Gastrocnemius Muscle Injury Is the Condition to Induce Cartilage Degeneration of the Rabbit Tibiofemoral Joint: A New Perspective

The knee osteoarthritis is a common joint disease that causes pain and inconvenience. Clinically, patients with knee osteoarthritis often have response points on the gastrocnemius. Gastrocnemius plays an essential role in stabilizing joints and changing gait and pace, which also has a close relationship with the knee joint. The objective of this study is to determine changes in the tibiofemoral joint after medial and lateral gastrocnemius injury. Rabbits were divided into a medial gastrocnemius injury group, a lateral gastrocnemius injury group, and a control group with two intervals: 6 and 8 weeks after modeling of the semisevered gastrocnemius. The gastrocnemius was weighed and sectioned for histology. The joint space and subchondral bone were observed using X-ray and microcomputed tomography. The cartilage was observed histologically using Safranin O fast green and Masson and immunohistochemically using antibodies to collagen type II, matrix metalloproteinase 13, and integrin beta1. Results showed muscle fiber atrophy, and fibrotic changes occurred after gastrocnemius semidissociation. After gastrocnemius injury, the femoral condyle of the tibiofemoral joint produced abnormal sclerosis and bone degeneration. The pathological changes of cartilage included disordered or reduced cell alignment, cartilage matrix loss, and collagen loss due to decreased collagen type II and increased matrix metalloproteinase 13 activity. The increase of integrin beta1 in the injured group may be related to mechanical conduction process. The results suggest that gastrocnemius injury is an essential factor in tibiofemoral arthritis.

WISP-2 modulates the induction of inflammatory mediators and cartilage catabolism in chondrocytes

Wnt-1 inducible signaling pathway protein 2 (WISP-2/CCN5) is a recently identified adipokine that has been described as an important mediator of canonical Wnt activation in adipogenic precursor cells. In osteoarthritis (OA), the most common form of arthritis, chondrocytes exhibit aberrant and increased production of pro-inflammatory mediators and matrix degrading enzymes such as IL-1β and MMP-13. Although recent evidence suggests a role for Wnt signaling in OA physiopathology, little is known about the involvement of WISP-2 in cartilage degradation. In the present study, we determined the expression of WISP-2 in healthy and OA human chondrocytes. WISP-2 expression is modulated along chondrocyte differentiation and downregulated at the onset of hypertrophy by inflammatory mediators. We also investigated the effect of WISP-2 on cartilage catabolism and performed WISP-2 loss-of-function experiments using RNA interference technology in human T/C-28a2 immortalized chondrocytes. We demonstrated that recombinant human WISP-2 protein reduced IL-1β-mediated chondrocyte catabolism, that IL-1β and WNT/b-catenin signaling pathways are involved in rhWISP-2 protein and IL-1β effects in human chondrocytes, and that WISP-2 has a regulatory role in attenuating the catabolic effects of IL-1β in chondrocytes. Gene silencing of WISP-2 increased the induction of the catabolic markers MMP-13 and ADAMTS-5 and the inflammatory mediators IL-6 and IL-8 triggered by IL-1β in human primary OA chondrocytes in a Wnt/β-catenin dependent manner. In conclusion, here we have shown for the first time that WISP-2 may have relevant roles in modulating the turnover of extracellular matrix in the cartilage and that its downregulation may detrimentally alter the inflammatory environment in OA cartilage. We also proved the participation of Wnt/β-catenin signaling pathway in these processes. Thus, targeting WISP-2 might represent a potential therapeutical approach for degenerative and/or inflammatory diseases of musculoskeletal system, such as osteoarthritis.

Lin28a induces SOX9 and chondrocyte reprogramming via HMGA2 and blunts cartilage loss in mice

Articular cartilage has low regenerative capacity despite permanent stress. Irreversible cartilage lesions characterize osteoarthritis (OA); this is not followed by tissue repair. Lin28a, an RNA binding protein, is detected in damaged cartilage in humans and mice. We investigated the role of LIN28a in cartilage physiology and in osteoarthritis. Lin28a-inducible conditional cartilage deletion up-regulated Mmp13 in intact mice and exacerbated the cartilage destruction in OA mice. Lin28a-specific cartilage overexpression protected mice against cartilage breakdown, stimulated chondrocyte proliferation and the expression of Prg4 and Sox9, and down-regulated Mmp13. Lin28a overexpression inhibited Let-7b and Let-7c miRNA levels while RNA-sequencing analysis revealed five genes of transcriptional factors regulated by Let-7. Moreover, Lin28a overexpression up-regulated HMGA2 and activated SOX9 transcription, a factor required for chondrocyte reprogramming. HMGA2 siRNA knockdown inhibited the cartilage protective effect of Lin28a overexpression. This study provides insights into a new pathway including the Lin28a-Let7 axis, thus promoting chondrocyte anabolism in injured cartilage in mice.

