Matrix Metalloproteinase Research Articles

Altered Endometrial Microbiota Profile Is Associated With Poor Endometrial Receptivity of Repeated Implantation Failure.

To gain insight into the endometrial pathophysiology of unexplained repeated implantation failure (RIF), we examined the characteristics of genital tract microbiota and explored the correlation between the microbiota and endometrial receptivity. Vaginal secretion (VS) and endometrial biopsy (EB) samples were collected from patients with RIF (RIF group, n=32) and those with infertility who had achieved pregnancy during their initial embryo transfer cycle (control group, n=18). 16S ribosomal RNA sequencing and quantitative PCR were performed to characterize the microbiota of the two groups. Spearman's correlation analysis was performed to determine the relationship between endometrial receptivity markers and endometrial microbiota. Endometrial microbiota exhibited distinct characteristics from vaginal microbiota, with a higher alpha-diversity. Alpha-diversity of the endometrial microbiota was higher in the RIF group than in the control group. Compared with the control group, the RIF group had a significant decrease in endometrial Lactobacillus abundance and an increase in Gardnerella and Acinetobacter abundances. The expression levels of endometrial receptivity markers, including homeobox A11, integrin αvβ3, leukemia inhibitor factor, matrix metalloproteinase-9, and vascular endothelial growth factor, were lower in the RIF group than in the control group. Moreover, the expression levels of these markers were correlated with endometrial Lactobacillus, Gardnerella, and Acinetobacter abundances. RIF is characterized by endometrial microbiota dysbiosis and poor endometrial receptivity. Moreover, abnormal endometrial microbiota is associated with impaired endometrial receptivity, which may be a potential cause of unexplained RIF.

Diabetes mellitus exacerbates inflammation in a murine model of ligature-induced peri-implantitis: A histological and microtomographic study.

To investigate the influence of diabetes mellitus (DM) in a murine model of peri-implantitis (PI). Twenty-seven 4-week-old C57BL/6J male mice had their first and second maxillary left molars extracted. Eight weeks later, one machined implant was placed in each mouse. Four weeks after osseointegration, the mice were divided into three groups: (a) control (C), (b) PI and (c) DM + PI. DM was induced by streptozotocin (STZ) administration. After DM induction, PI was induced using ligatures for 2 weeks. The hemimaxillae were collected for micro-CT and histological analyses. The primary outcomes consisted of linear (mm) and volumetric (mm3) bone loss. Secondary outcomes were based on histological analysis and included inflammatory infiltrate, osteoclastic activity, matrix organization, composition and remodelling. Data are presented as means ± SEM. Statistical analyses were performed using one-way ANOVA, followed by Tukey's test. Gingival tissue oedema was detected in the PI and DM + PI groups. Micro-CT showed significantly increased linear and volumetric bone loss in the DM + PI group compared to the C and PI groups. H&E staining showed greater inflammatory response and bone resorption in the PI and DM + PI groups than in the C group. The DM + PI group had significantly higher osteoclast numbers than the C and PI groups. Picrosirius red stained less for types I and III collagen in the PI and DM + PI groups than in the C group. There was a significant increase in monocyte/macrophage (CD-11b) counts and matrix metalloproteinases (MMP-2 and MMP-8) marker levels and a significant decrease in the matrix metalloproteinases inhibition marker (TIMP-2) levels in the DM + PI group compared to the C and PI groups. DM exacerbates PI-induced soft-tissue inflammation, matrix degradation and bone loss.

The pivotal role of osteopontin in UV-induced skin inflammation in a mouse model.

Osteopontin (OPN) is a pro-inflammatory protein that influences bone remodelling, wound healing, angiogenesis, allergic inflammation, and skin diseases such as psoriasis, contact dermatitis and skin cancer. However, the role of OPN in the skin remains unclear. Therefore, this study aimed to investigate the role of OPN in the skin, particularly in the context of ultraviolet (UV) irradiation-induced inflammation. OPN expression and its effects on inflammatory modulators were assessed in human skin, in a mouse model and in vitro, using a UV source emitting both UVB and UVA radiation, which collectively contribute to UV-induced skin inflammation. OPN expression increased in human and mouse skin after UV irradiation. Compared with wild-type mice, UV irradiation-induced skin phenotypes, such as erythema and skin thickening, were alleviated in OPN-/- mice. In addition, the number of immune cells recruited to the skin after UV irradiation and the expression of inflammatory cytokines and matrix metalloproteinases (MMPs) were observed to be decreased in the skin of OPN-/- mice compared with that of wild-type mice. By contrast, the degree of skin inflammation was higher in the hOPN KI mice than in wild-type mice. Treatment with recombinant OPN increased the expression of MMP-1 and inflammatory cytokines in human dermal fibroblasts and epidermal keratinocytes in vitro. Our results suggest that OPN may play a regulatory role in UV-induced skin inflammation.

