mRNA Expression Of Proinflammatory Mediators Research Articles

Streptococcus suis Induces Macrophage M1 Polarization and Pyroptosis

Streptococcus suis is an important bacterial pathogen that affects the global pig industry. The immunosuppressive nature of S. suis infection is recognized, and our previous research has confirmed thymus atrophy with a large number of necrotic cells. In this current work, we aimed to uncover the role of pyroptosis in cellular necrosis in thymic cells of S. suis-infected mice. Confocal microscopy revealed that S. suis activated the M1 phenotype and primed pyroptosis in the macrophages of atrophied thymus. Live cell imaging further confirmed that S. suis could induce porcine alveolar macrophage (PAM) pyroptosis in vitro, displaying cell swelling and forming large bubbles on the plasma membrane. Meanwhile, the levels of p-p38, p-extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) were increased, which indicated the mitogen-activated protein kinase (MAPK) and AKT pathways were also involved in the inflammation of S. suis-infected PAMs. Furthermore, RT-PCR revealed significant mRNA expression of pro-inflammatory mediators, including interleukin (IL)-1β, IL-6, IL-18, tumor necrosis factor (TNF)-α and chemokine CXCL8. The data indicated that the inflammation induced by S. suis was in parallel with pro-inflammatory activities of M1 macrophages, pyroptosis and MAPK and AKT pathways. Pyroptosis contributes to necrotic cells and thymocyte reduction in the atrophied thymus of mice.

L-citrulline Mitigates Systemic Inflammation and Associated Pulmonary Vascular Remodeling in a Neonatal Rat Model of Postnatal Undernutrition

Background & Aim: Preterm infants with postnatal growth restriction and undernutrition are at increased risk of developing bronchopulmonary dysplasia (BPD), pulmonary hypertension (PH), metabolic syndrome, and sepsis. Preclinical and clinical studies report increased systemic inflammation, and lung and pancreatic histopathology in growth-restricted neonates. Safe therapies to mitigate these adverse outcomes associated with postnatal growth restriction and undernutrition in preterm infants are needed. L-citrulline is a non-essential amino acid, involved in the urea and nitric oxide cycles, that exhibits anti-inflammatory properties. This study aims to investigate whether L-citrulline may decrease systemic inflammation and improve histopathology in the lung, heart, and pancreas in a neonatal model of postnatal undernutrition. Methods: Neonatal Sprague Dawley rat pups were divided into 2 groups, normal nutrition (litter size n=12) and undernutrition (litter size n=18) by altering the litter size of the nursing dam. Body weight was measured daily and both groups received daily intraperitoneal injections of saline or L-citrulline (2.5g/kg) for 21 days. On postnatal day 21, heart, lung, and pancreatic tissue were collected for histology and mRNA analyses. Lung and pancreatic tissue were processed for qPCR to detect mRNA expression of pro-inflammatory mediators (MCP-1/CCL2, MIP-1α /CCL3, IL-6, and TNF-α). Right ventricular hypertrophy was calculated using Fulton’s index (weight of the right ventricle divided by the combined weight of the left ventricle and the intraventricular septum). Lung sections were stained with Movat Pentachrome and examined for the presence of immune cells and medial wall thickening of pulmonary arteries. In a separate group of animals, bronchoalveolar lavage fluid (BALF) and blood obtained by cardiac puncture were cytocentrifuged and stained with hematoxylin & eosin for immune cell counts. Results: Undernourished rats had a lower body weight than normally nourished rats at postnatal day 21 (n=11-17; p<0.0001). Undernourished animals had an increased number of immune cells in BALF and lung tissue and an elevated neutrophil count in the blood which were all decreased with concurrent L-citrulline treatment (n=3-4; p<0.001). L-citrulline treatment also prevented the increased mRNA expression of pro-inflammatory mediators in the lungs [MCP-1/CCL2, TNF-α, and IL-1β] (n=8; p<0.05) and pancreas [MCP-1/CCL2, MIP-1α /CCL3, IL-6, and TNF-α] (n=3; p<0.05) of undernourished animals. These animals had a greater pulmonary artery medial wall area and Fulton’s index when compared to normally nourished animals treated with saline or L-citrulline (n=3-4; p<0.001). Concurrent L-citrulline treatment in undernourished animals prevented pulmonary artery vascular remodeling and heart tissue histopathology such that the medial wall area and Fulton’s index did not differ from that of animals in control groups (n=4; p<0.01). Conclusion: L-citrulline effectively mitigates the adverse effects of postnatal undernutrition, reducing lung, pancreatic, and systemic inflammation and histopathology in the lung and heart associated with PH. As a safe, well-tolerated, and inexpensive treatment, L-citrulline presents promising therapeutic potential that could prevent short and long-term morbidities associated with growth restriction and undernutrition in preterm infants. This work was funded by the Women's Auxiliary of The Hospital for Sick Children. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Replication of infectious bronchitis virus (IBV) Delmarva (DMV)/1639 variant in primary and secondary lymphoid organs leads to immunosuppression in chickens

