Clostridial Collagenase H (ColH).

Microbial infections are a significant threat to public health, and resistance is on the rise, so new antibiotics with novel modes of action are urgently needed. The extracellular zinc metalloprotease collagenase H (ColH) from Clostridium histolyticum is a virulence factor that catalyses tissue damage, leading to improved host invasion and colonisation. Besides the major role of ColH in pathogenicity, its extracellular localisation makes it a highly attractive target for the development of new antivirulence agents. Previously, we had found that a highly selective and potent thiol prodrug (with a hydrolytically cleavable thiocarbamate unit) provided efficient ColH inhibition. We now report the synthesis and biological evaluation of a range of zinc‐binding group (ZBG) variants of this thiol‐derived inhibitor, with the mercapto unit being replaced by other zinc ligands. Among these, an analogue with a phosphonate motif as ZBG showed promising activity against ColH, an improved selectivity profile, and significantly higher stability than the thiol reference compound, thus making it an attractive candidate for future drug development.

A Real-Time Recombinase Polymerase Amplification Method for Rapid Detection of Vibrio vulnificus in Seafood.

As an important foodborne pathogen, Vibrio vulnificus gives a significant threat to food safety and public health. Rapid and accurate detection methods for V. vulnificus are required to control its spread. The conventional detection methods are time-consuming and labor-intensive, while the polymerase chain reaction (PCR)- and quantitative PCR (qPCR)-based methods are limited because of their dependence on laboratory equipment. Nucleic acid isothermal amplification technologies have been applied to develop simpler assays. In this study, a rapid detection method based on real-time recombinase polymerase amplification (RPA) targeting the extracellular metalloprotease (empV) gene of V. vulnificus has been established. The method finished the detection in 2–14 min at 39°C with good specificity. The limit of detection was 17 gene copies or 1 colony-forming unit (CFU) per reaction, or 1 CFU/10 g of spiked food with enrichment. In a clinical sample detection test, the results of real-time RPA were 100% consistent with bioassay and qPCR. Moreover, the method could resist the effect of food matrix and could tolerate crude templates. The real-time RPA method established in this study is rapid and simple and has the potential to be widely applied for V. vulnificus detection in food safety control.

Drug-Induced Gingival Overgrowth: A Pilot Study on the Effect of Diphenylhydantoin and Gabapentin on Human Gingival Fibroblasts.

Introduction. The administration of several classes of drugs can lead to the onset of gingival overgrowth: anticonvulsants, immunosuppressants, and calcium channel blockers. Among the anticonvulsants, the main drug associated with gingival overgrowth is diphenylhydantoin. Materials and Methods. In this study, we compared the effects of diphenylhydantoin and gabapentin on 57 genes belonging to the “Extracellular Matrix and Adhesion Molecule” pathway, present in human fibroblasts of healthy volunteers. Results. Both molecules induce the same gene expression profile in fibroblasts as well as a significant upregulation of genes involved in extracellular matrix deposition like COL4A1, ITGA7, and LAMB3. The two treatments also induced a significant downregulation of genes involved in the expression of extracellular matrix metalloproteases like MMP11, MMP15, MMP16, MMP24, and transmembrane receptor ITGB4. Conclusions. Data recorded in our study confirmed the hypothesis of a direct action of these drugs at the periodontium level, inducing an increase in matrix production, a reduction in its degradation, and consequently resulting in gingival hyperplasia.

Screening and characterization of gelatinase producing Enterococcus faecalis MD4

Gelatinase is an extracellular metalloprotease and is capable of hydrolyzing gelatine, collagen, elastin, etc., which is used in processing industries, food technology and research. In this study, 216 bacterial strains isolated from diseased fishes were examined their ability to produce gelatinase. As a result, eleven strains (5.09%) were positive for gelatinase production. Gelatinase activity ranged from 0.3 to 0.64 U/ mL, in which the strain MD4 showed the highest gelatinase activity (0.64 ± 0.11 U/mL). Strain MD4 grew in the range of temperature from 25 to 45°C (optimum at 37°C), pH 4.0 ÷ 10.0 (optimum at pH 7.0), and NaCl concentration from 0.5 to 5% (optimum at 4%). Strain MD4 was characterized as Gram-positive, spheroidal, non-spore-forming, non-spore organism. As a consequence, strain MD4 was selected and genetically identificated using 16S rRNA gene sequence analysis. The 16S rRNA sequence of strain Enterococus faecalis MD4 (GenBank accession No. MG982575.1.) shared 99% identity with Enterococus faecalis NBRC 100480.

