Heilaohuacid G, a new triterpenoid from Kadsura coccinea inhibits proliferation, induces apoptosis, and ameliorates inflammation in RA-FLS and RAW 264.7 cells via suppressing NF-𝜅B pathway

Heilaohu, the roots of Kadsura coccinea, has been used in Tujia ethnomedicine to treat rheumatic arthritis (RA). Heilaohuacid G (1), a new 3,4-seco-lanostane type triterpenoid isolated from the ethanol extract of Heilaohu, whose structure was determined using HR-ESI-MS data, NMR spectroscopic analyses, and ECD calculations. In this study, our purpose is to elucidate the mechanisms of Heilaohuacid G in the treatment of RA by inhibited proliferation of rheumatoid arthritis-fibroblastoid synovial (RA-FLS) cells and inhibited the inflammatory reactions in LPS-induced RA-FLS and RAW 264.7 cell lines via inhibiting NF-κB pathway. The biological activity screening experiments indicated that Heilaohuacid G significantly inhibited proliferation of RA-FLS cells with IC50 value of 8.16 ± 0.47 μM. CCK-8 assay, ELISA, flow cytometry assay, and Western blot were used to measure the changes of cell viability, apoptosis, and the release of inflammatory cytokines. Heilaohuacid G was found not only induced RA-FLS cell apoptosis, but also inhibited the inflammatory reactions in LPS-induced RA-FLS and RAW 264.7 cell lines via inhibiting NF-κB pathway. Furthermore, Heilaohuacid G (p.o.) at doses of 3.0, 6.0, and 12.0 mg/kg and the ethanol extracts of Heilaohu (p.o.) at doses of 200, 400, and 800 mg/kg both were confirmed antiinflammatory effects on xylene-induced ear mice edema model.

A core-shell structure QRu-PLGA-RES-DS NP nanocomposite with photothermal response-induced M2 macrophage polarization for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a degenerative joint disease caused by autoimmunity; for the effective treatment of RA while avoiding the side effects of conventional drugs, we have proposed a new therapeutic strategy to eliminate the inflammatory response in RA by regulating the immune system that promotes the transformation of M1-type macrophages to M2-type macrophages. Herein, we designed and synthesized a core-shell nanocomposite (QRu-PLGA-RES-DS NPs), which showed an effective therapeutic effect on RA by accurately inducing the polarization of M2 macrophages. In this system, the quadrilateral ruthenium nanoparticles (QRuNPs) with a photothermal effect were utilized as a core and the thermosensitive molecular poly (lactic-co-glycolic acid) (PLGA) modified with the targeted molecule dextran sulfate (DS) was employed as a shell. Then, the nanocarrier QRu-PLGA-DS NPs effectively improved the water solubility and targeting of resveratrol (RES) through self-assembly. Therefore, the QRu-PLGA-RES-DS NPs significantly enhanced the ability of RES to reverse the M1 type macrophages to the M2 type macrophages through an accurate release. In vivo experiments further demonstrated that the QRu-PLGA-RES-DS NPs could effectively accumulate in the lesion area with an exogenous stimulus, and this significantly enhanced the transformation of the M2 type macrophages and decreased the recruitment of the M1 type macrophages. Furthermore, the QRu-PLGA-RES-DS NPs effectively treated RA by eliminating the inflammatory response; in addition, photoacoustic imaging (PA) of the QRu NPs provided image guidance for the distribution and analysis of nanomedicine in inflammatory tissues. Hence, this therapeutic strategy promotes the biological applications of Ru-based nanoparticles in disease treatment.

Rheumatic fever and rheumatic heart disease: genetics and pathogenesis

Molecular mimicry between streptococcal and human proteins is considered as the triggering factor leading to autoimmunity in rheumatic fever (RF) and rheumatic heart disease (RHD). Here, we present a review of the genetic susceptibility markers involved in the development of RF/RHD and the major immunopathological events underlying the pathogenesis of RF and RHD. Several human leucocyte antigen (HLA) class II alleles are associated with the disease. Among these alleles, HLA-DR7 is predominantly observed in different ethnicities and is associated with the development of valvular lesions in RHD patients. Cardiac myosin is one of the major autoantigens involved in rheumatic heart lesions and several peptides from the LMM (light meromyosin) region were recognized by peripheral and intralesional T-cell clones from RF and RHD patients. The production of TNF-alpha and IFN-gamma from heart-infiltrating mononuclear cells suggests that Th-1 type cytokines are the mediators of RHD heart lesions while the presence of few interleukin-4 producing cells in the valve tissue contributes to the maintenance and progression of the valvular lesions.