Pre-Clinical Study: Immunohistochemical evaluation of matrix metalloproteinase-13 on rabbit (Oryctolagus cuniculus) socket healing after application of platelet-rich fibrin with and without hydroxyapatite

Background: Tissue engineering technology has been used globally and proven to accelerate wound healing. This study aimed to analyse the effect of adding hydroxyapatite (HA) as a scaffold to platelet-rich fibrin (PRF) as a growth factor in accelerating the wound healing process as seen from the expression of matrix metalloproteinase-13 (MMP-13). Methods: This research is an animal experiment conducted on 18 rabbits (Oryctolagus cuniculus). Rabbits were randomly divided into the following three groups of treatment: (G1) the application of PRF group, (G2) the application of PRF+HA group and (C) the control group without any application. Furthermore, each treatment group was split randomly into three groups of observation time. Periodontal tissue biopsy was performed to analyse the histopathological features that were examined on the basis of the level of MMP-13 immunoexpression. Results: MMP-13 immunoexpression in the PRF+HA group showed better histoscore results, indicating a substantial reduction in MMP-13 values compared with other groups. The healing process was shown to increase with increasing observation time (p<0.05), and the PRF+HA group outperformed the PRF and control groups. On day 3, MMP-13 exhibited a dark brown colour of Immunohistochemistry (IHC), which indicated an increase in the expression value of MMP-13 in the early stages of healing, namely, inflammation. On day 14, light brown IHC was seen, especially in group 2, as a reference that the remodeling process had begun. Conclusions: This study indicates that the administration of PRF and HA was capable of reducing the MMP-13 expression that significantly accelerates the socket healing process. Hydroxyapatite is an alloplastic material that has inherent bioactive properties that support osteoconduction, can bind MMPs, and showed faster healing results based on the observation time as documented by immunohistochemistry.

Acute Physiological Effects of Continuous Versus Intermittent Walking During Golf in Individuals With Knee Osteoarthritis: A Pilot Study

OBJECTIVE

The aim of the study was to compare the acute effects of walking the golf course versus using a golf cart during a round of golf on biological markers of joint disease, joint pain, and cardiovascular parameters in individuals with knee osteoarthritis.

METHODS

Participants with knee OA (n = 10) older than 50 yrs were recruited for this crossover designed study in which they completed two 18-hole rounds of golf: (1) walking the course and (2) using a golf cart. Five control participants (n = 5) performed the walking condition only. Step count, heart rate, rating of perceived exertion and pain using the Numeric Pain Rating Scale were measured during the round. Serum was collected at baseline, 9th hole (halfway), and 18th hole (completion) and tested for biomarkers associated with tissue turnover (cartilage oligomeric matrix protein), inflammation (tumor necrosis factor α, interleukin 1β, interleukin 6), and degradative enzyme production (matrix metalloproteinase 3, matrix metalloproteinase 13).

RESULTS

In knee OA participants, walking the course was associated with significantly higher step count and duration of moderate/vigorous physical activity (72.2% vs. 32.6% of the round) but did lead to a significant increase in knee joint pain (P < 0.05). Both conditions caused cartilage oligomeric matrix protein and matrix metalloproteinase 13 concentration increases from baseline to completion (P < 0.05), but inflammatory markers (tumor necrosis factor α, interleukin 6, and interleukin 1β, P < 0.05) only increased when walking the course. Biomarker concentrations did not increase in control participants.

CONCLUSIONS

Walking the course optimizes the duration of moderate/vigorous activity during a round of golf, but the golf cart is a beneficial option in those with exacerbated joint pain and inflammation that would otherwise limit participation.

[Mechanism of microRNA-100-5p on mammalian target of rapamycin in temporomandibular arthritis]

PURPOSE

To investigate the mechanism of microRNA-100-5p (miR-100-5p) on mammalian target (mTOR) of rapamycin in temporomandibular arthritis.

METHODS

Sixty SD rats were randomly divided into group A, group B, group C, group D, and group E, with 12 rats in each group. Rat models of temporomandibular arthritis were prepared by injecting sodium iodoacetate solution into the bilateral spaces of temporomandibular joint. After establishment, group C was injected pcDNA3.1-miR-100-5p recombinant plasmid, group D was injected mTOR inhibitor rapamycin, group E was injected with pcDNA3.1-miR-100-5p recombinant plasmid and rapamycin, and group A was injected same amount of normal saline in the same way. Various indexes were observed in each group, including morphological changes of temporomandibular joint tissues, matrix metalloproteinase-3 (MMP-3), MMP-1, MMP-13, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), miR-100-5p, mTOR expression. The data were processed using SPSS 22.0 software package.

RESULTS

In group B, the structure of temporomandibular joint was fuzzy, with synovial hyperplasia, vascular dilatation, clustered cells and a large amount of inflammatory infiltration. Histopathological changes of temporomandibular joint in each interventional group were improved to different degrees compared with group B, among which group E showed the most obvious improvement. The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1β and TNF-α in group B were significantly higher than those in group A(P＜0.05). The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1β and TNF-α in group C, group D and group E were significantly lower than those in group B(P＜0.05). The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1β and TNF-α in group D were not significantly different from those in group C (P＜0.05). The levels of MMP-3, MMP-1, MMP-13, IL-6, IL-1β and TNF-α in group E were significantly lower than those in group D (P＜0.05). The expression level of miR-100-5p in group E was significantly higher than that in group B (P＜0.05). The expression level of mTOR protein in group E was significantly lower than that in group B (P＜0.05).