Infectious bronchitis virus (IBV) that primarily causes respiratory infection in chickens, disseminate to multiple body systems leading to pathology, results in economic losses to poultry industry. IBV replicates in the bursa of Fabricius (BF), Harderian gland (HG), cecal tonsils (CT), and spleen. The objective of this study was to investigate the immunosuppressive effect of IBV Delmarva (DMV/1639) variant in chickens. Specific pathogen free chickens were infected with the IBV DMV/1639 variant while maintaining an age-matched uninfected control group. At predetermined time points, subsets of the infected and control chickens were observed for changes in body weights and pathological changes. The histopathological lesions were observed in the CT and BF, with minimal lesions in the thymus and spleen. The mRNA expression of pro-inflammatory mediators suggested immunomodulation by IBV, favoring viral replication. Further studies are warranted to observe the functional impact of the IBV DMV/1639 variant's replication in immune organs.

MicroRNA-146b-5p Suppresses Pro-Inflammatory Mediator Synthesis via Targeting TRAF6, IRAK1, and RELA in Lipopolysaccharide-Stimulated Human Dental Pulp Cells.

MicroRNA-146b-5p (miR-146b-5p) is up-regulated during and to suppress the inflammation process, although mechanisms involved in the action of miR-146b-5p have not been fully elucidated. This study examined the anti-inflammation effects of miR-146b-5p in lipopolysaccharide (LPS)-stimulated human dental pulp cells (hDPCs). An increase in human miR-146b-5p (hsa-miR-146b-5p) expression following the mRNA expression of pro-inflammatory cytokines was observed in LPS-stimulated hDPCs. The expression of hsa-miR-146b-5p and pro-inflammatory cytokines was down-regulated by a nuclear factor-kappa B (NF-κB) inhibitor, and the expression of hsa-miR-146b-5p was also decreased by a JAK1/2 inhibitor. Enforced expression of hsa-miR-146b-5p abolished phosphorylation of NF-κB p65 and down-regulated the expression of pro-inflammatory cytokines and NF-κB signaling components, such as interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), and REL-associated protein involved in NF-κB (RELA). Expression of rat miR-146b-5p (rno-miR-146b-5p) and pro-inflammatory cytokine mRNA was also up-regulated in experimentally-induced rat pulpal inflammation in vivo, and rno-miR-146b-5p blocked the mRNA expression of pro-inflammatory mediators and NF-κB signaling components in LPS-stimulated ex vivo cultured rat incisor pulp tissues. These findings suggest that the synthesis of miR-146b-5p is controlled via an NF-κB/IL6/STAT3 signaling cascade, and in turn, miR-146b-5p down-regulates the expression of pro-inflammatory mediators by targeting TRAF6, IRAK1, and RELA in LPS-stimulated hDPCs.

Amine Functionalized Trimetallic Nitride Endohedral Fullerenes: A Class of Nanoparticle to Tackle Low Back/Leg Pain.

