Potency of Hexaconazole to Disrupt Endocrine Function with Sex Hormone-Binding Globulin.

Hexaconazole is widely used as a fungicide for agricultural purposes. However, the endocrine-disrupting potential of hexaconazole is still under investigation. In addition, an experimental study found that hexaconazole may disrupt the normal synthesis of steroidal hormones. The potency of hexaconazole to bind with sex hormone-binding globulin (SHBG), a plasma carrier protein that binds androgens and oestrogens, is unknown. In this study, we evaluated the efficacy of hexaconazole to bind with SHBG by molecular interaction, a molecular dynamics method. In addition, principal component analysis was performed to understand the dynamical behaviour of hexaconazole with SHBG in comparison with dihydrotestosterone and aminoglutethimide. The binding scores of hexaconazole, dihydrotestosterone, and aminoglutethimide with SHBG were found to be -7.12 kcal/mol, -11.41 kcal/mol, and -6.84 kcal/mol, respectively. With respect to stable molecular interaction, hexaconazole showed similar molecular dynamics patterns of root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), and hydrogen bonding. The solvent surface area (SASA) and principal component analysis (PCA) of hexaconazole exhibit similar patterns in comparison with dihydrotestosterone and aminoglutethimide. These results show that hexaconazole has a stable molecular interaction with SHBG, which may acquire the active site of the native ligand, resulting in significant endocrine disruption during agricultural work.

Development of surface modified bilosomes for the oral delivery of quercetin: optimization, characterization in-vitro antioxidant, antimicrobial, and cytotoxicity study.

Quercetin (QT) is a flavonoid that exhibits anti-oxidant and chemo-preventive activity. This research work aimed to develop surface-modified bilosomes (BS) of QT. The BS was prepared by the solvent evaporation method and optimized by the Box-Behnken design. The optimized QT-BS (QT-BS3opt) displayed vesicle size (143.51 nm), PDI (0.256), zeta potential (-15.4 mV), and entrapment efficiency (89.52%). Further, the optimized QT-BS formulation was coated with chitosan (CS). The XRD diffractogram of CS-QT-BS3opt1 did not exhibit extensive peaks of QT, revealing that QT is properly encapsulated in the polymer matrix. The QT-BS3opt and CS-QT-BS3opt1 exhibited sustained-release (86.62 ± 3.23% and 69.32 ± 2.57%, respectively) up to 24 h with the Korsmeyer-Peppas kinetic model (R2 =0.9089). CS-QT-BS3opt1 exhibited significantly (P < .05) high flux, i.e. 4.20-fold more than pure QT dispersion and 1.27-fold higher than QT-BS3opt. CS-QT-BS3opt1 showed significantly greater bio-adhesion (76.43 ± 2.42%) than QT-BS3opt (20.82 ± 1.45%). The antioxidant activity showed that QT from CS-QT-BS3opt1 has more remarkable (P < .05) antioxidant activity at each concentration than pure QT. The CS-QT-BS3opt1 exhibited 1.61-fold higher cytotoxicity against MFC7 and 1.44-fold higher cytotoxicity against MDA-MB-231 than pure QT. The CS-QT-BS3opt1 displayed a significantly greater antimicrobial potential against E. coli than against S. aureus. From all these findings, it could be concluded that surface-modified QT-BS might be an effective approach for increasing the efficacy of QT in the treatment of certain ailments.

Rosiridin Attenuates Scopolamine-Induced Cognitive Impairments in Rats via Inhibition of Oxidative and Nitrative Stress Leaded Caspase-3/9 and TNF-α Signaling Pathways.

