Geniposide prevents tumor growth by inhibiting colonic interleukin-1β and monocyte chemoattractant protein-1 via down-regulated expression of cyclooxygenase-2 and thymocyte selection-associated high mobility box proteins TOX/TOX2 in azoxymethane/dextran sulfate sodium-treated mice

Colon cancer was the second leading cause of cancer-related deaths in Japan in 2019. The effects of geniposide isolated from Gardenia jasminoides fructus (Rubiaceae) on the azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced growth of colon tumors and changes in interleukin (IL)-1 β, monocyte chemoattractant protein (MCP)-1, IL-10, and programmed cell death-1 (PD-1) levels in the colon were investigated. The intraperitoneal administration of AOM (10 mg/kg) on days 0 and 27 induced colorectal carcinogenesis. Free access to 1% (w/v) DSS drinking water was given to mice on days 7-15, 32-33, and 35-38. Geniposide (30 and 100 mg/kg) was orally administered on days 1-16, discontinued for 11 days (days 16 to 26), and then administered again on days 27-41. Colonic levels of cytokines, chemokine, and PD-1 were measured using by enzyme-linked immunosorbent assay (ELISA). Increases in colorectal tumor numbers and areas were significantly inhibited by geniposide. In addition, geniposide (100 mg/kg) reduced colonic levels of IL-1 β, MCP-1, PD-1 and IL-10 by 67.4, 57.2, 100%, and 100% respectively. Cyclooxygenase (COX)-2- and thymocyte selection high mobility group box proteins (TOX/TOX2)-positive cell numbers were significantly reduced by geniposide. Geniposide (30 and 100 mg/kg) decreased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) expressions in immunohistochemical analysis by 64.2 and 98.2%, respectively. Thus, the inhibitory effects of geniposide on colon tumor growth may be associated with reductions in the colonic levels of IL-1 β, MCP-1, IL-10, and PD-1 via the down-regulated expression of COX-2 and TOX/TOX2 through the inhibition of Phospho-STAT3 expression (in vivo and in vitro).

Anethole ameliorates inflammation induced by monosodium urate in an acute gouty arthritis model via inhibiting TLRs/MyD88 pathway

OBJECTIVE

To assess the effects of anethole on monosodium urate (MSU)-induced inflammatory response, investigate its role in acute gouty arthritis (AGA), and verify its molecular mechanism.

METHODS

Hematoxylin and eosin staining assay and time-dependent detection of degree of ankle swelling were performed to assess the effects of anethole on joint injury in MSU-induced AGA mice. Enzyme-linked-immunosorbent serologic assay was performed to demonstrate the production levels of inflammatory factors (interleukin 1β [IL-1β], interleukin 6 [IL-6], interleukin 8 [IL-8], tumor necrosis factor α [TNF-α], and monocyte chemo-attractant protein-1 [MCP-1]) in MSU-induced AGA mice. Western blot assays were used to confirm the effects of anethole on oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activity and the activation of toll-like receptors (TLRs)-myeloid differentiation factor 88 (MyD88) pathway in MSU-induced AGA mice.

RESULTS

We observed that a significant joint injury occurred in MSU-induced AGA mice. Anethole could alleviate the pathological injury of the synovium in MSU-induced AGA mice and suppressed ankle swelling. In addition, we observed that anethole could inhibit MSU-induced inflammatory response and inflammasome activation in MSU-induced AGA mice. Moreover, we discovered that anethole enabled to inhibit the activation of TLRs/MyD88 pathway in MSU-induced AGA mice. Our findings further confirmed that anethole contributed to the inhibitory effects on progression in MSU-induced AGA mice.

CONCLUSION

It confirmed that anethole ameliorated the MSU-induced inflammatory response in AGA mice in vivo via inhibiting TLRs-MyD88 pathway.

A unique cerebellar pattern of microglia activation in a mouse model of encephalopathy of prematurity

Preterm infants often show pathologies of the cerebellum, which are associated with impaired motor performance, lower IQ and poor language skills at school ages. Using a mouse model of inflammation-induced encephalopathy of prematurity driven by systemic administration of pro-inflammatory IL-1β, we sought to uncover causes of cerebellar damage. In this model, IL-1β is administered between postnatal day (P) 1 to day 5, a timing equivalent to the last trimester for brain development in humans. Structural MRI analysis revealed that systemic IL-1β treatment induced specific reductions in gray and white matter volumes of the mouse cerebellar lobules I and II (5% false discovery rate [FDR]) from P15 onwards. Preceding these MRI-detectable cerebellar volume changes, we observed damage to oligodendroglia, with reduced proliferation of OLIG2+ cells at P10 and reduced levels of the myelin proteins myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) at P10 and P15. Increased density of IBA1+ cerebellar microglia were observed both at P5 and P45, with evidence for increased microglial proliferation at P5 and P10. Comparison of the transcriptome of microglia isolated from P5 cerebellums and cerebrums revealed significant enrichment of pro-inflammatory markers in microglia from both regions, but cerebellar microglia displayed a unique type I interferon signaling dysregulation. Collectively, these data suggest that perinatal inflammation driven by systemic IL-1β leads to specific cerebellar volume deficits, which likely reflect oligodendrocyte pathology downstream of microglial activation. Further studies are now required to confirm the potential of protective strategies aimed at preventing sustained type I interferon signaling driven by cerebellar microglia as an important therapeutic target.

Silencing BLNK protects against interleukin-1β-induced chondrocyte injury through the NF-κB signaling pathway

BACKGROUND

Osteoarthritis (OA) is the most common joint disease in the elderly and is characterized by the progressive degeneration of articular cartilage. It is necessary to study the molecular pathology of OA. This study aimed to explore the role and mechanism of BLNK in regulating interleukin-1β (IL-1β)-induced chondrocyte injury and OA progression.

