Effects of Low-Protein Diets Supplemented with Ketoacid on Expression of TGF-β and Its Receptors in Diabetic Rats

Effects of isolated maternal hypothyroxinemia on adverse pregnancy outcomes

PURPOSE

There are conflicting results about the effects of maternal hypothyroidism (IMH) on adverse pregnancy outcomes. This study aimed to investigate the relationship between IMH identified in the first trimester of gestation and adverse pregnancy outcomes.

METHODS

In this prospective cohort study, we used data from the Tehran Thyroid and Pregnancy study (TTPs). To diagnose IMH, we considered a threshold of 2.04 for FTI, which was based on the 10th percentile of this marker identified in the 1st trimesters. A generalized linear regression (GLM) model adjusted for the gravidity, urine iodine, and TPOAb status was applied to assess the effects of IMH on adverse pregnancy outcomes, compared to the controls group.

RESULTS

Penalized logistic regression analysis indicated that the adjusted odds ratio (aOR) of Preterm premature rupture of the membranes (PPROM) in women with IMH was 5.43-folder higher than euthyroid group [aOR 5.43, 95% CI (1.40, 21.1), p = 0.01]. Besides, the adjusted odds ratio of low birth weight (LBW) in the IMH group was 2.53-folder higher than the healthy group [aOR 2.53, 95% CI (1.01, 6.33), p = 0.047]. Furthermore, the results of the GLM adjusted model revealed that the mean of neonatal head circumference and weight in the IMH group was around 0.43 cm (95% CI - 0.80, - 0.07, p = 0.02) and 145.4 g (95% CI - 242.6, - 48.1, p = 0.003) lower than euthyroid group, respectively.

CONCLUSIONS

This study demonstrated that women with IMH identified in early pregnancy have a higher odds ratio for developing some adverse pregnancy outcomes, including PPROM and LBW compared to their euthyroid counterparts. Also, the neonatal head circumference and weight in the IMH group were lower than in the euthyroid group.

Evidence for Toxic Advanced Glycation End-Products Generated in the Normal Rat Liver

Glucose/fructose in beverages/foods containing high-fructose corn syrup (HFCS) are metabolized to glyceraldehyde (GA) in the liver. We previously reported that GA-derived advanced glycation end-products (toxic AGEs, TAGE) are generated and may induce the onset/progression of non-alcoholic fatty liver disease (NAFLD). We revealed that the generation of TAGE in the liver and serum TAGE levels were higher in NAFLD patients than in healthy humans. Although we propose the intracellular generation of TAGE in the normal liver, there is currently no evidence to support this, and the levels of TAGE produced have not yet been measured. In the present study, male Wister/ST rats that drank normal water or 10% HFCS 55 (HFCS beverage) were maintained for 13 weeks, and serum TAGE levels and intracellular TAGE levels in the liver were analyzed. Rats in the HFCS group drank 127.4 mL of the HFCS beverage each day. Serum TAGE levels and intracellular TAGE levels in the liver both increased in the HFCS group. A positive correlation was observed between intracellular TAGE levels in the liver and serum TAGE levels. On the other hand, in male Wister/ST rats that drank Lactobacillus beverage for 12 weeks-a commercial drink that contains glucose, fructose, and sucrose- no increases were observed in intracellular TAGE or serum TAGE levels. Intracellular TAGE were generated in the normal rat liver, and their production was promoted by HFCS, which may increase the risk of NAFLD.

β-N-Oxalyl-L-α,β-diaminopropionic acid from Panax notoginseng plays a major role in the treatment of type 2 diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is one of the most serious and dangerous chronic complications of diabetes mellitus.Panax notoginseng has been widely used with great efficacy in the long-term treatment of kidney disease. However, the mechanism by which it exerts its effects has not been fully elucidated.

AIM

We sought to identify the major components ofPanax notoginseng that are effective in reducing the symptoms of DN in vitro and in vivo.

METHODS

Inhibition of cell proliferation and collagen secretion were used to screen the ten most highly concentrated components ofPanax notoginseng. The STZ-induced DN rat model on a high-fat-high-glucose diet was used to investigate the renal protective effect of Panax notoginseng and dencichine and their underlying molecular mechanisms.

