MMP Inhibitor Research Articles

Employing comparative QSAR techniques for the recognition of dibenzofuran and dibenzothiophene derivatives toward MMP-12 inhibition

Among various matrix metalloproteinases (MMPs), MMP-12 is one of the potential targets for cancer and other diseases. However, none of the MMP-12 inhibitors has passed the clinical trials to date. Therefore, designing potential MMP-12 inhibitors as new drug molecules can provide effective therapeutic strategies for several diseases. In this study, a series of dibenzofuran and dibenzothiophene derivatives were subjected to different 2D and 3D-QSAR techniques to point out the crucial structural contributions highly influential toward the MMP-12 inhibitory activity. These techniques identified some structural attributes of these compounds that are responsible for influencing their MMP-12 inhibition. The carboxylic group may enhance proper binding with catalytic Zn2+ ion at the MMP-12 active site. Again, the i-propyl sulfonamido carboxylic acid function contributed positively toward MMP-12 inhibition. Moreover, the dibenzofuran moiety conferred stable binding at the S1′ pocket for higher MMP-12 inhibition. The steric and hydrophobic groups were found favourable near the furan ring substituted at the dibenzofuran moiety. Besides these ligand-based approaches, molecular docking and molecular dynamic (MD) simulation studies not only elucidated the importance of several aspects of these MMP-12 inhibitors while disclosing the significance of the finding of these QSAR studies and their influences toward MMP-12 inhibition. The MD simulation study also revealed stable and compact binding between such compounds at the MMP-12 active site. Therefore, the findings of these validated ligand-based and structure-based molecular modeling studies can aid the development of selective and potent lead molecules that can be used for the treatment of MMP-12-associated diseases. Communicated by Ramaswamy H. Sarma

Identification of N-Acyl Hydrazones as New Non-Zinc-Binding MMP-13 Inhibitors by Structure-Based Virtual Screening Studies and Chemical Optimization.

Matrix metalloproteinase 13 plays a central role in osteoarthritis (OA), as its overexpression induces an excessive breakdown of collagen that results in an imbalance between collagen synthesis and degradation in the joint, leading to progressive articular cartilage degradation. Therefore, MMP-13 has been proposed as a key therapeutic target for OA. Here we have developed a virtual screening workflow aimed at identifying selective non-zinc-binding MMP-13 inhibitors by targeting the deep S1' pocket of MMP-13. Three ligands were found to inhibit MMP-13 in the µM range, and one of these showed selectivity over other MMPs. A structure-based analysis guided the chemical optimization of the hit compound, leading to the obtaining of a new N-acyl hydrazone-based derivative with improved inhibitory activity and selectivity for the target enzyme.

Poster 101: Evaluation of Novel Treatment Agents on Rotator Cuff Tendon and Muscle Pathology in a Murine Subacromial Impingement Model

Poster 101: Evaluation of Novel Treatment Agents on Rotator Cuff Tendon and Muscle Pathology in a Murine Subacromial Impingement Model

Auraptene Has Antiviral Activity against Human Coronavirus OC43 in MRC-5 Cells

Auraptene (7-geranyloxycoumarin) is the abundant prenyloxycoumarin found in the fruits of Citrus spp. Auraptene has a variety of pharmacological and therapeutic functions, such as anticancer, antioxidant, immunomodulatory, and anti-inflammation activities, with excellent safety profiles. In this study, we evaluated the anticoronaviral activity of auraptene in HCoV-OC43-infected human lung fibroblast MRC-5 cells. We found that auraptene effectively inhibited HCoV-OC43-induced cytopathic effects with 4.3 μM IC50 and 6.1 μM IC90, resulting in a selectivity index (CC50/IC50) of >3.5. Auraptene treatment also decreased viral RNA levels in HCoV-OC43-infected cells, as detected through quantitative real-time PCR, and decreased the expression level of spike proteins and nucleocapsid proteins in virus-infected cells, as detected through the Western blot analysis and immunofluorescence staining. Time-of-addition analysis showed auraptene’s inhibitory effects at the post-entry stage of the virus life cycle; however, auraptene did not induce the antiviral interferon families, IFN-α1, IFN-β1, and IFN-λ1. Additionally, auraptene-treated MRC-5 cells during HCoV-OC43 infection decreased the MMP-9 mRNA levels which are usually increased due to the infection, as auraptene is a previously reported MMP-9 inhibitor. Therefore, auraptene showed antiviral activity against HCoV-OC43 infection, and we suggest that auraptene has the potential to serve as a therapeutic agent against human coronavirus.