METHODS

GSE1919 (5 normal samples and 5 OA samples) was downloaded from the Gene Expression Omnibus (GEO) database. The limma package in R software was used to identify differentially expressed genes (DEGs) between control and OA-affected cartilage. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses of the differentially expressed genes were also performed. Apoptosis was assessed by flow cytometry. An OA rat model was established, and the relative expression of BLNK was assessed by real time quantitative PCR (qRT-PCR) and immunohistochemical staining. The expression of collagen II, MMP9, p65 and p-p65 was measured by Western blot analysis. Moreover, inflammatory factors (TNF-α and IL-18) were assessed by ELISA. The NF-κB inhibitor JSH-23 was used to assess the impact of BLNK on the NF-κB signaling pathway.

RESULTS

In total, 1318 DEGs were identified between normal and OA-affected cartilage according to the criteria (P-value <0.05 and |logFC > 1|). These DEGs were mainly enriched in the NF-κB pathway. BLNK was highly expressed in OA cartilage tissue and injured chondrocytes. Silencing BLNK significantly downregulated the IL-1β-induced apoptosis of chondrocytes. Silencing BLNK partially increased collagen II expression and downregulated MMP13 expression. Moreover, silencing BLNK partially decreased TNF-α and IL-18 expression. BLNK silencing inhibited the activation of NF-κB in OA. Silencing BLNK delayed OA progression through the NF-κB signaling pathway.

CONCLUSION

Silencing BLNK delayed OA progression and IL-1β-induced chondrocyte injury by regulating the NF-κB pathway.

High-Molecular-Weight Hyaluronic Acid Inhibits IL-1β-Induced Synovial Inflammation and Macrophage Polarization through the GRP78-NF-κB Signaling Pathway

Recent evidence has suggested that synovial inflammation and macrophage polarization were involved in the pathogenesis of osteoarthritis (OA). Additionally, high-molecular-weight hyaluronic acid (HMW-HA) was often used clinically to treat OA. GRP78, an endoplasmic reticulum (ER) stress chaperone, was suggested to contribute to the hyperplasia of synovial cells in OA. However, it was still unclear whether HMW-HA affected macrophage polarization through GRP78. Therefore, we aimed to identify the effect of HMW-HA in primary synovial cells and macrophage polarization and to investigate the role of GRP78 signaling. We used IL-1β to treat primary synoviocytes to mimic OA, and then treated them with HMW-HA. We also collected conditioned medium (CM) to culture THP-1 macrophages and examine the changes in the phenotype. IL-1β increased the expression of GRP78, NF-κB (p65 phosphorylation), IL-6, and PGE2 in primary synoviocytes, accompanied by an increased macrophage M1/M2 polarization. GRP78 knockdown significantly reversed the expression of IL-1β-induced GRP78-related downstream molecules and macrophage polarization. HMW-HA with GRP78 knockdown had additive effects in an IL-1β culture. Finally, the synovial fluid from OA patients revealed significantly decreased IL-6 and PGE2 levels after the HMW-HA treatment. Our study elucidated a new form of signal transduction for HMW-HA-mediated protection against synovial inflammation and macrophage polarization and highlighted the involvement of the GRP78-NF-κB signaling pathway.

Investigation of synovial fluid lubricants and inflammatory cytokines in the horse: a comparison of recombinant equine interleukin 1 beta-induced synovitis and joint lavage models

BACKGROUND

Lameness is a debilitating condition in equine athletes that leads to more performance limitation and loss of use than any other medical condition. There are a limited number of non-terminal experimental models that can be used to study early inflammatory and synovial fluid biophysical changes that occur in the equine joint. Here, we compare the well-established carpal IL-1β-induced synovitis model to a tarsal intra-articular lavage model, focusing on serial changes in synovial fluid inflammatory cytokines/chemokines and the synovial fluid lubricating molecules lubricin/proteoglycan 4 and hyaluronic acid. The objectives of this study were to evaluate clinical signs; synovial membrane and synovial fluid inflammation; and synovial fluid lubricants and biophysical properties in response to carpal IL-1β synovitis and tarsal intra-articular lavage.

RESULTS

Hyaluronic acid (HA) concentrations, especially high molecular weight HA, and synovial fluid viscosity decreased after both synovitis and lavage interventions. Synovial fluid lubricin concentrations increased 17-20-fold for both synovitis and lavage models, with similar changes in both affected and contralateral joints, suggesting that repeated arthrocentesis alone resulted in elevated synovial fluid lubricin concentrations. Synovitis resulted in a more severe inflammatory response based on clinical signs (temperature, heart rate, respiratory rate, lameness and joint effusion) and clinicopathological and biochemical parameters (white blood cell count, total protein, prostaglandin E2, sulfated glycosaminoglycans, tumor necrosis factor-α and CC chemokine ligands - 2, - 3, - 5 and - 11) as compared to lavage.

CONCLUSIONS

Synovial fluid lubricin increased in response to IL-1β synovitis and joint lavage but also as a result of repeated arthrocentesis. Frequent repeated arthrocentesis is associated with inflammatory changes, including increased sulfated glycosaminoglycan concentrations and decreased hyaluronic acid concentrations. Synovitis results in more significant inflammatory changes than joint lavage. Our data suggests that synovial fluid lubricin, TNF-α, CCL2, CCL3, CCL5, CCL11 and sGAG may be useful biomarkers for synovitis and post-lavage joint inflammation. Caution should be exercised when performing repeated arthrocentesis clinically or in experimental studies due to the inflammatory response and loss of HA and synovial fluid viscosity.