RESULTS

Among the ten components analysed, dencichine (β-N-oxalyl-L-α,β-diaminopropionic acid) was the most protective against DN. Dencichine andPanax notoginseng attenuated glucose and lipid metabolic disorders in STZ-induced DN rats on a high-fat-high-glucose diet. In the untreated DN rats, we observed albuminuria, renal failure, and pathological changes. However, treatment with dencichine and Panax notoginseng alleviated these symptoms. We also observed that dencichine suppressed the expression of TGF-β1 and Smad2/3, which mediates mesangial cell proliferation and extracellular matrix (ECM) accumulation in the glomerulus, and enhanced the expression of Smad7, the endogenous inhibitor of the TGF-β1/Smad signalling pathway.

CONCLUSION

From these results, we concluded that dencichine is the main compound inPanax notoginseng that is responsible for alleviating renal injury in the experimental DN model. Its mechanism may be related to the reduction of the deposition of ECM in glomeruli and inhibition of the epithelial mesenchymal transformation (EMT) by inhibition of the TGF-β1/Smad signalling pathway.

Very low protein diet plus ketoacid analogs of essential amino acids supplement to retard chronic kidney disease progression

Background

A very low protein diet (VLPD) with ketoacid analogs of essential amino acids (KA/EAA) administration can remarkably influence protein synthesis and metabolic disturbances of patients with advanced chronic kidney disease (CKD), and may also slow the decline in renal function.

Methods

A retrospective cohort study was carried out to monitor renal progression and metabolic and nutritional status among 140 patients with CKD stage III or IV. One group (n = 70) was on a low protein diet (LPD) with 0.6 g of protein intake, and another group (n = 70) was on a VLPD with 0.3 g of protein and KA/EAA supplementation of 100 mg/kg/day for 12 months.

Results

At 12-month follow-up, estimated glomerular filtration rate (GFR) significantly decreased from 41.6 ± 10.2 to 36.4 ± 8.8 mL/min/1.73 m² (P < 0.001) and urine protein increased from 0.6 ± 0.5 to 0.9 ± 1.1 g/day (P = 0.017) in the LPD group, but no significant changes in estimated GFR and urine protein were found in the VLPD plus KA/EAA group. A significant mean difference in rate of change in estimated GFR (-5.2 ± 3.6 mL/min/1.73 m² per year; P < 0.001) was observed between the two groups. After Cox regression analysis, treatment with VLPD plus KA/EAA significantly protected against the incidence of declining GFR > 10% annually (adjusted hazard ratio, 0.42; 95% confidence interval, 0.23-0.79; P = 0.006) and significant correlations were found between using VLPD plus KA/EEA and increased GFR.

Conclusion

VLPD supplementation with KA/EAA is associated with delayed renal progression while preserving the nutritional status in the patients with CKD. Co-administration of VLPD and KA/EAA may prove an effective alternative to conservative management of CKD.

Low-protein diet supplemented with ketoacids delays the progression of diabetic nephropathy by inhibiting oxidative stress in the KKAy mice model

Diabetic nephropathy (DN) is a major cause of chronic kidney disease. We aimed to investigate the effect of the low-protein diets (LPD) supplemented with ketoacids (LPD+KA) in KKAy mice, an early type 2 DN model. KKAy mice were treated with normal protein diet (NPD), LPD or LPD+KA from 12 to 24 weeks of age. A period of 12-week treatment with LPD significantly reduced albuminuria as compared with that observed after NPD treatment. Treatment with LPD+KA further reduced albuminuria as compared with that observed with LPD treatment alone. Moreover, LPD treatment reduced mesangial expansion, thickness of glomerular basement membrane and the severity of the podocyte foot process effacement in KKAy mice; these effects were more pronounced in KKAy mice treated with LPD+KA. Both LPD and LPD+KA treatments slightly reduced total body weight, but had no significant effect on kidney weight and blood glucose concentrations when compared with NPD-treated KKAy mice. LPD treatment slightly attenuated oxidative stress in kidneys as compared with that observed in NPD-treated KKAy mice; however, LPD+KA treatment remarkably ameliorated oxidative stress in diabetic kidneys as shown by decreased malondialdehyde concentrations, protein carbonylation, nitrotyrosine expression and increased superoxide dismutase expression. Nutritional therapy using LPD+KA confers additional renal benefits as compared with those of LPD treatment alone in early type 2 DN through inhibition of oxidative stress.