Miao medicine Gu Yan Xiao tincture inhibits mTOR to stimulate chondrocyte autophagy in a rabbit model of osteoarthritis

ETHNOPHARMACOLOGICAL RELEVANCE

The Gu Yan Xiao tincture, a blend of traditional Chinese herbs, is traditionally used for osteoarthritis and related pain. This study investigated its mechanism of action in order to rationalize and validate its therapeutic use.

AIM OF THE STUDY

This study analyzed, in a rabbit model of knee osteoarthritis, whether and how Gu Yan Xiao tincture exerts therapeutic benefits by modulating chondrocyte autophagy.

MATERIALS AND METHODS

The active constituents within the GYX tincture were identified using liquid chromatography-mass spectrometry. The rabbit model was established by injecting animals with type II collagenase intra-articularly, and the effects of topically applied tincture were examined on osteoarthritis lesions of the knee using histopathology, micro-computed tomography and x-ray imaging. Effects of the tincture were also evaluated on levels of inflammatory cytokines, matrix metalloproteases, and autophagy in chondrocytes. As a positive control, animals were treated with sodium diclofenac.

RESULTS

The tincture mitigated the reduction in joint space, hyperplasia of the synovium and matrix metalloproteases in serum that occurred after injection of type II collagenase in rabbits. These therapeutic effects were associated with inhibition of mTOR and activation of autophagy in articular chondrocytes. Inhibiting mTOR with rapamycin potentiated the therapeutic effects of the tincture, while inhibiting autophagy with 3-methyladenine antagonized them.

CONCLUSIONS

Gu Yan Xiao tincture mitigates tissue injury in a rabbit model of osteoarthritis, at least in part by inhibiting mTOR and thereby promoting autophagy in chondrocytes. These results rationalize the use of the tincture not only against osteoarthritis but also potentially other diseases involving inhibition of autophagy in bones and joints.

Based on Clinical Research Matrix Metalloprotease (MMP) Inhibitors to Promote Diabetic Wound Healing

Chronic inflammation is a common factor in obesity, diabetes mellitus, and the complications of diabetes, including diabetic wounds. These ulcers are characterized by persistent lesions that are challenging to heal, significantly decreasing patients' quality of life and imposing a substantial financial burden on society. MMP are zinc endopeptidases that play a role in wound healing in response to various stimuli, including diabetes mellitus. MMP levels fluctuate throughout the wound healing process in diabetic patients' serum, skin tissues, and wound fluid, indicating their potential as biomarkers for diabetic foot ulcers. Targeting MMP has emerged as a promising strategy for treating diabetic wounds, as these enzymes are involved in critical biological processes related to wound healing, including extracellular matrix secretion, angiogenesis, granulation tissue formation, collagen growth, re-epithelization, inflammatory response, and oxidative stress.

The Effect of Metformin on Triple-Negative Breast Cancer Cells and Nude Mice

Triple-negative breast cancer (TNBC) presents the most adverse prognosis due to its pronounced invasive and metastatic features. Existing research has highlighted that metformin, a prevalent diabetes medication, possesses strong anti-tumor properties, particularly in inhibiting tumor invasion and metastasis. This study delves deeper into the impact of metformin on TNBC by examining changes in proliferation, apoptosis, invasion, migration, and adhesion of TNBC cells, specifically MDA-MB-231, post-metformin exposure. The treatment of MDA-MB-231 with metformin in immunodeficient nude mice led to discernible changes in tumor metrics such as size, weight, lymph node engagement, and angiogenesis. Post-treatment, MDA-MB-231 cells exhibited a marked decline in proliferation, invasion, migration, and adhesion, alongside a significant rise in apoptosis. In the in vivo model with nude mice, tumors displayed notable reductions in size and weight post-metformin exposure. Furthermore, there was a pronounced decline in lymph node plasma cell proliferation and tumor angiogenesis. Through the use of both Enzyme-Linked Immunosorbent Assay and Real-Time Fluorescence Quantification, it was ascertained that the expression of Signal Transducer and Activator of Transcription 3 (STAT3) saw significant augmentation, while expressions of Matrix Metallopeptidase-2 (MMP-2), Matrix Metallopeptidase-9 (MMP-9), Interleukin-6 (IL-6), and Interleukin-7 (IL-7) decreased markedly. This suggests metformin's potential efficacy against TNBC, potentially mediated via the STAT3 signaling pathway and interleukins 6 and 7.

