Mg Of Monoiodoacetate Research Articles

Effects of acupuncture on serotonin, histamine, substance P, and tryptase levels at sensitized points in model rats with knee osteoarthritis

ObjectiveTo elucidate the differences in manual acupuncture effectiveness at sensitized points by investigating the mechanisms of local skin action at different sensitization points in rats with knee osteoarthritis (KOA). MethodsForty Sprague–Dawley rats were equally divided into control, model (1 mg of monoiodoacetate into the right knee joint cavity), sham operation, manual acupuncture at right Tianjing acupoint (MAR-SJ 10), and left SJ 10 groups. Safranine-O and fast green staining were used to assess the modeling. The morphological and functional changes in mast cells (MCs) were assessed during acupoint sensitization using toluidine blue and immunofluorescence staining. The levels of serotonin, histamine, substance P (SP), and tryptase at skin acupoints and serum levels of IL-β, IL-6, and TNF-α were detected using ELISA. ResultsAfter 14 days of treatment, the number of MCs and their degranulation rates were statistically higher in the model group than in the control group (both P < .001). After applying acupuncture, the levels of 5-HT, HA, and SP at skin acupoints were lower than those in the model group (all P < .05), and tryptase level was higher (both P < .05). Tryptase level was higher on the skin at the MAL-SJ 10 acupoint than that on the MAR-SJ 10 acupoint (P = .004). Compared with the model group, the serum levels of IL-1β, IL-6, and TNF-α in the MAR-SJ 10 and MAL-SJ 10 groups were lower (all P < .05). ConclusionAcupuncture at KOA-sensitized acupoints mitigates joint injury in KOA rats and may bidirectionally regulate local MCs of these acupoints. This finding not only enhances the reference value of sensitizing points in clinical diagnosis and treatment, but also contributes to the understanding of the biological mechanisms underlying acupuncture intervention at sensitizing points.

Alterations in DNA methylation machinery in a rat model of osteoarthritis of the hip

BackgroundThis study aimed to validate alterations in the gene expression of DNA methylation-related enzymes and global methylation in the peripheral blood mononuclear cell (PBMC) and synovial tissues of animal hip osteoarthritis (OA) models.MethodsAnimals were assigned to the control (no treatment), sham (25 µL of sterile saline), and OA (25 µL of sterile saline and 2 mg of monoiodoacetate) groups. Microcomputed tomography scan, histopathological assessment and pain threshold measurement were performed after induction. The mRNA expression of the DNA methylation machinery genes and global DNA methylation in the PBMC and hip synovial tissue were evaluated.ResultsThe OA group presented with hip joint OA histopathologically and radiologically and decreased pain threshold. The mRNA expression of DNA methyltransferase (Dnmt 3a), ten–eleven translocation (Tet) 1 and Tet 3 in the synovial tissue of the OA group was significantly upregulated. Global DNA methylation in the synovial tissue of the OA group was significantly higher than that of the control and sham groups.ConclusionsThe intra-articular administration of monoiodoacetate induced hip joint OA and decreased pain threshold. The DNA methylation machinery in the synovial tissues of hip OA was altered.

Circulating miR-146b and miR-27b are efficient biomarkers for early diagnosis of Equidae osteoarthritis

One of the most orthopedic problems seen in the equine is osteoarthritis (OA). The present study tracks some biochemical, epigenetic, and transcriptomic factors along different stages of monoiodoacetate (MIA) induced OA in donkeys in serum and synovial fluid. The aim of the study was the detection of sensitive noninvasive early biomarkers. OA was induced by a single intra-articular injection of 25 mg of MIA into the left radiocarpal joint of nine donkeys. Serum and synovial samples were taken at zero-day and different intervals for assessment of total GAGs and CS levels as well as miR-146b, miR-27b, TRAF-6, and COL10A1 gene expression. The results showed that the total GAGs and CS levels increased in different stages of OA. The level of expression of both miR-146b and miR-27b were upregulated as OA progressed and then downregulated at late stages. TRAF-6 gene was upregulated at the late stage while synovial fluid COL10A1 was over-expressed at the early stage of OA and then decreased at the late stages (P < 0.05). In conclusion, both miR-146b and miR-27b together with COL10A1 could be used as promising noninvasive biomarkers for the very early diagnosis of OA.