Maslinic acid prevents IL-1β-induced inflammatory response in osteoarthritis via PI3K/AKT/NF-κB pathways

Osteoarthritis (OA) is a degenerative joint disease characterized by destruction of articular cartilage. The inflammatory response is the most important factor affecting the disease process. As interleukin-1β (IL-1β) stimulates several key mediators in the inflammatory response, it plays a major role in the pathogenesis of OA. Maslinic acid (MA) is a natural compound distributed in olive fruit. Previous studies have found that maslinic acid has an inhibitory effect on inflammation, but its specific role in the progression of OA disease has not been studied so far. In this study, we aim to assess the protective effect of MA on OA progression by in vitro and in vivo experiments. Our results indicate that, in IL-1β-induced inflammatory response, MA is effective in attenuating some major inflammatory mediators such as nitric oxide (NO) and prostaglandin E2, and inhibits the expression of IL-6, inducible nitric oxide synthase, cyclooxygenase-2, and tumor necrosis factor-α (TNF-α) in a concentration-dependent manner. Also, MA downregulated the expression levels of thrombospondin motif 5 (ADAMTS5) and matrix metalloproteinase 13 in chondrocytes, resulting in reduced degradation of its extracellular matrix. Mechanistically, MA exhibits an anti-inflammatory effect by inactivating the PI3K/AKT/NF-κB pathway. In vivo, the protective effect of MA on OA development can be detected in a surgically induced mouse OA model. In summary, these findings suggest that MA can be used as a safe and effective potential OA therapeutic strategy.

Interleukin-1β-induced pancreatitis promotes pancreatic ductal adenocarcinoma via B lymphocyte-mediated immune suppression

OBJECTIVE

Long-standing chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC). Interleukin-1β (IL-1β) has been associated in PDAC with shorter survival. We employed murine models to investigate the mechanisms by which IL-1β and chronic pancreatitis might contribute to PDAC progression.

DESIGN

We crossed LSL-Kras^+/G12D;Pdx1-Cre (KC) mice with transgenic mice overexpressing IL-1β to generate KC-IL1β mice, and followed them longitudinally. We used pancreatic 3D in vitro culture to assess acinar-to-ductal metaplasia formation. Immune cells were analysed by flow cytometry and immunohistochemical staining. B lymphocytes were adoptively transferred or depleted in Kras-mutant mice. B-cell infiltration was analysed in human PDAC samples.

RESULTS

KC-IL1β mice developed PDAC with liver metastases. IL-1β treatment increased Kras^+/G12D pancreatic spheroid formation. CXCL13 expression and B lymphocyte infiltration were increased in KC-IL1β pancreata. Adoptive transfer of B lymphocytes from KC-IL1β mice promoted tumour formation, while depletion of B cells prevented tumour progression in KC-IL1β mice. B cells isolated from KC-IL1β mice had much higher expression of PD-L1, more regulatory B cells, impaired CD8⁺ T cell activity and promoted tumorigenesis. IL-35 was increased in the KC-IL1β pancreata, and depletion of IL-35 decreased the number of PD-L1⁺ B cells. Finally, in human PDAC samples, patients with PDAC with higher B-cell infiltration within tumours showed significantly shorter survival.

CONCLUSION

We show here that IL-1β promotes tumorigenesis in part by inducing an expansion of immune-suppressive B cells. These findings point to the growing significance of B suppressor cells in pancreatic tumorigenesis.

Proinflammatory Cytokine Interleukin 1β Disrupts β-cell Circadian Clock Function and Regulation of Insulin Secretion

Intrinsic β-cell circadian clocks are important regulators of insulin secretion and overall glucose homeostasis. Whether the circadian clock in β-cells is perturbed following exposure to prodiabetogenic stressors such as proinflammatory cytokines, and whether these perturbations are featured during the development of diabetes, remains unknown. To address this, we examined the effects of cytokine-mediated inflammation common to the pathophysiology of diabetes, on the physiological and molecular regulation of the β-cell circadian clock. Specifically, we provide evidence that the key diabetogenic cytokine IL-1β disrupts functionality of the β-cell circadian clock and impairs circadian regulation of glucose-stimulated insulin secretion. The deleterious effects of IL-1β on the circadian clock were attributed to impaired expression of key circadian transcription factor Bmal1, and its regulator, the NAD-dependent deacetylase, Sirtuin 1 (SIRT1). Moreover, we also identified that Type 2 diabetes in humans is associated with reduced immunoreactivity of β-cell BMAL1 and SIRT1, suggestive of a potential causative link between islet inflammation, circadian clock disruption, and β-cell failure. These data suggest that the circadian clock in β-cells is perturbed following exposure to proinflammatory stressors and highlights the potential for therapeutic targeting of the circadian system for treatment for β-cell failure in diabetes.

Knockdown of hsa_circ_0037658 inhibits the progression of osteoarthritis via inducing autophagy

Osteoarthritis (OA) is a chronic musculoskeletal degeneration disease that can result in chronic pain and functional disability. Circular RNAs (CirRNAs) are known to be involved in OA. It was reported that hsa_circ_0037658 was notably upregulated in OA tissues; however, the biological role of hsa_circ_0037658 in OA remains unclear. To investigate the function of hsa_circ_0037658 in OA, CHON-001 cells were treated with IL-1β. The effect of hsa_circ_0037658 knockdown on cell growth was tested by CCK-8 and immunofluorescence staining. In addition, the correlation between hsa_circ_0037658 and autophagy was explored by LC3 staining and western blot. The results indicated that hsa_circ_0037658 was significantly upregulated in IL-1β-treated CHON-001 cells. The silencing of hsa_circ_0037658 could protect CHON-001 cell injury against IL-1β. Moreover, hsa_circ_0037658 shRNA reversed IL-1β-induced cell growth inhibition via inducing cell autophagy. Furthermore, knockdown of hsa_circ_0037658 notably alleviated the symptom of OA in vivo. To sum up, knockdown of hsa_circ_0037658 suppressed the progression of OA via inducing autophagy. Thus, hsa_circ_0037658 might serve as a potential target for the treatment of OA.