CONCLUSIONS

MicroRNA-100-5p may alleviate temporomandibular arthritis by down-regulating the expression of mTOR.

miR-125a-5p-abundant exosomes derived from mesenchymal stem cells suppress chondrocyte degeneration via targeting E2F2 in traumatic osteoarthritis

miRNAs are broad participants in vertebrate biological processes, and they are also the major players in pathological processes. miR-125a-5p was recently found a modulator in the progression of osteoarthritis (OA). Our study was aimed to explore the role and underlying mechanisms of miR-125a-5p-abundant exosomes derived from mesenchymal stem cells (MSC) on OA progression. We separated bone marrow mesenchymal stem cells (BMSCs) as well as the exosomes from traumatic OA patients. The immunofluorescence and cartilage staining were implemented for the observation and the assessment on endocytosis of chondrocytes and exosomal miR-125a-5p efficacy to cartilage degradation. Dual luciferase reporter assay was performed to verified the relationship between miR-125a-5p and E2F2. Then, the function of exosomal miR-125a-5p were examined on chondrocyte degeneration in vitro and in vivo. Our findings indicated that E2F2 expression was elevated while the miR-125a-5p was down in traumatic OA cartilage tissue, showing a negative correlation of the former and the latter. miR-125a-5p targets E2F2 in traumatic OA cartilage tissue and leads to the down-expression of E2F2. The E2F2 expression in chondrocytes was decreased after internalization of exosomes. We additionally found that BMSCs-derived exosomes were rich in miR-125a-5p content and chondrocytes can have it internalized. miR-125a-5p is endowed with a trait of accelerating chondrocytes migration, which is going along with the up-expressions of Collagen II, aggrecan and SOX9 and the down-expression of MMP-13 in vitro. Besides that, the mice model with post-traumatic OA turned out that exosomal miR-125a-5p might beget an alleviation in chondrocyte extracellular matrix degradation. All these outcomes revealed that BMSCs-derived exosomal miR-125a-5p is a positive regulator for chondrocyte migration and inhibit cartilage degeneration We thus were reasonable to believe that transferring of exosomal miR-125a-5p is a prospective strategy for OA treatment.

The potential value of diagnostic and predictive serum biomarkers for preeclampsia

BACKGROUND

Preeclampsia (PE), one of the classes of hypertensive pregnancy disorders, is one of the three causes of maternal morbidity and mortality worldwide. The angiogenic and anti-angiogenic factors are useful markers in predicting and diagnosing PE.

AIM

This study aims to detect and measure the serum level of some biomarkers [hypoxia-inducible factor-1 subunit alpha (HIF-1A), vascular endothelial growth factor (VEGF), interferon-gamma-inducible protein of 10 kDa (IP-10), matrix metalloproteinase-13 (MMP-13)] in patients with PE and their correlation with the severity of the disease, to find a good predictor for PE.

PATIENTS, MATERIALS AND METHODS

This prospective study aims to monitor 48 pregnant women who address obstetric consultation and who present risk factors for PE, and a control group with characteristics similar to the study group. Patients were divided into three groups: Group I (n=15) including normal pregnant (NP) women with blood pressure <140∕90 mmHg, without proteinuria, Group II (n=18) including patients with mild PE (MildPE), Group III (n=15) including patients with severe PE (SeverePE). The analysis of serum biomarkers was based on a quantitative sandwich enzyme-linked immunosorbent assay (ELISA), according to the manufacturer's instructions.

RESULTS

In our study, we found that all biomarkers investigated have higher concentrations in the serum of patients with SeverePE and MildPE than those in the control subjects (Group I, NP), the concentrations were increasing along with the disease activity. The means concentrations of HIF-1A, VEGF, IP-10, MMP-13, better correlated with indices in SeverePE group than in MildPE group. We found that VEGF was the biomarker that best correlates with indices that assess the severity of PE. The best separation of patients with SeverePE from those with MildPE can be done with the help of MMP-13 (82% accuracy), followed by VEGF (80.40% accuracy) and the least good detection being done by dosing IP-10.

CONCLUSIONS

We can say that, due to high specificity diagnostic accuracy, determination of serum concentrations of MMP-13 and VEGF, could be useful in the diagnosis and distinguishing of patients with SeverePE and may prove useful in the monitoring of the disease course.

Targeting Dysregulation of Metalloproteinase Activity in Osteoarthritis

Metalloproteinases were first identified as collagen cleaving enzymes and are now appreciated to play important roles in a wide variety of biological processes. The aberrant activity and dysregulation of the metalloproteinase family are linked to numerous diseases including cardiovascular and pulmonary diseases, chronic wounds, cancer, fibrosis and arthritis. Osteoarthritis (OA) is the most prevalent age-related joint disorder that causes pain and disability, but there are no disease-modifying drugs available. The hallmark of OA is loss of articular cartilage and elevated activities of matrix-degrading metalloproteinases are responsible. These enzymes do not exist in isolation and their activity is tightly regulated by a number of processes, such as transcription, proteolytic activation, interaction with their inhibitors, cell surface and extracellular matrix molecules, and endocytic clearance from the extracellular milieu. Here, we describe the functions and roles of metalloproteinase family in OA pathogenesis. We highlight recent studies that have illustrated novel mechanisms regulating their extracellular activity and impairment of such regulations that lead to the development of OA. We also discuss how to stop or slow down the degenerative processes by targeting aberrant metalloproteinase activity, which may in future become therapeutic interventions for the disease.