Atheroma-Relevant 7-Oxysterols Differentially Upregulate Cd14 Expression.

The expression of CD14 in monocytic cells is elevated in atherosclerotic lesions where 7-oxyterols are abundant. However, it remains unknown whether atheroma-relevant 7-oxysterols are involved in receptor expression. Therefore, we investigated the effects of 7α-hydroxycholesterol (7αOHChol), 7β-hydroxycholesterol (7βOHChol), and 7-ketocholesterol (7K) on CD14 levels in THP-1 cells. The three 7-oxysterols increased CD14 transcript levels at a distinct time point, elevated cellular CD14 protein levels, and promoted the release of soluble CD (sCD14) from THP-1 cells. Our data revealed that CD14 expression was most strongly induced after treatment with 7αOHChol. Moreover, 7αOHChol alone upregulated membrane-bound CD14 levels and enhanced responses to lipopolysaccharides, as determined by CCL2 production and monocytic cell migration. The 7-oxysterols also increased the gelatinolytic activity of MMP-9, and a cell-permeable, reversible MMP-9 inhibitor, MMP-9 inhibitor I, significantly impaired sCD14 release. These results indicate that 7-oxysterols differentially induce CD14 expression in vascular cells and contribute to the monocytic cell expression of CD14 via overlapping, but distinct, mechanisms.

Correlation of TIMP1-MMP2/MMP9 Gene Expression Axis Changes with Treatment Efficacy and Survival of NSCLC Patients.

In the course of lung cancer, normal cells are transformed into cancerous ones, and changes occur in the microenvironment, including the extracellular matrix (ECM), which is not only a scaffold for cells, but also a reservoir of cytokines, chemokines and growth factors. Metalloproteinases (MMPs) are among the elements that enable ECM remodeling. The publication focuses on the problem of changes in the gene expression of MMP2, MMP9 and tissue inhibitor of metalloproteinases (TIMP1) in the blood of NSCLC patients during therapy (one year after surgical resection of the tumor). The paper also analyzes differences in the expression of the studied genes in the tumor tissue, as well as data collected in publicly available databases. The results of blood tests showed no differences in the expression of the tested genes during therapy; however, changes were observed in cancerous tissue, which was characterized by higher expression of MMP2 and MMP9, compared to non-cancerous tissue, and unchanged expression of TIMP1. Nevertheless, higher expression of each of the studied genes was associated with shorter patient survival. Interestingly, it was not only the increased expression of metalloproteinase genes, but also the increased expression of the metalloproteinase inhibitor (TIMP1) that was unfavorable for patients.

Serum TGF-β1 and CD14 Predicts Response to Anti-TNF-α Therapy in IBD.

Tumor necrosis factor-alpha (TNF-α) agonists revolutionized therapeutic algorithms in inflammatory bowel disease (IBD) management. However, approximately every third IBD patient does not respond to this therapy in the long term, which delays efficient control of the intestinal inflammation. We analyzed the power of serum biomarkers to predict the failure of anti-TNF-α. We collected serum of 38 IBD patients at therapy prescription and 38 weeks later and analyzed them with relation to therapy response (no-, partial-, and full response). We used enzyme-linked immunosorbent assay to quantify 16 biomarkers related to gut barrier (intestinal fatty acid-binding protein, liver fatty acid-binding protein, trefoil factor 3, and interleukin (IL)-33), microbial translocation, immune system regulation (TNF-α, CD14, lipopolysaccharide-binding protein, mannan-binding lectin, IL-18, transforming growth factor-β1 (TGF-β1), osteoprotegerin (OPG), insulin-like growth factor 2 (IGF-2), endocrine-gland-derived vascular endothelial growth factor), and matrix metalloproteinase system (MMP-9, MMP-14, and tissue inhibitors of metalloproteinase-1). We found that future full-responders have different biomarker profiles than non-responders, while partial-responders cannot be distinguished from either group. When future non-responders were compared to responders, their baseline contained significantly more TGF-β1, less CD14, and increased level of MMP-9, and concentration of these factors could predict non-responders with high accuracy (AUC = 0.938). Interestingly, during the 38 weeks, levels of MMP-9 decreased in all patients, irrespective of the outcome, while OPG, IGF-2, and TGF-β1 were higher in non-responders compared to full-responders both at the beginning and the end of the treatment. The TGF-β1 and CD14 can distinguish non-responders from responders. The changes in biomarker dynamics during the therapy suggest that growth factors (such as OPG, IGF-2, and TGF-β) are not markedly influenced by the treatment and that anti-TNF-α therapy decreases MMP-9 without influencing the treatment outcome.