Altered productions of prostaglandins and prostamides by human amnion in response to infectious and inflammatory stimuli identified by mutliplex mass spectrometry

INTRODUCTION

Prostaglandins are critical for the onset and progression of labor in mammals, and are formed by the metabolism of arachidonic acid. The products of arachidonic acid, 2-arachidonoylglycerol (2-AG), and anandamide (AEA) have a similar lipid back bone but differing polar head groups, meaning that identification of these products by immunoassay can be difficult.

MATERIALS AND METHODS

In the current study, we present the use of mass spectrometry as multiplex method of identifying the specific end products of arachidonic and anandamide metabolism by human derived amnion explants treated with either an infectious agent (LPS) or inflammatory mediator (IL-1β or TNF-α).

RESULTS

Human amnion tissue explants treated with LPS, IL-1β, or TNF-α increased production of prostaglandin E₂ (PGE₂; p < 0.05) but decreased PGFM. Overall, PGE₂ production was greater compared to the other prostaglandins and prostamides irrespective of treatment.

CONCLUSIONS

The findings of the current study are in keeping with the literature which describes amnion tissues as predominantly producing PGE₂. The use of mass spectrometry for the differential identification of prostaglandins, prostamides, and other eicosanoids may help better elucidate mechanisms of preterm labor, and lead to new targets for the prediction of risk for preterm labor and/or birth.

Effects of Orally Administered Resveratrol on TNF, IL-1β, Leukocyte Phagocytic Activity and Oxidative Burst Function in Horses: A Prospective, Randomized, Double-Blinded, Placebo-Controlled Study

Resveratrol, a phytophenol, is a commonly used equine nutraceutical supplement touted to exert anti-inflammatory effects. The effect of orally administered resveratrol on tumor necrosis factor (TNF), interleukin-1β (IL-1β), leukocyte phagocytic activity or oxidative burst function have not been reported in horses. The objective of this study was to determine the effects of a commercially available, orally administered resveratrol product on innate immune functions in healthy adult horses. Whole blood was collected from 12 horses prior to and following 3 weeks of treatment with either the manufacturer’s recommended dose of resveratrol or placebo. Phagocytosis, oxidative burst and pathogen associated molecular pattern (PAMP) motif-stimulated leukocyte production of TNF and IL-1β were compared pre- and post-treatment between treatment groups. Phagocytosis and oxidative burst capacity were evaluated via flow cytometry. Tumor necrosis factor and IL-1β were measured using cytotoxicity and ELISA assays, respectively. There were no significant differences in phagocytosis, oxidative burst or stimulated TNF or IL-1β production between resveratrol and placebo treatment groups. Orally administered resveratrol at a routinely recommended dose for a duration of 3 weeks did not significantly affect phagocytic activity, oxidative burst function or PAMP-stimulated leukocyte cytokine production.

The NF-κB/miR-425-5p/MCT4 axis: A novel insight into diabetes-induced endothelial dysfunction

Endothelial cells (ECs) primarily rely on glycolysis for their energy metabolism, and the final product of glycolysis-lactate-is transferred out of cells via monocarboxylate transporter 4 (MCT4). We previously showed that MCT4 downregulation is involved in diabetic endothelial injury. However, the underlying regulatory mechanisms of MCT4 in diabetes remain unclear. This study showed that miR-425-5p was significantly upregulated in diabetic patients and human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG) and interleukin-1β (IL-1β). MCT4 was shown to be a direct target gene of miR-425-5p, and miR-425-5p expression led to MCT4 downregulation, lactate accumulation and increased apoptosis in HUVECs. Furthermore, the results indicated that NF-κB signaling activation increased miR-425-5p levels and induced MCT4 downregulation, lactate accumulation and apoptosis in HUVECs. In conclusion, NF-κB/miR-425-5p/MCT4 axis activation plays a crucial role in the EC injury induced by HG and IL-1β.

LncRNA MALAT1/MiR-145 Adjusts IL-1β-Induced Chondrocytes Viability and Cartilage Matrix Degradation by Regulating ADAMTS5 in Human Osteoarthritis

PURPOSE

Accumulating evidence suggests that microRNA-145 (miR-145) plays an important role in osteoarthritis (OA), which is a chronic progressive joint disease. Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) promotes metastasis in cancers and functions as a sponge for miR-145. However, the role of MALAT1/miR-145 in OA pathogenesis has not yet been elucidated.

MATERIALS AND METHODS

The expression of MALAT1 and miR-145 was examined by quantitative real-time PCR; the interaction between miR-145, MALAT1 and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5 was verified by luciferase reporter assay. Correlations among MALAT1, miR-145, and ADAMTS5 were analyzed by Spearman rank analysis. Chondrocytes viability and cartilage extracellular matrix (ECM) degradation were investigated with cell viability assay and Western blotting analyzing expression of ADAMTS5, collagen type 2 alpha 1 (COL2A1), aggrecan (ACAN), and cartilage oligomeric matrix protein (COMP).

RESULTS

MALAT1 was upregulated, and miR-145 was downregulated in OA samples and IL-1β-induced chondrocytes. Mechanically, miR-145 could directly bind to MALAT1 and ADAMTS5. Moreover, miR-145 expression was negatively correlated with MALAT1 and ADAMTS5 expression in OA patients, whereas MALAT1 and ADAMTS5 expression was positively correlated. Functionally, overexpression of MALAT1 inhibited chondrocyte viability and promoted cartilage ECM degradation in IL-1β-induced chondrocytes. In support thereof, MALAT1 silencing and miR-145 upregulation exerted the opposite effect in IL-1β-induced chondrocytes. Moreover, the effect of MALAT1 was counteracted by miR-145 upregulation, and ADAMTS5 restoration could abate miR-145 effects.

