Application of a Simple Quantitative Assessment of Atherosclerotic Lesions in Freshly Isolated Aortas from Rabbits

Reversal of atherosclerosis by restoration of vascular copper homeostasis

Atherosclerosis has traditionally been considered as a disorder characterized by the accumulation of cholesterol and thrombotic materials within the arterial wall. However, it is now understood to be a complex inflammatory disease involving multiple factors. Central to the pathogenesis of atherosclerosis are the interactions among monocytes, macrophages, and neutrophils, which play pivotal roles in the initiation, progression, and destabilization of atherosclerotic lesions. Recent advances in our understanding of atherosclerosis pathogenesis, coupled with results obtained from experimental interventions, lead us to propose the hypothesis that atherosclerosis may be reversible. This paper outlines the evolution of this hypothesis and presents corroborating evidence that supports the potential for atherosclerosis regression through the restoration of vascular copper homeostasis. We posit that these insights may pave the way for innovative therapeutic approaches aimed at the reversal of atherosclerosis.

Addition of glomerular lesion severity improves the value of anemia status for the prediction of renal outcomes in Chinese patients with type 2 diabetes

We aimed to determine the utility of biopsy data and anemia for the prediction of renal outcomes in Chinese patients with type 2 diabetes. In total, 441 Chinese patients with type 2 diabetes and biopsy-confirmed diabetic nephropathy (DN) were enrolled in a retrospective study. Their renal pathology was assessed using the Renal Pathology Society system. Cox proportional hazards models were used to estimate hazard ratios (HRs) for end-stage renal disease (ESRD), and immunofluorescence staining was used to assess the expression of hypoxia-inducible factor (HIF)-α in patients’ kidneys. We found that glomerular pathology classification was an independent pathological predictor of low hemoglobin concentration, according to linear and logistic regression analyses. Each 1 g/dL decrease in baseline hemoglobin concentration was associated with a 42% higher risk of an adverse renal outcome, after adjustment for clinical and pathologic covariates. In patients with severe glomerular lesions, the risk of progression to ESRD was significantly higher if mild or moderate/severe anemia was present, but in patients with mild glomerular lesions, the risk was only significantly higher in those with moderate or severe anemia than in the absence of anemia. Harrell’s C Concordance was improved, but the Akaike information criterion was worsened by adding the glomerular pathology classification to the use of anemia status and clinical data. Immunofluorescence staining revealed that renal HIF-1α and HIF-2α expression was significantly higher in classes II–IV than class I. Thus, the addition of glomerular pathology classification increases the value of anemia status for the prediction of the progression to ESRD.

Effects of withdrawing an atherogenic diet on the atherosclerotic plaque in rabbits

Lifestyle interventions and pharmacotherapy are the most common of non-invasive treatments for atherosclerosis, but the individual effect of diet on plaques remains unclear. The current study aimed to investigate the effect of withdrawing the atherogenic diet on plaque in the aortas of rabbits. Experimental atheroma was induced in 33 rabbits using a 1% high cholesterol diet for 30 days (H-30 d) or 90 days (H-90 d, baseline group). After 90 days of the atherogenic diet, the remaining animals were divided into four groups: A total of 10 rabbits continued to consume the atherogenic diet for 50 days (H-90 d & H-50 d; n=5) or 140 days (H-90 d & H-140 d; n=5). Another 13 rabbits were switched to a chow diet for 50 days (H-90 d & C-50 d; n=7) or 140 days (H-90 d & C-140 d; n=6). A total of 10 age-matched rabbits in the control groups were fed a chow diet for 90 and 230 days, respectively. The en face or cross-sectional plaque areas were determined using oil red O staining and elastic van Gieson staining. Immunohistochemistry analyses were used to assess the macrophages or smooth muscle cell contents. When fed an atherogenic diet for 90 days, the rabbits' abdominal aortas exhibited severe atherosclerotic lesions (the median en face plaque area was 63.6%). After withdrawing the atherogenic diet, the plaque area did not shrink with feeding the chow diet compared with the baseline, but increased to 71.8 or 80.5% after 50 or 140 days, respectively. After removing cholesterol from the diet, the lipids content in the plaques increased during the first 50 days, and then decreased compared with the baseline group. Furthermore, withdrawing the atherogenic diet increased the total collagen content and the percentage of the smooth muscle cells, alleviated macrophage infiltration, decreased the vulnerable index and promoted the cross-linking of collagen. Feeding the rabbits an atherogenic diet followed by removal of cholesterol from the diet did not lead to the regression of established lesions but instead delayed the progression of the lesions and promoted the stabilization of the plaque.