COL4A3 Mutation Induced Podocyte Apoptosis by Dysregulation of NADPH Oxidase 4 and MMP-2

Podocyte apoptosis is a common mechanism driving progression in Alport syndrome (AS). This study aimed to investigate the mechanism of podocyte apoptosis caused by COL4A3 mutations. We recruited patients with autosomal dominant AS (ADAS). Patients with minimal change disease (MCD) were recruited as controls. Microarray analysis was carried out on isolated glomeruli from the patients and validated. Then, corresponding mutant human podocytes (p.C1616Y) and 129 mice (p.C1615Y, the murine homolog to the human p.C1616Y) were constructed. The highest differentially expressed genes (DEGs) from microarray analysis were validated in transgenic mice and podocytes before and after administration of MMP-2 inhibitor (SB-3CT) and NOX4 inhibitor (GKT137831). We further validated NOX4/MMP-2/apoptosis pathway by real-time polymerase chain reaction (PCR), immunohistochemistry, and western blot in renal tissues from the ADAS patients. Using microarray analysis, we observed that DEGs, including NOX4/H2O2, MMP-2, and podocyte apoptosis-related genes were significantly upregulated. These genes were validated by real-time PCR, histologic analysis, and western blot in corresponding mutant human podocyte (p.C1616Y) and/or mice models (p.C1615Y). Moreover, we found podocyte apoptosis was abrogated and MMP-2 expression was down-regulated both invivo and invitro by NOX4 inhibition, urinary albumin-to-creatinine ratio, 24-hour proteinuria; and renal pathologic lesion was attenuated by NOX4 inhibition invivo. Furthermore, podocyte apoptosis was attenuated whereas NOX4 expression remained the same by inhibition of MMP-2 both invivo and invitro. These results indicated that NOX4 might induce podocyte apoptosis through the regulation of MMP-2 in patients with COL4A3 mutations. Our findings provided new insights into the mechanism of ADAS.

Expressions of MMP2, MMP9, and TIMP-1 in the inflammatory cells of nasal polyps: granulocytes, monocytes, and mast cells.

We investigated the role of matrix metalloproteinase-2 (MMP-2) and MMP-9 in nasal polyp (NP) pathogenesis. In group 1 (n = 24), polyp specimens were obtained from maxillary sinus, ethmoid sinus, and nasal cavity. In group 2 without NP (control) (n = 11), inferior turbinate samples were taken. Inflammatory cell count and MMP2, MMP9 and tissue inhibitor of metalloproteinase-1 (TIMP-1), positivity indexes (PIs) were evaluated. Granulocyte and mast cell-MMP2 and MMP9-PI were higher than the rate of monocyte-MMP2-PI and monocyte-MMP9-PI, respectively, in the ethmoid sinus, maxillary sinus, and nasal cavity. Mast Cell-TIMP1-PI was higher than the rates of granulocyte-TIMP1-PI and monocyte-TIMP1-PI in the maxillary sinus and was higher than the rate of monocyte-TIMP1-PI in the ethmoid sinus. Excessive MMP2 and MMP9, compared to TIMP1, are present in granulocytes and mast cells, respectively. With matrix MMPs, the extracellular matrix is destroyed, leading inflammatory cells to pass through, causing polypoid degeneration.