miR‑654‑5p inhibits autophagy by targeting ATG7 via mTOR signaling in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a common chronic disease characterized by the loss of extracellular matrix (ECM) in the nucleus pulposus (NP). Accumulating evidence has revealed that abnormal expression of microRNAs (miRs) is closely associated with IDD development. The present study aimed to investigate the precise role and possible mechanism underlying the effects of miR‑654‑5p in the pathogenesis of IDD. NP cells were isolated from patients with IDD. Monodansylcadaverine staining was conducted to reveal cell autophagy, while western blotting was performed to detect the expression of ECM‑related proteins in NP cells. Luciferase reporter and RNA immunoprecipitation assays were conducted to identify the binding between RNAs. The results demonstrated that miR‑654‑5p was significantly upregulated in degenerated NP tissues from patients with IDD and high miR‑654‑5p expression was positively associated with disc degeneration grade. Functional assays suggested that miR‑654‑5p facilitated ECM degradation by increasing the expression levels of MMP‑3, MMP‑9 and MMP‑13, as well as decreasing collagen I, collagen II, SOX9 and aggrecan expression by inhibiting autophagy. Furthermore, autophagy‑related gene 7 (ATG7) was verified as a direct downstream target gene of miR‑654‑5p. miR‑654‑5p could bind to the 3' untranslated region of ATG7 to inhibit its mRNA expression and further reduce its translation. Notably, ATG7 knockdown abrogated the effects of the miR‑654‑5p inhibitor on ECM degradation and autophagy regulation. Furthermore, miR‑654‑5p inhibited autophagy in NP cells by increasing the protein expression levels of phosphorylated (p)‑PI3K, p‑AKT and p‑mTOR in an ATG7‑dependent manner. In conclusion, the results of the present study revealed that miR‑654‑5p may enhance ECM degradation via inhibition of autophagy by targeting ATG7 to activate the PI3K/AKT/mTOR signaling pathway. These findings may provide novel insights into the treatment of IDD.

Matrix Metalloproteinase 13 Inhibitors for Modulation of Osteoclastogenesis: Enhancement of Solubility and Stability

Matrix metalloproteinase 13 (MMP-13) activity has been correlated to breast cancer bone metastasis. It has been proposed that MMP-13 contributes to bone metastasis through the promotion of osteoclastogenesis. To explore the mechanisms of MMP-13 action, we previously described a highly efficacious and selective MMP-13 inhibitor, RF036. Unfortunately, further pursuit of RF036 as a probe of MMP-13 in vitro and in vivo activities was not practical due to the limited solubility and stability of the inhibitor. Our new study has explored replacing the RF036 backbone sulfur atom and terminal methyl group to create inhibitors with more favorable pharmacokinetic properties. One compound, designated inhibitor 3, in which the backbone sulfur and terminal methyl group of RF036 were replaced by nitrogen and oxetane, respectively, had comparable activity, selectivity, and membrane permeability to RF036, while exhibiting greatly enhanced solubility and stability. Inhibitor 3 effectively inhibited MMP-13-mediated osteoclastogenesis but spared collagenolysis, and thus represents a next-generation MMP-13 probe applicable for in vivo studies of breast cancer metastasis.

WNT16 is upregulated early in mouse TMJ osteoarthritis and protects fibrochondrocytes against IL-1β induced inflammatory response by regulation of RUNX2/MMP13 cascade

WNT16 has been shown to play important roles in joint formation, bone homeostasis and knee joint osteoarthritis. However, whether WNT16 has any effect during temporomandibular joint osteoarthritis (TMJOA) is still unknown. Here, we first established a surgically induced TMJOA model by performing partial discectomy in discs of TMJ in mice. Further, we investigated the role of WNT16 during the initiation and progression of TMJOA. Our results showed that WNT16 expression is upregulated early at 4 weeks after initiation of osteoarthritis by partial discectomy in mouse TMJ cartilage, but decreased after 12 weeks post-surgery. Further cellular and molecular analyses revealed that WNT16 signals via both the canonical WNT/β-catenin and non-canonical WNT/JNK-cJUN pathways, upregulates the expression of Lubricin and SOX9, and protects against IL-1β induced inflammatory response by regulation of RUNX2/MMP13 cascade in fibrochondrocytes. In conclusion, WNT16 may play an important role in the early stage of TMJOA by regulating cartilage anabolic and catabolic factors, and may serve as novel therapeutic targets for TMJOA.

Nuclear Stiffness Decreases with Disruption of the Extracellular Matrix in Living Tissues

Reciprocal interactions between the cell nucleus and the extracellular matrix lead to macroscale tissue phenotype changes. However, little is known about how the extracellular matrix environment affects gene expression and cellular phenotype in the native tissue environment. Here, it is hypothesized that enzymatic disruption of the tissue matrix results in a softer tissue, affecting the stiffness of embedded cell and nuclear structures. The aim is to directly measure nuclear mechanics without perturbing the native tissue structure to better understand nuclear interplay with the cell and tissue microenvironments. To accomplish this, an atomic force microscopy needle-tip probe technique that probes nuclear stiffness in cultured cells to measure the nuclear envelope and cell membrane stiffness within native tissue is expanded. This technique is validated by imaging needle penetration and subsequent repair of the plasma and nuclear membranes of HeLa cells stably expressing the membrane repair protein CHMP4B-GFP. In the native tissue environment ex vivo, it is found that while enzymatic degradation of viable cartilage tissues with collagenase 3 (MMP-13) and aggrecanase-1 (ADAMTS-4) decreased tissue matrix stiffness, cell and nuclear membrane stiffness is also decreased. Finally, the capability for cell and nucleus elastography using the AFM needle-tip technique is demonstrated. These results demonstrate disruption of the native tissue environment that propagates to the plasma membrane and interior nuclear envelope structures of viable cells.