Molecular pathogenesis of rheumatic fever and rheumatic heart disease

Molecular mimicry between streptococcal and human proteins has been proposed as the triggering factor leading to autoimmunity in rheumatic fever (RF) and rheumatic heart disease (RHD). This article summarises studies on genetic susceptibility markers involved in the development of RF/RHD. It also focuses on the molecular mimicry in RHD mediated by the responses of B and T cells of peripheral blood, and T cells infiltrating heart lesions, against streptococcal antigens and human tissue proteins. The molecular basis of T-cell recognition is assessed through the definition of heart-crossreactive antigens. The production of cytokines from peripheral and heart-infiltrating mononuclear cells suggests that T helper 1 (Th1)-type cytokines are the mediators of RHD heart lesions. An insufficiency of interleukin 4 (IL-4)-producing cells in the valvular tissue might contribute to the maintenance and progression of valve lesions.

TNF-alpha G-308A polymorphism is associated with rheumatic fever and correlates with increased TNF-alpha production

Previous studies suggested that abnormal regulation of TNF-alpha production may have a role in the pathogenesis of rheumatic fever (RF). Polymorphism at the promoter region of TNF-alpha gene (-308 A) has recently been shown to be associated with rheumatic heart disease (RHD) in Mexican patients. Although this polymorphism has long been shown to affect TNF-alpha gene expression in cell lines, its role in production of the cytokine in RF patients has not been studied. We therefore investigated TNF-alpha G-308A single nucleotide polymorphism and its effect on TNF-alpha production in 71 Turkish RF patients and 89 ethnically matched healthy controls. The TNF-alpha-308A allele frequency was found to be significantly higher in RF patients (RHD+arthritis) than in healthy controls [p<0.0032 Odds ratio (OR)=3.4, 95% confidence interval (CI) (1.5-7.7)]. When RHD patients were analyzed as a separate group, significant difference persisted [p<0.0055, OR=3.3, 95% CI (1.5-7.6)]. More importantly, ELISPOT analysis demonstrated that existence of A allele was associated with higher TNF-alpha production compared with G allele. Our data suggest that carrying a high responder TNF-alpha-308A allele may be a genetic factor in increasing the susceptibility to develop RF disease.

Inverse relationship between the ratio of ICAM-1 expressing lymphocytes and serum TGF-β1 concentrations in acute rheumatic fever

Autoimmunity in acute rheumatic fever (ARF) is triggered by group-A beta hemolytic streptococci (GAS). Although most of the recent work has focused on the major impact of lymphocytes, the exact immunopathogenesis is still unresolved. Regulation of self-tolerance in response to GAS has been investigated in various animal experiments. This study aimed to associate the ratio of lymphocytes bearing adhesion/costimulatory molecules, Bcl-2/CD95 and serum TGF-beta1 concentrations with clinical stages of ARF. Thirty-five patients were assigned according to the clinical stages. Bcl-2 expression on CD19+ and CD3+ lymphocytes was similar within patient groups and controls. CD62p expression was higher in patients with carditis. The ratio of ICAM-1 bearing lymphocytes was significantly different between patient groups and controls and was increased through acute to remission stages longitudinally. In contrast, a gradual and significant decrease in TGF-beta1 concentrations was observed longitudinally from acute to chronic stages. A positive correlation has been documented between ICAM-1+ lymphocyte ratios and Fas+ cytotoxic T cell ratios supported by a prominent increase in CD95+ T cells. These data draw our attention to the role of ICAM-1, Fas and TGF-beta1 in ARF pathogenesis through the perspective of self-tolerance in a clinical setting.

Therapy with statins in patients with refractory rheumatic diseases: a preliminary study

We have explored the therapeutic potential of statins in patients with different inflammatory rheumatic diseases refractory to conventional therapy. We found that simvastatin (80mg o.d. for eight days) induced a rapid and significant reduction in proteinuria levels in three systemic lupus erythematosus (SLE) patients. A similar kind of therapy had a marked beneficial effect in a patient with Wegener's granulomatosis and a patient with erythema nodosum. On the other hand, five patients with rheumatoid arthritis (RA) who received atorvastatin for eight days (20mg/day) showed reduction in C-reactive protein levels and a clinical improvement that was classified as an ACR20 response. Prior to the administration of statins, all these patients had received aggressive conventional therapy with no satisfactory response. A significant reduction in spontaneous apoptosis of peripheral blood lymphocytes and expression of CD69 and HLA-DR was observed in SLE patients after simvastatin therapy. These results prompted us to perform a pilot short-time comparative (simvastatin versus chloroquine) open clinical trial in 15 patients with RA who were receiving methotrexate as a single disease modifying antirheumatic drug with no satisfactory response. Most patients (9/10) who received simvastatin (40mg/day) showed an ACR50 or better response after eight weeks, whereas such a response was not observed in any patient (0/5) treated with chloroquine. Our preliminary results indicate that statins may be an important therapeutic tool for the treatment of inflammatory rheumatic diseases.