Low back pain is the most common health problem with a prevalence of over 80% worldwide and an estimated annual cost of $100 billion in the United States. Intervertebral disc degeneration accounts for a major cause of low back pain. However, there is still a lack of safe and effective treatment to tackle this devastating condition. In this study, we synthesized four functionalized trimetallic nitride endohedral metallofullerenes (carboxyl-f-Sc3N@C80, carboxyl-f-Gd3N@C80, amino-f-Sc3N@C80, and amino-f-Gd3N@C80) and characterized them with X-ray photoelectron spectroscopy, matrix-assisted laser desorption/ionization-time of flight mass spectrometry, and UV-vis. Via electron paramagnetic resonance, all four metallofullerene derivatives possessed dose-dependent radical scavenging capabilities (hydroxyl radicals and superoxide anions), with the most promising radical scavenging properties shown in the amine functionalized C80 metallofullerenes. Both amino-f-Sc3N@C80 and amino-f-Gd3N@C80 at 1 μM significantly reduced lipopolysaccharide induced reactive oxygen species production and mRNA expressions of pro-inflammatory mediators (inos, tnf-α, il-1, and cox-2) in macrophages without apparent cytotoxicity through regulating activity of p38 MAPK, p65, and nuclear translocation of NF-κB. Furthermore, in an established mouse model of lumbar radiculopathy, amino-f-Sc3N@C80 and amino-f-Gd3N@C80 effectively alleviated ipsilateral mechanical hyperalgesia for up to 2 weeks. In dorsal root ganglia explant culture, we also showed that amino-f-Sc3N@C80 and amino-f-Gd3N@C80 ameliorated TNF-α elicited neuroinflammation. In summary, we presented results for a potent radical scavenging, anti-inflammatory and analgesic nanoparticle, amino-functionalized eighty-carbon metallofullerenes in vitro and in vivo. Our study provides important assets for developing pleiotropic treatment strategies to tackle the inflammation, a significant pathological hallmark in the intervertebral disc degeneration and associated pain.

Identification of Paracentrone in Fucoxanthin-Fed Mice and Anti-Inflammatory Effect against Lipopolysaccharide-Stimulated Macrophages and Adipocytes.

Fucoxanthin is converted to fucoxanthinol and amarouciaxanthin A in the mouse body. However, further metabolism such as cleavage products (i.e., apocarotenoids) remains unclear. The fucoxanthin-derived apocarotenoid in vivo is investigated and the anti-inflammatory effect of apocarotenoids with fucoxanthin partial structure such as allenic bond and epoxide residue against activated macrophages and adipocytes in vitro is evaluated. LC-MS analysis indicates the presence of paracentrone, a C31 -allenic-apocarotenoid, in white adipose tissue of diabetic/obese KK-Ay and normal C57BL/6J mice fed 0.2% fucoxanthin diet for 1 week. In lipopolysaccharide-activated RAW264.7 macrophages, paracentrone as well as C26 - and C28 -allenic-apocarotenoids suppresses the overexpression of inflammatory factors. Further, apo-10'-fucoxanthinal, a fucoxanthin-derived apocarotenoid which retained epoxide residue, exhibits a most potent anti-inflammatory activity through regulating mitogen-activated protein kinases and nuclear factor-κB inflammatory signal pathways. In contrast, β-apo-8'-carotenal without allenic bond and epoxide residue lacks suppressed inflammation. In 3T3-L1 adipocytes, paracentrone, and apo-10'-fucoxanthinal downregulate the mRNA expression of proinflammatory mediators and chemokines induced by co-culture with RAW264.7 cells. Dietary fucoxanthin accumulates as paracentrone as well as fucoxanthinol and amarouciaxanthin A in the mouse body. Allenic bond and epoxide residue of fucoxanthin-derived apocarotenoids have pivotal roles for anti-inflammatory action against activated macrophages and adipocytes.

Pre-ischemic renal lavage protects against renal ischemia-reperfusion injury by attenuation of local and systemic inflammatory responses.

Postischemic acute kidney injury (AKI) is a common clinical complication and often fatal, with no effective treatment available. Little is known about the role of leukocytes trapped in renal vessels during ischemia-reperfusion injury (IRI) in the postischemic AKI. We designed a new animal model in rats with preforming renal artery lavage prior to IRI to investigate the effect of diminishing the residual circulating leukocytes on kidney damage and inflammation. Moreover, the functional changes of macrophages in hypoxia reoxygenation condition were also analyzed. We found pre-ischemic renal lavage significantly decreased the serum creatinine and blood urea nitrogen levels, and downregulated the mRNA and protein expressions in kidneys and urinary secretion of kidney injury molecule-1 of rats after IRI. The renal pathological damage caused by IRI was also ameliorated by pre-ischemic renal lavage, as evidenced by fewer cast formation, diminished morphological signs of AKI in the tissue at 24hours after IRI. Pre-ischemic renal lavage reduced the numbers of infiltrating CD68+ macrophages and MPO+ neutrophils. The mRNA expression of pro-inflammatory mediator in IRI kidneys and the levels of pro-inflammatory cytokines in circulatory system and urine were also reduced due to pre-ischemic lavage. Compared with nontreated rats with IRI, pre-ischemic renal lavage significantly reduced the phosphorylation levels of ERK and p65 subunit of NF-κB in the kidney after IRI. In addition, we found hypoxia/reoxygenation could promote the expression of pro-inflammatory mediators and inhibit the expression of anti-inflammatory factors by regulating ERK/NF-κB signaling pathway. Thus, pre-ischemic renal lavage could clearly reduce the renal damage after IRI by attenuating inflammation, and macrophages trapped in renal vessels during IRI could be important pathogenic factors driving tissue injury.

