Diabetes mellitus is a potential risk factor for aseptic loosening around hip and knee arthroplasty.

BACKGROUND: Aseptic loosening is a leading cause of revision following total hip and knee arthroplasty which is caused by chronic inflammation around the prosthesis. Diabetes mellitus causes systemic inflammatory changes which could increase the risk of aseptic loosening. This study investigated the association between diabetes mellitus and aseptic loosening around hip and knee arthroplasty. METHODS: A case-control study was conducted at a single arthroplasty centre over the seven-year period of January 2015 to December 2021. Cases were defined as any adult patient undergoing revision hip or knee arthroplasty for aseptic loosening. Controls were randomly selected patients undergoing primary total hip or knee arthroplasty during the same period at a 1:4 ratio. Risk factors were compared between the two groups. RESULTS: A total of 440 patients were included in our study - 88 in the aseptic loosening group and 352 patients in the control group. The odds of having diabetes mellitus in the aseptic loosening group was 2.78 (95%CI 1.31-5.92, P = 0.01). Other risk factors were not significantly different between the two groups. CONCLUSIONS: The incidence of diabetes mellitus is significantly greater in patients undergoing revision arthroplasty for aseptic loosening. Further research is required to explore whether this association is indeed causative.

Arthritogenic alphaviral infection perturbs osteoblast function and triggers pathologic bone loss.

Arthritogenic alphaviruses including Ross River virus (RRV), Sindbis virus, and chikungunya virus cause worldwide outbreaks of musculoskeletal disease. The ability of alphaviruses to induce bone pathologies remains poorly defined. Here we show that primary human osteoblasts (hOBs) can be productively infected by RRV. RRV-infected hOBs produced high levels of inflammatory cytokine including IL-6. The RANKL/OPG ratio was disrupted in the synovial fluid of RRV patients, and this was accompanied by an increase in serum Tartrate-resistant acid phosphatase 5b (TRAP5b) levels. Infection of bone cells with RRV was validated using an established RRV murine model. In wild-type mice, infectious virus was detected in the femur, tibia, patella, and foot, together with reduced bone volume in the tibial epiphysis and vertebrae detected by microcomputed tomographic (µCT) analysis. The RANKL/OPG ratio was also disrupted in mice infected with RRV; both this effect and the bone loss were blocked by treatment with an IL-6 neutralizing antibody. Collectively, these findings provide previously unidentified evidence that alphavirus infection induces bone loss and that OBs are capable of producing proinflammatory mediators during alphavirus-induced arthralgia. The perturbed RANKL/OPG ratio in RRV-infected OBs may therefore contribute to bone loss in alphavirus infection.

Uptake and protective effects of ergothioneine in human endothelial cells.

Ergothioneine is a thiourea derivative of histidine found in food, especially mushrooms. Experiments in cell-free systems and chemical assays identified this compound as a powerful antioxidant. Experiments were designed to test the ability of endothelial cells to take up ergothioneine and hence benefit from protection against oxidative stress. Reverse-transcription polymerase chain reaction and Western blotting demonstrated transcription and translation of an ergothioneine transporter in human brain microvascular endothelial cells (HBMECs). Uptake of [(3)H]ergothioneine occurred by the organic cation transporter novel type-1 (OCTN-1), was sodium-dependent, and was reduced when expression of OCTN-1 was silenced by small interfering RNA (siRNA). The effect of ergothioneine on the production of reactive oxygen species (ROS) in HBMECs was measured using dichlorodihydrofluorescein and lucigenin, and the effect on cell viability was studied using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. ROS production and cell death induced by pyrogallol, xanthine oxidase plus xanthine, and high glucose were suppressed by ergothioneine. The antioxidant and cytoprotective effects of ergothioneine were abolished when OCTN-1 was silenced using siRNA. The expression of NADPH oxidase 1 was decreased, and those of glutathione reductase, catalase, and superoxide dismutase enhanced by the compound. In isolated rat basilar arteries, ergothioneine attenuated the reduction in acetylcholine-induced relaxation caused by pyrogallol, xanthine oxidase plus xanthine, or incubation in high glucose. Chronic treatment with the compound improved the response to acetylcholine in arteries of rats with streptozotocin-induced diabetes. In summary, ergothioneine is taken up by endothelial cells via OCTN-1, where the compound then protects against oxidative stress, curtailing endothelial dysfunction.