Solidified glomerulosclerosis, identified using single glomerular proteomics, predicts end-stage renal disease in Chinese patients with type 2 diabetes

Few histological prognostic indicators for end-stage renal disease (ESRD) have been validated in diabetic patients. This biopsy-based study aimed to identify nephropathological risk factors for ESRD in Chinese patients with type 2 diabetes. Histological features of 322 Chinese type 2 diabetic patients with biopsy-confirmed diabetic nephropathy (DN) were retrospectively analysed. Cox proportional hazards analysis was used to estimate the hazard ratio (HR) for ESRD. Single glomerular proteomics and immunohistochemistry were used to identify differentially expressed proteins and enriched pathways in glomeruli. During the median follow-up period of 24 months, 144 (45%) patients progressed to ESRD. In multivariable models, the Renal Pathology Society classification failed to predict ESRD, although the solidified glomerulosclerosis (score 1: HR 1.65, 95% confidence interval [CI] 1.04-2.60; score 2: HR 2.48, 95% CI 1.40-4.37) and extracapillary hypercellularity (HR 2.68, 95% CI 1.55-4.62) were identified as independent risk factors. Additionally, single glomerular proteomics, combined with immunohistochemistry, revealed that complement C9 and apolipoprotein E were highly expressed in solidified glomerulosclerosis. Therefore, solidified glomerulosclerosis and extracapillary hypercellularity predict diabetic ESRD in Chinese patients. Single glomerular proteomics identified solidified glomerulosclerosis as a unique pathological change that may be associated with complement overactivation and abnormal lipid metabolism.

Associations Between High-Altitude Residence and End-Stage Kidney Disease in Chinese Patients with Type 2 Diabetes

Zhao, Lijun, Xi Wang, Tingli Wang, Wenxin Fan, Honghong Ren, Rui Zhang, Yutong Zou, Huan Xu, Jie Zhang, Yunhong Wu, and Fang Liu. Associations between high-altitude residence and end-stage kidney disease in Chinese patients with type 2 diabetes. High Alt Med Biol. 21:396-405, 2020. Background: This study investigated whether living at high altitude was associated with progression to end-stage kidney disease (ESKD) in Chinese patients with diabetic nephropathy (DN). Materials and Methods: This retrospective study included 369 patients with type 2 diabetes mellitus (T2DM) and biopsy-confirmed DN. Cox proportional hazards models were used to estimate hazard ratios (HRs) for the influence of living at high altitude on ESKD. Results: Patients living at ≥2,000 m above sea level were more likely to be Tibetan, and they had higher mean body mass indexes, glycosylated hemoglobin, hemoglobin concentrations, and baseline estimated glomerular filtration rates than those living at lower altitudes. During a median follow-up period of 20 months, 141 (38%) patients progressed to ESKD. In multivariable Cox analysis adjusted for age, sex, ethnicity, and clinical and pathological parameters, living at high altitude was independently associated with progression to ESKD in Chinese DN patients [HR 2.83, 95% confidence interval (CI) 1.05-7.58]. Compared with Han Chinese, Tibetans were at a lower risk of progression to ESKD (HR 0.15, 95% CI 0.04-0.59). Conclusions: Living at high altitude was independently associated with renal outcome in Han Chinese patients with T2DM and DN, but not native Tibetans.

Serum transferrin predicts end-stage Renal Disease in Type 2 Diabetes Mellitus patients

Background: To investigate the relationship between serum iron status and renal outcome in patients with type 2 diabetes mellitus (T2DM). Methods: Chinese patients (n=111) with T2DM and biopsy-proven diabetic nephropathy (DN) were surveyed in a longitudinal, retrospective study. Serum iron, total iron-binding capacity, ferritin, and transferrin were measured at the time of renal biopsy. Iron deposition and transferrin staining were performed with renal biopsy specimens of DN patients and potential kidney donors. End-stage renal disease (ESRD) was the end-point. ESRD was defined as an estimated glomerular filtration rate <15 mL/min/1.73 m² or the need for chronic renal replacement therapy. Cox proportional hazard models were used to estimate the hazard ratios (HRs) for the influence of serum iron metabolism on ESRD. Results: During a median follow up of 30.9 months, 66 (59.5%) patients progressed to ESRD. After adjusting for age, sex, baseline systolic blood pressure, renal functions, hemoglobin, HbA1c, and pathological findings, lower serum transferrin concentrations were significantly associated with higher ESRD in multivariate models. Compared with patients in the highest transferrin quartile (≥1.65 g/L), patients in the lowest quartile (≤1.15 g/L) had multivariable-adjusted HR (95% confidence interval) of 7.36 (1.40-38.65) for ESRD. Moreover, tubular epithelial cells in DN exhibited a higher deposition of iron and transferrin expression compared with healthy controls. Conclusions: Low serum transferrin concentration was associated with diabetic ESRD in patients with T2DM. Free iron nephrotoxicity and poor nutritional status with accumulated iron or transferrin deposition might contribute to ESRD.