Drug-Induced Gingival Overgrowth: The Effect of Cyclosporin A and Mycophenolate Mophetil on Human Gingival Fibroblasts.

Drug-induced gingival overgrowth may occur after a chronic administration of three classes of systemic drugs: Anticonvulsants, immunosuppressants, and calcium channel blockers. This study aimed to investigate how cyclosporin A and mycophenolate mophetil (immunosuppressive drugs) could interfere with human gingival fibroblasts functions, leading to gingival enlargement. Human gingival fibroblasts derived from the tissue of a 60-year-old female were cultured in a DMEME medium. A stock solution with 1 mg/mL of mycophenolate and 1 mg/mL of cyclosporine were prepared and dissolved in a DMEM medium to prepare a serial dilution at the concentrations of 5000, 2000, 1000, 500, and 100 ng/mL, for both treatments. Cell viability was measured using the PrestoBlue™ Reagent Protocol. Quantitative real-time RT-PCR was performed in order to analyze the expression of 57 genes coding for gingival fibroblasts “Extracellular Matrix and Adhesion Molecules”. Mycophenolate and cyclosporine had no effect on fibroblast cell viability at 1000 ng/mL. Both the treatments showed similar effects on the expression profiling of treated cells: Downregulation of most extracellular matrix metalloproteases genes (MMP8, MMP11, MMP15, MMP16, MMP24) was assessed, while CDH1, ITGA2, ITGA7, LAMB3, MMP12, and MMP13 were recorded to be upregulated in fibroblasts treated with immunosuppressive drugs. It has been demonstrated that gingival overgrowth can be caused by the chronic administration of cyclosporin A and mycophenolate mophetil. However, given the contrasting data of literature, further investigations are needed, making clear the possible effects of immunosuppressive drugs on fibroblasts.

Escherichia coli strain engineering for enhanced production of serratiopeptidase for therapeutic applications

Serratiopeptidase is an extracellular zinc-containing metalloprotease that is produced by Serratia marcescens having molecular weight of about 53kD. It has shown therapeutic (anti-inflammatory, anti-fibrinolytic and analgesic) as well as industrial applications (detergents, food processing, leather, paper and brewing etc.). The evolution of Serratia marcescens as an opportunistic pathogen associated with various infections has led researchers to think and develop an alternate strategy for its industrial production. The study presents successful cloning, expression and purification of active serratiopeptidase, using Escherichia coli BL21 [DE3] and pET SUMO vector followed by optimization of synthetic media and culture conditions for enhanced serratiopeptidase production. Initial optimization of physical parameters was done followed by a screening of different carbon and nitrogen sources. The significant media components for serratiopeptidase production as shown by factorial screening experiment were subjected to Response Surface Methodology (RSM) based optimization. The optimized media yielded 86 mg L−1 of biologically active refolded serratiopeptidase from 20 g L−1 wet weight of induced pellet as predicted by the equation. The success of the application of a statistical model for designing an optimized media for enhanced serratiopeptidase production also suggests a new insight for the scale-up of serratiopeptidase towards industrial applications.

Identification and Genome Analysis of Vibrio coralliilyticus Causing Mortality of Pacific Oyster (Crassostrea gigas) Larvae.