Osteoblasts from osteoarthritis patients show enhanced susceptibility to Ross River virus infection associated with delayed type I interferon responses.

BACKGROUND: Arthritogenic alphaviruses such as Ross River virus (RRV) and chikungunya virus (CHIKV) have caused widespread outbreaks of chronic polyarthritis. The inflammatory responses in alphavirus-induced arthritis and osteoarthritis (OA) share many similar features, which suggests the possibility of exacerbated alphavirus-induced bone pathology in individuals with pre-existing OA. Here, we investigated the susceptibility of osteoblasts (OBs) from OA patients to RRV infection and dissected the immune mechanisms elicited from infection. METHODS: Primary hOBs obtained from trabecular bone of healthy donors and OA patients were infected with RRV. Infectivity and viral replication were determined using flow cytometry and plaque assay, respectively. Real-time PCR was performed to determine expression kinetics of type I interferon (IFN)-related immune mediators and osteotropic factors. RESULTS: OA hOBs showed enhanced RRV infectivity and replication during infection, which was associated with delayed induction of IFN-ß and RIG-I expression. Enhanced susceptibility of OA hOBs to RRV was associated with a more pronounced increase in RANKL/OPG ratio and expression of osteotropic factors (IL-6, IL-1ß, TNF-α and CCL2) in comparison to RRV-infected healthy hOBs. CONCLUSIONS: Delayed activation of type I IFN-signalling pathway may have contributed to enhanced susceptibility to RRV infection in hOBs from OA patients. RRV-induced increases in RANKL/OPG ratio and expression of osteotropic factors that favour bone resorption, which may be exacerbated during osteoarthritis. This study provides the novel insight that osteoarthritis may be a risk factor for exacerbated arthritogenic alphaviral infection.

Aseptic loosening around total joint replacement in humans is regulated by miR-1246 and miR-6089 via the Wnt signalling pathway.

BACKGROUND: Total joint replacement for osteoarthritis is one of the most successful surgical procedures in modern medicine. However, aseptic loosening continues to be a leading cause of revision arthroplasty. The diagnosis of aseptic loosening remains a challenge as patients are often asymptomatic until the late stages. MicroRNA (miRNA) has been demonstrated to be a useful diagnostic tool and has been successfully used in the diagnosis of other diseases. We aimed to identify differentially expressed miRNA in the plasma of patients with aseptic loosening. METHODS: Adult patients undergoing revision arthroplasty for aseptic loosening and age- and gender-matched controls were recruited. Samples of bone, tissue and blood were collected, and RNA sequencing was performed in 24 patients with aseptic loosening and 26 controls. Differentially expressed miRNA in plasma was matched to differentially expressed mRNA in periprosthetic bone and tissue. Western blot was used to validate protein expression. RESULTS: Seven miRNA was differentially expressed in the plasma of patients with osteolysis (logFC >|2|, adj-P < 0.05). Three thousand six hundred and eighty mRNA genes in bone and 427 mRNA genes in tissue samples of osteolysis patients were differentially expressed (logFC >|2|, adj-P < 0.05). Gene enrichment analysis and pathway analysis revealed two miRNA (miR-1246 and miR-6089) had multiple gene targets in the Wnt signalling pathway in the local bone and tissues which regulate bone metabolism. CONCLUSION: These results suggest that aseptic loosening may be regulated by miR-1246 and miR-6089 via the Wnt signalling pathway.

A Novel Approach of Customized Pelvic Implant Design Based on Symmetrical Analysis and 3D Printing.