The Impact of JWH-133 on Articular Cartilage Regeneration in Osteoarthritis Via Metalloproteinase 13-Dependent Mechanism

Objective: Osteoarthritis (OA) is common degenerative joint disease, mostly characterized by gradual cartilage breakdown. Currently there are no disease-modifying drugs available, therefore, there is an increasing need for basic research to focus on cartilage function in OA. Changes in cannabinoid receptor 2 (CB2) expression were observed in the OA-affected joints, although its action on cartilage chondrocytes remain unclear. We studied the action of dimethylbutyl-deoxy-delta-8-THC (JWH-133), selective CB2 agonist, on chondrocytes metabolism using both in vitro and in vivo studies. Design: Intraarticular (i.a.) injection of monoiodoacetate (MIA) was used to induce OA in rats. OA-related pain symptoms were assessed by pressure application measurements (PAMs). Primary human chondrocytes treated with MIA were used to investigate action of JWH-133 on chondrocytes viability, proliferation, and motility. Cannabinoid system components, inflammatory cytokines and metalloproteinases (MMPs) expression was measured on messenger RNA and protein levels in chondrocytes and animal cartilage. Results: Repeated, i.a. administration of JWH-133 showed antinociceptive potential in PAM, as well as decreased levels of MMPs, which suggests that CB2 agonism may modify degradation of cartilage. JWH-133 administration partially reduced toxicity, increased proliferation, and chondrocytes' migration. Moreover, our data suggest that CB2 agonism leads to alleviation of MMPs expression both in vitro and in vivo. Conclusions: In this study, we demonstrate modifying effect of JWH-133 local administration on cartilage metabolism and MMP13 expression that was shown to be involved in cartilage degradation. CB2 receptors' activation may be of benefit for chondrocytes' proliferation, therefore delaying disease progression. Our results propose direction of studies on OA-modifying treatment that can benefit in management of human OA.

Suramin analogues protect cartilage against osteoarthritic breakdown by increasing levels of tissue inhibitor of metalloproteinases 3 (TIMP-3) in the tissue

Osteoarthritis is a chronic degenerative joint disease affecting millions of people worldwide, with no disease-modifying drugs currently available to treat the disease. Tissue inhibitor of metalloproteinases 3 (TIMP-3) is a potential therapeutic target in osteoarthritis because of its ability to inhibit the catabolic metalloproteinases that drive joint damage by degrading the cartilage extracellular matrix. We previously found that suramin inhibits cartilage degradation through its ability to block endocytosis and intracellular degradation of TIMP-3 by low-density lipoprotein receptor-related protein 1 (LRP1), and analysis of commercially available suramin analogues indicated the importance of the 1,3,5-trisulfonic acid substitutions on the terminal naphthalene rings for this activity. Here we describe synthesis and structure-activity relationship analysis of additional suramin analogues using ex vivo models of TIMP-3 trafficking and cartilage degradation. This showed that 1,3,6-trisulfonic acid substitution of the terminal naphthalene rings was also effective, and that the protective activity of suramin analogues depended on the presence of a rigid phenyl-containing central region, with para/para substitution of these phenyl rings being most favourable. Truncated analogues lost protective activity. The physicochemical characteristics of suramin and its analogues indicate that approaches such as intra-articular injection would be required to develop them for therapeutic use.

Kaempferol from Moringa oleifera demonstrated potent antivenom activities via inhibition of metalloproteinase and attenuation of Bitis arietans venom-induced toxicities

Bitis arietans venom (BAV) can induce severe pathophysiological disorders after envenoming. However, studies have shown that the Moringa oleifera fraction is effective against BAV toxicities and contains bioactive compounds with significant antivenom potency. This research aimed to identify the main active antivenom compound in the M. oleifera fraction responsible for neutralizing the toxicities induced by BAV. The compounds identified from M. oleifera fraction were docked in silico against the catalytic site of the Snake Venom Metalloproteinase (SVMP) to determine the lead inhibitor compound. The antivenom potency of the lead inhibitor compound was tested against BAV toxicities and metalloproteinase isolated from BAV using in vitro and in vivo methods, while EchiTab-Plus polyvalent antivenom served as a standard drug. The in silico prediction revealed kaempferol as the lead inhibitor compound with a docking score of -7.0 kcal/mol. Kaempferol effectively inhibited metalloproteinase activity at 0.2 mg/ml, compared to antivenom (0.4 mg/ml) and demonstrated significant antihaemorrhagic, antihaemolytic and coagulant effects against BAV activities. Furthermore, kaempferol showed a significant dose-dependent effect on altered haematological indices observed in rats challenged with LD50 of BAV. Envenomed rats also showed an increase in oxidative stress biomarkers and antioxidant enzyme activity in the heart and kidney. However, treatment with kaempferol significantly (P < 0.05) decreased malondialdehyde levels and SOD activity with concomitant enhancement of glutathione levels. Severe histopathological defects noticed in the organ tissues of envenomed rats were ameliorated after kaempferol treatment. Kaempferol is identified as the main active antivenom compound in M. oleifera, and this research highlights the potential of the compound as an effective alternative to snakebite treatment.

