Systemic Lupus Erythematosus Premature Atherosclerosis Sclerosis Clinical And Basic Research

BackgroundSystemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease that disproportionally affects women, especially women at child bearing age. In recent30years, studies found that SLE has close relationship with atherosclerosis (AS) disease. They found the prevalence of coronary heart disease (CAD) in SLE patients was significantly higher than that of the general population, the atherosclerosis of the coronary was more serious and the CAD onset age was younger. Framingham traditional risk factors can not fully explain these features of CAD in SLE patients, it suggests that SLE disease itself is an independent risk factors for CAD or AS. In medical advanced countries, clinical and basic research of premature CAD (AS) in SLE patients has developed quickly, while domestic research in this field is still at the initial stage. It is necessary to further our clinical research and develop our basic research, especially to build our SLE premature AS mouse model for pathogenesis study and intervention trial.Objective1. To study the characteristics of traditional risk factors and coronary atherosclerosis in SLE patients with premature CAD.2. To evaluation the prevalence of hypertension, diabetes, dyslipidemia in SLE patients, and investigate factors that affecting lipid levels in SLE patients.3. To create our SLE premature AS mouse model.4. To study the characteristics and explore the pathogenesis of AS in our SLE premature AS mouse model.Methods1. Comparison of traditional risk factors (hypertension, diabetes, high cholesterol, family history of premature CAD, early menopause, and smoking), and comparison the number of traditional risk factors and coronary artery involvement between11female premature CAD patients with SLE and64female premature CAD patients without SLE (age=60years) diagnosed by coronary angiography (CAG).2. The prevalence rate of hypertension, diabetes, dyslipidemia and the levels of serum lipid were compared between540SLE patients and1080gender, age1:2matched healthy controls, the clinical features of SLE patients with dyslipidemia were retrospectively analyzed.3. We use the following two methods to create our SLE premature CAD mouse model:(1) Take spontaneous lupus mouse model MRL/lpr as the experimental group, hyperlipidemia mouse LDLr-/-as control group. At8weeks of age, all mouse were fed high fat diet [standard diet+21%(weight/weght) fat+0.15%(weight/weight) cholesterol]. After14weeks of high fat diet, all mice were weighed and sacrificed. The pathological changes of hair and skin, the size of lymph node and spleen were observed and recorded. The plasma levels of albumin, creatinine, urea, TC, TG, HDL-C, LDL-C, IgG, C3, ANA and anti ds-DNA antibody were measured. HE staining, PAS staining, IgG direct immunofluorescence and C3direct immunofluorescence were used to detect renal lesions. Aortic root were stained with Oil red O detect AS lesions.(2) Take4-week-old hyperlipidemia mouse model LDLr-/-+intraperitoneal injection of Pristane0.5ml as the experimental group one, take8-week-old hyperlipidemia mouse model LDLr-/-+intraperitoneal injection of Pristane0.5ml as the experimental group two, use LDLr-/-+intraperitoneal injection of saline0.5ml as control group. After injection, all mice were fed high fat diet [standard diet+21%(weight/weght) fat+0.15%(weight/weight) cholesterol]. After14weeks of high fat diet, mice were weighed and sacrificed. The pathological changes of hair and skin, the size of lymph node and spleen were observed and recorded. The plasma levels of albumin, creatinine, urea, TC, TG, HDL-C, LDL-C, IgG, C3, ANA and anti ds-DNA antibody were measured. HE staining, PAS staining, IgG direct immunofluorescence and C3direct immunofluorescence were used to detect renal lesions. Aortic root were stained with Oil red O and HE to detect AS lesions.4. After SLE premature AS mouse model was successfully created, the fiber content of the aortic root tissue of the experimental groups and control group were detected by masson staining, the smooth muscle content was detected by a-SM-actin monoclonal antibody, the macrophage content was detected by CD68immunohistochemical staining. TUNEL staining was used to detect apoptosis cells in aortic root, IgG direct immunofluorescence and C3direct immunofluorescence were used to detect the deposition of IgG and C3in the AS lesions.Results1. No significant difference between the two groups in all traditional risk factors, the number of traditional risk factor [(1.6±0.8) vs (1.8±1.0)] and the number of coronary stenosis (P>0.05), but the proportion of three coronary artery stenosis was more higher in SLE group than that of non SLE group [(7/11) vs (17/64), P<0.05].2. The percentage of hypertension, diabetes, dyslipidemia, elevated total cholesterol (TC), elevated triglyceride (TG), decreased high density lipoprotein cholesterol (HDL-C) and elevated low density lipoprotein cholesterol (LDL-C) in SLE patients were significantly higher than those in healthy controls (P=0.000). Compared with control groups, SLE patients had significantly higher TC, TG, LDL-C levels and significantly lower HDL-C levels (P=0.000). Multifactor regression analysis showed that TC and LDL-C levels were positively correlated with lupus nephritis, corticosteroids therapy, complement C4levels and24hours urine protein content (P<0.05), negatively correlated with serum albumin (Alb) and high sensitive C reactive protein (hsCRP) levels (P<0.05). TG levels were positively correlated with female sex, lupus nephritis and24hours urine protein content (P<0.05), negatively correlated with age and Alb levels. HDL-C levels were positively correlated with age, lupus nephritis, corticosteroids therapy, cumulative corticosteroids dose of consecutive30days before serum lipid were measured, and complement C3levels (P<0.05), negatively correlated with hsCRP levels (P<0.05). Serum lipid levels had no significant correlation with disease duration, disease activity, corticosteroids therapy time, corticosteroids daily dose before serum lipid were measured, hydroxychloroquine (HCQ) treatment, amino transferase (ALT) levels, serum creatinine (Cr) levels and erythrocyte sedimentation rate (ESR)(P>0.05).3. MRL/lpr mice have features similar to human SLE, including hair loss, skin lesions, lymph and spleen enlargement, significantly decreased complement C3, significantly increased immunoglobulin IgG, significantly high ANA and anti ds-DNA antibody titers, more cellular glomeruli, more thickening basement membrane, increased mesangial matrix, inflammatory cell infiltration, immunoglobulin IgG and complement C3glomerular deposition. LDLr-/-and C57BL/6J mice without the above performance.4. After14weeks of high fat diet, LDLr-/-mice showed significantly hyperlipidemia and AS lesions, but MRL/lpr mice and C57BL/6J mice were unable to show elevated lipid levels and obvious AS lesions. The levels of TC、TG、 HDL-C and LDL-C in MRL/lpr group were lower than that in C57BL/6J group, TG and LDL-C levels of the most obvious.5. After intraperitoneal injection of Pristane0.5ml and14weeks high fat diet,4-week-old and8-week-old LDLr-/-mice all showed obvious renal lesions which similar to MRL/lpr mice.4-week-old pristane injection mice also showed hair removal, skin lesions, swollen lymph, spleen enlargement, increased IgG levels.8-week-old pristane injection mice had no above performance. Significantly decreased complement C3and significantly increased autoantibodies (ANA, anti ds-DNA antibody) were hardly ever observed.6. Mice in the control group did not show SLE-like phenotype, serology changes, immunological abnormalities and renal lesions.7. After14weeks high fat diet, mice in experimental groups and control group exhibited overt hyperlipidemia and AS lesions. Mice in experimental group two had the highest lipid levels, followed by control group, experimental group one has the lowest lipid levels. But experimental group one has the most serious AS lesions, followed by experimental group two, control group has the lightest AS lesions.8. AS lesions of SLE premature AS mouse model is characterized by significantly fibrous hyperplasia, a large amount of apoptotic cells, a few macrophages and smooth muscle. Immunoglobulin IgG deposition were observed in the plaque surface of experimental group and control group. But complement C3deposition did not detect in experimental group, while the control group detected complement C3deposition.Conclusions1. The traditional risk factors of female SLE patients with premature CAD do not significantly reduce, but their coronary artery lesion are more extension.2. Traditional cardiovascular risk factors in SLE patients are increased significantly. Dyslipidemia in SLE are closely related to corticosteroids therapy, renal damage and immune inflammation reaction.3. Hyperlipidemia is an important condition for the development of atherosclerosis, but only SLE disease itself does not able to produce significant AS lesions.4. Except the effect of corticosteroids and nephritis, SLE disease itself may tend to make the lipid levels decreased.5. Pristane can induce LDLr-/-mouse display lupus, juvenile mice administered will significantly accelerate the SLE lesions.6.4-week-old LDLr-/-+single intraperitoneal injection of0.5ml pristane+14weeks of high fat diet can successfully create SLE premature AS mouse model, if observe for a long time, effect may be more pronounced.7. The AS lesion that based on the SLE disease is more serious, vascular lesions characterized by fiber hyperplasia, plaque tend to stable plaque.8. Increased apoptotic cells and immunoglobulin IgG deposition, while decreased macrophages and complement C3clearance may promote AS in SLE.