Prospective assessment of cytokines and regulatory proteins concentration in the tear fluid of POAG patients with various hypotensive effects after non-penetrating deep sclerectomy

The aim. To assess the dynamics of cytokine content in tear fluid of primary openangle glaucoma (POAG) patients at various terms after non-penetrating deep sclerectomy (NPDS) in relation to the functional state of the outflow tracts.Material and methods. We carried out prospective examination of 65 patients with advanced stage of primary open-angle glaucoma after NPDS. Depending on the course of the postoperative period and the conditions for achieving the hypotensive effect of NPDS, all patients were divided into three groups: group 1 – with the optimal hypotensive effect; group 2 – with the conditional hypotensive effect; group 3 – with no hypotensive effect after NPDS. The intraocular pressure and the concentration of TGF-β, MMP-9, IL-6, IL-8, VEGF-A (121 and 165) in the tear fluid were studied using ELISA method in pre- and postoperative period. We studied the outflow tracts using optical coherence tomography and carried out ultrastructural analysis of filtering blebs tissue.Results. In group 1, the minimum initial concentrations of IL-6, IL-8 and TGF-β in the tear fluid and their moderate increase in the postoperative period; high concentrations of MMP-9 at all stages and an increase in VEGF-A by 2 months after NPDS were registered. In group 2, there was a high level of VEGF-A in the tear fluid before and 2 months after NPDS, an increase in TGF-β, IL-6 and IL-8 in the tear fluid in the early period with their suppression in the late period, as well as an increase in MMP-9 in the early postoperative period. Group 3 had maximum concentrations of TGF-β and IL-8 in the tear fluid initially and in the early postoperative period, suppression of MMP-9 in the tear fluid 2 weeks after and of VEGF-A 2 months after NPDS.Conclusion. Initially high concentrations of IL-6, IL-8, and TGF-β in the tear fluid and the suppression of MMP-9 and VEGF-A in the postoperative period contribute to the surgical failure of the NPDS.

Impact of house dust mite in vitiligo skin: environmental contribution to increased cutaneous immunity and melanocyte detachment.

Vitiligo is an autoimmune skin disorder characterized by loss of melanocytes. Protease-mediated disruption of junctions between keratinocytes and/or keratinocyte intrinsic dysfunction may directly contribute to melanocyte loss. House dust mite (HDM), an environmental allergen with potent protease activity, contributes to respiratory and gut disease but also to atopic dermatitis and rosacea. To verify if HDM can contribute to melanocyte detachment in vitiligo and if so, by which mechanism(s). Using primary human keratinocytes, human skin biopsies from healthy donors and patients with vitiligo, and 3D reconstructed human epidermis, we studied the effect of HDM on cutaneous immunity, tight and adherent junction expression and melanocyte detachment. HDM increased keratinocyte production of vitiligo-associated cytokines and chemokines and increased expression of toll-like receptor (TLR)-4. This was associated with increased in situ matrix-metalloproteinase (MMP)-9 activity, reduced cutaneous expression of adherent protein E-cadherin, increased soluble E-cadherin in culture supernatant and significantly increased number of suprabasal melanocytes in the skin. This effect was dose-dependent and driven by cysteine protease Der p1 and MMP-9. Selective MMP-9 inhibitor, Ab142180, restored E-cadherin expression and inhibited HDM-induced melanocyte detachment. Keratinocytes from patients with vitiligo were more sensitive to HDM-induced changes than healthy keratinocytes. All results were confirmed in a 3D model of healthy skin and in human skin biopsies. Our results highlight that environmental mite may act as an external source of pathogen-associated molecular pattern molecules in vitiligo and topical MMP-9 inhibitors may be useful therapeutic targets. Whether HDM contributes to the onset of flares in vitiligo remains to be tested in carefully controlled trials.

Physiological Properties, Functions, and Trends in the Matrix Metalloproteinase Inhibitors in Inflammation-Mediated Human Diseases.