Topical Treatment of Actinic Keratosis and Metalloproteinase Expression: A Clinico-Pathological Retrospective Study

Actinic keratosis is an intraepithelial proliferation of atypical keratinocytes that could progress into invasive squamous cell carcinoma. Most evidence suggests an important role of the dermal matrix metalloproteinases in the progression of atypical skin epithelial lesions. We evaluated the clinical efficacy of three different therapeutic modalities (a medical device containing 0.8% piroxicam cream and 50+ sunscreen, photodynamic therapy, and ingenol mebutate gel) to treat suspicious actinic keratoses, which were biopsied for histopathological examination and then analyzed for the expression of matrix metalloproteinases by immunohistochemistry. Clinical, dermoscopic, and reflectance confocal microscopy evaluations revealed a gradual decrease in all standard scores validated for actinic keratosis assessment at the end of the treatments. From a histopathological point of view, we documented the substantial restoration of normal skin architecture, while the immunohistochemical evaluation of matrix metalloproteinases showed a reduction in expression in the treated skin lesions compared to the baseline. As actinic keratoses are considered the precursors of squamous cell carcinoma, their treatment is crucial to prevent the development of a more aggressive disease. Our study monitored the evolution of actinic keratoses subjected to three different topical therapies, with the value of correlating clinical and histopathological findings. Moreover, as the matrix metalloproteinases are largely recognized factors involved in the pathogenesis and evolution of actinic keratosis to squamous cell carcinoma, the demonstration by immunohistochemistry of a reduction in their expression after the treatments adds new valuable concern to the field.

Arazyme Suppresses Hepatic Steatosis and Steatohepatitis in Diet-Induced Non-Alcoholic Fatty Liver Disease-Like Mouse Model

Arazyme, a metalloprotease from the spider Nephila clavata, exerts hepatoprotective activity in CCL₄-induced acute hepatic injury. This study investigated the hepatoprotective effects in high-fat diet (HFD)-induced non-alcoholic fatty liver disease-like C57BL/6J mice. The mice were randomly divided into four groups (n = 10/group): the normal diet group, the HFD group, the arazyme group (HFD with 0.025% arazyme), and the milk thistle (MT) group (HFD with 0.1% MT). Dietary supplementation of arazyme for 13 weeks significantly lowered plasma triglyceride (TG) and non-esterified fatty acid levels. Suppression of HFD-induced hepatic steatosis in the arazyme group was caused by the reduced hepatic TG and total cholesterol (TC) contents. Arazyme supplementation decreased hepatic lipogenesis-related gene expression, sterol regulatory element-binding transcription protein 1 (Srebf1), fatty acid synthase (Fas), acetyl-CoA carboxylase 1 (Acc1), stearoyl-CoA desaturase-1 (Scd1), Scd2, glycerol-3-phosphate acyltransferase (Gpam), diacylglycerol O-acyltransferase 1 (Dgat1), and Dgat2. Arazyme directly reduced palmitic acid (PA)-induced TG accumulation in HepG2 cells. Arazyme suppressed macrophage infiltration and tumor necrosis factor α (Tnfa), interleukin-1β (Il1b), and chemokine-ligand-2 (Ccl2) expression in the liver, and inhibited secretion of TNFα and expression of inflammatory mediators, Tnfa, Il1b, Ccl2, Ccl3, Ccl4, and Ccl5, in PA-induced RAW264.7 cells. Arazyme effectively protected hepatic steatosis and steatohepatitis by inhibiting SREBP-1-mediated lipid accumulation and macrophage-mediated inflammation.

Direct Fibrinolytic Snake Venom Metalloproteinases Affecting Hemostasis: Structural, Biochemical Features and Therapeutic Potential

Snake venom metalloproteinases (SVMPs) are predominant in viperid venoms, which provoke hemorrhage and affect hemostasis and thrombosis. P-I class enzymes consist only of a single metalloproteinase domain. Despite sharing high sequence homology, only some of them induce hemorrhage. They have direct fibrin(ogen)olytic activity. Their main biological substrate is fibrin(ogen), whose Aα-chain is degraded rapidly and independently of activation of plasminogen. It is important to understand their biochemical and physiological mechanisms, as well as their applications, to study the etiology of some human diseases and to identify sites of potential intervention. As compared to all current antiplatelet therapies to treat cardiovascular events, the SVMPs have outstanding biochemical attributes: (a) they are insensitive to plasma serine proteinase inhibitors; (b) they have the potential to avoid bleeding risk; (c) mechanistically, they are inactivated/cleared by α2-macroglobulin that limits their range of action in circulation; and (d) few of them also impair platelet aggregation that represent an important target for therapeutic intervention. This review will briefly highlight the structure–function relationships of these few direct-acting fibrinolytic agents, including, barnettlysin-I, isolated from Bothrops barnetti venom, that could be considered as potential agent to treat major thrombotic disorders. Some of their pharmacological advantages are compared with plasmin.