Molecular docking study of flavonoid compounds for possible matrix metalloproteinase-13 inhibition

OBJECTIVES

Matrix metalloproteinase-13 (MMP-13) has been reported to be involved in different biological processes such as degradation of extracellular matrix proteins, activating or degrading some significant regulatory proteins, wound healing, tissue remodeling, cartilage degradation, bone development, bone mineralization, ossification, cell migration, and tumor cell invasion. Further, MMP-13 participates in many oral diseases such as tooth decay, gingivitis, and degradation of enamel and tissue around the implant. In addition, inhibition of MMP-13 has shown therapeutic properties for Alzheimer's disease (AD). We performed molecular docking to assess the binding affinity of 29 flavonoid compounds with the MMP-13. Additionally, pharmacokinetic and toxicity characteristics of the top-ranked flavonoids were studied. The current study also intended to identify the most important amino acids involved in the inhibition of MMP-13 based on topological feature (degree) in the ligand-amino acid network for MMP-13.

METHODS

Molecular docking and network analysis were studied using AutoDock and Cytoscape software, respectively. Pharmacokinetic and toxicity characteristics of compounds were predicted using bioinformatics web tools.

RESULTS

The results revealed that nine of the studied flavonoids had considerable estimated free energy of binding and inhibition constant: Rutin, nicotiflorin, orientin, vitexin, apigenin-7-glucoside, quercitrin, isoquercitrin, quercitrin-3-rhamnoside, and vicenin-2. Proline-242 was found to be the most important amino acid inhibiting the enzyme.

CONCLUSIONS

The results of the current study may be helpful in the prevention and therapeutic procedures of many disorders such as cancer, tooth caries, and AD. Nevertheless, validation tests are required in the future.

Cleavage by MMP-13 renders VWF unable to bind to collagen but increases its platelet reactivity

BACKGROUND

Atherosclerotic plaque rupture and subsequent thrombosis underpin thrombotic syndromes. Under inflammatory conditions in the unstable plaque, perturbed endothelial cells secrete von Willebrand Factor (VWF) which, via its interaction with GpIbα, enables platelet rolling across and adherence to the damaged endothelium. Following plaque rupture, VWF and platelets are exposed to subendothelial collagen, which supports stable platelet adhesion, activation, and aggregation. Plaque-derived matrix metalloproteinase (MMP)-13 is also released into the surrounding lumen where it may interact with VWF, collagen, and platelets.

OBJECTIVES

We sought to discover whether MMP-13 can cleave VWF and whether this might regulate its interaction with both collagen and platelets.

METHODS

We have used platelet adhesion assays and whole blood flow experiments to assess the effects of VWF cleavage by MMP-13 on platelet adhesion and thrombus formation.

RESULTS

Unlike the shear-dependent cleavage of VWF by a disintegrin and metalloprotease with thrombospondin motif member 13 (ADAMTS13), MMP-13 is able to cleave VWF under static conditions. Following cleavage by MMP-13, immobilized VWF cannot bind to collagen but interacts more strongly with platelets, supporting slower platelet rolling in whole blood under shear. Compared with intact VWF, the interaction of cleaved VWF with platelets results in greater GpIbα upregulation and P-selectin expression, and the thrombi formed on cleaved VWF-collagen co-coatings are larger and more contractile than platelet aggregates on intact VWF-collagen co-coatings or on collagen alone.

CONCLUSIONS

Our data suggest a VWF-mediated role for MMP-13 in the recruitment of platelets to the site of vascular injury and may provide new insights into the association of MMP-13 in atherothrombotic and stroke pathologies.

Investigation of the efficacy of daidzein in experimental knee osteoarthritis-induced with monosodium iodoacetate in rats

BACKGROUND

Osteoarthritis (OA) is a degenerative chronic illness that most frequently occurs in the knee joint. Daidzein (DZ) an isoflavone has anti-inflammatory and antioxidant activity. The aim of this study was to evaluate the effectiveness of DZ as a treatment for experimental knee OA (KOA) in rats.

METHOD

An experimental KOA model was induced by monosodium iodoacetate (MIA) in rats. Thereafter, 49 Wistar albino male rats (250-300 g, 12-16 weeks old) were randomly divided into 7 groups: C (healthy control); DC (KOA + saline); hyaluronic acid (HA); HA+ intraarticular (ia) DZ; oral (po) DZ; ia DZ; HA + po DZ groups. DZ and/or HA were administered intraarticularly to the rats as 50 μL on days 1, 7, 14, and 21. Alternatively, the DZ was administered orally as 0.5 mL twice daily for 21 days. After the treatment, rats were sacrificed by decapitation under general anesthesia. Serum samples were analyzed to determine the total oxidant status (TOS) and total antioxidant status (TAS) and the levels of TNF-α, IL-1β, MMP-13, and DZ. Knee joint samples underwent histopathological examination, and TNF-α, IL-1β, NOS2, and MMP-13 were analyzed with immunohistochemical methods.