Matrix metalloproteinases (MMPs), also known as metalloproteinases, are enzymes that degrade proteins and require the presence of active metal atoms. There are more than 20 types of MMPs, and they promote cell migration through the proteolytic degradation of the extracellular basement. MMPs are upregulated in cancers and inflamed regions. MMPs have three conservation regions: pro-MMP, catalysis, and hemopexin. Through these domains, MMPs cleave matrixes and cell-cell barriers. Consequently, MMPs cleave the whole extracellular matrix (ECM). In other words, they decompose most of the components related to the ECM, in their roles as key enzymes in cellular and pathophysiological events in the body. Zn2+-containing endo-type peptidases directly degrade and remodel the ECM region in the progression of various diseases. MMPs are frequently found in abnormal disease status of inflammatory responses, periodontal lesion, inflammatory pulmonary lesion, arteriosclerotic smooth muscles, arthritis, and tumor metastasis and invasion. They are also known to participate in aging processes-such as wrinkle formation-by destroying collagen in the dermis. In particular, the onset of diseases via the MMP-dependent inflammatory response is caused by the breakdown of proteins in the ECM and the basement membranous region, which are the supporting structures of cells. This review describes the developments in the research examining the general and selective inhibitors for MMP associated with various human diseases over the past 20 years in terms of structure remodeling, substrate-recognizing specificities, and pharmacological applicability. Among two similar types of MMPs, MMP-2 is known as gelatinase-A with a 72 kDa, while MMP-9 is termed gelatinase-B with a 92 kDa. Both of these play a key role in this action. Therefore, both enzymatic expression levels coincide during the onset and progression of diseases. Endogenous tissue inhibitors of matrix metalloproteinases (TIMPs) are highly specific for each MMP inhibitor type. The intrinsic factors regulate various MMP types by inhibiting the onset of various diseases mediated by MMP-dependent or independent inflammatory responses. The MMP- 9 and MMP-2 enzyme activity related to the prognosis of diseases associated with the inflammatory response are selectively inhibited by TIMP1 and TIMP2, respectively. The major pathogenesis of MMP-mediated diseases is related to the proliferation of inflammatory cells in various human tissues, which indicates their potential to diagnose or treat these diseases. The discovery of a substance that inhibits MMPs would be very important for preventing and treating various MMP-dependent diseases. Considerable research has examined MMP inhibitors, but most of these have been synthetic compounds. Research using natural products as MMP inhibitors has only recently become a subject of interest. This review intends to discuss recent research trends regarding the physiological properties, functions, and therapeutic agents related to MMPs.

Osteoprogenitor-GMP crosstalk underpins solid tumor-induced systemic immunosuppression and persists after tumor removal

Remote tumors disrupt the bone marrow (BM) ecosystem (BME), eliciting the overproduction of BM-derived immunosuppressive cells. However, the underlying mechanisms remain poorly understood. Herein, we characterized breast and lung cancer-induced BME shifts pre- and post-tumor removal. Remote tumors progressively lead to osteoprogenitor (OP) expansion, hematopoietic stem cell dislocation, and CD41- granulocyte-monocyte progenitor (GMP) aggregation. The tumor-entrained BME is characterized by co-localization between CD41- GMPs and OPs. OP ablation abolishes this effect and diminishes abnormal myeloid overproduction. Mechanistically, HTRA1 carried by tumor-derived small extracellular vesicles upregulates MMP-13 in OPs, which in turn induces the alterations in the hematopoietic program. Importantly, these effects persist post-surgery and continue to impair anti-tumor immunity. Conditional knockout or inhibition of MMP-13 accelerates immune reinstatement and restores the efficacies of immunotherapies. Therefore, tumor-induced systemic effects are initiated by OP-GMP crosstalk that outlasts tumor burden, and additional treatment is required to reverse these effects for optimal therapeutic efficacy.