CONCLUSION

An MALAT1/miR-145 axis contributes to ECM degradation in IL-1β-induced chondrocytes through targeting ADAMTS5, suggesting that MALAT1/miR-145/ADAMTS5 signaling may underlie human OA pathogenesis.

Role of astrocytic GABAergic system on inflammatory cytokine-induced anxiety-like behavior

Recent studies have shown that not only neurons but astrocytes contain a considerable amount of γ-aminobutyric acid (GABA), which can be released and activate the receptors responsive to GABA. The purpose of this study is to test whether gliotransmitters from astrocytes may play a role in etiology of anxiety symptoms. Intracerebroventricular (i.c.v.) infusion of interleukin-1β (IL-1β), one of potent inflammatory cytokines, induced anxiety-like behaviors and activated the glial fibrillary acidic protein (GFAP) in the paraventricular nucleus (PVN) of the hypothalamus. Pretreatment with astrocytes toxin, l-α-aminoadipate (L-AAA) reduced anxiety-like behaviors and the GFAP expression in the PVN. Intraparaventricular nucleus (iPVN) infusion of IL-1β produced markedly anxiety-like behaviors and increased release of GABA from astrocytes. However, treatment of glial cell inhibitor, L-AAA or blocker of Bestrophin-1 (Best1), 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) markedly inactivated astrocytes and also reduced the anxiety-like behaviors. Treatment of L-AAA or NPPB decreased IL-1β-induced gliotransmitter GABA release measured by in vivo microdialysis. These results suggest that selective inhibition of astrocytes or astocytic GABA release in the PVN may serve as an effective therapeutic strategy for treating anxiety and affective disorders.

Hybrid complexes of high and low molecular weight: evaluation using an in vitro model of osteoarthritis

Hyaluronan (HA) is central in joint and cartilage functions and to restore synovial fluid viscosity. In patients with osteoarthritis (OA), molecular weight (MW) and concentration of hyaluronic acid (HA) are reduced, diminishing joint lubrication. IL-1β treatment was used to mimic osteoarthritis in a chondrocytes based in vitro model. The aim of our research, using this model and human chondrocytes was to assess the anti-inflammatory effect of H/L-HA hybrid complexes (SINOVIAL-HL®) in comparison with HA at high (H-HA) and low molecular weight (L-HA) separately used, through the evaluation of specific biomarkers involved in cartilage degradation and correlated to osteoarthritis. Specifically, TNF-α and IL-6 mRNA were evaluated by qRT-PCR. Cytokines levels were measured using Bio-plex assays and COMP-2 through immunofluorescence staining and western blot. H/L-HA significantly reduced inflammation biomarkers respect to both L-HA or H-HA separately considered at transcriptional and protein level.

24R,25-Dihydroxyvitamin D3 Protects against Articular Cartilage Damage following Anterior Cruciate Ligament Transection in Male Rats

Osteoarthritis (OA) in humans is associated with low circulating 25-hydroxyvitamin D3 [25(OH)D3]. In vitamin D replete rats, radiolabeled 24R,25-dihydroxyvitamin D3 [24R,25(OH)2D3] accumulates in articular cartilage following injection of [3H]-25(OH)D3. Previously, we showed that 24R,25(OH)2D3 blocks chondrocyte apoptosis via phospholipase D and p53, suggesting a role for 24R,25(OH)2D3 in maintaining cartilage health. We examined the ability of 24R,25(OH)2D3 to prevent degenerative changes in articular cartilage in an OA-like environment and the potential mechanisms involved. In vitro, rat articular chondrocytes were treated with IL-1β with and without 24R,25(OH)2D3 or 1α,25(OH)2D3. 24R,25(OH)2D3 but not 1α,25(OH)2D3 blocked the effects of IL-1β in a dose-dependent manner, and its effect was partially mediated through the TGF-β1 signaling pathway. In vivo, unilateral anterior cruciate ligament transections were performed in immunocompetent rats followed by intra-articular injections of 24R,25(OH)2D3 or vehicle (t = 0, 7, 14, 21 days). Tissues were harvested on day 28. Joints treated with vehicle had changes typical of OA whereas joints treated with 24R,25(OH)2D3 had less articular cartilage damage and levels of inflammatory mediators. These results indicate that 24R,25(OH)2D3 protects against OA, and suggest that it may be a therapeutic approach for preventing trauma-induced osteoarthritis.

Anti-inflammatory and chondroprotective effects of atorvastatin in a cartilage explant model of osteoarthritis

OBJECTIVE

This study aimed to assess the chondroprotective potential of atorvastatin in rat's cartilage explant culture model of osteoarthritis, stimulated by interleukin-1β (IL-1β).

MATERIALS AND METHODS

The cartilage explants were treated with 20 ng/ml IL-1β alone or with 20 ng/ml IL-1β + various concentration of atorvastatin (1, 3, or 10 µM dissolved in DMSO) and incubated at 37 °C for 24 h. Also, control (0.25% DMSO), stimulated (20 ng IL-1β) and treatment (atorvastatin 10 µM) cartilage explants were incubated without and with 1400W (10 µM). After 24 h of incubation, TNF-α, PGE2, MMP-13, TIMP-1, NO, and superoxide anion formation (O2(-)) concomitant with glycosaminoglycans (GAGs) were estimated in the medium.