In pelvic trauma patients, the mismatch of complex geometries between the pelvis and fixation implant is a fundamental cause of unstable and displaced pelvic ring disruption, in which secondary intervention is strongly considered. The geometrical matching in the current customized implant design and clinical practice is through the nonfractured hemi-pelvis for the fractured pelvis. This design philosophy overlooks the anatomical difference between the hemipelves, and further, the geometrical asymmetry at local area still remains unknown. This study analyzed the anatomical asymmetry of a patient's 3D pelvic models from 13 patients. The hemipelves of each patient were registered by using an iterative closet algorithm to an optimum position with minimum deviations. The high deviation regions were summarized between the hemipelves in each case, and a color map was drawn on a hemipelvis model that identified the areas that had a high possibility to be symmetrically different. A severe pelvic trauma case was used to comprehend the approach by designing a 3D printed implant. Each fracture was then registered to the mirrored uninjured hemipelvis by using the same algorithm, and customized fixation implants were designed with reference to the fractured model. The customized fixation plates showed that the implants had lower geometrical deviation when attached onto the re-stitched fracture side than onto the mirrored nonfractured bone. These results indicate that the symmetrical analysis of bone anatomy and the deviation color map can assist with implant selection and customized implant design given the geometrical difference between symmetrical bones. The novel approach provides a scientific reference that improves the accuracy and overall standard of 3D printed implants.

Physiological and pharmacological roles of vascular nucleoside transporters.

Adenosine modulates various vascular functions such as vasodilatation and anti-inflammation. The local concentration of adenosine in the vicinity of adenosine receptors is fine tuned by 2 classes of nucleoside transporters: equilibrative nucleoside transporters (ENTs) and concentrative nucleoside transporters (CNTs). In vascular smooth muscle cells, 95% of adenosine transport is mediated by ENT-1 and the rest by ENT-2. In endothelial cells, 60%, 10%, and 30% of adenosine transport are mediated by ENT-1, ENT-2, and CNT-2, respectively. In vitro studies show that glucose per se increases the expression level of ENT-1 via mitogen-activating protein kinase-dependent pathways. Similar results have been demonstrated in diabetic animal models. Hypertension is associated with the increased expression of CNT-2. It has been speculated that the increase in the activities of ENT-1 and CNT-2 may reduce the availability of adenosine to adenosine receptors, thereby weakening the vascular functions of adenosine. This may explain why patients with diabetes and hypertension suffer greater morbidity from ischemia and atherosclerosis. No oral hypoglycemic agents can inhibit ENTs, but an exception is troglitazone (a thiazolidinedione that has been withdrawn from the market). ENTs are also sensitive to dihydropyridine-type calcium-channel blockers, particularly nimodipine, which can inhibit ENT-1 in the nanomolar range. Those calcium-channel blockers are noncompetitive inhibitors of ENTs, probably working through the reversible interactions with allosteric sites. The nonsteroidal anti-inflammatory drug sulindac sulfide is a competitive inhibitor of ENT-1. In addition to their original pharmacological actions, it is believed that the drugs mentioned above may regulate vascular functions through potentiation of the effects of adenosine.

Pharmacological prevention of renal ischemia-reperfusion injury in a rat model.

INTRODUCTION: Renal ischemia-reperfusion injury (IRI) can lead to significant morbidity and mortality. It remains a leading cause of acute kidney injury and is therefore an important issue in trauma and renal transplant surgery. Various pharmaceutical agents have been used in an attempt to dampen the harmful effects of IRI but few have been shown to be useful clinically. Riluzole, Lidocaine and Lamotrigine have been demonstrated to show anti-ischaemic properties in other organs; however, their use has not been tested in the kidneys. We investigated Riluzole, Lidocaine and Lamotrigine for their preventive effects of renal IRI using a rat model. METHODS: Winstar rats (n = 48) were divided into four groups (n = 12 per group)-three treatment groups and one control group. Riluzole, Lidocaine and Lamotrigine were given prior to renal ischemia only (IO) or IRI. The degree of ischemia was measured by glutathione levels and a TUNEL assay was used to measure DNA fragmentation. RESULTS: Riluzole, Lidocaine and Lamotrigine pre-treatment each resulted in statistically higher glutathione levels compared to controls (P = 0.002; P = 0.007 and P = 0.005, respectively). Riluzole and Lidocaine were also effective at preventing depletion of glutathione following IO (P = 0.007 and P = 0.014 respectively), while Lamotrigine was ineffective in IO (P = 0.71). The degree of DNA fragmentation seen on the TUNEL assay was markedly reduced in all three-drug groups in both IO and IRI. DISCUSSION: Riluzole, Lidocaine and Lamotrigine all have anti-ischaemic effects in the rat kidney and can have potential therapeutic implications.