Repurposing the inhibitors of MMP-9 and SGLT-2 against ubiquitin specific protease 30 in Parkinson’s disease: computational modelling studies

Ubiquitin specific protease 30 (USP30) has been attributed to mitochondrial dysfunction and impediment of mitophagy in Parkinson’s disease (PD). This happens once ubiquitin that supposed to bind with deformed mitochondria at the insistence of Parkin, it’s been recruited by USP30 via the distal ubiquitin binding domain. This is a challenge when PINK1 and Parkin loss their functions due to mutation. Although, there are reports on USP30s’ inhibitors but no study on the repurposing of inhibitors approved against MMP-9 and SGLT-2 as potential inhibitors of USP30 in PD. Thus, the highlight therein, is to repurpose approved inhibitors of MMP-9 and SGLT-2 against USP30 in PD using extensive computational modelling framework. 3D structures of Ligands and USP30 were obtained from PubChem and protein database (PDB) servers respectively, and were subjected to molecular docking, ADMET evaluation, DFT calculation, molecular dynamics simulation (MDS) and free energy calculations. Out of the 18 drugs, 2 drugs showed good binding affinity to the distal ubiquitin binding domain, moderate pharmacokinetic properties and good stability. The findings showed canagliflozin and empagliflozin as potential inhibitors of USP30. Thus, we present these drugs as repurposing candidates for the treatment of PD. However, the findings in this current study needs to be validated experimentally. Communicated by Ramaswamy H. Sarma

Elevated PDGF-BB from Bone Impairs Hippocampal Vasculature by Inducing PDGFRβ Shedding from Pericytes.

Evidence suggests a unique association between bone aging and neurodegenerative/cerebrovascular disorders. However, the mechanisms underlying bone-brain interplay remain elusive. Here platelet-derived growth factor-BB (PDGF-BB) produced by preosteoclasts in bone is reported to promote age-associated hippocampal vascular impairment. Aberrantly elevated circulating PDGF-BB in aged mice and high-fat diet (HFD)-challenged mice correlates with capillary reduction, pericyte loss, and increased blood-brain barrier (BBB) permeability in their hippocampus. Preosteoclast-specific Pdgfb transgenic mice with markedly high plasma PDGF-BB concentration faithfully recapitulate the age-associated hippocampal BBB impairment and cognitive decline. Conversely, preosteoclast-specific Pdgfb knockout mice have attenuated hippocampal BBB impairment in aged mice or HFD-challenged mice. Persistent exposure of brain pericytes to high concentrations of PDGF-BB upregulates matrix metalloproteinase 14 (MMP14), which promotes ectodomain shedding of PDGF receptor β (PDGFRβ) from pericyte surface. MMP inhibitor treatment alleviates hippocampal pericyte loss and capillary reduction in the conditional Pdgfb transgenic mice and antagonizes BBB leakage in aged mice. The findings establish the role of bone-derived PDGF-BB in mediating hippocampal BBB disruption and identify the ligand-induced PDGFRβ shedding as a feedback mechanism for age-associated PDGFRβ downregulation and the consequent pericyte loss.

Expression, purification and refolding of pro-MMP-2 from inclusion bodies of E. coli

MMP-2 has been reported as the most validated target for cancer progression and deserves further investigation. However, due to the lack of methods for obtaining large amounts of highly purified and bioactive MMP-2, identifying specific substrates and developing specific inhibitors of MMP-2 remains extremely difficult. In this study, the DNA fragment coding for pro-MMP-2 was inserted into plasmid pET28a in an oriented manner, and the resulting recombinant protein was effectively expressed and led to accumulation as inclusion bodies in E. coli. This protein was easy to purify to near homogeneity by the combination of common inclusion bodies purification procedure and cold ethanol fractionation. Then, our results of gelatin zymography and fluorometric assay revealed that pro-MMP-2 at least partially restored its natural structure and enzymatic activity after renaturation. We obtained approximately 11 mg refolded pro-MMP-2 protein from 1 L LB broth, which was higher than other strategies previously reported. In conclusion, a simple and cost-effective procedure for obtaining high amounts of functional MMP-2 was developed, which would contribute to the progress of studies on the gamut of biological action of this important proteinase. Furthermore, our protocol should be appropriate for the expression, purification, and refolding of other bacterial toxic proteins.

A molecular network-based pharmacological study on the protective effect of Panax notoginseng rhizomes against renal ischemia-reperfusion injury.