RESULTS

HA, DZ, and DZ + HA effectively reduced the levels of TNF-α, IL-1β, and MMP-13 in the serum of the DC group (p < 0.001). In groups that received HA, DZ, or DZ + HA, the serum TAS increased compared with the DC group (p < 0.05). When the DZ + HA combination was used, a more pronounced reduction in the levels of TNFα, NOS2, IL-1β, and MMP-13 was observed in knee joints. In addition, the cracks on the cartilage surface and fibrillation were completely improved in the groups that received HA, DZ, or DZ + HA compared with the DC group.

CONCLUSION

DZ had anti-inflammatory and antioxidant effects in a rat OA model. Therefore, DZ, as monotherapy or especially in combination with HA, may be a promising and beneficial therapy for OA. Key Points •DZ has been shown to reduce TNF-α, IL-1β, and MMP-13 both in serum and in tissue samples taken from the knee-joints. •The cracks on the cartilage surface and fibrillation in KOA were completely improved by using DZ and DZ + HA combination. •DZ may be useful to eliminate/reduce/ameliorate inflammation and oxidative damage in the pathogenesis of KOA. •DZ, alone or in combination with HA, may be a promising natural compound with beneficial effects in the treatment of KOA.

Dexmedetomidine inhibits the NF-κB pathway and NLRP3 inflammasome to attenuate papain-induced osteoarthritis in rats

Context: Dexmedetomidine (Dex) has been reported to have an anti-inflammatory effect. However, its role on osteoarthritis (OA) has not been explored. Objective: This study investigates the effect of Dex on OA rat model induced by papain. Materials and methods: The OA Wistar rat model was induced by intraluminal injection of 20 mL of papain mixed solution (4% papain 0.2 mL mixed with 0.03 mol L^-1 l-cysteine 0.1 mL) into the right knee joint. Two weeks after papain injection, OA rats were treated by intra-articular injection of Dex (5, 10, or 20 μg kg^-1) into the right knee (once a day, continuously for 4 weeks). Articular cartilage tissue was obtained after Dex treatment was completed. Results: The gait behavior scores (2.83 ± 0.49), PWMT (15.2 ± 1.78) and PTWL (14.81 ± 0.92) in H-DEX group were higher than that of OA group, while Mankin score (5.5 ± 0.81) was decreased (p < 0.05). Compared with the OA group, the IL-1β (153.11 ± 16.05 pg mg^-1), IL-18 (3.71 ± 0.7 pg mg^-1), IL-6 (14.15 ± 1.94 pg/mg) and TNF-α (40.45 ± 10.28 pg mg^-1) levels in H-DEX group were decreased (p < 0.05). MMP-13, NLRP3, and caspase-1 p10 expression in Dex groups were significantly lower than that of OA group (p < 0.05), while collagen II was increased (p < 0.05). p65 in the nucleus of Dex groups was significantly down-regulated than that of OA group (p < 0.05). Discussion and Conclusions: Dex can improve pain symptoms and cartilage tissue damage of OA rats, which may be related to its inhibition of the activation of NF-κB and NLRP3 inflammasome.

Novel Pituitary Actions of Epidermal Growth Factor: Receptor Specificity and Signal Transduction for UTS1, EGR1, and MMP13 Regulation by EGF

Epidermal growth factor (EGF) is a member of the EGF-like ligands family, which plays a vital role in cell proliferation, differentiation, and folliculogenesis through binding with EGF receptors, including ErbB1 (EGFR/HER1), ErbB2 (HER2), ErbB3 (HER3), and ErbB4 (HER4). In mammals, many functional roles of EGF have been reported in the ovaries and breasts. However, little is known about the functions of EGF in the pituitary, especially in teleost. In this study, using grass carp pituitary cells as the model, we try to examine the direct pituitary actions of EGF in teleost. Firstly, transcriptomic analysis showed that 599 different expressed genes (DEGs) between the control and EGF-treatment group were mainly involved in cell proliferation, cell migration, signal transduction, and transcriptional regulation. Then, we further confirmed that EGF could significantly induce UTS1, EGR1, and MMP13 mRNA expression in a time-and dose-dependent manner. The stimulatory actions of EGF on UTS1 and EGR1 mRNA expression were mediated by the MEK_1/2/ERK_1/2 and PI₃K/AKT/mTOR pathways coupled with both ErbB1 and ErbB2 in grass carp pituitary cells. The receptor specificity and signal transductions for the corresponding responses on MMP13 mRNA expression were also similar, except that the ErbB2 and PI₃K/AKT/mTOR pathway were not involved. As we know, MMP13 could release EGF from HB-EGF. Interestingly, our data also showed that the MMPs inhibitor BB94 could suppress EGF-induced UTS1 and EGR1 mRNA expression. These results, taken together, suggest that the stimulatory actions of EGF on UTS1 and EGR1 mRNA expression could be enhanced by EGF-induced MMP13 expression in the pituitary.