Comparison of 2 open-sourced 3-dimensional modeling techniques for orthopaedic application.

Objectives: Although 3-dimensional (3D) printing is becoming more widely adopted for clinical applications, it is yet to be accepted as part of standard practice. One of the key applications of this technology is orthopaedic surgical planning for urgent trauma cases. Anatomically accurate replicas of patients' fracture models can be produced to guide intervention. These high-quality models facilitate the design and printing of patient-specific implants and surgical devices. Therefore, a fast and accurate workflow will help orthopaedic surgeons to generate high-quality 3D printable models of complex fractures. Currently, there is a lack of access to an uncomplicated and inexpensive workflow. Methods: Using patient DICOM data sets (n = 13), we devised a novel, simple, open-source, and rapid modeling process using Drishti software and compared its efficacy and data storage with the 3D Slicer image computing platform. We imported the computed tomography image directory acquired from patients into the software to isolate the model of bone surface from surrounding soft tissue using the minimum functions. One pelvic fracture case was further integrated into the customized implant design practice to demonstrate the compatibility of the 3D models generated from Drishti. Results: The data sizes of the generated 3D models and the processing files that represent the original DICOM of Drishti are on average 27% and 12% smaller than that of 3D Slicer, respectively (both P < 0.05). The time frame needed to reach the stage of viewing the 3D bone model and the exporting of the data of Drishti is 39% and 38% faster than that of 3D Slicer, respectively (both P < 0.05). We also constructed a virtual model using third-party software to trial the implant design. Conclusions: Drishti is more suitable for urgent trauma cases that require fast and efficient 3D bone reconstruction with less hardware requirement. 3D Slicer performs better at quantitative preoperative planning and multilayer segmentation. Both software platforms are compatible with third-party programs used to produce customized implants that could be useful for surgical training. Level of Evidence: Level V.

Gallium-Strontium Phosphate Conversion Coatings for Promoting Infection Prevention and Biocompatibility of Magnesium for Orthopedic Applications.

Device-associated infections remain a clinical challenge. The common strategies to prevent bacterial infection are either toxic to healthy mammalian cells and tissue or involve high doses of antibiotics that can prompt long-term negative consequences. An antibiotic-free coating strategy to suppress bacterial growth is presented herein, which concurrently promotes bone cell growth and moderates the dissolution kinetics of resorbable magnesium (Mg) biomaterials. Pure Mg as a model biodegradable material was coated with gallium-doped strontium-phosphate through a chemical conversion process. Gallium was distributed in a gradual manner throughout the strontium-phosphate coating, with a compact structure and a gallium-rich surface. It was demonstrated that the coating protected the underlying Mg parts from significant degradation in minimal essential media at physiological conditions over 9 days. In terms of bacteria culture, the liberated gallium ions from the coatings upon Mg specimens, even though in minute quantities, inhibited the growth of Gram-positiveStaphylococcus aureus, Gram-negative Escherichia coli, andPseudomonas aeruginosa ─ key pathogens causing infection and early failure of the surgical implantations in orthopedics and trauma. More importantly, the gallium dopants displayed minimal interferences with the strontium-phosphate-based coating which boosted osteoblasts and undermined osteoclasts in in vitro co-cultures. This work provides a new strategy to prevent bacterial infection and control the degradation behavior of Mg-based orthopedic implants, while preserving osteogenic features of the devices.

Anterior single screw fixation of odontoid fracture with intraoperative Iso-C 3-dimensional imaging.