Neuronatin Promotes the Progression of Non-small Cell Lung Cancer by Activating the NF-κB Signaling.

Understanding the regulatory mechanisms involving neuronatin (NNAT) in non-small cell lung cancer (NSCLC) is an ongoing challenge. This study aimed to elucidate the impact of NNAT knockdown on NSCLC by employing both in vitro and in vivo approaches. To investigate the role of NNAT, its expression was silenced in NSCLC cell lines A549 and H226. Subsequently, various parameters, including cell proliferation, invasion, migration, and apoptosis, were assessed. Additionally, cell-derived xenograft models were established to evaluate the effect of NNAT knockdown on tumor growth. The expression of key molecules, including cyclin D1, B-cell leukemia/lymphoma 2 (Bcl-2), p65, matrix metalloproteinase (MMP) 2, and nerve growth factor (NGF) were examined both in vitro and in vivo. Nerve fiber density within tumor tissues was analyzed using silver staining. Upon NNAT knockdown, a remarkable reduction in NSCLC cell proliferation, invasion, and migration was observed, accompanied by elevated levels of apoptosis. Furthermore, the expression of cyclin D1, Bcl-2, MMP2, and phosphorylated p65 (p-p65) showed significant downregulation. In vivo, NNAT knockdown led to substantial inhibition of tumor growth and a concurrent decrease in cyclinD1, Bcl-2, MMP2, and p-p65 expression within tumor tissues. Importantly, NNAT knockdown also led to a decrease in nerve fiber density and downregulation of NGF expression within the xenograft tumor tissues. Collectively, these findings suggest that neuronatin plays a pivotal role in driving NSCLC progression, potentially through the activation of the nuclear factor-kappa B signaling cascade. Additionally, neuronatin may contribute to the modulation of tumor microenvironment innervation in NSCLC. Targeting neuronatin inhibition emerges as a promising strategy for potential anti-NSCLC therapeutic intervention.

A comparative evaluation of the effect of matrix metalloproteinase inhibitor on the fracture resistance of endodontically treated teeth restored with Everstick-reinforced composite resin: An in vitro study

Aim: To evaluate the effect of applying a matrix metalloproteinase (MMP) inhibitor on the fracture resistance of root-filled teeth restored with Everstick fiber-reinforced composite resin. Subjects and Methods: After the selection of 60 freshly extracted human mandibular first molar, root canal access and standard uniformly sized mesio-occluso-distal (MOD) cavities were made and the teeth were randomly assigned into three groups (n = 20 each): Group I, the MOD cavity was first lined with flowable composite resin and then restored with composite resin. In Group II, Everstick fiber was placed into the bed of flowable composite in buccal–pulpal–lingual direction before the composite restoration was placed. In Group III, after etching of the cavity, a 2% chlorhexidine MMP inhibitor was applied. Then, the MOD cavity was restored same as group II. A universal testing machine was employed to compressively load the teeth at a cross-head speed of 0.5 mm/min till fracture. The maximum fracture loads were recorded in Newtons (N) and data were analyzed with one-way ANOVA and post-hoc Tukey tests. Results: Group III exhibited significantly higher fracture resistance compared to all other groups (P < 0.001), whereas Group I demonstrated the lowest fracture resistance. Conclusion: The utilization of Everstick glass fiber, combined with MMP inhibitor treatment, yielded the greatest fracture resistance. Hence, this method may be prioritized over conventional restoration techniques for strengthening root canal-treated teeth with structurally compromised crowns.

Endogenous Tissue Inhibitor of Metalloproteinase-2 Levels Are Associated With High-Quality Neat Semen but Unrelated to Sperm Cryoresistance in Bulls.

Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) is part of the tissue inhibitors of the metalloproteinases (TIMPs) family. Its primary function is to regulate the activity of matrix metalloproteinases (MMPs) across various tissues, including those of the reproductive system. This study aimed to quantify the natural levels of TIMP-2 in seminal plasma (SP) and sperm membrane (SM) of bulls, explore potential associations between TIMP-2 levels and semen quality parameters, and examine the relationship between TIMP-2 levels and sperm cryoresistance in bulls. Thirty semen samples from Frieswal breeding bulls were categorized into two groups based on their initial progressive motility (IPM): Good (IPM ≥ 70%; n = 21) and Poor (IPM ≤ 40%; n = 9). The samples were evaluated for their quality parameters at the fresh stage, and TIMP-2 levels were measured in SP and SM using a bovine-specific ELISA kit. Following cryopreservation of Good samples (n = 21), post-thaw motility (PTM) was used to further classify samples into Freezeable (PTM ≥ 50%; n = 14) and Non-Freezable (PTM < 50%; n = 7) groups. In frozen-thawed samples, sperm attributes, kinetics, and functional parameters were assessed, and the results were correlated with retrospective TIMP-2 levels of SP/SM. Our study revealed that the quantified levels of TIMP-2 ranged from 100.27 to 535.95 ng/L in SP and from 0 to 115.78 ng/10 million spermatozoa in SM. TIMP-2 levels in both SP and SM were significantly higher in Good ejaculates compared to Poor ejaculates (p < 0.01). Furthermore, total TIMP-2 levels in the SP/SM of semen samples from bulls showed a positive correlation with fresh semen attributes. However, SP/SM TIMP-2 levels in the Freezeable group did not show any significant differences compared to the Non-Freezable group in post-thaw semen quality attributes, kinetic parameters, and functional tests, except for a significant positive correlation (r = 0.530, p < 0.05) between sperm DNA integrity and SP-TIMP-2 levels. In conclusion, the findings suggested that TIMP-2 can be a positive regulator of semen quality at the neat stage. However, when it comes to the resilience of sperm to cryopreservation, the levels of TIMP-2 do not seem to exert any significant influence in breeding bulls.

Clerodendrum trichotomum Extract Attenuates UV-B-Induced Skin Impairment in Hairless Mice by Inhibiting MAPK Signaling.

Exposure to solar ultraviolet-B (UV-B) radiation significantly accelerates skin aging by inducing the expression of matrix metalloproteinases (MMPs) such as MMP-1, leading to alterations in the extracellular matrix and consequent photoaging. Some plant components, renowned for their UV-absorbing and antioxidative properties, show potential for mitigating photoaging by reducing UV-B-induced MMP levels. In this context, we explored the inhibitory effects of Clerodendrum trichotomum extract (CTE) on UV-B-induced skin damage. The mechanism of CTE was predicted using network pharmacology approach. Also, antiaging efficacy was evaluated by mouse model and cellular system using human epidermal keratinocytes (HEKa), including its modulation of mitogen-activated protein kinase (MAPK) signaling pathways. CTE effectively counters UV-B-induced skin damage, as evidenced by the suppression of MMP-9 and MMP-1 expression in mice. We found that each fraction and chemical constituents of CTE suppressed UV-B-induced MMP-1 secretion in HEKa cells. CTE inhibits UV-B-induced skin aging by partially suppressing MMP-1 and MMP-9 secretion via the modulation of MAPK signaling pathways.

Diabetes-induced alteration of metal ion levels declines the activity of MMPs to decrease aortic aneurysm risk.

Diabetes mellitus (DM) links the risk of cardiovascular diseases. Inverse to the enhanced expression of matrix metalloproteinases (MMPs), the development of aortic aneurysm is lower in diabetic population. We examined the hypothesis that DM-induced alteration of metal ion levels declines the activity of MMPs to decrease aortic aneurysm risk. By culturing vascular smooth muscle cells (VSMCs) or macrophages with different concentrations of glucose in the medium, we confirmed that high glucose significantly increased the expression of fibronectin and CTGF in VSMCs, and induced MMP2 expression and MMP9 secretion in macrophages. We also established an abdominal aortic aneurysm model in streptozotocin-induced diabetic mice and evaluated aneurysm development six weeks later. Compared to the healthy controls, diabetic mice had significantly lower levels of Zn2+ and Mg2+ in serum and developed significantly smaller sizes of aneurysms with higher expression of fibronectin and CTGF; but dietary zinc supplementation to diabetic mice effectively neutralized these differences. Gelatin zymography assay indicated that the enzymatic digestion activity of MMP2 was changed under different concentrations of ZnSO4 and MgSO4. Clinical data analysis also confirmed that DM, serum Zn2+ level, and aortic aneurysm risk closely correlated with each other. It seems that DM-induced alteration of metal ion levels declines the activity of MMPs to negate aortic aneurysm development. Our data provide novel mechanistical insight and therapeutic strategy for aortic aneurysms.