RESULTS

Atorvastatin inhibited IL-1β-induced GAGs release, TNF-α, MMP-13, and O2(-) with no effect on TIMP-1 and NO. In addition, the source of NO in normal and atorvastatin-treated cartilage was eNOS, while for IL-1β-stimulated cartilage it was iNOS. The cartilage degradation was associated with the combined effects of increased NO and O2 (-) rather than only NO.

CONCLUSION

The present study suggests that atorvastatin has the ability to protect cartilage degradation following IL-1β-stimulated cartilage in in vitro OA model and supports additional therapeutic application of atorvastatin in OA.

Inhibition of NADPH oxidase-1 preserves beta cell function

AIMS/HYPOTHESIS

Upregulation of the reactive oxygen species (ROS)-producing enzyme NADPH oxidase (NOX)-1 in islets and beta cells follows acute exposure to inflammatory cytokines and is concomitant with beta cell dysfunction. NOX-1 is a candidate mediator of inflammation-induced beta cell dysfunction. This study aimed to determine whether selective inhibition of NADPH oxidase-1 presents a new strategy to preserve beta cell function.

METHODS

Induced beta cell dysfunction was studied in primary human donor islets, isolated mouse islets and murine beta cell lines. Islets and beta cells were stimulated with inflammatory cytokines (TNF-α, IL-1β, IFN-γ). NOX-1 activity was blocked by the selective inhibitor ML171.

RESULTS

Cytokine induction of intracellular ROS was reduced 80% with 1 μmol/l ML171 in murine beta cell lines (p < 0.01). Cytokine-induced apoptosis, measured by caspase-3 activation or quantified fluorescence microscopy, was prevented in islets and beta cell lines up to 100% with ML171 in a concentration-dependent manner (p < 0.05). Functionally, glucose-stimulated insulin secretion was abolished by cytokine exposure but preserved by ML171 in isolated mouse islets and murine beta cell lines. A feed-forward regulation of NOX-1 in islets and beta cell lines was disrupted by ML171.

CONCLUSIONS/INTERPRETATION

Stimulation of NOX-1 activity is a major component of inflammatory cytokine-induced beta cell dysfunction. Significant protection of beta cells is conferred with selective inhibition of NOX-1. Suppression of NOX-1 activity may present a new therapeutic strategy to preserve and protect beta cell function in diabetes.

CRFR1 activation protects against cytokine-induced β-cell death

During the development of diabetes β-cells are exposed to elevated concentrations of proinflammatory cytokines, TNFα and IL1β, which in vitro induce β-cell death. The class B G-protein-coupled receptors (GPCRs): corticotropin-releasing factor receptor 1 (CRFR1) and CRFR2 are expressed in pancreatic islets. As downstream signaling by other class B GPCRs can protect against cytokine-induced β-cell apoptosis, we evaluated the protective potential of CRFR activation in β-cells in a pro-inflammatory setting. CRFR1/CRFR2 ligands activated AKT and CRFR1 signaling and reduced apoptosis in human islets. In rat and mouse insulin-secreting cell lines (INS-1 and MIN6), CRFR1 agonists upregulated insulin receptor substrate 2 (IRS2) expression, increased AKT activation, counteracted the cytokine-mediated decrease in BAD phosphorylation, and inhibited apoptosis. The anti-apoptotic signaling was dependent on prolonged exposure to corticotropin-releasing factor family peptides and followed PKA-mediated IRS2 upregulation. This indicates that CRFR signaling counteracts proinflammatory cytokine-mediated apoptotic pathways through upregulation of survival signaling in β-cells. Interestingly, CRFR signaling also counteracted basal apoptosis in both cultured INS-1 cells and intact human islets.

[Applying of recombinant interleukin-1β to treat chronic hepatitis C for patients non-response to the previous antiviral therapy]

The search for rational treatment of CHC patients, non-response to the primary antiviral therapy especially with unfavorable genotypes for interleukin-28B, remains valid.

PURPOSE

To evaluate the efficacy and safety of recombinant IL-1β (Betaleukin) in combined antiviral therapy in patients with chronic hepatitis C who did not respond to previous treatment. The study included 26 patients with HCV-1. Patients were divided into 2 groups depending on retreatment scheme: group 1 (n = 10) was treated with recombinant IFN-a2b ("Interal"-P) 5 million IU daily subcutaneously for 12 weeks then every other day until the end of treatment; ribavirin, depending on body weight (800-1200 mg/day) and "Betaleukin" subcutaneously 0.005 mcg/kg every other day for 12 weeks (45 injections); group 2 (n = 16)--recombinant IFN-a2b ("Interal"-P) 3 million IU every other day subcutaneously for 48 weeks; ribavirin--1000 mg/day (for a body weight < 75 kg), 1200 mg/day (for a body weight > 75 kg) and "Betaleukin" subcutaneously 0.005 mcg/kg every other day, five courses for 3 weeks (50 injections).

RESULTS

Combined antiviral therapy (α-IFN2b and RIB) with IL-1β (Betaleukin) in patients who had not responded to previous therapy, with a predominance of unfavorable genetic background for IL-28B typing helped to improve SVR (44%) with more efficient 45-day administration of the medications in the first 12 weeks in combination with inductive α-IFN therapy and achieve biochemical response at week 24 of treatment. Adverse effects of the IL-1β mainly limited with fever, moderate local reactions and do not require discontinuation of treatment.