AIM: A monoterpene and bioactive component of the plant Rhodiola rosea (R. rosea), rosiridin has beneficial effects on the human central nervous system and enhances brain function. The goal of this scientific study was to determine if rosiridin might shield rats from neurocognitive problems induced by scopolamine. METHODS: To track the potential toxicities in rats, the acute toxicity in rats was clarified. Rosiridin at a dose of 10 mg/kg was tested in rats for 14 days. At the conclusion of the investigation, behavioral parameters that were used to identify the rats' cognitive and motor abilities were evaluated. Several biochemical parameters were estimated using the prepared homogenate, including acetylcholine esterase (AChE), choline acetyltransferase (ChAT), radical scavengers produced by the body (Catalase-CAT, superoxide dismutase-SOD, and reduced glutathione-GSH), indicators of oxidative and nitrative burnout, pro-inflammatory (Interleukins- IL-1ß, IL-6, interferon gamma IFN-ꝩ, and tumor necrosis factor-TNF-α), and cell apoptosis caspases 3 and 9. RESULTS AND CONCLUSION: A significant behavioral parameter restoration was seen in the rosiridin-treated group, including reduction in latency time during acquisition and retention trial in the Morris water maze test, and percentage of spontaneous alterations in the y-maze test, when compared to the disease control group that received scopolamine; rosiridin also altered the oxidative stress and neuroinflammatory markers, as well as restoring Ach and ChAT activities and normalizing GSH, SOD, MDA, TNF-α, nitrate, IL-1ß, IL-6, IFN-ꝩ, caspases 3 and 9 levels. The results imply that rosiridin limits the effect of scopolamine on rat cognitive function.

Arabinoxylan-Carboxymethylcellulose Composite Films for Antibiotic Delivery to Infected Wounds.

Modern dressings should provide for local delivery of antibiotics and protect the wound from bacterial infection, dehydration and environmental factors to achieve optimal healing. The local delivery of antibiotics can reduce adverse effects and resistance challenges. In this study, we fabricated film dressings composed of arabinoxylan (AX) from Plantago ovata seed husks and carboxymethylcellulose (CMC) by a solvent cast method for the delivery of the antibiotic amikacin (AMK). To determine the suitability of the prepared AX-CMC composite films as wound dressings and drug delivery materials, their physical, chemical, mechanical, morphological, thermal, pharmaceutical, antimicrobial, cytocompatible, and drug delivery properties were investigated. The results demonstrated that the dressings were suitable for delivering the drug at the wound site in a sustained manner and keeping the environment moist for rapid healing. The AMK-loaded AX-CMC films exhibited controlled release of AMK, excellent antibacterial activity, and cytocompatibility. Thus, the AX-CMC composite films appear to be promising bioactive dressing materials for the prevention of wound infections.

Formulation of Self-Nanoemulsifying Drug Delivery System of Cephalexin: Physiochemical Characterization and Antibacterial Evaluation.

A cephalexin (CEP) self-nanoemulsifying drug delivery system (SNEDDS) was developed in this study to improve the drug's oral administration. The CEP-SNEDDS was made utilizing an aqueous titration method employing Lauroglycol 90, Poloxamer 188, and Transcutol-HP. Box-Behnken design (BBD) with three factors at three levels was used for optimization, and their impacts on globule size (nm), transmittance (percent), and emulsification time (s) were assessed. The optimized formulation (Opt-F3) was further tested for zeta potential, refractive index, percent transmittance, thermodynamic stability, in-vitro release, ex vivo permeability, antibacterial activity, and bioavailability. The chosen formulation (Opt-F3) had a globule size of 87.25 ± 3.16 nm, PDI of 0.25, zeta potential of -24.37 mV, self-emulsification duration of 52 ± 1.7 s, and percentage transmittance of 99.13 ± 1.5%, viscosity of 96.26 ± 2.72 cp, and refractive index of 1.29 ± 0.1. It showed a sustained release profile (94.28 ± 5.92 percent in 24 h). The Opt-F3 formulation had 3.95 times the permeability of CEP-dispersion. In comparison to CEP-dispersion, it also demonstrated greater antibacterial efficacy against tested Gram-positive and Gram-negative pathogens. The oral bioavailability of Opt-F3 is 3.48 times higher than that of CEP-dispersion, according to an in-vivo investigation. It has been determined that the prepared CEP-SNEDDS may be an advantageous carrier for CEP delivery.

Development and Optimization of Nanolipid-Based Formulation of Diclofenac Sodium: In Vitro Characterization and Preclinical Evaluation.