Objective: We aimed to explore the protective effect of Panax notoginseng rhizomes (PNR) on renal ischemia and reperfusion injury (RIRI) and the underlying molecular network mechanism based on network pharmacology and combined systemic experimental validation. Methods: A bilateral RIRI model was established, and Cr, SCr, and BUN levels were detected. Then, the PNR was pretreated 1week before the RIRI model was prepared. To determine the effects of the PNR in RIRI, histopathological damage and the effect of PNRs to the kidney was assessed, using TTC, HE, and TUNEL staining. Furthermore, the underlying network pharmacology mechanism was detected by screening drug-disease intersection targets from PPI protein interactions and GO and KEGG analysis, and the hub genes were screened for molecular docking based on the Degree value. Finally, the expression of hub genes in kidney tissues was verified by qPCR, and the protein expression of related genes was further detected by Western blot (WB). Results: PNR pretreatment could effectively increase Cr level, decrease SCr and BUN levels, reduce renal infarct areas and renal tubular cell injury areas, and inhibit renal cell apoptosis. By using network pharmacology combined with bioinformatics, we screened co-targets both Panax notoginseng (Sanchi) and RIRI, acquired ten hub genes, and successfully performed molecular docking. Of these, pretreatment with the PNR reduced the mRNA levels of IL6 and MMP9 at postoperative day 1 and TP53 at postoperative day 7, and the protein expression of MMP9 at postoperative day 1 in IRI rats. These results showed that the PNR could decrease kidney pathological injury in IRI rats and inhibit apoptotic reaction and cell inflammation so as to improve renal injury effectively, and the core network mechanism is involved in the inhibition of MMP9, TP53, and IL-6. Conclusion: The PNR has a marked protective effect for RIRI, and the underlying mechanism is involved in inhibiting the expression of MMP9, TP53, and IL-6. This striking discovery not only provides fruitful evidence for the protective effect of the PNR in RIRI rats but also provides a novel mechanic explanation.

Role of Doxycycline as an Osteoarthritis Disease-Modifying Drug.

Doxycycline is a drug that has been proposed to modify osteoarthritis (OA) progression, in addition to its role as an antibiotic. However, available evidence thus far comprises sporadic reports, with no consensus on its benefits. Hence, this review attempts to analyze the evidence available thus far on the role of doxycycline as a disease-modifying osteoarthritis drug (DMOAD) in knee osteoarthritis. The earliest evidence of doxycycline in OA appeared in 1991 when doxycycline was found to inhibit the type XI collagenolytic activity of extracts from the human osteoarthritic cartilage, and gelatinase and tetracycline were found to inhibit this metalloproteinase activity in articular cartilage in vivo, which could modify cartilage breakdown in osteoarthritis. Apart from the inhibition of cartilage damage by metalloproteinases (MMPs) and other cartilage-related mechanisms, doxycycline also affects the bone and interferes with many enzyme systems. The most significant finding after reviewing various studies was that doxycycline has a definitive role in structural changes in osteoarthritis progression and radiological joint space width, but its role in the improvement of clinical outcomes as a DMOAD has not been established. However, there is much of a gap and lack of evidence in this regard. Doxycycline, as an MMP inhibitor, has theoretical advantages for clinical outcomes, but the present studies reveal only beneficial structural changes in osteoarthritis and very minimal or nonexistent advantages in clinical outcomes. Current evidence does not favor the regular use of doxycycline for the treatment of osteoarthritis as an individual treatment option or in combination with others. However, multicenter large cohort studies are warranted to determine the long-term benefits of doxycycline.

Abstract 3071: Pituitary adenylate cyclase activating polypeptide stimulates NSCLC growth by increasing HER4 tyrosine phosphorylation in a neuregulin-1 dependent manner