Parecoxib inhibits tumorigenesis and angiogenesis in hepatocellular carcinoma through ERK-VEGF/MMPs signaling pathway.

Parecoxib, a well-recognized nonsteroidal anti-inflammatory drug, has been reported to possess anticancer properties in various tumor types. In this work, we aimed to investigate the potential anticancer effects of parecoxib on hepatocellular carcinoma (HCC) cells. To assess the impact of parecoxib on HCC cell proliferation, we employed Cell Counting Kit-8, colony formation, and 5-ethynyl-2'-deoxyuridine assays. Hoechst/propidium iodide (PI) double staining and flow cytometry were performed to evaluate apoptosis and cell cycle analysis. Wound healing and transwell assays were utilized to assess cell migration and invasion. Tube formation assay was employed to analyze angiogenesis. Protein levels were determined using western blotting, and mRNA expression levels were assessed using quantitative real-time polymerase chain reaction (PCR). A xenograft mouse model was used to confirm the antitumor effects of parecoxib on HCC tumors in vivo. Our data demonstrated that parecoxib effectively inhibited the proliferation of HCC cells in a dose- and time-dependent manner. In addition, parecoxib induced cell cycle arrest in the G2 phase and promoted apoptosis. Moreover, parecoxib hindered tumor migration and invasion by impeding the epithelial-mesenchymal transition process. Further investigation showed that parecoxib could significantly suppress angiogenesis through the inhibition of extracellular signal-regulated kinase (ERK)-vascular endothelial growth factor (VEGF) axis. Notably, treatment with the ERK activator phorbol myristate acetate upregulated the expression of matrix metalloproteinase (MMP)-2, MMP-9, and VEGF and reversed the function of parecoxib in HCC cells. Besides, parecoxib displayed its antitumor efficacy in vivo. Collectively, our results suggest that parecoxib ameliorates HCC progression by regulating proliferation, cell cycle, apoptosis, migration, invasion, and angiogenesis through the ERK-VEGF/MMPs signaling pathway.

Identification and validation of miR-21 key genes in cervical cancer through an integrated bioinformatics approach

Cervical cancer is one of the most prevalent female reproductive cancers. miR-21 is a multi-target oncomiR that has shown its potential in regulating several cancers including colon, pancreatic, breast, prostate, ovarian, and cervical cancer. However, the signaling network of miR-21 remains underexplored, and only a limited number of miR-21 gene targets in cervical cancer have been reported. In this context, the present study was undertaken to evaluate the role of miR-21 in cervical cancer by combining in silico analysis with in vitro validation in cervical cancer cells. The miR-21 target genes were predicted using four different prediction tools: miRwalk, DIANA, miRDBs, and TargetScan. A total of 113 overlapping target genes, common in at least three of the prediction tools, were shortlisted and subjected to functional enrichment analysis. The analysis predicted that JAK-STAT, MAPK, neurotrophin, and Ras signaling pathways are significantly (p≤0.05) targeted by miR-21. The MCODE plugin identified the potential cluster in the protein-protein interaction network based on the highest degree of connectivity. After GEPIA2 validation of all 20 hub genes, NTF3, LIFR, and IL-6R were shortlisted for validation in cervical cancer cell lines. The results showed that NTF3, LIFR, and IL-6R were significantly upregulated in the miR-21 knockdown CaSki cell lines in 6.27, 1.92 and 1.71 folds (p≤0.01), respectively. Similarly, in HeLa cell lines expression of NTF3, LIFR, and IL-6R were overexpressed in 4,06, 5.65, 2.42 folds (p≤0.001), respectively. confirming the role of miR-21 in regulating the expression of these genes. Additionally, the knockdown of miR-21 significantly inhibited the secretion of matrix metalloproteinases by CaSki cells. These results highlight that miR-21 could be a potential therapeutic target for cervical cancer, although further preclinical and clinical studies are required to validate its role and efficacy.

The Neuroprotection of 1,2,4-Triazole Derivative by Inhibiting Inflammation and Protecting BBB Integrity in Acute Ischemic Stroke.