In the present research study, we formulate bilosomes (BMs) of diclofenac (DC) for oral delivery for enhancement of therapeutic efficacy (anti-inflammatory disease). The BMS were prepared by thin film hydration method and optimized by Box−Behnken design (BBD) using cholesterol (A), lipid (B), surfactant (C), and bile salt (D) as formulation factors. Their effects were evaluated on vesicle size (Y1) and entrapment efficacy (Y2). The optimized DC-BMs-opt showed a vesicle size of 270.21 ± 3.76 nm, PDI of 0.265 ± 0.03, and entrapment efficiency of 79.01 ± 2.54%. DSC study result revealed that DC-BMs-opt exhibited complete entrapment of DC in BM matrix. It also depicted significant enhancement (p < 0.05) in release (91.82 ± 4.65%) as compared to pure DC (36.32 ± 4.23%) and DC-liposomes (74.54 ± 4.76%). A higher apparent permeability coefficient (2.08 × 10−3 cm/s) was also achieved compared to pure DC (6.6 × 10−4 cm/s) and DC-liposomes (1.33 × 10−3 cm/s). A 5.21-fold and 1.43-fold enhancement in relative bioavailability was found relative to pure DC and DC liposomes (DC-LP). The anti-inflammatory activity result showed a significant (p < 0.05) reduction of paw edema swelling compared to pure DC and DC-LP. Our findings revealed that encapsulation of DC in BMs matrix is a good alternative for improvement of therapeutic efficacy.

Hexaconazole exposure ravages biosynthesis pathway of steroid hormones: revealed by molecular dynamics and interaction.

Widespread application of hexaconazole for agriculture purpose poses a threat to human health by disrupting normal endocrine homeostasis. To avoid adverse health effects on human, it is crucial to identify the effects of hexaconazole on key enzymes responsible for steroidal hormone synthesis. In view of this, present study was conducted to investigate the interaction mechanisms of hexaconazole with key enzymes in comparison with their food drug administration (FDA) approved inhibitor by molecular docking and molecular dynamics simulations. Results indicate that hexaconazole contacts with the active site of the key enzymes required for steroidal hormonal synthesis. Results pertaining to root-mean-square deviation, root-mean-square calculation, radius of gyration, hydrogen bonding and solvent accessible surface area exhibited that the interaction pattern and stability of interaction of hexaconazole was similar to enzyme specific inhibitor. In addition, ligand and enzyme complex interaction energy of hexaconazole was almost similar to key enzyme and FDA-approved enzyme specific inhibitor complex. This study offers a molecular level of understanding of hexaconazole with different enzymes required for steroidal hormonal synthesis. Findings of the study clearly suggest that hexaconazole has efficacy to stably interact with various enzyme required to progress the pathway of hormonal synthesis. If incessant exposure of hexaconazole occurs during agricultural work it may lead to ravage hormonal synthesis or potent endocrine disruption. The result of binding energy and complex interaction energy is depicted in the graphical abstract.

Role of platelet rich plasma mediated repair and regeneration of cell in early stage of cardiac injury.

Platelet-rich plasma (PRP) is a widely accepted treatment approach and has heightened the quality of care among physicians. PRP has been used over the last decade to boost clinical results of plastic therapies, periodontal surgery and intra-bony defects. According to certain research, elevated levels of PRP growth factors that could promote tissue repair and have the potential for PRP to be beneficial in regenerating processes that Maxillofacial and Oral Surgeons, Veterinary Officers, Athletic medicine specialists and Dermatologists have long admired. PRP is an autologous whole blood fraction that has a heavy amount of a variety of growth factors such as epidermal growth factor (EGF), Vascular Endothelial Growth Factor (VEGF), hepatocyte growth factor (HGF), fibroblast growth factors (FGFs), transforming growth factor beta-1 (TGF-b), insulin-like growth factor-I (IGF-I) and platelet-derived growth factor (PDGF) which can facilitate repair and regeneration. Moreover, a clinical trial of PRP in severe angina patients has shown its excellent safety profile. However, PRP is a very complex biological substance with an array of active biomolecules, its functions are yet to be fully clarified. In-addition, there was insufficient work assessing possible cardiovascular tissue benefits from PRP. Thus, it still remains necessary to identify the most clinically important cardiovascular applications and further research in clinical scenario need to be validated.

Development and Optimization of Hybrid Polymeric Nanoparticles of Apigenin: Physicochemical Characterization, Antioxidant Activity and Cytotoxicity Evaluation.