Vibrio coralliilyticus is known as a coral pathogen that also infects marine bivalve larvae worldwide. It is considered to be one of the major constraints in artificial marine bivalve seed production as it causes mortality. In this study, we first isolated and characterized a high virulent of V. coralliilyticus designated as SNUTY-1 that was the cause of Pacific oyster larvae mortality in Korea. In the pathogenicity test, exposure to 2.14 × 105 CFU/mL for 24 h caused mortality to 88.65 ± 2.4% of the tested healthy Pacific oyster larvae. SNUTY-1 showed anti-microbial resistance to β-lactams, such as penicillins, cephalosporins, and carbapenems. We sequenced and assembled the complete genome of SNUTY-1 (5,842,676 bp), consisting of two chromosomes (Chr I and Chr II) and two plasmids (pSNUTY1 and pSNUTY2). The COG functional analysis confirmed that Chr I had more genes associated with basic cellular functions in comparison to Chr II. The results of the phylogenetic trees based on OrthoANI values indicated that the SNUTY-1 was closely related to V. coralliilyticus strains. SNUTY-1 had a unique plasmid (pSNUTY2), which could mean that the Korean isolate is different from other sequenced V. coralliilyticus strains from different geographical origins. Toxic proteins such as cytolysin/hemolysin and extracellular metalloprotease genes were encoded on Chr I and Chr II of SNUTY-1. These data facilitate the control of V. coralliilyticus infections in aquaculture by providing valuable insights into the biodiversity of this organism and valuable information for the study of virulence factors.

Role of Cyclosporine in Gingival Hyperplasia: An In Vitro Study on Gingival Fibroblasts.

Background: Gingival hyperplasia could occur after the administration of cyclosporine A. Up to 90% of the patients submitted to immunosuppressant drugs have been reported to suffer from this side effect. The role of fibroblasts in gingival hyperplasia has been widely discussed by literature, showing contrasting results. In order to demonstrate the effect of cyclosporine A on the extracellular matrix component of fibroblasts, we investigated the gene expression profile of human fibroblasts after cyclosporine A administration. Materials and methods: Primary gingival fibroblasts were stimulated with 1000 ng/mL cyclosporine A solution for 16 h. Gene expression levels of 57 genes belonging to the “Extracellular Matrix and Adhesion Molecules” pathway were analyzed using real-time PCR in treated cells, compared to untreated cells used as control. Results: Expression levels of different genes were significantly de-regulated. The gene CDH1, which codes for the cell adhesion protein E-cadherin, showed up-regulation. Almost all the extracellular matrix metalloproteases showed down-regulation (MMP8, MMP11, MMP15, MMP16, MMP24, MMP26). The administration of cyclosporine A was followed by down-regulation of other genes: COL7A1, the transmembrane receptors ITGB2 and ITGB4, and the basement membrane constituents LAMA2 and LAMB1. Conclusion: Data collected demonstrate that cyclosporine inhibits the secretion of matrix proteases, contributing to the accumulation of extracellular matrix components in the gingival connective tissue, causing gingival overgrowth. Patients affected by gingival overgrowth caused by cyclosporine A need to be further investigated in order to determine the role of this drug on fibroblasts.

Pseudomonas aeruginosa ExsA Regulates a Metalloprotease, ImpA, That Inhibits Phagocytosis of Macrophages.

Pseudomonas aeruginosa is an opportunistic pathogenic bacterium whose type III secretion system (T3SS) plays a critical role in acute infections. Translocation of the T3SS effectors into host cells induces cytotoxicity. In addition, the T3SS promotes the intracellular growth of P. aeruginosa during host infections. The T3SS regulon genes are regulated by an AraC-type regulator, ExsA. In this study, we found that an extracellular metalloprotease encoded by impA (PA0572) is under the regulation of ExsA. An ExsA consensus binding sequence was identified upstream of the impA gene, and direct binding of the site by ExsA was demonstrated via an electrophoretic mobility shift assay. We further demonstrate that secreted ImpA cleaves the macrophage surface protein CD44, which inhibits the phagocytosis of the bacterial cells by macrophages. Combined, our results reveal a novel ExsA-regulated virulence factor that cooperatively inhibits the functions of macrophages with the T3SS.