The oxidative stress and neuroinflammation are important factors in acute ischemic stroke (AIS). Our former study showed the 1,2,4- triazole derivative (SYS18) had obviously neuroprotection by anti- oxidative stress on rat middle cerebral artery occlusion (MCAO) model. In this study, we continue to investigate its neuroprotection by anti-inflammatory effects and protecting BBB integrity in AIS. First, its effect on acute inflammation was evaluated by the mice model of increased peritoneal capillary permeability. Then, the MCAO cerebral edema models were built to evaluate its neuroprotection by reducing the neurological score, cerebral edema, improving the biochemical indicators, and pathological damage of brain tissue. At the same time, its protection on blood-brain barrier (BBB) integrity was proved by decreasing the BBB permeability and inhibiting glycocalyx degradation and regulating the BBB tight junction proteins expression of matrix metalloproteinase- 9 (MMP- 9) and claudin- 5 in brain tissue. Meanwhile, pharmacokinetic experiments showed that the compound had good BBB penetration. It has some advantages in the intensity of efficacy compared with the marketed drug edaravone. Based on these findings, SYS18 has a strong potential to become a neuroprotectant in the future.

Whole Blood Transcriptome Analysis in Dairy Ewes Fed a Dietary Grape Pomace Supplementation

The present study aims to evaluate the effect of a dietary supplementation with 10% grape pomace (GP) on the whole blood transcriptome of lactating ewes. By applying a log2FC higher than 0.5 or lower than −0.5 and a false discovery rate (FDR) &lt;0.05, the down-regulation of genes coding for plexin C1, ethanolamine kinase 1, tax1-binding protein 1, transmembrane 9 superfamily member 2, and Beclin-1 was observed in animals that received the dietary supplementation. This aspect was also accompanied by a reduction in the blood activity of matrix metalloproteinase 9 (MMP-9; p &lt; 0.05), a gelatinase commonly involved in both acute and chronic pathological events. The ELISA test on other factors involved in inflammatory processes, interleukin 1 (IL-1) and tumor necrosis factor α (TNF-α), as well as in the antioxidant response, glutathione peroxidase (GPx), and catalase (CAT), did not reveal any significant changes (p &gt; 0.05). Overall, the introduction of GP in the diet of ewes gave indications of greater efficacy in preserving animal welfare, with interesting cues regarding the valorization of a by-product with a high biological value.

Retinol-Loaded Deep Eutectic Solvent emulsion: Improved Stability and Therapeutic Efficiency

Retinol is used to manage epidermal and keratin metabolism, promote collagen formation, erase wrinkles for firmer skin, and restore suppleness and smoothness. Retinol can be difficult to store and use owing to the potential for skin irritation, oxidation, and biological ineffectiveness. The linolenic acid and phosphatidylcholine deep eutectic solvent (DES) had a low melting point, high bioactivity, and integrated capsule technology for retinol encapsulation. Safety evaluation tests revealed that the formulated DES-retinol emulsion was less cytotoxic than free retinol, as well as less irritant toward chicken embryos, pig skin, and human patches. In a keratinocyte inflammatory factor inhibition assay, the DES-retinol emulsion reduced monocyte chemoattractant protein-1 expression, indicating the potential to reduce the inflammatory response of the skin to retinol-induced irritation. The DES-retinol emulsion exhibited pro-permeability, anti-wrinkle, firming, and antioxidant characteristics in cellular, skin, and clinical investigations. The DES-retinol emulsion promoted type I collagen production, suppressed matrix metalloproteinase-1 activity, and reduced the release of reactive oxygen species. Consequently, the quantity, size, and depth of wrinkles were substantially improved, along with an enhanced anti-aging effect, heightened skin hydration, increased collagen intensity and flexibility, and diminished retinol-induced irritation. In conclusion, the retinol-loaded linolenic acid and phosphatidylcholine DES emulsion exhibited improved stability, enhanced transdermal efficiency, and notable therapeutic effects.

MMP-9 as a clinical marker for endometriosis: a meta-analysis and bioinformatics analysis.