Circulating levels of IL-1B+IL-6 cause ER stress and dysfunction in islets from prediabetic male mice

Elevated levels of circulating proinflammatory cytokines are associated with obesity and increased risk of type 2 diabetes, but the mechanism is unknown. We tested whether proinflammatory cytokines IL-1B+IL-6 at low picogram per milliliter concentrations (consistent with serum levels) could directly trigger pancreatic islet dysfunction. Overnight exposure to IL-1B+IL-6 in islets isolated from normal mice and humans disrupted glucose-stimulated intracellular calcium responses; cytokine-induced effects were more severe among islets from prediabetic db/db mice that otherwise showed no signs of dysfunction. IL-1B+IL-6 exposure reduced endoplasmic reticulum (ER) calcium storage, activated ER stress responses (Nos2, Bip, Atf4, and Ddit3 [CHOP]), impaired glucose-stimulated insulin secretion, and increased cell death only in islets from prediabetic db/db mice. Furthermore, we found increased serum levels of IL-1B and IL-6 in diabetes-prone mice at an age before hyperglycemia was exhibited, suggesting that low-grade systemic inflammation develops early in the disease process. In addition, we implanted normal outbred and inbred mice with subcutaneous osmotic mini-pumps containing IL-1B+IL-6 to mimic the serum increases found in prediabetic db/db mice. Both IL-1B and IL-6 were elevated in serum from cytokine-pump mice, but glucose tolerance and blood glucose levels did not differ from controls. However, when compared with controls, isolated islets from cytokine-pump mice showed deficiencies in calcium handling and insulin secretion that were similar to observations with islets exposed to cytokines in vitro. These findings provide proof of principle that low-grade systemic inflammation is present early in the development of type 2 diabetes and can trigger ER stress-mediated islet dysfunction that can lead to islet failure.

[The influence of neonatal interleukin-1beta increase on the formation of adult rats' spatial memory]

Children's and adults' cognitive dysfunctions are frequently caused by various types of pathology such as birth injuries, hypoxias, and infections suffered in prenatal and early postnatal periods of ontogenesis. These abnormal conditions trigger high production of proinflammatory cytokines by the cells of nervous and immune systems. The role of interleukin-1 beta (IL-1beta), one of such proteins, in the formation of cognitive deficit in early ontogenesis is not sufficiently studied. In present research it was revealed that administration of IL-1beta during the third week of postnatal ontogenesis impaired the learning of adult rats in Morris Water Maze. The differences between rats of control and experimental groups were observed during the training of searching for hidden platform and during the alteration of formed reflex (when the platform was in a different place). Meanwhile the spatial extinction has not been disrupted. The nature of experimental rats' learning abnormalities allows us to assume that the mechanisms of long-term but not short-term spatial memory are damaged in this experimental situation.

Metformin counters both lipolytic/inflammatory agents-decreased hormone sensitive lipase phosphorylation at Ser-554 and -induced lipolysis in human adipocytes

OBJECTIVE

To study the effects of metformin on lipolysis and hormone sensitive lipase (HSL) phosphorylation in human adipocytes treated with lipolytic and inflammatory agents.

METHODS

Lipolysis and phosphorylation status of HSL were assessed in subcutaneous pre-adipocytes surgically isolated from patients and differentiated into mature adipocytes in vitro.

RESULTS

Stimulation for 1 h with forskolin, isoproterenol and IBMX or stimulation for 24 h with LPS, IL-1β and TNF-α increased lipolysis (p < 0.05 vs. basal). The phosphorylation of HSL at Ser-554 was decreased while the Ser-552 phosphorylation was increased. Pre-incubation with metformin (24 h, 1 mM) inhibited forskolin-, isoproterenol-, IBMX-, LPS-, IL-1β- and TNF-α-induced glycerol release and prevented p(Ser554)HSL decrease and p(Ser-552)HSL increase due to lipolytic and inflammatory agents. AMPKα1 is involved in metformin-induced HSL phosphorylation at Ser-552.

CONCLUSION

Phosphorylation of HSL at Ser-554 inversely correlates with lipolysis and HSL phosphorylation at Ser552 in human adipocytes.

[Glitazones protects beta cell function from cytotoxic cytokines through PPAR gamma-dependent mechanisms]

OBJECTIVE

To investigate the protective effects of glitazones on islet beta cells and PPAR gamma dependence of such effects.

METHODS

IL-1beta and IFN-gamma were used to treat NIT-1 cells, a beta cell line, to induce beta cell damage. The cells were pretreated with rosiglitazone and pioglitazone at different concentrations to study the protective effects of these drugs. The cell apoptosis rate was determined with Annexin V-FITC by flow cytometry, and the insulin secretion capacity of the cells was assessed with ELISA. GW9662 and PPARgamma-SiRNA were used to specifically inhibit PPAR to investigate the PPAR gamma-dependent mechanisms.

RESULTS

Rosiglitazone and pioglitazone at 10 micromol/L could significantly decrease the apoptosis of beta cells induced by the cytokines (apoptotic rates of 13.99% and 16.67% vs 51.33%, P<0.01). Rosiglitazone at 10 micromol/L and pioglitazone at 20 micromol/L were less effective than 10 micromol/L rosiglitazone and pioglitazone. The insulin secretion of the cytokine-treated cells decreased from 8.5-/+0.6 ng/ml of the control group to 3.6-/+0.5 ng/ml, while rosiglitazone and pioglitazone could increase the insulin secretion to 6.8-/+0.7 ng/ml and 5.9-/+0.9 ng/ml, respectively. When PPAR gamma was specifically inhibited by GW9662 and PPARgamma-SiRNA, the protective effects of rosiglitazone and pioglitazone were almost undetectable, and the apoptotic rate increased and insulin secretion decreased to the level of the cytokine-treated cells.

CONCLUSION

Glitazones can protect beta cells from apoptosis and impairment of insulin secretion function resulting from the cytotoxic cytokines via a PPAR gamma-dependent mechanism.