PURPOSE: The purpose of this study was to assess the value of isocentric C-arm three-dimensional (Iso-C 3D) fluoroscopy for the insertion of an anterior odontoid screw. The results of the Iso-C 3D group were compared with that of an historic control group using conventional fluoroscopy. METHODS: Twenty-nine patients diagnosed with type II or rostral-type III odontoid fractures were treated with a single anterior screw fixation in this study. The Iso-C 3D group included 13 patients and the other 16 patients were in the historic control group. All operations were performed by a single surgeon using standard procedure and manner. The clinical and radiographic results were recorded and compared between the two groups. RESULTS: The fluoroscopy time in the Iso-C 3D group was 42.9 s as compared to 68.1 s in the control group (P < 0.01). The mean operative time was 91.5 min in the Iso-C 3D group when compared with 81.6 min in the control group (P = 0.20). The rate of bony fusion was 96.6% (28/29), the failure rate of reduction or fixation was 13.8% (7.7% in Iso-C 3D group; 18.8% in control group). The Smiley-Webster scale showed that 90% of patients achieved good or better outcomes CONCLUSIONS: In conclusion, this technique can be safely extended to the treatment of technically difficult to treat spinal injuries and at the same time reduce total radiation exposure time both for the patient and the surgeon.

Riluzole protects against skeletal muscle ischaemia-reperfusion injury in a porcine model.

INTRODUCTION: Skeletal muscle ischaemia-reperfusion injury (IRI) can be a life threatening condition. It is relevant to various aspects of the management of trauma and surgical patients. Currently there lacks a pharmacological agent that can be used to dampen the effects of IRI. Riluzole has been shown to reduce the effects of IRI on various organ systems, but there have yet to be any studies on the effects in IRI of skeletal muscle. Our aim was to investigate the effects of Riluzole on IRI in the skeletal muscle of pigs. METHODS: Twenty-two pigs were randomly divided into groups. Riluzole was administered before ligation of the femoral artery to produce ischaemia in the tibialis anterior muscle in the experimental group but not the control group. The microscopic appearance of muscles were recorded, a TUNEL assay was used to identify DNA damage and glutathione levels were measured. RESULTS: In the Riluzole group, muscle fibres appeared less wavy and less oedematous compared to the control group. The Riluzole group also had less evidence of DNA fragmentation on the TUNEL assay. The glutathione levels in the Riluzole group were also significantly greater than the control group. DISCUSSION: Our findings suggest that Riluzole can potentially reduce the effects of IRI on skeletal muscle. This is potentially due to the ability of Riluzole to block sodium channels, decreasing action potentials and therefore glutamate release. It also acts to decrease intracellular calcium levels, which prevents apoptosis. Riluzole is a promising drug for the prevention of IRI in skeletal muscle, but further research is required.

The status of KRAS mutations in patients with non-small cell lung cancers from mainland China.

KRAS mutation is closely associated to carcinogenesis and prognosis of non-small cell lung cancer (NSCLC). Detection of KRAS mutation can also be used to select NSCLC patients for drug targeting with EGFR tyrosine kinase inhibitors. Data regarding the status of KRAS mutation in mainland China, which would assist in these interventions, is lacking. We have detected KRAS mutation from 103 NSCLC patients in mainland China with high resolution melting analysis (HRM) on LightScanner, and compared this method of detection with sequencing, and found HRM to have greater sensitivity. We found 6 patients (5.8%) with KRAS mutation (3 patients, G12C; 1 patient, G12S; 1 patient, G12V; 1 patient, G13D). KRAS mutation was significantly associated to gender (p=0.027) and pathology types (p=0.000), but not to smoking. The mutation frequency of KRAS in NSCLC patients in mainland China is similar to those in East Asian countries, but lower than those in western countries. However, the spectrum of KRAS mutation in mainland China is similar to those found in the USA. The results also exhibit dependence of KRAS mutation in China on ethnicity. The clinical significance of the spectral pattern of KRAS mutations in TKI resistance or tumorigenesis among patients with NSCLC in mainland China requires further investigation.

The SuprMam1 breast cancer susceptibility locus disrupts the vitamin D/ calcium/ parathyroid hormone pathway and alters bone structure in congenic mice.