This study systematically evaluated the potential efficacy of serum matrix metalloproteinase-9 (MMP-9) concentration as a diagnostic marker for endometriosis through meta-analysis. Early and accurate diagnosis of endometriosis, a common gynecological disease, is crucial for improving patient prognosis. Hence, this study aimed to comprehensively analyze the data from multiple studies to assess the diagnostic value of serum MMP-9 concentration for endometriosis. Articles investigating the association between MMP-9 and endometriosis, published from the inception of the databases until February 2024, were systematically retrieved from multiple databases, including PubMed, Embase, Cochrane, Web of Science, Scopus, and CNKI. Download and analyze the GSE7305, GSE23339, and GSE51981 datasets. Statistical analyses of all eligible studies were conducted using RevMan 5.4, Stata 11.0, and R software version 4.3.3. Fifteen studies fully met the inclusion criteria for the meta-analysis. The concentration of MMP-9 in the blood of patients with endometriosis was significantly higher compared to that of the control group (p < 0.0001). Subgroup analysis based on different stages of endometriosis revealed a trend towards significantly higher serum MMP-9 concentrations in patients, whether in stages I-II or III-IV. Bioinformatics analysis revealed differences in the expression of MMP-9 in endometrial tissue between EMT patients and healthy controls in the GSE7305 and GSE23339 datasets. Additionally, in the GSE51981 dataset, we found significant differences between the normal group and both mild and severe cases of endometriosis. Both the current meta-analysis and bioinformatics analysis indicate differences in MMP-9 concentration levels between endometriosis patients and healthy individuals, with potentially elevated MMP-9 concentrations in serum samples from patients with endometriosis. https://www.crd.york.ac.uk/prospero, identifier CRD42024525864.

Ononin delays the development of osteoarthritis by down-regulating MAPK and NF-κB pathways in rat models.

Osteoarthritis (OA) is featured as cartilage loss, joint pain and loss of labor, which the inflammatory reaction may play critical roles. Ononin is an isoflavone isolating from medicinal plants and has anti-inflammatory effects. Our study investigated the anti-inflammation response of ononin on OA. Anterior cruciate ligament transection (ACLT)-induced OA operation was used to establish research model, then treated with ononin for 8 weeks. The condition of joint injury was assessed using pathological staining. The concentration of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in serum were measured by Elisa kit. The expression of collagen II and matrix metalloproteinase 13 (MMP-13) proteins to assess cartilage metabolism level by immunohistochemistry and Western blot. We detected the expression of proteins involved in the MAPK and NF-κB signaling pathways. Finally, we used molecular docking to assess the affinity of ononin for the target proteins ERK1/2, JNK1/2, p38 and p65. Our results confirmed that ononin ameliorated cartilage impairment through histopathological analysis by improving the morphological structures and cartilage tidal lines and decreasing Osteoarthritis Research Society International (OARSI) scores in OA rats. Moreover, ononin inhibited the secretion of above factors in OA rats. Furthermore, ononin has been shown to improve cartilage content levels in OA rats. In addition, ononin inhibited the reactivity of MAPK and NF-κB pathways in OA rats. And molecular docking indicated the ligand molecules could stably bind to the proteins of above receptors. Our results demonstrated that ononin may ameliorate cartilage damage and inflammatory response in OA rats by downgrading MAPK and NF-κB pathways, thus identifying ononin as a potential novel drug to treat OA.

Early expression of osteopontin glycoprotein on the ocular surface and in tear fluid contributes to ocular surface diseases in type 2 diabetic mice.