Prostaglandins are necessary and sufficient to induce contextual fear learning impairments after interleukin-1 beta injections into the dorsal hippocampus

The intra-hippocampal administration of interleukin-1beta (IL-1beta) as well as the induction of elevated but physiological levels of IL-1beta within the hippocampus interferes with the formation of long-term memory. There is evidence suggesting that the induction of prostaglandin (PG) formation by IL-1beta is involved in impairments in working and spatial memory following IL-1beta. The present experiments extend these findings by showing that PGs are responsible for memory deficits in contextual fear conditioning that occur following IL-1beta injection into the dorsal hippocampus of Sprague-Dawley rats. Cyclooxygenase (COX) inhibition blocked the disruption in contextual fear conditioning produced by IL-1beta and COX inhibition alone also disrupted contextual memory, suggesting an inverted U-shaped relationship between PG levels and memory. In addition to demonstrating the necessity of PGs in IL-1beta-mediated memory deficits, we also show that PGs injected directly into the dorsal hippocampus are sufficient to impair context memory and significantly reduce post-conditioning levels of BDNF within the hippocampus, suggesting a possible mechanism for the memory-impairing effects of PGs.

[Upregulated Rho-kinase and increased phosphorylation of myosin-binding subunit of myosin phosphates are key players in a porcine coronary artery spasm model with interleukin-1beta]

OBJECTIVE

Phosphorylation of myosin light chain (MLC) is one of the most important steps for vascular smooth muscle contraction and Rho-kinase is involved in this process. We investigated the role of Rho-kinase in a porcine coronary artery spasm model with interleukin-1beta.

METHODS

Segments of left coronary artery adventitia were surrounded by normal saline (n = 8) or IL-1beta agarose microne (n = 8) for 2 weeks. Vasospastic responses to intracoronary serotonin or histamine then studied at the saline or IL-1beta-treated site. The Rho-kinase mRNA expression in the treated site was measured by reverse transcription-polymerase chain reaction analysis (RT-PCR). The extent of phosphorylation of myosin-binding subunit of myosin phosphates (MBS, one of the major substrates of Rho-kinase) were quantified by Western blot analysis.

RESULTS

Intracoronary serotonin or histamine repeatedly induced coronary artery spasm and coronary arterial stenosis was evidenced at IL-1beta-treated site. Expression of Rho-kinase mRNA in IL-1beta-treated site was significantly increased compared to saline treated site (98.20% +/- 7.66% vs. 63.70% +/- 4.26%, P < 0.05). Western blot analysis showed that during the serotonin-induced contractions the extent of phosphorylation of MBS was also significantly increased in the spastic site (25,485 +/- 4745 vs. 6510 +/- 779, P < 0.05).

CONCLUSION

Rho-kinase upregulation at the spastic site and increased phosphorylation of myosin-binding subunit of myosin phosphates are key players in inducing vascular smooth muscle hypercontraction in this porcine model.

[Experimental study on the expression and function of aquaporin-1 and aquaporin-5 in rats with acute lung injury induced by lipopolysaccharide]

OBJECTIVE

To investigate whether the expression and function of aquaporin-1 (AQP-1) is altered by tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in primary rat lung microvessel endothelial cells (LMECs) after exposure to lipopolysaccharide (LPS), and to study the expressions of AQP-1 and AQP-5 in lung tissue of rats with acute lung injury (ALI) induced by LPS. The aim is to further clarify the pathogenesis of ALI/acute respiratory distress syndrome (ARDS).

METHODS

(1) In vitro: The third passage LMECs were randomly divided into LPS group, TNF-alpha group, IL-1beta group and DMEM control group, and the experimental groups were exposed to LPS, TNF-alpha and IL-1beta respectively. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to quantify AQP-1 mRNA changes and an immunocytochemistry method was used for determining AQP-1 protein changes in cultured rat LMECs. Isotope tracer technique was applied for the assay of the intra-cellular tritium water ((3)H2O) signal intensity in rat LMECs. (2) In vivo: Forty male Wistar rats were randomly divided into five groups: LPS 2 h group, LPS 4 h group, LPS 6 h group, LPS 8 h group and a control group, eight rats per group; The LPS treated groups served as the ALI models. RT-PCR was used to observe the changes of AQP-1 and AQP-5 mRNA and the immunohistochemistry method was used for determining AQP-1 and AQP-5 protein changes in ALI rats.

RESULTS

(1) In vitro: The expression of AQP-1 mRNA and protein in LMECs were decreased significantly in the LPS group (0.428 +/- 0.026, 0.366 +/- 0.009), the TNF-alpha group (0.446 +/- 0.029, 0.374 +/- 0.014) and IL-1beta group (0.454 +/- 0.023, 0.377 +/- 0.007) as compared to the DMEM control group (0.793 +/- 0.035, 0.660 +/- 0.013, respectively; all P < 0.01). The quantities of tritium water's permeability in the LPS group, the TNF-alpha group and the IL-1beta group [(726 +/- 58), (738 +/- 45), (774 +/- 44) counts per minute] were significantly less than that in the DMEM control group [(1 148 +/- 70) counts per minute, P < 0.01]. (2) In vivo: The expression levels of AQP-1 and AQP-5 mRNA in ALI rats (LPS 2 h group 0.409 +/- 0.018, 0.421 +/- 0.020; LPS 4 h group 0.421 +/- 0.023, 0.412 +/- 0.023; LPS 6 h group 0.435 +/- 0.020, 0.388 +/- 0.031; LPS 8 h group 0.438 +/- 0.016, 0.386 +/- 0.019, respectively) were significantly lower than that in the control group (0.794 +/- 0.015, 0.787 +/- 0.022; all P < 0.01).

CONCLUSION

AQP-1 and AQP-5 may play a role in abnormal fluid transportation and probably involve in the formation of pulmonary edema in ALI/ARDS.