Evaluation of articular changes using a rat mono-iodoacetate-induced shoulder arthritis model by histology and radiology.

The rat mono-iodoacetate (MIA) arthritis model has been used in studies on the hip, knee, and ankle joints. Few studies have explored its utility in shoulder arthritis research, and none have evaluated the effects of time and different MIA doses on arthritis progression. Therefore, we developed a rat MIA shoulder arthritis model to evaluate articular changes through radiological and histological analyses. Sprague-Dawley rats (n = 108) were equally divided into groups that were intra-articularly injected with 0.5 mg of MIA (in 50 µL of purified water), 2.0 mg of MIA (in 50 µL of purified water), or purified water (50 µL; sham group). Throughout the study period, 18 rats (six per group) were evaluated by computed tomography and assessed using the Larsen's classification system; 90 rats were further evaluated histologically using the Osteoarthritis Research Society International scoring system. Computed tomography revealed that the groups injected with MIA developed arthritis and osteophytes 14 days after injection, which progressed temporally. The Larsen's grades worsened over time; at all time points, the scores were higher in the group injected with 2.0 mg of MIA than in the group injected with 0.5 mg of MIA. Furthermore, concurrent with the worsening Larsen's grades, the Osteoarthritis Research Society International scores also significantly increased over time; at all time points, they were higher in the group injected with 2.0 mg of MIA than in the group injected with 0.5 mg of MIA. Our rat MIA shoulder arthritis model revealed radiologically and histologically confirmed temporal and MIA dose-dependent arthritic changes.

Regenerative Effect of Low-Intensity Pulsed Ultrasound and Platelet-Rich Plasma on the Joint Friction and Biomechanical Properties of Cartilage: A Non-traumatic Osteoarthritis Model in the Guinea Pig.

This study was aimed at investigating the effects of platelet-rich plasma (PRP) and low-intensity pulsed ultrasound (LIPUS) on the joint friction parameters and biomechanical properties of articular cartilage in a non-traumatic knee osteoarthritis (OA) model. Fifty adult male Dunkin Hartley guinea pigs were randomly divided into five groups: control, OA60, OA+US, OA+PRP and OA+US+PRP). Non-traumatic knee OA was induced with a single dose of 3 mg of mono-iodoacetate (MIA) by intra-articular injection. Intra-articular PRP was injected twice in the OA+PRP and OA+US+PRP groups. LIPUS was delivered in 10 sessions in the OA+US and OA+US+PRP groups. By use of the pendulum free oscillation test, joint friction (coefficient of friction) was measured. In addition, the instantaneous elastic modulus and aggregate modulus were measured using the stress-relaxation test. MIA injection decreased cartilage thickness, instantaneous elastic modulus and aggregate modulus, and increased joint friction. The friction coefficients in the OA+US and OA+US+PRP groups reached near-normal values, and there was no significant difference compared with the control group (p=0.232 and p=0.459, respectively). The instantaneous elastic modulus and aggregate modulus in the OA+US group increased significantly compared with the OA+PRP group (p < 0.05). It seems that both LIPUS and PRP injection effectively improved joint lubrication, but LIPUS was superior to PRP in improving the mechanical properties of the articular cartilage.

Analgesic effects and arthritic changes following tramadol administration in a rat hip osteoarthritis model.

We investigated the analgesic effects of tramadol and the arthritic changes following tramadol administration in the rat hip osteoarthritis (OA) model using mono-iodoacetate (MIA). The right hip joints of male Sprague-Dawley rats (n = 5 rats/group) in the Sham group were injected with 25 μl of sterile saline and 1% of fluorogold (FG) retrograde neurotracer. In the MIA + Vehicle and MIA + Tramadol groups, FG and 25 μl of sterile saline with 0.5 mg of MIA were injected into the right hip joint. The MIA + Vehicle and MIA + Tramadol groups were administered daily for 4 weeks, either sterile saline (10 mg/kg, intraperitoneal [i.p.]) or tramadol (10 mg/kg, i.p.). We assessed hyperalgesia every week after MIA administration. Histopathological changes and immunoreactive neurons for calcitonin gene-related peptide (CGRP) in dorsal root ganglia (DRG) were evaluated after 4 weeks of treatment. MIA injection into the hip joint led to mechanical hyperalgesia (p < 0.01), which was significantly reduced by tramadol administration (p < 0.01). Furthermore, daily i.p injection of tramadol significantly suppressed CGRP expression in DRG (p < 0.0001). MIA + Vehicle and MIA + Tramadol groups showed significant cartilage reduction and degeneration compared to the Sham group (p < 0.0001). Interestingly, OA changes significantly progressed in the MIA + Tramadol group compared to the MIA + Vehicle group (p < 0.0001).