Breast cancer is a complex disease, and approximately 30% of cases are considered to be hereditary or familial, with a large fraction of this being polygenic. However, it is difficult to demonstrate the functional importance of genes of small effect in population studies, and these genes are not always easily targeted for prevention. The SuprMam (suppressor of mammary tumour) breast cancer susceptibility alleles were previously identified as contributors to spontaneous mammary tumour development in Trp53+/- mice. In this study, we have generated and characterised congenic mice that contain the BALB/c SuprMam1 (susceptibility) locus on a C57BL/6 (resistant) background and discovered a subtle impairment in the vitamin D/ calcium/ parathyroid hormone (PTH) pathway. This was evident as altered gene expression in the mammary glands of key players in this pathway. Further functional analysis of the mice revealed elevated PTH levels, reduced Cyp27b1 expression in kidneys, and reduced trabecular bone volume/ tissue volume percentage. Plasma 25(OH)D and serum calcium were unchanged. This impairment was a result of genetic differences and occurred only in females, but the elevated PTH levels could be overcome with either calcium or vitamin D dietary supplementation. Either low levels of active vitamin D (1,25(OH)2D) or chronically elevated PTH levels may contribute to increased breast cancer susceptibility. These indicators are not easily measured in human population studies, but either mechanism may be preventable with dietary calcium or vitamin D supplements. Therefore, SuprMam congenic mice could serve as a valuable model for studying the role of gene-hormone-environment interactions of the vitamin D/ calcium/ PTH pathway in cancer and other diseases and for testing preventive interventions.

Inhibition of human equilibrative nucleoside transporters by dihydropyridine-type calcium channel antagonists.

Dihydropyridine-type calcium channel antagonists, in addition to having a vasodilatory effect, are known to inhibit cellular uptake of nucleosides such as adenosine. However, the nucleoside transporter subtypes involved and the mechanism by which this occurs are not known. Therefore, we have studied the inhibitory effects of dihydropyridines on both human equilibrative nucleoside transporters, hENT-1 and hENT-2, which are the major transporters mediating nucleoside transport in most tissues. Among the dihydropyridines tested, nimodipine proved to be the most potent inhibitor of hENT-1, with an IC(50) value of 60+/-31 muM, whereas nifedipine, nicardipine, nitrendipine, and felodipine exhibited 100-fold less effective inhibitory activity. Nifedipine, nitrendipine, and nimodipine inhibited hENT-2 with IC(50) values in the micromolar range; however, nicardipine and felodipine had no significant effect on hENT-2. Removal of the 4-aryl ring or changing the nitro group at the 4-aryl ring proved not to be detrimental to the inhibitory effects of dihydropyridines on hENT-1, but resulted in a drastic decrease in their inhibitory effects on hENT-2. Kinetic studies revealed that nimodipine and nifedipine reduced V(max) of [(3)H]uridine transport without affecting K(m). The inhibitory effects of nimodipine and nifedipine could be washed out. In addition, nimodipine and nifedipine inhibited the rate of NBTGR-induced dissociation of [(3)H]NBMPR from hENT-1 cell membrane. We conclude that dihydropyridines are non-competitive inhibitors of hENT-1 and hENT-2, probably working through reversible interactions with the allosteric sites. The inhibitory potencies of dihydropyridines may be associated with the structure of the 4-aryl ring, as well as the ester groups at the C-3 and C-5 positions.

Modelling osteoblast adhesion on surface-engineered biomaterials: optimisation of nanophase grain size.

A double-layered model is proposed for numerically simulating osteoblast adhesion on surface-engineered biomaterials. The proposed model consists of molecular and cellular motions based on theoretical and experimental evidence and creates predictive simulations from sparse experimental data. The comparison of numerical solutions and experimental data reveals that the proposed model can explain the nonlinear behaviour of osteoblast adhesion on material surfaces in respect to nanophase grain size (0-100 nm). The model further provides insight into the optimisation of nanophase grain size on the surface of the biomaterial.

Specific inhibition of NLRP3 in chikungunya disease reveals a role for inflammasomes in alphavirus-induced inflammation.