Obesity-Induced Increase in Cystatin C Alleviates Tissue Inflammation.

We recently demonstrated that removal of one kidney (uninephrectomy [UniNx]) in mice reduced high-fat diet (HFD)-induced adipose tissue inflammation, thereby improving adipose tissue and hepatic insulin sensitivity. Of note, circulating cystatin C (CysC) levels were increased in UniNx compared with sham-operated mice. Importantly, CysC may have anti-inflammatory properties, and circulating CysC levels were reported to positively correlate with obesity in humans and as shown here in HFD-fed mice. However, the causal relationship of such observation remains unclear. HFD feeding of CysC-deficient (CysC knockout [KO]) mice worsened obesity-associated adipose tissue inflammation and dysfunction, as assessed by proinflammatory macrophage accumulation. In addition, mRNA expression of proinflammatory mediators was increased, whereas markers of adipocyte differentiation were decreased. Similar to findings in adipose tissue, expression of proinflammatory cytokines was increased in liver and skeletal muscle of CysC KO mice. In line, HFD-induced hepatic insulin resistance and impairment of glucose tolerance were further aggravated in KO mice. Consistently, chow-fed CysC KO mice were more susceptible to lipopolysaccharide-induced adipose tissue inflammation. In people with obesity, circulating CysC levels correlated negatively with adipose tissue Hif1α as well as IL6 mRNA expression. Moreover, healthy (i.e., insulin-sensitive) subjects with obesity had significantly higher mRNA expression of CysC in white adipose tissue. In conclusion, CysC is upregulated under obesity conditions and thereby counteracts inflammation of peripheral insulin-sensitive tissues and, thus, obesity-associated deterioration of glucose metabolism.

Lignin-derived low-molecular-weight oxidized lignophenol stimulates AMP-activated protein kinase and suppresses renal inflammation and interstitial fibrosis in high fat diet-fed mice

Excess weight and obesity increase the risk of developing major risk factors for chronic kidney disease. Lignin comprises 20%–30% of the global plant biomass; however, it is not well utilized because of its resistance to chemical and biological degradation. We investigated whether low-molecular-weight oxidized lignophenol (LOLP), a lignin derivative, could alter inflammation and fibrosis in the kidneys of a high-fat diet (HFD)-fed mice. Male mice were divided into three treatment groups: HFD; HFD +0.3% LOLP; and HFD +0.6% LOLP. The control mice (Cont) were fed a low-fat diet. Macrophage kinetics, the degree of fibrosis, the extent of phosphorylation of AMP-activated protein kinase (AMPK), and mRNA expression of proinflammatory mediators in the kidneys were examined. The number of macrophages, the percentage of fibrotic area, and the mRNA expression of proinflammatory markers, TNF-α and Ccl2, and a marker of fibrosis, TGF-β, were significantly higher in the kidneys of mice in the HFD group than those in the Cont group. Conversely, treatment with 0.6% LOLP for 8 weeks significantly suppressed the degree of macrophage infiltration, interstitial fibrotic area, and the increased mRNA expression of proinflammatory and fibrosis markers induced by HFD. In conclusion, LOLP suppressed macrophage infiltration and the increase in fibrotic area, and upregulated AMPK phosphorylation in the kidneys of HFD-fed mice; thus, it may ameliorate HFD-induced kidney injury.

Cryogen spray cooling mitigates inflammation and injury-induced CISD2 decline in rat spinal cord hemisection model.