Breast cancer is the most common cancer in females and ranked second after skin cancer. The use of natural compounds is a good alternative for the treatment of breast cancer with less toxicity than synthetic drugs. The aim of the present study is to develop and characterize hybrid Apigenin (AN) Nanoparticles (NPs) for oral delivery (AN-NPs). The hybrid AN-NPs were prepared by the self-assembly method using lecithin, chitosan and TPGS. Further, the NPs were optimized by Box-Behnken design (3-factor, 3-level). The hybrid NPs were evaluated for particle size (PS), entrapment efficiency (EE), zeta potential (ZP), and drug release. The optimized hybrid NPs (ON2), were further evaluated for solid state characterization, permeation, antioxidant, cytotoxicity and antimicrobial study. The formulation (ON2) exhibited small PS of 192.6 ± 4.2 nm, high EE 69.35 ± 1.1%, zeta potential of +36.54 mV, and sustained drug release (61.5 ± 2.5% in 24 h), as well as significantly (p < 0.05) enhanced drug permeation and antioxidant activity. The IC50 of pure AN was found to be significantly (p < 0.05) lower than the formulation (ON2). It also showed significantly greater (p < 0.05) antibacterial activity than pure AN against Bacillus subtilis and Salmonella typhimurium. From these findings, it revealed that a hybrid AN polymeric nanoparticle is a good carrier for the treatment of breast cancer.

Formulation and Evaluation of Topical Nano-Lipid-Based Delivery of Butenafine: In Vitro Characterization and Antifungal Activity.

The present research work was designed to prepare butenafine (BN)-loaded bilosomes (BSs) by the thin-film hydration method. BN is a sparingly water-soluble drug having low permeability and bioavailability. BSs are lipid-based nanovesicles used to entrap water-insoluble drugs for enhanced permeation across the skin. BSs were prepared by the thin-film hydration method and optimized by the Box-Behnken design (BBD) using lipid (A), span 60 (B), and sodium deoxycholate (C) as independent variables. The selected formulation (BN-BSo) was converted into the gel using Carbopol 940 as a gelling agent. The prepared optimized gel (BN-BS-og) was further evaluated for the gel characterization, drug release, drug permeation, irritation, and anti-fungal study. The optimized bilosomes (BN-BSo) showed a mean vesicle size of 215 ± 6.5 nm and an entrapment efficiency of 89.2 ± 1.5%. The DSC study showed that BN was completely encapsulated in the BS lipid matrix. BN-BSog showed good viscosity, consistency, spreadability, and pH. A significantly (p < 0.05) high release (81.09 ± 4.01%) was achieved from BN-BSo compared to BN-BSog (65.85 ± 4.87%) and pure BN (17.54 ± 1.37 %). The permeation study results revealed that BN-BSo, BN-BSog, and pure BN exhibited 56.2 ± 2.7%, 39.2 ± 2.9%, and 16.6 ± 2.3%. The enhancement ratio of permeation flux was found to be 1.4-fold and 3.4-fold for the BN-BS-og and pure BN dispersion. The HET-CAM study showed that BN-BSog was found to be nonirritant as the score was found within the limit. The antifungal study revealed a significant (p < 0.05) enhanced antifungal activity against C. albicans and A. niger. The findings of the study revealed that BS is an important drug delivery system for transdermal delivery.

Hibiscetin attenuates oxidative, nitrative stress and neuroinflammation via suppression of TNF-α signaling in rotenone induced parkinsonism in rats.

Parkinson's disease (PD) is the gradual and selective degradation of dopamine-releasing neurons in substantia nigra pars compacta (SNpc) and results in postural instability, stiffness, bradykinesia, and resting tremor. The goal of this research was to see how hibiscetin action on PD in rotenone-treated rats. Rats were administered orally with hibiscetin (10 mg/kg) after 1 h rotenone (0.5 mg/kg, s.c.). This therapy regimen was followed on a daily basis for 28 days. Rats were tested for catalepsy and akinesia on day 29 after the last dosage of rotenone. Biochemical parameters were performed to measure reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), nitrite, neuroinflammatory cytokines, and neurotransmitter and their metabolite levels such as dopamine (DA), norepinephrine (NE), serotonin (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA). Rotenone-induced akinesia and catatonia in rats decreased endogenous antioxidant (GSH, CAT, and SOD) levels, increased MDA and nitrite levels, and changed neurotransmitter and metabolite levels. Hibiscetin effectively reduced rotenone-induced akinesia and catatonia, improved endogenous antioxidant (GSH, CAT and SOD) levels, and reduced oxidative and nitrative stress in the treated rats. Moreover, hibiscetin restored altered neurotransmitters and their metabolites to normal levels in rotenone-treated rats. The study results showed that hibiscetin has anti-Parkinson's activity against rotenone-induced PD in rats.