Matrix-degrading protease ADAMTS-5 cleaves inter-α-inhibitor and releases active heavy chain 2 in synovial fluids from arthritic patients

Destruction of the cartilage matrix in joints is an important feature of arthritis. Proteolytic degradation of cartilage glycoproteins can contribute to the loss of matrix integrity. Human inter-α-inhibitor (IαI), which stabilizes the extracellular matrix, is composed of the light-chain serine proteinase inhibitor bikunin and two homologous heavy chains (HC1 and HC2) covalently linked through chondroitin 4-sulfate. Inflammation promotes the transfer of HCs from chondroitin 4-sulfate to hyaluronan by tumor necrosis factor-stimulated gene-6 protein (TSG-6). This reaction generates a covalent complex between the heavy chains and hyaluronan that can promote leukocyte invasion. This study demonstrates that both IαI and the HC-hyaluronan complex are substrates for the extracellular matrix proteases ADAMTS-5 and matrix metalloprotease (MMP) -3, -7, and -13. The major cleavage sites for all four proteases are found in the C terminus of HC2. ADAMTS-5 and MMP-7 displayed the highest activity toward HC2. ADAMTS-5 degradation products were identified in mass spectrometric analysis of 29 of 33 arthropathic patients, indicating that ADAMTS-5 cleavage occurs in synovial fluid in arthritis. After cleavage, free HC2, together with TSG-6, is able to catalyze the transfer of heavy chains to hyaluronan. The release of extracellular matrix bound HC2 is likely to increase the mobility of the HC2/TSG-6 catalytic unit and consequently increase the rate of the HC transfer reaction. Ultimately, ADAMTS-5 cleavage of HC2 could alter the physiological and mechanical properties of the extracellular matrix and contribute to the progression of arthritis.

Purification and study of anti-cancer effects of Serratia marcescens serralysin

Serralysin is an extracellular metalloprotease from Serratia marcescens which has been the subject of extensive biological investigations. The goal of this study was to extract and purify serralysin from S. marcescens and to investigate its cytotoxic activity on the colorectal cancer cell line. The presence of the serralysin gene was confirmed using PCR. The supernatant of bacterial culture was collected and precipitated using ammonium sulfate. The precipitated protein was dialyzed and subjected to ion exchange chromatography for further purification. Casein assay and skim milk assay was used to confirm the enzymatic activity. SDS-PAGE was used to visualize the presence of serralysin. Metalloprotease inhibition activity was performed using 50 mM EDTA. Cytotoxic activity of serralysin was assessed on MTT assay. The PCR product corresponding to serralysin was estimated to be approximately 1500 bp. A transparent zone around the bacterial colonies on skim milk agar and casein digestion confirmed the proteolytic activity of serralysin. A 52 kDa band in SDS-PAGE corresponding to serralysin was observed before and after purification processes. MTT assay showed IC50 values 24.78 μg/ml and 19.16 μg/ml after 24 h and 48 h exposure of Caco-2 cells to serralysin, respectively. Our results showed that native serralysin has anticancer potential and may be a candidate for further pharmaceutical research and development. Further in vivo and in vitro mechanistic studies are suggested to confirm the biological activities.

Pseudomonas fluorescens: a potential food spoiler and challenges and advances in its detection

This review focuses on the spoilage strategies used by the Pseudomonas fluorescens, and in addition, it also discusses various diagnostic approaches used for its identification in food items. Some challenges faced and advances in the detection of P. fluorescens and also discussed in this review. An extensive literature search was performed with published work and data was analyzed in detail to meet the requirements of the objectives. P. fluorescens are unicellular rods, with long straight or curved axis, but not helical, motility by one or more polar flagella, Gram-negative, non-spores former, stalks, or sheaths. P. fluorescens is represented by seven biotypes denoted by the letters A, B, C, D, E, F, and G. The microbe shows wide choice of growth temperature and causes contamination and spoilage in ordinary and refrigerated food items by its enzymes and pigment production. The biofilm formation by P. fluorescens poses another serious threat to the food industries. Molecular identification of P. fluorescens is generally done by 16S rRNA, intergenic spacer (ITS1) utilizing traditional polymerase chain reactions (PCR). Nowadays, qPCR and multiplex PCR are largely utilized in identification of P. fluorescens based on AprX gene (extracellular caseinolytic metalloprotease) in the milk and meat spoilage strains. The available methods still show some disadvantages with accuracy and specificity of detection. Rapid detection of P. fluorescens in food samples is the need of hour to improve the detection efficiency.