Therapeutic strategies for traumatic spinal cord injury generally involve rectifying concomitant destruction to the spinal cord from inflammation, mitochondrial dysfunction, and eventual neuronal apoptosis. Elevating the expression of spinal cord injury-attenuated CDGSH iron-sulfur domain-2 has been shown to mitigate the pathologies above. In the current work, hypothermia was induced via continuous cryogen spray cooling in a rat spinal cord hemisection model. Spinal cord injury was shown to elevate the mRNA expression of proinflammatory mediators, including NFκB, iNOS, TNF-α, and regulated upon activation, normal T-cell expressed and secreted as well as lower CDGSH iron-sulfur domain-2 expression. Cryogen spray cooling treatment was shown to attenuate inflammatory reactions and elevate CDGSH iron-sulfur domain-2 expression. Immunohistochemical analysis of the glial fibrillary acidic protein, caspase-3 and NeuN in spinal cord injured rats that underwent cryogen spray cooling treatment revealed notable reductions in injury-induced astrocytic activation, apoptosis, neuronal loss, and decline in CDGSH iron-sulfur domain-2 expression. These results demonstrate the CDGSH iron-sulfur domain-2 preserving effects of cryogen spray cooling, which could contribute to the prevention of astrocytic activation, astrocyte-mediated neuroinflammation, apoptosis, and neuron loss.

Inhibition of soluble epoxide hydrolase regulates monocyte/macrophage polarization and improves neurological outcome in a rat model of ischemic stroke.

It is generally understood that continuing neuroinflammation after ischemic stroke can exacerbate the brain damage. During the inflammatory hematogenous recruitment process, the monocytes and macrophages are activated into proinflammatory M1 and anti-inflammatory M2 cell types. Inhibition of soluble epoxide hydrolase (sEH) activity has been reported to regulate monocytes/macrophages, and attenuates neuroinflammation. This study aimed to evaluate whether a selective sEH inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), can regulate monocyte/macrophage polarization and improve motor function in the rats with ischemic stroke induced by middle cerebral artery occlusion. We measured the infarct volume with 2,3,5-triphenyltetrazolium chloride staining and used the rotarod test to assess motor performance in rats. The monocyte/macrophage activation and mRNA expression of proinflammatory mediators were measured by flow cytometry and reverse-transcription quantitative PCR, respectively. Our results showed better neurological function and less infarct volume in the rats treated with AUDA. Compared with the vehicle group, the AUDA-treated group showed a reduction in M1 monocyte/macrophage activation and proinflammatory mRNA expressions in the infarct cortex of rats. Our data suggest that the sEH inhibition may regulate monocyte/macrophage polarization and improve neurological outcome after ischemic stroke.

Suppression of pulmonary group B streptococcal proliferation and translocation by surfactants in ventilated near-term newborn rabbits.

The pathogenesis of neonatal group B Streptococcus (GBS) lung infection may be associated with surfactant dysfunction or deficiency. This study aimed to investigate the efficacy of surfactants on early postnatal GBS infection in ventilated newborn rabbit lungs. A near-term newborn rabbit model was established by intratracheal GBS instillation immediately at birth, followed by mechanical ventilation. At postnatal 1 h, a porcine surfactant was given intratracheally at 100 or 200 mg/kg. After 6 h, animals were euthanized, and lung and blood samples were collected for bacterial counting. Lung histopathology and messenger RNA (mRNA) expression of inflammatory mediators, surfactant proteins, and growth factors in lung tissue were assessed. The surfactants significantly suppressed (by >50%) pulmonary bacterial proliferation and systemic translocation, alleviated lung inflammatory injury, and improved alveolar expansion by morphometry, in favor of high-dose surfactants. Though the survival rate and lung mechanics were not improved, the surfactants significantly suppressed mRNA expression of proinflammatory mediators, while that for surfactant proteins and growth factors was differentially expressed, compared to the control and GBS infection groups. Exogenous surfactants may provide a therapeutic alternative for neonatal lung infection by suppressing pulmonary GBS proliferation and translocation into systemic circulation, alleviating inflammatory injury and regulating growth factor expression.