Formulation of Genistein-HP ß Cyclodextrin-Poloxamer 188 Ternary Inclusion Complex: Solubility to Cytotoxicity Assessment.

The current study was designed to prepare the inclusion complex Genistein (GS) using Hydroxypropyl ß cyclodextrin (HP ß CD) and poloxamer 188 (PL 188). The binary inclusion complex (GS BC) and ternary inclusion complex (GS TC) were developed by microwave irradiation technique and evaluated for a comparative dissolution study. Further, the samples were assessed for FTIR, DSC, XRD, and NMR for the confirmation of complex formation. Finally, antioxidant and antimicrobial studies and cytotoxicity studies on a breast cancer (MCF-7) cell line were conducted. The dissolution study result showed a marked increment in GS dissolution/release after incorporation in binary (GS: HP ß CD, 1:1) and ternary (GS: HP ß CD: PL 188; 1:1:0.5) inclusion complexes. Moreover, the ternary complex exhibited a significant enhancement (p < 0.05) in dissolution than did the binary complexes. This might be due to the presence of PL 188, which helps in solubility enhancement of GS. DSC, XRD and SEM evaluation confirmed the modification in the structure of GS. FTIR and NMR results indicated the formation of an inclusion complex. The antioxidant and antimicrobial activity results revealed that GS TC has shown significant (p < 0.05) higher activity than pure GS. The cytotoxicity study results also depicted concentration-dependent cytotoxicity. GS TC exhibited significantly (p < 0.05) high cytotoxicity to cancer cells (IC50 = 225 µg/mL) than pure GS (IC50 = 480 µg/mL). Finally, it was concluded that a remarkable enhancement in the dissolution was observed after the inclusion of GS in the ternary complex and it therefore has significant potential for the treatment of breast cancer.

Current Overview on Therapeutic Potential of Vitamin D in Inflammatory Lung Diseases.

Inflammatory lung disorders (ILDs) are one of the world's major reasons for fatalities and sickness, impacting millions of individuals of all ages and constituting a severe and pervasive health hazard. Asthma, lung cancer, bronchiectasis, pulmonary fibrosis acute respiratory distress syndrome, and COPD all include inflammation as a significant component. Microbe invasions, as well as the damage and even death of host cells, can cause and sustain inflammation. To counteract the negative consequences of irritants, the airways are equipped with cellular and host defense immunological systems that block the cellular entrance of these irritants or eliminate them from airway regions by triggering the immune system. Failure to activate the host defense system will trigger chronic inflammatory cataracts, leading to permanent lung damage. This damage makes the lungs more susceptible to various respiratory diseases. There are certain restrictions of the available therapy for lung illnesses. Vitamins are nutritional molecules that are required for optimal health but are not produced by the human body. Cholecalciferol (Vitamin D) is classified as a vitamin, although it is a hormone. Vitamin D is thought to perform a function in bone and calcium homeostasis. Recent research has found that vitamin D can perform a variety of cellular processes, including cellular proliferation; differentiation; wound repair; healing; and regulatory systems, such as the immune response, immunological, and inflammation. The actions of vitamin D on inflammatory cells are dissected in this review, as well as their clinical significance in respiratory illnesses.

Molecular docking and dynamics simulation to screen interactive potency and stability of fungicide tebuconazole with thyroid and sex hormone-binding globulin: Implications of endocrine and reproductive interruptions.