Osteopontin (OPN) is a glycosylated, secreted phosphoprotein known to be elevated in both human and mouse retinas during various stages of diabetic retinopathy. However, its specific roles in modulating ocular surface dynamics and immune responses in diabetes remain unexplored. This study aims to investigate the role of OPN in the development of ocular surface disease (OSD) in type 2 diabetic (T2D) mice. Three- to four-week-old C57BL/6 wild-type (WT) and OPN-knockout (OPN-/-) mice were fed a high-fat diet (HFD) and were rendered diabetic by streptozotocin (STZ; 40 mg/kg body weight) in citrate buffer (vehicle); non-diabetic controls were injected with vehicle alone. Diabetes was confirmed if blood glucose levels were >200 mg/dL, measured 1-2 weeks post-STZ injection. Control, age- and sex-matched db/db diabetic mice fed a standard chow diet were also included in this study. Ocular surface inflammation was assessed using ELISA to quantify inflammatory cytokine proteins and wheat germ agglutinin (WGA) staining was utilized to highlight corneal surface irregularities. Clinical signs were evaluated by corneal fluorescein staining, tear production measurements, and tear sodium (Na+) concentration assessments. These evaluations were conducted 4, 6, 8 and 16-weeks post-diabetes onset in WT and OPN-/- mice and were compared to those obtained in non-diabetic controls. Statistical analysis was performed using a two-way ANOVA, with significance set at P < 0.05. Both WT and OPN-/- mice developed T2D within 4 and 8 weeks, respectively, following HFD + STZ treatment. Corneal OPN levels in WT diabetic mice increased ~2-fold at 2 weeks and ~4-fold at 16 weeks compared to non-diabetic controls, with similar elevations observed in their tear fluid. Diabetic db/db mice also exhibited elevated OPN levels in the blood and ocular surface, which persisted as diabetes progressed. Enhanced fluorescein staining, indicating corneal irregularities, appeared in WT mice at 8 weeks and in OPN-/- mice at 10 weeks post-T2D induction. Additionally, WGA staining showed a significant reduction in fluorescence intensity in WT mice treated with HFD and STZ, confirming corneal surface irregularities that were delayed in OPN-/- mice. Elevated tear sodium concentration was observed in both WT and OPN-/- diabetic mice without affecting tear production rates. Notably, OPN levels increased early, at week 2, following HFD and STZ treatment, preceding changes in interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and matrix metalloproteinase-9 (MMP-9). Upregulation of IL-6 became apparent at 6 weeks in WT mice and was delayed until 10 weeks in OPN-/- mice post-T2D induction. Elevated OPN levels were detected early post-T2D induction in diabetic WT and db/db mice corneas without initial subclinical changes. This early increase in OPN precedes other proinflammatory cytokines associated with eventual ocular surface inflammation as diabetes progresses. Persistence of OPN also correlated with clinical signs such as increased corneal surface irregularities and elevated tear Na+ concentration. Future research will explore OPN's role as a biomarker in ocular surface disease (OSD), including dry eye disease (DED), and investigate its impact on inflammatory processes and other mechanistic pathways in diabetic ocular complications.

A Pvr-AP-1-Mmp1 signaling pathway is activated in astrocytes upon traumatic brain injury.

Traumatic brain injury (TBI) caused by external mechanical forces is a major health burden worldwide, but the underlying mechanism in glia remains largely unclear. We report herein that Drosophila adults exhibit a defective blood-brain barrier, elevated innate immune responses, and astrocyte swelling upon consecutive strikes with a high-impact trauma device. RNA sequencing (RNA-seq) analysis of these astrocytes revealed upregulated expression of genes encoding PDGF and VEGF receptor-related (Pvr, a receptor tyrosine kinase), adaptor protein complex 1 (AP-1, a transcription factor complex of the c-Jun N-terminal kinase pathway) composed of Jun-related antigen (Jra) and kayak (kay), and matrix metalloproteinase 1 (Mmp1) following TBI. Interestingly, Pvr is both required and sufficient for AP-1 and Mmp1 upregulation, while knockdown of AP-1 expression in the background of Pvr overexpression in astrocytes rescued Mmp1 upregulation upon TBI, indicating that Pvr acts as the upstream receptor for the downstream AP-1-Mmp1 transduction. Moreover, dynamin-associated endocytosis was found to be an important regulatory step in downregulating Pvr signaling. Our results identify a new Pvr-AP-1-Mmp1 signaling pathway in astrocytes in response to TBI, providing potential targets for developing new therapeutic strategies for TBI.

A Pvr–AP-1–Mmp1 signaling pathway is activated in astrocytes upon traumatic brain injury

Traumatic brain injury (TBI) caused by external mechanical forces is a major health burden worldwide, but the underlying mechanism in glia remains largely unclear. We report herein that Drosophila adults exhibit a defective blood–brain barrier, elevated innate immune responses, and astrocyte swelling upon consecutive strikes with a high-impact trauma device. RNA sequencing (RNA-seq) analysis of these astrocytes revealed upregulated expression of genes encoding PDGF and VEGF receptor-related (Pvr, a receptor tyrosine kinase), adaptor protein complex 1 (AP-1, a transcription factor complex of the c-Jun N-terminal kinase pathway) composed of Jun-related antigen (Jra) and kayak (kay), and matrix metalloproteinase 1 (Mmp1) following TBI. Interestingly, Pvr is both required and sufficient for AP-1 and Mmp1 upregulation, while knockdown of AP-1 expression in the background of Pvr overexpression in astrocytes rescued Mmp1 upregulation upon TBI, indicating that Pvr acts as the upstream receptor for the downstream AP-1–Mmp1 transduction. Moreover, dynamin-associated endocytosis was found to be an important regulatory step in downregulating Pvr signaling. Our results identify a new Pvr–AP-1–Mmp1 signaling pathway in astrocytes in response to TBI, providing potential targets for developing new therapeutic strategies for TBI.