Exclusive expression of transmembrane TNF aggravates acute glomerulonephritis despite reduced leukocyte infiltration and inflammation

Tumor necrosis factor-α (TNF) is a cytokine mediating inflammatory kidney diseases such as immune complex glomerulonephritis. Its two receptors, TNFR1 and TNFR2, play distinct roles in this process, with TNFR2 strongly required for induction of disease. In contrast to soluble TNF (sTNF), transmembrane TNF robustly activates TNFR2. Thus, we examined the functional role of transmembrane TNF by inducing heterologous nephrotoxic serum nephritis in wild-type and transgenic TNFΔ1-9,K11E knock-in mice expressing transmembrane TNF but no sTNF (memTNF mice). Compared to wild-type, nephritis was exacerbated in memTNF mice on day 5, indicated by increased albuminuria, higher serum urea levels, and more pronounced glomerular deposits, together with higher numbers of dying and proliferating glomerular cells. This was associated with greater loss of glomerular endothelial cells, increased podocyte stress, and signs of augmented necroptosis in memTNF kidneys. Aggravation of nephritis was dependent on transmembrane TNF expression in parenchymal cells, but not leukocytes. Surprisingly, increased kidney injury was associated with reduced renal leukocyte infiltration in memTNF mice, which correlated with decreased renal mRNA expression of pro-inflammatory mediators. This effect was also present in isolated memTNF glomeruli stimulated with interleukin-1β invitro. Thus, uncleaved transmembrane TNF is an important mediator of renal tissue damage characterized by increased renal cell death and loss of glomerular endothelial cells in murine glomerulonephritis. In contrast, sTNF predominantly mediates renal leukocyte recruitment and inflammation. These findings highlight the importance of transmembrane TNF in inflammatory kidney disease as a possible therapeutic target.

Nobiletin alleviates endometriosis via down-regulating NF-κB activity in endometriosis mouse model.

Nobiletin exhibits protective potential on inflammation and inhibits the activation of transcription factors nuclear factor-κB (NF-κB). However, its effects on the progression of endometriosis remain unsettled. The present study aimed to explore the in vivo alleviation of nobiletin on endometriosis and its mechanism of action. The mouse model of endometriosis was established and administered with nobiletin. The ectopic lesion size was measured and the hotplate test was performed to assess the amelioration of nobiletin on endometriosis. The expression of proliferation and angiogenesis relevant genes including proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and E-cadherin was measured by immunostaining and the mRNA expression of proinflammatory mediators including interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, matrix metalloproteinases (MMP)-1, and MMP-3 was measured by RT-PCR. The change of NF-κB activity in endometriotic cells was evaluated by Western blotting and confirmed by luciferase assay. Administration of nobiletin significantly reduced lesions size and pain in endometriosis mice. Nobiletin significantly altered the expression of PCNA, VEGF, and E-cadherin in ectopic endometrium, as well as the levels of IL-6, IL-1β, TNF-α, MMP-1, and MMP-3. Nobiletin also showed remarkably impairment on the activation of NF-κB in promoting endometriotic cells, likely targeting on the activity of IκB kinases (IKKs). The present study provides the first evidence that nobiletin exerts protection on endometriosis via inhibition the activation of NF-κB, specifically on the activity of IκB kinases.

Piper sarmentosum Roxb. confers neuroprotection on beta-amyloid (Aβ)-induced microglia-mediated neuroinflammation and attenuates tau hyperphosphorylation in SH-SY5Y cells

Ethnopharmacological relevancePiper sarmentosum Roxb. (PS), belonging to Piperaceae family, is an edible plant with medicinal properties. It is traditionally used by the Malays to treat headache and boost memory. Pharmacological studies revealed that PS exhibits anti-inflammatory, anti-oxidant, anti-acetylcholinesterase, and anti-depressant-like effects. In view of this, the present study aimed to investigate the anti-inflammatory actions of PS and its potential neuroprotective effects against beta-amyloid (Aβ)-induced microglia-mediated neurotoxicity. Materials and methodsThe inhibitory effects of hexane (LHXN), dichloromethane (LDCM), ethyl acetate (LEA) and methanol (LMEOH) extracts from leaves of PS on Aβ-induced production and mRNA expression of pro-inflammatory mediators in BV-2 microglial cells were assessed using colorimetric assay with Griess reagent, ELISA kit and real-time RT-PCR respectively. Subsequently, MTT reduction assay was used to evaluate the neuroprotective effects of PS leaf extracts against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y neuroblastoma cells. The levels of tau proteins phosphorylated at threonine 231 (pT231) and total tau proteins (T-tau) were determined using ELISA kits. ResultsPolar extracts of PS leaves (LEA and LMEOH) reduced the Aβ-induced secretion of pro-inflammatory cytokines (IL-1β and TNF-α) in BV-2 cells by downregulating the mRNA expressions of pro-inflammatory cytokines. The inhibition of nitric oxide (NO) production could be due to the free radical scavenging activity of the extracts. In addition, conditioned media from Aβ-induced BV-2 cells pre-treated with LEA and LMEOH protected SH-SY5Y cells against microglia-mediated neurotoxicity. Further mechanistic study suggested that the neuroprotective effects were associated with the downregulation of phosphorylated tau proteins. ConclusionsThe present study suggests that polar extracts of PS leaves confer neuroprotection against Aβ-induced microglia-mediated neurotoxicity in SH-SY5Y cells by attenuating tau hyperphosphorylation through their anti-inflammatory actions and could be a potential therapeutic agent for Alzheimer's disease.