Tebuconazole is a widely used fungicide in agriculture, and it may easily enter in the human food chain. In addition, tebuconzaol skin permeation coefficient (Log Kp) is -5.55 cm/s and it does not violate Lipinski's rule. It may mimic as a ligand for various endocrine and reproductive receptor leading to toxicological response or disease manifestation. We studied interactive potential of tebuconazole with thyroid and sex hormone-binding globulin. The main methods for this in silico analyses are molecular docking and molecular dynamic (MD) simulation. This paper explores how agriculture fungicide tebuconzaol exposure can be a risk for endocrine and reprotoxicity due to its stable interactive potency with thyroid and sex hormone-binding globulin (2CEO and 1D2S). Thyroid impairment is one of the most common endocrine issues in human health. In molecular docking analyses, tebuconazole exhibited binding potency of -6.28 kcal/mol with 2CEO compared to its native ligand thyroxin and inhibitor propylthiouracil which had the binding potency of -9.9 and -4.49 kcal/mol, respectively. The binding score of tebuconzaol with 1D2S was found to be -7.54 kcal/mol compared to native ligand dihydrotestosteron and inhibitor aminoglutethimide which exhibited the binding score of -6.84 and -11.41 kcal/mol, respectively. Therefore, each complex was subjected to MD simulation for comparative assessment of physical movement. The root mean square deviation (RMSD), root mean square fluctuation (RMSF), Radius of Gyration and hydrogen bonding exhibited that fluconazole had stable binding pattern with 2CEO and 1D2S which was almost similar to native ligand and its inhibitor. Study revealed that tebuconazole may lead to potent endocrine and reproductive disruptions.

Repetitive Traumatic Brain Injury Causes Neuroinflammation before Tau Pathology in Adolescent P301S Mice.

Repetitive closed head injury (rCHI) is commonly encountered in young athletes engaged in contact and collision sports. Traumatic brain injury (TBI) including rCHI has been reported to be an important risk factor for several tauopathies in studies of adult humans and animals. However, the link between rCHI and the progression of tau pathology in adolescents remains to be elucidated. We evaluated whether rCHI can trigger the initial acceleration of pathological tau in adolescent mice and impact the long-term outcomes post-injury. To this end, we subjected adolescent transgenic mice expressing the P301S tau mutation to mild rCHI and assessed tau hyperphosphorylation, tangle formation, markers of neuroinflammation, and behavioral deficits at 40 days post rCHI. We report that rCHI did not accelerate tau pathology and did not worsen behavioral outcomes compared to control mice. However, rCHI induced cortical and hippocampal microgliosis and corpus callosum astrocytosis in P301S mice by 40 days post-injury. In contrast, we did not find significant microgliosis or astrocytosis after rCHI in age-matched WT mice or sham-injured P301S mice. Our data suggest that neuroinflammation precedes the development of Tau pathology in this rCHI model of adolescent repetitive mild TBI.

Scavenger receptors.

Scavenger receptors (SRs) are a large family of cell-surface receptors that are diverse in their structure and biological function and are divided into different classes. SRs can bind to a range of ligands and enhance the elimination of altered-self or non-self targets. The functional mechanisms that lead to their clearance of harmful substances involve phagocytosis, endocytosis, adhesion, and signaling.

The autocrine role of proteoglycan-4 (PRG4) in modulating osteoarthritic synoviocyte proliferation and expression of matrix degrading enzymes.