Sodium Monoiodoacetate Dose-Dependent Changes in Matrix Metalloproteinases and Inflammatory Components as Prognostic Factors for the Progression of Osteoarthritis.

Osteoarthritis (OA) is a degenerative joint disease that primarily affects people over 65 years old. During OA progression irreversible cartilage, synovial membrane and subchondral bone degradation is observed, which results in the development of difficult-to-treat chronic pain. One of the most important factors in OA progression is joint inflammation. Both proinflammatory and anti-inflammatory factors, as well as extracellular matrix degradation enzymes (matrix metalloproteinases (MMPs), play an important role in disease development. One of the most widely used animal OA models involves an intra-articular injection of sodium monoiodoacetate (MIA) directly into the joint capsule, which results in glycolysis inhibition in chondrocytes and cartilage degeneration. This model mimics the degenerative changes observed in OA patients. However, the dose of MIA varies in the literature, ranging from 0.5 to 4.8 mg. The aim of our study was to characterize grading changes after injection of 1, 2 or 3 mg of MIA at the behavioral and molecular levels over a 28-day period. In the behavioral studies, MIA injection at all doses resulted in a gradual increase in tactile allodynia and resulted in abnormal weight bearing during free walking sequences. At several days post-OA induction, cartilage, synovial membrane and synovial fluid samples were collected, and qPCR and Western blot analyses were performed. We observed significant dose- and time-dependent changes in both gene expression and protein secretion levels. Inflammatory factors (CCL2, CXCL1, IL-1β, COMP) increased at the beginning of the experiment, indicating a transient inflammatory state connected to the MIA injection and, in more severe OA, also in the advanced stages of the disease. Overall, the results in the 1 mg MIA group were not consistently clear, indicating that the lowest tested dose may not be sufficient to induce long-lasting OA-like changes at the molecular level. In the 2 mg MIA group, significant alterations in the measured factors were observed. In the 3 mg MIA group, MMP-2, MMP-3, MMP-9, and MMP-13 levels showed very strong upregulation, which may cause overly strong reactions in animals. Therefore, a dose of 2 mg appears optimal, as it induces significant but not excessive OA-like changes in a rat model.

Molecular Understanding of the Activation of CB1 and Blockade of TRPV1 Receptors: Implications for Novel Treatment Strategies in Osteoarthritis.

Osteoarthritis (OA) is a joint disease in which cartilage degenerates as a result of mechanical and biochemical changes. The main OA symptom is chronic pain involving both peripheral and central mechanisms of nociceptive processing. Our previous studies have implicated the benefits of dual- over single-acting compounds interacting with the endocannabinoid system (ECS) in OA treatment. In the present study, we focused on the specific molecular alterations associated with pharmacological treatment. OA was induced in Wistar rats by intra-articular injection of 3 mg of monoiodoacetate (MIA). Single target compounds (URB597, an FAAH inhibitor, and SB366791, a TRPV1 antagonist) and a dual-acting compound OMDM198 (FAAH inhibitor/TRPV1 antagonist) were used in the present study. At day 21 post-MIA injection, rats were sacrificed 1 h after i.p. treatment, and changes in mRNA expression were evaluated in the lumbar spinal cord by RT-qPCR. Following MIA administration, we observed 2-4-fold increase in mRNA expression of targeted receptors (Cnr1, Cnr2, and Trpv1), endocannabinoid degradation enzymes (Faah, Ptgs2, and Alox12), and TRPV1 sensitizing kinases (Mapk3, Mapk14, Prkcg, and Prkaca). OMDM198 treatment reversed some of the MIA effects on the spinal cord towards intact levels (Alox12, Mapk14, and Prkcg). Apparent regulation of ECS and TRPV1 in response to pharmacological intervention is a strong justification for novel ECS-based multi-target drug treatment in OA.