Anti-Inflammatory Activity of Rg3-Enriched Korean Red Ginseng Extract in Murine Model of Sepsis.

Ginseng has therapeutic effects on various bodily disorders ranging from minor inflammation to major cardiovascular diseases. In our study, we explored the anti-inflammatory effects of Rg3-enriched red ginseng extract (Rg3-RGE), a ginsenoside belonging to the panaxadiol group. We employed nitric oxide assay (NO) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), western blot, and hematoxylin and eosin staining (H&E) to elucidate the anti-inflammatory activity of Rg3-RGE. Rg3-RGE potently suppressed NO production in the murine macrophage cell line, RAW 264.7 cells, without any cytotoxicity across dosages. Additionally, it inhibited the mRNA expression of proinflammatory mediators and cytokines like iNOS, COX-2, IL-1β, IL-6, and TNF-α. Moreover it also inhibited the levels of malondialdehyde levels in serum of septic shock mice. Immunoblot analysis showed that Rg3-RGE induced anti-inflammatory signal transduction via the NF-κB and MAPK pathways. A remarkable attenuation of inflammation by oral treatment with Rg3-RGE in mice was observed in the survival study. The in vivo study using a septic shock mouse model also showed similar results as the in vitro study. Our findings suggest that Rg3-RGE can potentially be a potent anti-inflammatory agent that likely mediates its anti-inflammatory effects via the NF-κB and MAPK pathways.

Curcumin Prevents Osteoarthritis by Inhibiting the Activation of Inflammasome NLRP3.

Curcumin has shown protective potential on osteoarthritis. However, its effect on treatment of osteoarthritis remains elusive so far. This study aimed to determine whether curcumin could ameliorate osteoarthritis in vivo and the underline mechanisms. The mice subjected to destabilization of the medial meniscus (DMM) surgery were administered curcumin. Cartilage integrity was evaluated by immunohistological staining. Expression levels of inflammatory cytokines from mice arthrodial cartilage were detected. THP-1 cells were primed by lipopolysaccharide (LPS)/ATP to induce inflammation, followed by the addition of curcumin. The expression of proinflammatory cytokines was also detected. Moreover, the expression of pro-caspase-1, cleaved caspase-1, and NLRP3 inflammasome was examined. Administration of curcumin significantly reduced osteoarthritis disease progression in DMM model of osteoarthritis. Curcumin suppressed mRNA expression of proinflammatory mediators in arthrodial cartilage of mice subjected to surgery. In LPS- and ATP-induced THP-1 macrophage cells, curcumin significantly suppressed the expression of interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) at both RNA and protein levels. Compared to vehicle-treated controls, curcumin also showed remarkably increased pro-caspase-1 and decreased cleaved caspase-1. This study provides the first evidence that curcumin exerts protection on osteoarthritis by inhibition to the release of inflammasome NLRP3, leading to the downregulation of inflammatory cytokines.

Anti-inflammatory effects of traditional mixed extract of medicinal herbs (MEMH) on monosodium urate crystal-induced gouty arthritis