Antiproliferative effect of the jararhagin toxin on B16F10 murine melanoma

BACKGROUND

Malignant melanoma is a less common but highly dangerous form of skin cancer; it starts in the melanocytes cells found in the outer layer of the skin. Jararhagin toxin, a metalloproteinase isolated from Bothrops jararaca snake venom acts upon several biological processes, as inflammation, pain, platelet aggregation, proliferation and apoptosis, though not yet approved for use, may one day be employed to treat tumors.

METHODS

B16F10 murine melanoma cells were treated with jararhagin (jara), a disintegrin-like metalloproteinase isolated from Bothrops jararaca snake venom, and jari (catalytic domain inactivated with 1,10-phenanthroline). Viability and adhesion cells were evaluated by MTT assay. The expression of caspase-3 active, phases of the cell cycle and apoptosis were assessed by flow cytometry. We analyze in vivo the effects of jararhagin on melanoma growth, apoptosis and metastasis.

RESULTS

The tumor cells acquired round shapes, lost cytoplasmic expansions, formed clusters in suspension and decreased viability. Jari was almost 20 times more potent toxin than jara based on IC50 values and on morphological changes of the cells, also observed by scanning electron microscopy. Flow cytometry analysis showed 48.3% decrease in the proliferation rate of cells and 47.2% increase in apoptosis (jara) and necrosis (jari), following 1.2 μM jara and 0.1 μM jari treatments. Caspase-3 activity was increased whereas G0/G1 cell cycle phase was on the decline. Proliferative rate was assessed by staining with 5,6-carboxyfluoresceindiacetate succinimidyl ester, showing a significant decrease in proliferation at all concentrations of both toxins.

CONCLUSIONS

In vivo treatment of the toxins was observed reduction in the incidence of nodules, and metastasis and antiproliferative inhibition capacity. This data strengthens the potential use jararhagin as an anti-neoplastic drug.

[Structural properties and functional importance of metzincin metalloproteinases]

Here wediscuss known properties of metzincin metalloproteinases, their structure, physiological roles in the cell and potential medical uses. We also present results describing a novel extracellular metzincin metalloproteinase from Bacillus pumilus with a unique combination of properties typical for both astacins and adamalysins.

Peripheral delivery of a CNS targeted, metalo-protease reduces aβ toxicity in a mouse model of Alzheimer's disease

Alzheimer's disease (AD), an incurable, progressive neurodegenerative disorder, is the most common form of dementia. Therapeutic options have been elusive due to the inability to deliver proteins across the blood-brain barrier (BBB). In order to improve the therapeutic potential for AD, we utilized a promising new approach for delivery of proteins across the BBB. We generated a lentivirus vector expressing the amyloid β-degrading enzyme, neprilysin, fused to the ApoB transport domain and delivered this by intra-peritoneal injection to amyloid protein precursor (APP) transgenic model of AD. Treated mice had reduced levels of Aβ, reduced plaques and increased synaptic density in the CNS. Furthermore, mice treated with the neprilysin targeting the CNS had a reversal of memory deficits. Thus, the addition of the ApoB transport domain to the secreted neprilysin generated a non-invasive therapeutic approach that may be a potential treatment in patients with AD.

Integrins in pulmonary inflammatory diseases

Integrins are a family of heterodimeric transmembrane glycoproteins that mediate cell-cell and cell-matrix interactions. They participate in inflammatory reactions mainly by regulation of leukocyte migration, activation and survival. Elevated expression of the cell adhesion molecules, such as VCAM, ICAM and MAdCAM on the lumenal surface of vascular endothelial cells is a critical early event in organ inflammatory processes - including the lung. Adhesive interactions with their counter-receptors on leukocytes, selectins and integrins, result in migration of the leukocytes to the inflammed tissues. Integrins also participate in physiological and pathological reorganization of the lung structure during e.g. pneumonia healing, airway remodeling, angiogenesis, emphysema and pulmonary fibrosis. Agents that could inhibit the function of one or more of these integrins could provide a novel therapeutic strategy targeted to inhibit inflammatory and immune phenomena in the lung.