Pain-related behavior and the characteristics of dorsal-root ganglia in a rat model of hip osteoarthritis induced by mono-iodoacetate.

The principal aim of this study was to clarify the time course of pain-related behavior and pain-related sensory innervation in a rat model of hip osteoarthritis (OA) induced by intra-articular injection of mono-iodoacetate (MIA). Using 6-week-old male Sprague Dawley rats, 25 μl of sterile saline of 1% Fluoro-Gold solution (FG) (control group; n = 30) and 25 μl of sterile saline of 1% FG with 2 mg of MIA (MIA group; n = 30) was injected into the right hip joints. Gait function was evaluated using a CatWalk system after 7, 14, 28, 42, and 56 days (n = 5, respectively). Neurons in the dorsal root ganglion (DRG) between L1 and L5 were immunostained for calcitonin gene-related peptide (CGRP) and activating transcription factor-3 (ATF3). Gait analysis revealed the mean six parameters of hind paws at all time points were significantly lower in the MIA group (p = 0.05). The number of CGRP-immunoreactive (-IR) DRG neurons was significantly increased on days 7, 14, 28, and 42 peaking at 14 days in the MIA group. By contrast, expression of ATF3-IR in FG-labeled DRG neurons was significantly increased on days 42 and 57. The FG-labeled DRG neurons were distributed between L1 and L5, mainly at the L4 level. Pain-related behavior indicated by gait disturbance was observed in a MIA model of hip OA in rat. Early elevation of CGRP expression and late expression of ATF-3 were demonstrated in DRG neurons, possibly reflecting inflammatory pain and neuropathic pain in hip OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1424-1430, 2017.

Intra-articular injection of mono-iodoacetate induces osteoarthritis of the hip in rats.

BackgroundThe mechanism for hip pain has been unclear because of a lack of experimental animal models. We aimed to establish an intra-articular injection technique to the rat hip and to document the effect of intra-articular mono-iodoacetate (MIA) injection to the rat hip with radiography and histology.MethodsUsing 60 6-week-old male Sprague Dawley rats, 25 μl of sterile saline (control group; n = 30) and 25 μl of sterile saline with 2 mg of MIA (MIA group; n = 30) was injected into the right hip joints via posterior approach using a 27G needle. The animals were examined with X-ray and histology 7, 14, 28, 42, and 56 days later (MIA group [n = 6] and control group [n = 6], respectively).ResultsThe MIA group showed progressive radiographic changes to the hip joint during the experimental period, whereas the control group maintained a normal appearance. The microanatomic appearance was consistent with X-ray images of progressive destruction in the MIA group and normal tissue in the control group. Osteoarthritic (OA) changes became apparent at 42 and 56 days in the MIA group.ConclusionsWe established an intra-articular injection technique to the rat hip, creating a hip OA model in the rat by intra-articular injection of MIA.

Dose-Dependent Expression of Neuronal Injury Markers during Experimental Osteoarthritis Induced by Monoiodoacetate in the Rat

BackgroundIt was recently reported that the mono-iodoacetate (MIA) experimental model of osteoarthritis (OA) courses with changes of neurons innervating the affected joints that are commonly interpreted as a neuronal response to axonal injury. To better characterize these changes, we evaluated the expression of two markers of neuronal damage, ATF-3 and NPY, and the growth associated protein GAP-43, in primary afferent neurons of OA animals injected with three different doses of MIA (0.3, 1 or 2 mg). Measurements were performed at days 3, 7, 14, 21 and 31 post-MIA injection.ResultsOA animals showed the characteristic histopathological changes of the joints and the accompanying nociceptive behaviour, evaluated by the Knee-Bed and CatWalk tests. An increase of ATF-3 expression was detected in the DRG of OA animals as early as 3 days after the injection of 1 or 2 mg of MIA and 7 days after the injection of 0.3 mg. NPY expression was increased in animals injected with 1 or 2 mg of MIA, at day 3 or in all time-points, respectively. From day 7 onwards there was a massive increase of GAP-43 expression in ATF-3 cells.ConclusionsThe expression of the neuronal injury markers ATF-3 and NPY as well as an up-regulation of GAP-43 expression, indicative of peripheral fibre regeneration, suggests that axonal injury and a regeneration response may be happening in this model of OA. This opens new perspectives in the unravelling of the physiopathology of the human disease.