Molybdenum interferes with MMPs/TIMPs expression to reduce the receptivity of porcine endometrial epithelial cells

To investigate the effect of trace element molybdenum (Mo) on the receptivity of porcine endometrial epithelial cells (PEECs) and evaluate Mo toxicity and its potential molecular mechanisms, Mo-treated PEECs models were established by incubating the cells with various concentrations of medium containing Mo (0, 0.005, 0.020, 0.200, and 5 mmol/L MoNa2O4·2H2O). The results showed that Mo disrupted the morphology and ultrastructure of PEECs, triggered blurred cell edges, cell swelling, cell cycle arrest, and increased apoptosis. At the molecular level, Mo treatment activated the TGF-β1/SMAD2 and PI3K/AKT1 pathways, causing a significant increase in matrix metalloproteinase (MMP)-9 and MMP-2 protein expression. Accompanied by markedly increased tissue inhibitors matrix metalloproteinase (TIMP)-2 and decreased TIMP-1, the balance of MMP2/TIMP-2 and MMP-9/TIMP-1 were disrupted. Ultimately, the receptivity of PEECs was destroyed by excessive Mo, which is revealed by the significant decrease of receptive marker molecules, including leukemia inhibitory factor (LIF), integrins β3 (ITGβ3), heparin-binding epidermal growth factor (HB-EGF), and vascular endothelial growth factor (VEGF). To sum up, the current study demonstrated the potential toxicity of Mo to PEECs, indicating reproductive toxicity at high Mo concentrations and suggesting that the content of Mo should be evaluated as a potential risk factor.

Potential Strategies for Overcoming Drug Resistance Pathways Using Propolis and Its Polyphenolic/Flavonoid Compounds in Combination with Chemotherapy and Radiotherapy.

Conventional cancer treatments include surgical resection, chemotherapy, hyperthermia, immunotherapy, hormone therapy, and locally targeted therapies such as radiation therapy. Standard cancer therapies often require the use of multiple agents, which can activate nuclear factor kappa B (NF-κB) in tumor cells, leading to reduced cell death and increased drug resistance. Moreover, the use of multiple agents also contributes to added toxicity, resulting in poor treatment outcomes. Cancer cells gradually develop resistance to almost all chemotherapeutics through various mechanisms, such as drug efflux, alterations in drug metabolism and transport, changes in signal transduction pathways, enhanced DNA repair capacity, evasion of apoptosis, increased mutations, reactivation of drug targets, interaction with the cancer microenvironment, cancer cell-stroma interactions, epithelial-mesenchymal transition (EMT)-mediated chemoresistance, epigenetic modifications, metabolic alterations, and the effect of cancer stem cells (CSCs). Developing new strategies to improve chemotherapy sensitivity while minimizing side effects is essential for achieving better therapeutic outcomes and enhancing patients' quality of life. One promising approach involves combining conventional cancer treatments with propolis and its flavonoids. These natural compounds may enhance tumor response to treatment while reducing toxicity. Propolis and its components can sensitize cancer cells to chemotherapeutic agents, likely by inhibiting NF-κB activation, reprogramming tumor-associated macrophages (TAMs; an M2-like phenotype), and thereby reducing the release of matrix metalloproteinase (MMP)-9, cytokines, chemokines, and the vascular endothelial growth factor (VEGF). By reducing TAMs, propolis and its components may also overcome EMT-mediated chemoresistance, disrupt the crosstalk between macrophages and CSCs, inhibit the maintenance of stemness, and reverse acquired immunosuppression, thus promoting an antitumor response mediated by cytotoxic T-cells. This review highlights the potential of flavonoids to modulate the responsiveness of cancer to conventional treatment modalities. The evidence suggests that novel therapeutic strategies incorporating flavonoids could be developed to improve treatment outcomes. The positive effects of combining propolis with chemotherapeutics include reduced cytotoxicity to peripheral blood leukocytes, liver, and kidney cells. Therefore, polyphenolic/flavonoid components may hold potential for use in combination with chemotherapeutic agents in the clinical treatment of various types of cancers.