Effects of Tumor Necrosis Factor Inhibitor on Stress-Shielded Tendons

Mechanical stress plays an important role in preserving the integrity of bone and ligament. Stress shielding reduces mechanical load on bone or tendons, resulting in tissue degradation. Previous studies showed that deterioration of the tendon structure during stress shielding is associated with elevated expression of tumor necrosis factor (TNF)-α. This study examined the therapeutic potential of the TNF inhibitor etanercept in preventing morphologic deterioration of the Achilles tendon after stress shielding. Rats (N=48) were exposed to stress shielding of the left Achilles tendon and treated with etanercept or phosphate-buffered saline for 2 or 4 weeks. The right Achilles tendons were used as controls. After 2 or 4 weeks, stress-shielded tendons appeared less smooth than control tendons, and the stress-shielded tendons formed adhesions with surrounding tissues. Transmission electron microscopy also showed disarray of the collagen fibrils and a significant increase in the number of small-diameter collagen fibrils. These changes were associated with increased expression of TNF-α, matrix metalloproteinase (MMP)-13, MMP-3, collagen I, and collagen III. Treatment with 2 weeks of etanercept injection reduced morphologic changes in collagen organization and structure induced by stress shielding. Etanercept treatment also attenuated upregulation of MMP-13, MMP-3, and collagen III levels. However, no significant difference was observed between the etanercept group and the phosphate-buffered saline group after 4 weeks of treatment. The current findings show that TNF-α inhibition can protect against the early stages of tendon tissue remodeling induced by stress shielding, but additional interventions may be necessary to prevent tendon degeneration with long-term stress shielding. [Orthopedics. 2017; 40(1):49-55.].

[Roles of biochemical factors in lateral compartment wear from varus knee osteoarthritis]

OBJECTIVE

To explore the roles of type II collagen C-terminal telopeptide (CTX-II), matrix metalloproteinase-13 (MMP-13) and interleukin-6 (IL-6) in lateral compartment wear in varus knee osteoarthritis.

METHODS

Prospective reviews were conducted for the clinical data of varus knee osteoarthritis patients with lateral compartment wear undergoing total knee arthropalsty from June 2013 to June 2014. The gross findings of lateral compartment articular cartilage were recorded intraoperatively. And the slices were evaluated histologically. Synovial fluid was obtained by arthrocentesis. An equal number of operative patients from varus knee osteoarthritis without lateral compartment wear during the same period were selected and matched with respects to age, varus, preoperative range of motion and radiological grade of knee arthrosis. Synovial fluid concentrations of CTX-II, MMP-13 and IL-6 were evaluated.

RESULTS

Histologic examination showed microscopic cartilage degeneration in both groups. The concentrations of CTX-II, IL-6 and MMP-13 in synovial fluid from lateral compartment wear group were (111.8±55.7) ng/L, (2.5±1.0) ng/L and (134.4±33.1) µg/L respectively. And there were no differences with control group (91.7±57.1) ng/L, (2.1±0.5) ng/L, (122.7±28.3) µg/L respectively.

CONCLUSION

The above biochemical factors may not play key roles in lateral compartment wear of varus knee osteoarthritis.

[EXPRESSIONS OF CARTILAGE DEGENERATIVE RELATED GENES AND microRNAs IN TORN MENISCUS]

OBJECTIVE

To investigate the expressions of cartilage degenerative related genes in meniscus, and to evaluate the potential effect of meniscal damage on cartilage degeneration, and to analyze the relationship between microRNAs (miRNAs) expression and cartilage degeneration.

METHODS

Meniscal tissue was collected from 5 patients undergoing partial meniscectomy between September 2012 and October 2013 (experimental group), and normally meniscal tissue without tearing from amputees was used as controls (control group). Pathological changes of menisci were observed; and real-time fluorescent quatitative PCR was performed to examine the relative expression levels of cartilage degenerative related genes and miRNAs: Aggrecan (ACAN), type X collagen (COL10A1), matrix metalloproteinases 13 (MMP-13), CCAAT enhancer binding protein β (CEBP-β), a disintegrin and metalloproteinase with thrombospondinmotif 5 (ADAMTS-5), miR-193b, miR-92a, and miR-455-3p in meniscus.

RESULTS

There were varying degrees of degenerative pathological changes in torn meniscus of experimental group. Compared with normal meniscus of control group, the expression of ACAN was decreased, while the expressions of COL10A1, CEBP-β, ADAMTS-5, and MMP-13 were increased in torn meniscus of experimental group; and significant difference was found (P < 0.05) except ACAN and MMP-13 (P > 0.05). The expressions of miR-92a, miR-455-3p, and miR-193b in torn meniscus of experimental group were significantly higher than those in normal meniscus of control group (P < 0.05).

CONCLUSION

Meniscal tissue has the intrinsic tendency of degeration after meniscus tear. The torn meniscus has greater stimulative impact on cartilage degeneration than normally morphological meniscus without tearing. The cartilage degenerative related miRNAs, including miR-193b, miR-92a, and miR-455-3p may contribute to the up-regulation of osteoarthritis.

[The invasion ability and expressions of matrix metalloproteinase-13 and calcium-binding protein S100A4 are inhibited by hyperthermia in human Tca8113 cells]

OBJECTIVE

To study the effect of hyperthermia on anti-invasion of Tca8113 and the expression change of matrix metalloproteinase-13 (MMP-13) and calcium-binding protein S100A4 (S100A4).