Korean oriental medicine prescription is widely used for the treatment of gouty diseases. In the present study, we investigated anti-inflammatory effects of modified Korean herbal formulation, mixed extract of medicinal herbs (MEMH), and its modulatory effects on inflammatory mediators associated with gouty arthritis. Both in vitro and in vivo studies were carried out to assess the anti-inflammatory efficacy of MEMH on monosodium urate (MSU) crystals-induced gouty inflammation. MSU crystals stimulated human chondrosarcoma cell line, SW1353, and human primary chondrocytes were treated with MEMH in vitro. The expression levels of pro-inflammatory mediators and metalloproteases were analyzed. The effect of MEMH on NFκB signaling pathway in SW1353 cells was examined. Effect of MEMH on the mRNA expression level of pro-inflammatory mediators and chemotactic factor from human monocytic cell line, THP-1, was also analyzed. The probable role of MEMH in the differentiation process of osteoblast like cells, SaOS-2, after MSU treatment was also observed. To investigate the effects of MEMH in vivo, MSU crystals-induced ankle arthritic model was established. Histopathological changes in affected joints and plasma levels of pro-inflammatory mediators (IL-1β and TNFα) were recorded. MEMH inhibited NFκB signaling pathway and COX-2 protein expression in chondrocytes. MSU-induced mRNA expressions of pro-inflammatory mediators and chemotactic cytokines were suppressed by MEMH. In MSU crystals-induced ankle arthritic mouse model, administration of MEMH relieved inflammatory symptoms and decreased the plasma levels of IL-1β and TNFα. The results indicated that MEMH can effectively inhibit the expression of inflammatory mediators in gouty arthritis, demonstrating its potential for treating gouty arthritis.

Stauntoside B inhibits macrophage activation by inhibiting NF-κB and ERK MAPK signalling

Inflammation is a defensive reaction of body to resist foreign invasion. However, it has been demonstrated that excessive and continuous inflammatory responses contribute to various inflammatory diseases, including rheumatoid arthritis. Nuclear factor-κB (NF-κB) regulates the expression of an array of inflammatory mediators, cytokines and chemokine genes in activated macrophages. Therefore, NF-κB has become an attractive drug target for controlling inflammation. In this study, stauntoside B, a C21 steroidal glycosides compound isolated from a Chinese medicine Cynanchi Stauntonii, was for the first time found to suppress macrophage activation induced by lipopolysaccharide (LPS) in RAW264.7 cells and rat primary peritoneal macrophages and could be a potent NF-κB inhibitor. The results showed that stauntoside B significantly reduced the release of inflammatory mediators in activated RAW264.7 cells and rat peritoneal macrophages, including nitric oxide (NO) and prostaglandin E2 (PGE2). The mRNA expressions of pro-inflammatory mediators and cytokines, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), microsomal prostaglandin synthetase-1 (mPGES-1), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) as well as the production of TNF-α and IL-6 were also inhibited by stauntoside B. Mechanistic investigation implies that the anti-inflammatory activity of stauntoside B could result from the suppression of LPS-induced IKKα/β activation, IκBα phosphorylation, p65 (ser536) NF-κB phosphorylation, and ERK MAPK activation by stauntoside B treatment in activated macrophages. Meanwhile, stauntoside B could induce apoptosis in LPS-activated macrophages. The current study suggests stauntoside B being a valuable candidate drug for the treatment of inflammatory diseases, especially for NF-κB activation associated inflammatory diseases.

Vaccination of cattle with a high dose of BCG vaccine 3 weeks after experimental infection with Mycobacterium bovis increased the inflammatory response, but not tuberculous pathology

A study was undertaken to determine whether BCG vaccination of cattle post-challenge could have an effect on a very early Mycobacterium bovis infection. Three groups of calves (n=12/group) were challenged endobronchially with M.bovis and slaughtered 13 weeks later to examine for tuberculous lesions. One group had been vaccinated prophylactically with BCG Danish vaccine 21 weeks prior to challenge; a second group was vaccinated with a 4-fold higher dose of BCG Danish 3 weeks post-challenge and the third group, remained non-vaccinated. Vaccination prior to challenge induced only minimal protection with just a significant reduction in the lymph node lesion scores. Compared to the non-vaccinated group, BCG vaccination post-challenge produced no reduction in gross pathology and histopathology, but did result in significant increases in mRNA expression of pro-inflammatory mediators (IFN-γ, IL-12p40, IL-17A, IRF-5, CXCL9, CXCL10, iNOs, and TNF-α) in the pulmonary lymph nodes. Although there was no significant differences in the gross pathology and histopathology between the post-challenge BCG and non-vaccinated groups, the enhanced pro-inflammatory immune responses observed in the post-challenge BCG group suggest caution in the use of high doses of BCG where there is a possibility that cattle may be infected with M.bovis prior to vaccination.