Establishment of a novel objective and quantitative method to assess pain-related behavior in monosodium iodoacetate-induced osteoarthritis in rat knee

IntroductionPain in osteoarthritis (OA) patients can be present at rest but typically worsens with movement of the affected joint. However, useful assessment methods of movement-induced pain in animal models are limited. Here, we describe the reduction of spontaneous activity in a rat model of OA as an objective and quantifiable behavioral pain that can predict the analgesic activity of a variety of agents following single-dose administration. MethodsOA was induced in male Sprague–Dawley (SD) rats by intra-articular injection of monoiodoacetate (MIA), and the joint degeneration was assessed with histologic and radiographic analyses. Spontaneous activities were measured in nonhabituated rats using standard, photocell-based monitor systems in the dark. To investigate the potential of the OA model to predict analgesic activity, a number of nonsteroidal anti-inflammatory drugs (NSAIDs) and atypical analgesic drugs were used. ResultsBiphasic reduction of total distance and number of rears was observed during the course of experiment after administering 1mg and 0.3mg of MIA, respectively. We found that number of rears was the most sensitive to MIA-induce OA and displayed the greatest percentage decrease in activity. Joint degeneration was observed with decreased bone mineral density and loss of articular cartilage 28days post-MIA injection. Appropriate dosage of opioids reversed MIA-induced decrease of number of rears indicating that reduction of this vertical spontaneous activity reflects pain-associated behavior. As high-doses of opioids reduced spontaneous activity, the sedative effect can be distinguished from the analgesic effect. Analgesic treatment indicates the coexistence of an inflammatory pain state (early phase) sensitive to NSAIDs and a non-inflammatory pain state (late phase) resistant to NSAID treatment. DiscussionThis study indicates that unlike standard measures of analgesia such as alteration in thermal or mechanical sensitivity, measurement of spontaneous activity is a validated method for measuring the effects of analgesics in rats with OA knee joints. Moreover, the animals require no habituation, and thus behavioral observation subjectivity is eliminated.

Phenotypic alterations of neurons that innervate osteoarthritic joints in rats

Pain is a prominent feature of osteoarthritis (OA). To further understand the primary mechanisms of nociception in OA, we studied the expression of the phenotype markers calcitonin gene-related peptide (CGRP), isolectin B4 (IB4), and neurofilament 200 (NF200) in sensory neurons innervating the OA knee joint in rats. OA was induced in rats by intraarticular injection of 2 mg of mono-iodoacetate (MIA) into the knee. Neurons innervating the joint were identified by retrograde labeling with fluorogold in dorsal root ganglia (DRG) and colocalized with neurochemical markers by immunofluorescence. The total number of DRG cells was determined by stereologic methods in Nissl-stained sections. A 37% decrease in the number of fluorogold-backlabeled cells was observed in rats with OA when compared with control rats, even though no decrease in the total number of cells was observed. However, an increase in the number of medium/large cell bodies and a decrease in the number of the smallest cells were observed, suggesting the occurrence of perikarya hypertrophy. The percentage of CGRP-positive cells increased significantly, predominantly in medium/large cells, suggesting the occurrence of a phenotypic switch. Colocalization of CGRP and NF200 revealed no significant changes in the percentage of double-labeled cells, but an increase in the number of medium/large double-labeled cells was observed. No differences in the expression of either IB4 or NF200 were observed in fluorogold-backlabeled cells. These results indicate that MIA-induced OA causes an up-regulation of CGRP in different subpopulations of primary afferent neurons in DRG due to a phenotypic switch and/or cell hypertrophy which may be functionally relevant in terms of the onset of pain in this pathologic condition.