METHODS

Tca8113 cell pools were incubated at 43 degrees C for 0, 40, 80, 120 min, respectively, and at 37, 41, 43, 45 degrees C respectively for 80 min. The effect of high temperatures on the invasion ability of Tca8113 was measured in vitro. The slides of cells were made and incubated at 43 degrees C for 0, 40, 80, 120 min, respectively. Immunocytochemical method was employed for detecting the expression change of MMP-13 and S100A4 protein. Tca8113 cells were incubated at 43 degrees C for 0, 40, 80, 120 min respectively and at 37, 41, 43, 45 degrees C respectively for 80 min. Western blot method was conducted for detecting the expressionchange of MMP-13 and S100A4 protein.

RESULTS

As incubating time at higher temperature lasted, the proportion of the cells with invasion ability decreased. Except groups of 40 min and 80 min at 43 degrees C and 41, 43 degrees C for 80 min, the rest groups show significant statistic differences (P < 0.05). The expression intensity of MMP-13 and S100A4 proteins in Tca8113 cells would decrease as incubating time at higher temperature lasted. The content of MMP-13 and S100A4 proteins would decrease as incubating time at higher temperature lasted or incubating temperature increased. Except the groups of 40, 80 min at 43 degrees C and 41, 43 degrees C for 80 min, statistic differences were identified (P < 0.05).

CONCLUSION

The invasion of Tca8113 could be inhibited by hyperthermia. The mechanism of this effect may be due to protein expression inhibition of MMP-13 and S100A4.

Incorporation of vancomycin-supplemented bone allograftsRadiographical, histopathological and immunohistochemical study in pigs

We compared the incorporation of bone allografts with or without vancomycin in tibial defects of 18 pigs. High-quality radiographs, histological examination, immunological expression of metalloproteinase-13 (MMP-13) and transforming growth factor-beta 2 (TGFbeta2) indicated that there was no significant difference in bone allograft incorporation between up to 220 times the MIC (minimum inhibitory concentration) in bone allografts with 1 g of vancomycin in each 300 g of allograft or without this supplement.

The expression of collagenase 3 (MMP-13) mRNA in the synovial tissue is associated with histopathologic type II synovitis in rheumatoid arthritis

The histopathologic analysis of the synovial tissue is important to distinguish rheumatoid arthritis (RA) from other forms of synovitis and to provide information about prognosis and therapeutic strategies at early stages of the disease. In this context, the present study was performed to investigate the correlation between immunohistopathological and morphological features of synovitis and the expression of collagenase 3 (MMP-13) known to contribute significantly to cartilage degradation in RA. In the histopathologic scoring system used in this study, type I synovitis is characterized by B lymphocyte infiltration and an intact lining, and is only mild destructive to cartilage and bone. Type II shows marked diffuse infiltrations of macrophages and T lymphocytes, an ulcerated lining, fibrin exudation, and invasive growth into cartilage and bone tissue. Investigating 36 patients with RA, 21 patients (58%) were positive for the expression of collagenase 3 mRNA in the synovial tissue. Among these patients, 19 showed a histopathologic type II synovitis and only 2 patients had undifferentiated synovitis. In contrast, synovial tissue samples from patients without collagenase 3 mRNA expression were characterized in 6 cases by type I, in 5 cases by type II and in 4 cases by undifferentiated synovitis. The analysis of the clinical data revealed that RA patients with a histopathologic type II synovitis and synovial tissue collagenase 3 mRNA expression had elevated levels of systemic markers of inflammation and received stronger therapies. The data suggest, that collagenase 3 expression and the histopathologic type II synovitis are associated with a severe and destructive course of RA.

The signalling of AT2 and the influence on the collagen metabolism of AT2 receptor in adult rat cardiac fibroblasts

OBJECTIVES

Angiotensin (Ang) II exerts its roles on cardiac fibroblasts by two receptors: type I (AT1) and type 2 (AT2). The role of AT1 has been well known, but less is known about AT2. The present study was designed to explore signal pathways of AT2 and observe whether AT2 is involved in the collagen metabolism of cardiac fibroblasts.

METHODS AND RESULTS

Adult rat cardiac fibroblasts were extracted, cultured and treated with Ang-II alone, Ang-II plus losartan or PD123319. G protein-coupled receptors signalling pathway finder gene arrays were used to analyse expression changes of 96 genes associated with 11 signal pathways. With a 10-fold change in threshold, 7 genes were differentially expressed specific to AT1 blockade associated to 5 signal pathways including PKC, PLC, MAPK, NO/cGMP and NFkappaB; while 24 genes were specific to AT2 blockade related to 10 signal pathways including cAMP/PKA, Ca2+, PKC, PTK, MAPK, PI-3K, NO/cGMP, Rho, NFkappaB and JAK-STAT. RT-PCR were used to confirm the results of arrays and measure collagen (Col) I and tissue inhibitor of metalloproteinase (TIMP)-1 mRNA levels. AT2 blockade decreased Col I and TIMP-1 mRNA levels compared to the Ang II-treated group, which was similar with AT1 blockade.

CONCLUSION

In adult rat cardiac fibroblasts, AT2 was obviously distinct from AT1 in signalling responses. AT2 appeared to spread more widely than AT1. AT2 might be involved in the collagen metabolism of rat cardiac fibroblasts by regulating Col I and TIMP1 mRNA levels.