[Activity of lipid peroxidation processes in children with rheumatic fever]

Pathogenic mechanism of acute and chronic inflammation is connected to the increased production of superoxide anion, hydrogen peroxide, and other free radicals. Clinical role of lipid peroxidation (LPO) processes was studied in 38 patients in the age from 3 to 15 years old with different variants of Rheumatic Fever (RF). We have investigated the relationship between malonidialdehide (MDA) and RF. We measured the levels of MDA in the plasma in patients with acute rheumatic fever (ARF) and chronic rheumatic heart disease (CRHD). Our study revealed that the levels of MDA in patients with ARF are significantly higher than in patients with CRHD. These levels were also significantly higher in patients with history of disease for up to 2 years, than in patients with history longer than 2 years. Thus, the measurement of MDA in the plasma could be used as a laboratory test for relation of active state of rheumatic fever.

Nitric oxide metabolities in acute rheumatic fever

Acute rheumatic fever (ARF), is a systemic inflammatory disease etiologically related to infection with group A beta hemolytic streptococcus, characterized by a broad spectrum of disorders in cellular immunity. To estimate the activity of the immunopathological process in patients with ARF, plasma nitric oxide metabolities (NOx) concentrations, IL-1alpha and IL-2 levels were investigated in 22 patients with ARF at the time on admission, and after 3 months, in children with chronic rheumatic heart disease (CRHD). Plasma NOx concentrations, IL-1alpha and IL/2 levels in patients with ARF on admission were significantly higher than in the same patients 3 months later, and higher than in CRHD, or controls. Increased plasma NO may be a useful index for the quantitative assessment of the activity during immunological challenge. This information may be useful for the prognosis and monitoring of ARF.

Serum-soluble receptors for tumor necrosis factor-alpha and interleukin-2, and neopterin in acute rheumatic fever

Immune activation may play an important role in the pathogenesis of acute rheumatic fever (ARF). The objective of the present study was to investigate serum concentrations of various markers of immune activation in ARF patients. Sera of 32 patients with ARF were investigated, 20 of them in follow-up. Radioimmunoassay was used to quantify neopterin and ELISA for the measurement of 55-kDa-type soluble tumor necrosis factor receptor (sTNF-R) and soluble interleukin-2 receptor (sIL2-R). Markers of immune activation were found to be raised in 48% (sTNF-R), 28% (sIL2-R), and 78% (neopterin) of patients at the onset of ARF. There were significant correlations between the concentrations of neopterin and sTNF-R (rs = 0.60, P < 0.001) or sIL2-R (rs = 0.35, P < 0.05). Higher neopterin concentrations were found in patients with combined aortic and mitral insufficiency than in patients with mitral valve lesions alone (U = 2.67, P < 0.05) or without valve lesion (U = 2.36, P < 0.05). Increased concentrations of neopterin, sTNF-R, and sIL2-R demonstrate activation of the cellular immune system in patients with ARF. Higher serum neopterin concentrations are associated with development of combined aortic and mitral insufficiency during the first episode of ARF.

Action of oxygen free radical scavengers and inhibitors on the chemiluminescence response of monocytes and neutrophils in rheumatic fever

Various scavengers of oxygen free radicals or inhibitors of their production were used to measure the relative amounts of oxygen free radicals generated in phagocytic cells. The agents used were iodoacetate, superoxide dismutase, sodium benzoate, catalase and mannitol. The studies were made in patients with a recurrence of rheumatic activity, chronic rheumatic heart disease or pharyngitis, and in normal controls. Monocytes and neutrophils of the subjects were stimulated with latex in the presence or absence of a scavenger/inhibitor and the per cent inhibition of the chemiluminescence response was calculated. There were 10 patients in each group. Follow-up studies were done at 15 days, 3 months and 6 months. In the patients with a recurrence of rheumatic activity, the level of oxygen free radicals generated in the initial study was so high that the scavenger/inhibitors were able to reduce the chemiluminescence only in part. The diminution in chemiluminescence increased during the follow-up period. In the patients with chronic rheumatic heart disease, the per cent inhibition of the chemiluminescence response was significantly higher in the initial study than that observed in patients with a recurrence of rheumatic activity, and it remained constant during the follow-up period. The scavenger/inhibitors were almost completely able to inhibit the generation of oxygen free radicals in patients with pharyngitis and in normal controls.

