What is the significance of CD34 immunostaining in the extraglomerular and intraglomerular mesangium?

The severity of glomerular endothelial cell injury is associated with infiltrating macrophage heterogeneity in endocapillary proliferative glomerulonephritis

Endocapillary proliferation occurs in various types of glomerulonephritis (GN), with varying prognoses. We examined 42 renal biopsy samples representing endocapillary proliferative lesions from post-streptococcal acute GN (PSAGN), Henoch–Schönlein purpura nephritis (HSPN), and lupus nephritis (LN). In PSAGN, the glomerular capillary network was maintained, although severe lesions displayed dots or short, curved lines, indicating CD34-positive capillaries and suggesting capillary obstruction. Conversely, patients with LN and HSPN displayed obstruction of CD34-positive capillaries with dissociation from the glomerular basement membrane even in mild lesions. According to computer-assisted morphologic analysis, the cell density did not differ between the diseases. However, in PSAGN, the number of capillary loops was significantly increased, with a larger glomerular capillary luminal area than in the other groups. In addition, the number and frequency of CD163-positive cells (M2 macrophages) tended to be higher in PSAGN, while there were no significant differences in the number of CD68-positive (total) macrophages. These results indicate that in PSAGN, endothelial cell damage is less severe, and angiogenesis may be promoted. The severity of endothelial cell injury in each disease may be associated with differences in infiltrating inflammatory cell phenotypes.

Relationship between interstitial CD34 positive cells and active phase of lupus nephritis

Objective

Lupus nephritis is one of the most serious and common complications of systemic lupus erythematosus. It has an unpredictable course, and the type, severity, and activity of renal lesions cannot be assessed only by clinical and laboratory findings. The aim of the present study was to determine the relationship between the expression of CD34 and the histopathological findings of lupus nephritis.

Methods

A total of 73 renal biopsy samples of patients with a diagnosis of lupus nephritis were examined for CD34 expression by immunohistochemistry. Samples without staining were considered as 0, mild staining as 1+, moderate as 2+, and strong staining as 3+. The relationship between CD34 expression and histopathological and clinical data (including activity index, chronicity index, lupus nephritis class, age, sex, blood pressure, complete blood count, renal function tests, and serological findings) was analyzed.

Results

The mean age of the patients was 29.3±11.3 years. CD34 was expressed in all of the cases but with different intensities. There was a significant relationship between the expression of CD34 and the activity index, as a strong expression was seen in lower activity indices (p<0.001). CD34 expression was correlated with patients’ white blood cell (WBC) count and systolic blood pressure (SBP). Patients with strong (score 3) CD34 expression had higher SBPs and lower WBC counts (p=0.03 and 0.04, respectively).

Conclusion

A strong interstitial expression of CD34 was observed in lower activity indices. It seems that CD34 expression could play a protective role in lupus nephritis and could reduce renal activity.

Investigating the Vascularization of Tissue-Engineered Bone Constructs Using Dental Pulp Cells and 45S5 Bioglass® Scaffolds

Identification of a suitable cell source combined with an appropriate 3D scaffold is an essential prerequisite for successful engineering of skeletal tissues. Both osteogenesis and angiogenesis are key processes for bone regeneration. This study investigated the vascularization potential of a novel combination of human dental pulp stromal cells (HDPSCs) with 45S5 Bioglass^® scaffolds for tissue-engineered mineral constructs in vivo and in vitro. 45S5 Bioglass scaffolds were produced by the foam replication technique with the standard composition of 45 wt% SiO₂, 24.5 wt% Na₂O, 24.5 wt% CaO, and 6 wt% P₂O₅. HDPSCs were cultured in monolayers and on porous 45S5 Bioglass scaffolds under angiogenic and osteogenic conditions for 2–4 weeks. HDPSCs expressed endothelial gene markers (CD34, CD31/PECAM1, and VEGFR2) under both conditions in the monolayer. A combination of HDPSCs with 45S5 Bioglass enhanced the expression of these gene markers. Positive immunostaining for CD31/PECAM1 and VEGFR2 and negative staining for CD34 supported the gene expression data, while histology revealed evidence of endothelial cell-like morphology within the constructs. More organized tubular structures, resembling microvessels, were seen in the constructs after 8 weeks of implantation in vivo. In conclusion, this study suggests that the combination of HDPSCs with 45S5 Bioglass scaffolds offers a promising strategy for regenerating vascularized bone grafts.

Swimming exercise prevents fibrogenesis in chronic kidney disease by inhibiting the myofibroblast transdifferentiation

Background

The renal function of chronic kidney disease (CKD) patients may be improved by a number of rehabilitative mechanisms. Swimming exercise training was supposed to be beneficial to its recovery.

Methodology/Principal Findings

Doxorubicin-induced CKD (DRCKD) rat model was performed. Swimming training was programmed three days per week, 30 or 60 min per day for a total period of 11 weeks. Serum biochemical and pathological parameters were examined. In DRCKD, hyperlipidemia was observed. Active mesangial cell activation was evidenced by overexpression of PDGFR, P-PDGFR, MMP-2, MMP-9, α-SMA, and CD34 with a huge amount collagen deposition. Apparent myofibroblast transdifferentiation implicating fibrogenesis in the glomerular mesangium, glomerulonephritis and glomeruloscelorosis was observed with highly elevated proteinuria and urinary BUN excretion. The 60-min swimming exercise but not the 30 min equivalent rescued most of the symptoms. To quantify the effectiveness of exercise training, a physical parameter, i.e. “the strenuosity coefficient” or “the myokine releasing coefficient”, was estimated to be 7.154×10⁻³ pg/mL-J.

Conclusions

The 60-min swimming exercise may ameliorate DRCKD by inhibiting the transdifferentiation of myofibroblasts in the glomerular mesangium. Moreover, rehabilitative exercise training to rescue CKD is a personalized remedy. Benefits depend on the duration and strength of exercise, and more importantly, on the individual physiological condition.

Ferulic acid is nephrodamaging while gallic acid is renal protective in long term treatment of chronic kidney disease

BACKGROUNDS & AIMS

The long term therapeutic effect of ferulic acid (FA) and gallic acid (GA) in treatment of chronic kidney disease (CKD) has been lacking.

METHODS

Doxorubicin (DR, Adriamycin)-induced CKD rat model was established for this study.

RESULTS

DR significantly reduced levels of serum albumin, GOT, GPT, RBC, TNF-α, and urinary creatinine and elevated serum cholesterol, TG, BUN, creatinine, uric acid, WBC, platelet count, and IL-6. In DRCKD rats, FA and GA significantly increased kidney weight and glomerular volume. FA reduced glomerular filtration rate but GA did not. FA enhanced more collagen deposition than GA in renal cortex and glomeruli. Both FA and GA showed crucial hyperlipidemic activity. The inhibitory effects of FA and GA on MMP-2 were very comparable. GA suppressed MMP-2 more effectively than FA in DRCKD rats. Both FA and GA induced SOD elevation and MDA elimination. In DRCKD rats, Western blot analysis indicated that FA further up-regulated CD34, α-SMA, tissue pDGFR, p-PDGFR, and TGF-β; and down-regulated p-PI3K, and p-Akt. Since both PDGF-BB and TGF-β are considered to induce kidney prefibrosis stage, GA was proved to be more beneficial in this regard.

CONCLUSIONS

GA tends to protect the CKD while FA is not recommended for the long term CKD therapy.