Mosquito-borne viruses can cause severe inflammatory diseases and there are limited therapeutic solutions targeted specifically at virus-induced inflammation. Chikungunya virus (CHIKV), a re-emerging alphavirus responsible for several outbreaks worldwide in the past decade, causes debilitating joint inflammation and severe pain. Here, we show that CHIKV infection activates the NLRP3 inflammasome in humans and mice. Peripheral blood mononuclear cells isolated from CHIKV-infected patients showed elevated NLRP3, caspase-1 and interleukin-18 messenger RNA expression and, using a mouse model of CHIKV infection, we found that high NLRP3 expression was associated with peak inflammatory symptoms. Inhibition of NLRP3 activation using the small-molecule inhibitor MCC950 resulted in reduced CHIKV-induced inflammation and abrogated osteoclastogenic bone loss and myositis, but did not affect in vivo viral replication. Mice treated with MCC950 displayed lower expression levels of the cytokines interleukin-6, chemokine ligand 2 and tumour necrosis factor in joint tissue. Interestingly, MCC950 treatment abrogated disease signs in mice infected with a related arthritogenic alphavirus, Ross River virus, but not in mice infected with West Nile virus-a flavivirus. Here, using mouse models of alphavirus-induced musculoskeletal disease, we demonstrate that NLRP3 inhibition in vivo can reduce inflammatory pathology and that further development of therapeutic solutions targeting inflammasome function could help treat arboviral diseases.

Citrus polymethoxylated flavones improve lipid and glucose homeostasis and modulate adipocytokines in fructose-induced insulin resistant hamsters.

The present study was undertaken to determine whether supplementation with polymethoxylated flavones (PMFs) could ameliorate the fructose-induced hypertriglyceridemia and other metabolic abnormalities associated with insulin resistance (IR) in hamsters. Following feeding with the fructose diet, hamsters were supplemented orally with PMF-L or PMF-H (62.5 and 125 mg/kg/day) for 4 weeks. Both PMF-treated groups showed a statistically significant (p<0.05) decrease in serum triglyceride (TG) and cholesterol levels compared to the fructose-fed control group. The fructose control group at the end of the study showed elevated serum insulin and impaired insulin sensitivity (glucose intolerance). On the other hand, PMF-supplemented groups showed a reversal in these metabolic defects, including a decrease in insulin level and an improvement in glucose tolerance. PMF supplementation also reduced TG contents in the liver and heart and was able to regulate adipocytokines by significantly suppressing TNF-alpha, INF-gamma, IL-1beta and IL-6 expression and increasing adiponectin in IR hamsters. The mechanism of PMF on the activation of peroxisome proliferator-activated receptors (PPAR) was also explored. PMF-H supplementation significantly increased PPARalpha and PPARgamma protein expression in the liver. This is the first report of positive effects of PMF on adipocytokine production and on PPAR expression in IR hamsters. This study suggests that PMF can ameliorate hypertriglyceridemia and its anti-diabetic effects may occur as a consequence of adipocytokine regulation and PPARalpha and PPARgamma activation.

Inhibition of COXs and 5-LOX and activation of PPARs by Australian Clematis species (Ranunculaceae).

The species of Clematis (Ranunculaceae) have been traditionally used for inflammatory conditions by indigenous Australians. We have previously reported that the ethanol extract of Clematis pickeringii inhibited COX-1. In this study, we examined the ethanol extracts and fractions of three Clematis species, Clematis pickeringii, Clematis glycinoides and Clematis microphylla, on cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX). We further examined the activating effects on the protein expression of peroxisome proliferator-activated receptor alpha (PPARalpha) and gamma (PPARgamma) in HepG2 cells. The ethanol extracts of three Clematis species inhibited the activities of COX-1, COX-2 and 5-LOX in the different extents. The stem extract of Clematis pickeringii showed the highest inhibitory activities among the three species on COX-1, COX-2 and 5-LOX with the IC(50) values of 73.5, 101.2 and 29.3 microg/mL. One of its fractions also significantly elevated PPARalpha expression by 173, 280 and 435% and PPARgamma expression by 140, 228 and 296% at 4, 8 and 16 microg/mL, respectively.