Release of oxygen free radicals by macrophages and neutrophils in patients with rheumatic fever

The generation of oxygen free radicals (OFR) by peripheral blood monocytes and neutrophils of patients with rheumatic fever (RF) and rheumatic heart disease (RHD) has been studied using the luminol-enhanced chemiluminescence technique. The mechanism of OFR generation was studied by measuring NADPH oxidase enzyme activity. The effect of substrate was studied by measuring the hexose monophosphate (HMP) shunt enzymes: glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Three groups of patients [i) recurrent rheumatic activity, (ii) chronic RHD, (iii) acute pharyngitis) and normal controls were studied at day 0 and followed-up serially at 15, 90 and 180 days. The release of OFR, was significantly higher (P less than 0.001) in patients with recurrent rheumatic activity than in those with acute pharyngitis or chronic RHD, throughout the study period. A significant decline (P less than 0.001) in OFR release was observed from day 0 to day 180 in these patients, whereas no such change was observed in the chronic RHD group. This study raises the possibility that these phagocytic cells, which infiltrate the myocardium, may through generation of OFR, have a role in the pathogenesis of cardiac damage seen in patients with RHD.

Role of oxygen free radicals generated by blood monocytes and neutrophils in the pathogenesis of rheumatic fever and rheumatic heart disease

The generation of oxygen free radicals by peripheral blood monocytes and neutrophils of patients with rheumatic fever and rheumatic heart disease has been studied using luminol enhanced chemiluminescence technique. Five groups of patients; acute rheumatic fever, recurrence of rheumatic activity, chronic rheumatic heart disease, acute pharyngitis and normal controls were studied. In all groups except the controls, measurements were made on 0, 15, 90 and 180 days. The chemiluminescence was measured in response to streptococcal membrane antigen, carbohydrate antigen and latex as triggering agents. Chemiluminescent response of monocytes, as well as, neutrophils was significantly higher (P less than 0.01) in acute rheumatic fever and recurrence of rheumatic heart disease as compared to patients with acute pharyngitis and chronic rheumatic heart disease through the study period and with all the triggering agents. A significant decline (P less than 0.001) in chemiluminescence was observed from day 0 to day 180 in the acute rheumatic fever, recurrence of rheumatic heart disease and pharyngitis patients while no such change, was observed in the chronic rheumatic heart disease group. This study raises the possibility that these phagocytic cells, which infiltrate the myocardium, may have a role in the pathogenesis of cardiac disease seen in patients with rheumatic heart disease, through the generation of oxygen free radicals.

Salicylate hepatotoxicity: the potential role of hypoalbuminemia

Seventeen patients suffering from an initial attack of acute rheumatic fever were studied during treatment with phenoxymethyl penicillin and salicylates (600 mg orally every 4 or 6 hours). Elevated transaminase (SGOT) levels occurred in nine patients. The SGOT levels were directly related to serum salicylate levels (r = 0.668) and inversely to the serum albumin level (r = -0.418). SGOT response was greater in patients with a serum albumin of less than 3.5 g/dl (P < 0.001). In hypoalbuminemia, the ratio of free salicylate to bound salicylate rises and the free salicylate might be more active and thus more hepatotoxic even at relatively low total serum salicylate levels. In all patients with hypoalbuminemia of less than 3.5 g/dl, close monitoring the SGOT is advisable, especially if the level of total serum salicylate is 15 mg/dl or higher.

Myocardial lysis in acute rheumatic fever followed by regeneration of cardiac muscle and origin of Aschoff bodies

In acute rheumatic heart disease, lysis of cardiac muscle fibres with or without retention of sarcolemma is found to be the most damaging feature in many cases. In deeper myocardium the cellular lysis often forms anastomosing clefts or sinus-like spaces between surviving muscle bundles and in the outer portion of myocardium cellular lysis may leave the sarcolemma more or less intact. From lysing cardiac muscle fibres there arise dedifferentiated cells with remarkable potentiality for regeneration. For the origin of these dedifferentiated cells, which are often indistinguishable from lymphocytes, no mitosis is seen in cardiac muscle cells. The successive stages of development of muscle cell from these dedifferentiated cells within the remaining or newly formed sarcolemma have been observed in this study. This study infers that the increased number of fibrous septa, when seen, denotes the tracks of previous muscle degeneration and subsequent replacement of it with incomplete muscle regeneration and fibrous tissue formation. In an area of muscle lysis the origin of Aschoff bodies from these dedifferentiated cells has been followed. Ashoff bodies arising in this was behave as an abortive and atypical growth of muscle fibres in a nodular fashion specific to rheumatic fever.