A diet containing cod backbone proteins attenuated the development of mesangial sclerosis and tubular dysfunction in male obese BTBR ob/ob mice

PURPOSE

The obese black and tan, brachyuric (BTBR) ob/ob mouse spontaneously develops features comparable to human diabetic nephropathy. The primary aim of the present study was to investigate if a diet containing fish proteins would attenuate or delay the development of glomerular hypertrophy (glomerulomegaly), mesangial sclerosis and albuminuria in obese BTBR ob/ob mice.

METHODS

Obese BTBR.CgLepob/WiscJ male mice were fed diets containing 25% of protein from Atlantic cod backbones and 75% of protein from casein (Cod-BB group), or casein as the sole protein source (control group). Kidneys were analysed morphologically, and markers for renal dysfunction were analysed biochemically in urine and serum.

RESULTS

The Cod-BB diet attenuated the development of mesangial sclerosis (P 0.040) without affecting the development of glomerular hypertrophy and albuminuria. The urine concentration of cystatin C (relative to creatinine) was lower in mice fed the Cod-BB diet (P 0.0044).

CONCLUSION

A diet containing cod backbone protein powder attenuated the development of mesangial sclerosis and tubular dysfunction in obese BTBR ob/ob mice, but did not prevent the development of glomerular hypertrophy and albuminuria in these mice.

Pathological and clinical characteristics of late-onset oligomeganephronia based on a histomorphometric study

BACKGROUND

Late-onset oligomeganephronia (OMN) is a rare chronic kidney disease and has no quantitative criteria for diagnosis yet. The current study aimed to explore its clinicopathological features by histomorphometric analysis.

METHODS

We retrospectively re-reviewed all patients with enlarged and sparse glomeruli by light microscopy at Peking University First Hospital from 2012 to 2021, excluding those with any factor known to contribute to similar changes. Age- and sex-matched patients with thin basement membrane nephropathy were selected as control to establish the cut-off values for glomerulomegaly and rarity. Late-onset OMN cases were then confirmed and the clinicopathological characteristics were summarized.

RESULTS

Mean diameter and density of cortical glomeruli in control was 156.53 ± 27.50 μm and 4.07 ± 0.63 /mm², giving a lower limit of 211.53 μm for glomerulomegaly and an upper of 2.81 /mm² for rarity. Seven adults of three females and four males were finally diagnosed as late-onset OMN with a mean age of 26.57 years. They showed mild to moderate proteinuria and/or renal dysfunction at biopsy with the mean proteinuria, serum creatinine (Scr) level, and estimated glomerular filtration rate of 0.50 g/d (0.10-0.95 g/d), 140.9 µmol/L (95.1-227.1 µmol/L), and 58.7 mL/min/1.73m² (21.3-98.0 mL/min/1.73m²), respectively. Four patients (57.1%) had normal Scr at diagnosis. Six patients with available data showed renal tubular injury with increased urinary microalbumin in all, elevated N-acetyl-β-glucosaminidase in two, and elevated α1 microglobulin in five. Kidney size was normal or slightly reduced. The mean density and glomerular diameter of the seven cases was 0.86 mm² (0.55-1.41 /mm²) and 229.73 μm (211.88-260.66 μm). Segmental glomerular sclerosis was observed in six (85.7%) with four (66.7%) of perihilar type. Proximal tubule dilation was observed in all, focal to diffuse, lining with enlarged epithelial cells. The mean foot process width was 634.02 nm, wider than 472.54 nm of the control (P = 0.0002).

CONCLUSION

Late-onset OMN should be considered a special entity with relatively slow clinical progress characterized by hypertrophy of the sparsely distributed nephron.

Baseline High Blood Pressure is Associated with Clinico-Pathologic Findings and Later Renal Progression in Chronic Glomerulonephritis

Background

Several factors had been suggested to contribute to the development of hypertension in chronic glomerulonephritis (GN). This study was conducted to find the association of baseline blood pressure (BP) with pathophysiologic findings and later renal progression in chronic GN.

Methods

Clinico-pathological findings including serum creatinine (Cr), proteinuria, pathological findings, and urinary Na excretion were analyzed in a total of 233 patients with IgA nephropathy from The Kyung-Hee Cohort of GN. Glomerular surface area (GSA) was measured by imaging analysis and urine angiotensinogen (AGT) concentrations by human ELISA kits.

Results

Systolic BP was ≥130mmHg in 124 patients (53%). Systolic BP was negatively correlated with follow-up eGFR (r=−0.32, p<0.0001) and positively serum uric acid concentrations, while it had no significant relationships with initial serum Cr and eGFR. As compared with patients with systolic BP<130 mmHg, those with ≥130 mmHg were older and showed higher serum Cr, proteinuria, 24 hr urinary Na excretion, mean GSA, and T-I fibrosis, lower follow-up eGFR, and steeper decline in slope of eGFR. The results in patients with normal serum Cr concentrations were comparable to those in whole group. Systolic BP was positively correlated with age, baseline and follow-up proteinuria, serum uric acid concentrations and IgM deposit and negatively with follow-up eGFR. In subgroup analysis, systolic BP was also positively correlated with mean GSA and urinary AGT concentrations.

Conclusion

This study showed that baseline systolic BP is related to urinary Na excretion, glomerulomegaly, T-I fibrosis and later renal progression in patients with IgA nephropathy.

Ultrasound Imaging of the Renal Parenchyma of Premature Neonates for the Assessment of Renal Growth and Glomerulomegaly

Evidence is increasingly showing that prematurity results in chronic kidney disease. We hypothesized that we could use ultrasound imaging to measure and monitor the growth of the renal parenchyma in premature neonates. We conducted a prospective, case-control study to compare renal parenchymal growth between neonates born prematurely and term neonates. The study patients underwent ultrasound assessment at 32 wk postmenstrual age (PMA) and 37 wk PMA. Term neonates (gestation >37 completed wk) admitted to the neonatal unit with minor neonatal conditions were recruited into the control group. Complete data sets were available in 91 premature neonates and during the same period, 56 term neonates were recruited as the control. The median birth weight (preterm babies) was 930 g (780-1220 g), and the mean gestational age was 27.0 wk (2.1 wk). Total renal volume (TRV) increased from 14.6 (4.3) cm³ to 20.5 (5.3) cm³ from 32 to 37 wk PMA. During the same period, the total renal parenchyma (TRP) thickness increased from 1.6 (0.3) cm to 1.8 (0.3) cm. At 37 wk PMA, ex-premature neonates have a significantly smaller total renal volume (20.5 [5.3] versus 25.9 [6.4] cm³; p < 0.001) and total renal parenchyma thickness (1.8 [0.3] versus 2.0 [0.2] cm; p = 0.015) compared with term (control) neonates. However, premature neonates at 37 wk PMA have a larger TRP:TRV ratio compared with term neonates (0.09 [0.02] versus 0.0 8 [0.02] cm^-2; p < 0.001). Reduced nephron endowment as a result of prematurity may cause the remaining nephrons to undergo compensatory glomerulomegaly and we postulate this is the reason for the observed differences. Ultrasound imaging of the renal parenchyma shows promise in assessing the effects of prematurity on the developing kidney.