Abstract Pituitary adenylate cyclase activating polypeptide [PACAP] is a 27 amino acid peptide which stimulates the growth of numerous cancers including non-small cell lung cancer (NSCLC). PACAP binds with high affinity to the type B G protein-coupled receptor [GPCR] PAC1 (Moody et al., Peptides 2021; 137: 170480). PAC1 activation causes phosphatidyl inositol [PI] turnover stimulating matrix metalloprotease [MMP]. By ELISA, PACAP increased secretion of neuregulin [NRG1] from NSCLC cells. NRG1 binds with high affinity to HER4. Here the ability of PAC1 to regulate transactivation of HER4 was investigated. By RT-PCR and Western blot, PAC1, NRG1 and HER4 but not HER3 or NRG2 were detected in NCI-H522 and H661 cells. Adding PACAP-27 (0.1 μM) or NRG1 (0.01 μg/ml) to NCI-H522 or H661 cells increased P-Tyr1284-HER4 3-fold after 5 min. Using immunoprecipitation techniques, adding PACAP TO NSCLC cells increased formation of HER4 homodimers and HER4-EGFR as well as HER4-HER2 heterodimers. The increase in P-HER4 caused by PACAP-27 was impaired by PACAP(6-38) [PAC1 antagonist], HER4 siRNA, NRG1 antibody [Ab] or ibrutinib [TKI]. The PAC1 regulation of HER4 transactivation is impaired by GM6001 [MMP inhibitor]. The clonal growth of NSCLC cells was stimulated by PACAP-27 or NRG1 but inhibited by PACAP(6-38) or ibrutinib. The results indicate that PACAP-27 stimulates the growth of NSCLC due to release of NRG1 which activates receptor tyrosine kinases such as HER4. Citation Format: Terry W. Moody, Irene Ramos Alvarez, Robert T. Jensen. Pituitary adenylate cyclase activating polypeptide stimulates NSCLC growth by increasing HER4 tyrosine phosphorylation in a neuregulin-1 dependent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3071.

Abstract 3613: Effect of thrombomodulin and plasminogen interaction on melanoma spheroid invasion

Abstract Background: Thrombomodulin (TM), a transmembrane glycoprotein that acts as a plasminogen (Plg) receptor, has been found as a potential molecular and prognostic marker that impacts the spread of various cancers, including malignant melanoma. A previous study showed that TM plays a vital function in angiogenesis activity [1] but its role in the malignant melanoma invasion is unclear. Here, we investigate the role of TM-Plg by using melanoma spheroid (MS) embedded in an extracellular matrix (ECM) modeled to understand how TM-Plg affects the progression of MS invasion. Methods: In this work, A2058 (A2058-GFP and A2058-TMGFP) and MeWo (siC and siTM) MS with different TM expressions were formed, harvested, and embedded in type I collagen gel for invasion assay. TM and Plg expression were determined by western blot. The surface of A2058 MS was observed by SEM imaging. Human Plg, MMPs, and Plg inhibitors, tranexamic acid (TXA) and epsilon-aminocaproic acid (ε-ACA), were utilized to investigate the effect of TM on the plasmin system. Immunofluorescence of TM and F-actin were validated. Results: When the two cell lines expressed with TM, the formed MS invaded to the surrounding matrix more distinctively than that of the TM-silencing ones, with a 2.5-fold difference in the ratio invasive area change. Upon placing the two A2058-TMGFP MS in the vicinity of each other within the ECM, they showed a strong interaction with an observed distance between the two MS from 50 μm to 280 μm. Immunofluorescence of TMGFP assessed the role of TM in MS invasion and interaction in ECM. Microvilli structures were found on the surface of A2058-TMGFP cells that may help the cell have more cellular processes such as adhesion, signal transduction, and metabolic activities. Furthermore, TXA, ε-ACA, and MMP inhibitors inhibited the invasion of A2058-TMGFP MSs in a dose-dependent manner. Human Plg stimulated invasion in TM-expressing MSs while no effect on non-TM MSs. The results suggested that the human Plg only significantly increased the MS invasion with the presence of TM. Conclusion: We concluded that with the presence of TM, the MS invasion and interaction become stronger than MS without TM expression. Moreover, TM enhances MS invasion in the 3D model via interacting Plg. This study provides evidence for the development of TM antagonists in the future to analyze the drug's potential as an anti-metastasis treatment.[1] P. K. Chen et al., “Thrombomodulin functions as a plasminogen receptor to modulate angiogenesis,” FASEB J., vol. 27, no. 11, pp. 4520-4531, 2013, doi: 10.1096/fj.13-227561. Citation Format: Thi Kim Ngan Ngo, Hua-Lin Wu, Cheng-Hsiang Kuo, Ting-Yuan Tu. Effect of thrombomodulin and plasminogen interaction on melanoma spheroid invasion. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3613.