Purification and Characterization of Metalloprotease from Serratia marcescens PPB-26 and Its Application for Detergent Additive

In this study, the extracellular metalloprotease from Serratia marcescens PPB-26 was purified to homogeneity via ethanol fractionation and DEAE-cellulose column chromatography. Thus, a 3.8-fold purification was achieved with a 20% yield and specific activity of 76.2 U/mg. The purified protease was a 50-kDa monomer whose optimum pH and temperature for activity were 7.5 and 30℃ respectively; however, it was found to remain active in the 5-9 pH range and up to 40℃ for 6 h. The protease had a half-life of 15 days at 4℃, an optimum reaction time of 10 min, and an optimum substrate (casein) concentration of 0.25%. Furthermore, the Michaelis constant (Km) and reaction velocity (Vmax) of the protease were calculated to be 0.28% and 111.11 μmoles/(min·mg)-1, respectively. The protease was stable when subjected to metal ions (2 mM), showing increased activity with most (especially CoCl2 and MgSO4 (30.54% increase)). It was also stable when exposed to oxidizing agents, bleaching agents, and detergents (5% v/v for 60 min). It retained 93% of its activity in non-ionic detergents (Tween-20, Tween-80, and Triton X-100). Moreover, wash performance analysis in commercial detergents (Ariel and Tide) showed that not only was the protease capable of protein stain removal, but also reduced cleaning time by 80% when added to detergents. Thus, the Serratia marcescens PPB-26 metalloprotease appears to be a promising new candidate as a laundry additive in the detergent industry.

The cancer-associated meprin β variant G32R provides an additional activation site and promotes cancer cell invasion.

The extracellular metalloprotease meprin β is expressed as a homodimer and is primarily membrane bound. Meprin β can be released from the cell surface by its known sheddases ADAM10 and ADAM17. Activation of pro-meprin β at the cell surface prevents its shedding, thereby stabilizing its proteolytic activity at the plasma membrane. We show that a single amino acid exchange variant (G32R) of meprin β, identified in endometrium cancer, is more active against a peptide substrate and the IL-6 receptor than wild-type meprin β. We demonstrate that the change to an arginine residue at position 32 represents an additional activation site used by furin-like proteases in the Golgi, which consequently leads to reduced shedding by ADAM17. We investigated this meprin β G32R variant to assess cell proliferation, invasion through a collagen IV matrix and outgrowth from tumor spheroids. We found that increased meprin β G32R activity at the cell surface reduces cell proliferation, but increases cell invasion.

The Extracellular Protease AprX from Pseudomonas and its Spoilage Potential for UHT Milk: A Review.

The negative effects of proteases produced by psychrotrophic bacteria on dairy products, especially ultra-high-temperature (UHT) milk, are drawing increasing attention worldwide. These proteases are especially problematic, because it is difficult to control psychrotrophic bacteria during cold storage and to inactivate their heat-resistant proteases during dairy processing. The predominant psychrotrophic species with spoilage potential in raw milk, Pseudomonas, can produce a thermostable extracellular protease, AprX. A comprehensive understanding of AprX on the aspects of its biological properties, regulation, proteolytic potential, and its impact on UHT milk can contribute to finding effective approaches to minimize, detect, and inactivate AprX. AprX also deserves attention as a representative of all extracellular metalloproteases produced by psychrotrophic bacteria in milk. The progress of current research on AprX is summarized in this review, including a view on the gap in current understanding of this enzyme. Reducing the production and activity of AprX has considerable potential for alleviating the problems that arise from the instability of UHT milk during shelf-life.

Quantifying the Vasculogenic Potential of Induced Pluripotent Stem Cell-Derived Endothelial Progenitors in Collagen Hydrogels.

Our work reinforces the role of extracellular matrix (ECM) density and matrix metalloprotease activity on the formation of microvasculature from induced pluripotent stem cell (iPSC)-derived vascular cells. The cell-matrix interactions discussed in this study underscore the importance of understanding the role of mechanoregulation and matrix degradation on vasculogenesis and can potentially drive the development of ECM-mimicking angiogenic biomaterials. Furthermore, our work has broader implications concerning the response of iPSC-derived cells to the mechanics of engineered microenvironments. An understanding of these interactions will be critical to creating physiologically relevant transplantable tissue replacements.