BACKGROUND: Lubricin/proteoglycan 4 (PRG4) is a mucinous glycoprotein secreted by synovial fibroblasts and superficial zone chondrocytes. Recently, we showed that recombinant human PRG4 (rhPRG4) is a putative ligand for CD44 receptor. rhPRG4-CD44 interaction inhibits cytokine-induced rheumatoid arthritis synoviocyte proliferation. The objective of this study is to decipher the autocrine function of PRG4 in regulating osteoarthritic synoviocyte proliferation and expression of catabolic and pro-inflammatory mediators under basal and interleukin-1 beta (IL-1ß)-stimulated conditions. METHODS: Cytosolic and nuclear levels of nuclear factor kappa B (NFκB) p50 and p65 subunits in Prg4 +/+ and Prg4 -/- synoviocytes were studied using western blot. Nuclear translocation of p50 and p65 proteins in osteoarthritis (OA) fibroblast-like synoviocytes (FLS) in response to IL-1ß stimulation in the absence or presence of rhPRG4 was studied using DNA binding assays. OA synoviocyte (5000 cells per well) proliferation following IL-1ß (20 ng/ml) treatment in the absence or presence of rhPRG4 (50-200 µg/ml) over 48 hours was determined using a colorimetric assay. Gene expression of matrix metalloproteinases (MMPs), tissue inhibitor of metallproteinases-1 (TIMP-1), TIMP-2, IL-1ß, IL-6, IL-8, TNF-α, cycloxygenae-2 (COX2) and PRG4 in unstimulated and IL-1ß (1 ng/ml)-stimulated OA synoviocytes, in the presence or absence of rhPRG4 (100 and 200 µg/ml), was studied following incubation for 24 hours. RESULTS: Prg4 -/- synoviocytes contained higher nuclear p50 and p65 levels compared to Prg4 +/+ synoviocytes (p < 0.05). rhPRG4 (100 µg/ml) reduced p50 and p65 nuclear levels in Prg4 +/+ and Prg4 -/- synoviocytes (p < 0.001). Similarly, rhPRG4 (200 µg/ml) inhibited NFκB translocation and cell proliferation in OA synoviocytes in a CD44-dependent manner (p < 0.001) via inhibition of IκBα phosphorylation. IL-1ß reduced PRG4 expression in OA synoviocytes and rhPRG4 (100 µg/ml) treatment reversed this effect (p < 0.001). rhPRG4 (200 µg/ml) reduced basal gene expression of MMP-1, MMP-3, MMP-13, IL-6, IL-8, and PRG4 in OA synoviocytes, while increasing TIMP-2 and cycloxygenase-2 (COX2) expression (p < 0.001). rhPRG4 (200 µg/ml) reduced IL-1ß induction of MMP-1, MMP-3, MMP-9, MMP-13, IL-6, IL-8, and COX2 expression in a CD44-dependent manner (p < 0.001). CONCLUSION: PRG4 plays an important anti-inflammatory role in regulating OA synoviocyte proliferation and reduces basal and IL-1ß-stimulated expression of catabolic mediators. Exogenous rhPRG4 autoregulates native PRG4 expression in OA synoviocytes.

The interaction of lubricin/proteoglycan 4 (PRG4) with toll-like receptors 2 and 4: an anti-inflammatory role of PRG4 in synovial fluid.

BACKGROUND: Lubricin/proteoglycan-4 (PRG4) is a mucinous glycoprotein secreted by synovial fibroblasts and superficial zone chondrocytes. PRG4 has a homeostatic multifaceted role in the joint. PRG4 intra-articular treatment retards progression of cartilage degeneration in pre-clinical posttraumatic osteoarthritis models. The objective of this study is to evaluate the binding of recombinant human PRG4 (rhPRG4) and native human PRG4 (nhPRG4) to toll-like receptors 2 and 4 (TLR2 and TLR4) and whether this interaction underpins a PRG4 anti-inflammatory role in synovial fluid (SF) from patients with osteoarthritis (OA) and rheumatoid arthritis (RA). METHODS: rhPRG4 and nhPRG4 binding to TLR2 and TLR4 was evaluated using a direct enzyme linked immunosorbent assay (ELISA). Association of rhPRG4 with TLR2 and TLR4 overexpressing human embryonic kidney (HEK) cells was studied by flow cytometry. Activation of TLR2 and TLR4 on HEK cells by agonists Pam3CSK4 and lipopolysaccharide (LPS) was studied in the absence or presence of nhPRG4 at 50, 100 and 150 µg/ml. Activation of TLR2 and TLR4 by OA SF and RA SF and the effect of nhPRG4 SF treatment on receptor activation was assessed. PRG4 was immunoprecipitated from pooled OA and RA SF. TLR2 and TLR4 activation by pooled OA and RA SF with or without PRG4 immunoprecipitation was compared. RESULTS: rhPRG4 and nhPRG4 exhibited concentration-dependent binding to TLR2 and TLR4. rhPRG4 associated with TLR2- and TLR4-HEK cells in a time-dependent manner. Co-incubation of nhPRG4 (50, 100 and 150 µg/ml) and Pam3CSK4 or LPS reduced TLR2 or TLR4 activation compared to Pam3CSK4 or LPS alone (p <0.05). OA SF and RA SF activated TLR2 and TLR4 and nhPRG4 treatment reduced SF-induced receptor activation (p <0.001). PRG4 depletion by immunoprecipitation significantly increased TLR2 activation by OA SF and RA SF (p <0.001). CONCLUSION: PRG4 binds to TLR2 and TLR4 and this binding mediates a novel anti-inflammatory role for PRG4.