Risk factors for progression in ADPKD

Acyl-CoA thioesterase 13 (ACOT13) attenuates the progression of autosomal dominant polycystic kidney disease in vitro via triggering mitochondrial-related cell apoptosis

PURPOSE

Autosomal dominant polycystic kidney disease (ADPKD) is the most common cause of end-stage kidney disease. It has been shown that Acyl-CoA thioesterase 13 (ACOT13) level was reduced in renal cystic tissues from ADPKD patients. However, the role of ACOT13 in ADPKD remains largely elusive.

METHODS

The data in the GSE7869 dataset were acquired from the GEO database to determine ACOT13 level between normal renal cortical tissues and renal cystic tissues. Next, the potential functions of ACOT13 were explored by gene set enrichment analysis (GSEA). Furthermore, ACOT13 level in ADPKD cells (WT9-12) was verified by RT-qPCR. The effects of ACOT13 on WT9-12 cell growth were evaluated using the EdU staining and flow cytometry assays.

RESULTS

Compared to normal group, ACOT13 mRNA level was obviously reduced in renal cystic tissues and WT9-12 cells. Meanwhile, GSEA results showed that compared to the low ACOT13 expression group, PI3K-Akt and MAPK signaling pathways were inactivated, and PPAR signaling pathway and fatty acid metabolism were activated in high ACOT13 expression group. Furthermore, overexpression of ACOT13 notably reduced WT9-12 cell proliferation and triggered cell cycle arrest. Moreover, ACOT13 overexpression remarkably triggered apoptosis, increased cleaved caspase 3 protein level, reduced ATP production and induced loss of mitochondrial membrane potential in WT9-12 cells, suggesting that ACOT13 overexpression could trigger mitochondrial-related apoptosis in WT9-12 cells.

CONCLUSIONS

Collectively, our results showed that overexpression of ACOT13 could suppress WT9-12 cell proliferation and trigger mitochondrial-mediated cell apoptosis, suggesting that ACOT13 may exert a protective role in ADPKD.

Total kidney volume: the most valuable predictor of autosomal dominant polycystic kidney disease progression

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the progressive development of kidney cysts resulting in damage to kidney structure and function. Yu et al. showed that height-adjusted total kidney volume (htTKV) was a significant independent predictor of ADPKD progression after a follow-up of 14.5 years. The genotype was not an independent prognostic factor after adjusting for htTKV. This commentary discusses several considerations in model comparison, biomarker validation, and future challenges in ADPKD research.

Total Kidney Volume as a Biomarker of Disease Progression in Autosomal Dominant Polycystic Kidney Disease

Purpose of review:

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder characterized by the formation of kidney cysts and kidney enlargement, which progresses to kidney failure by the fifth to seventh decade of life in a majority of patients. Disease progression is evaluated primarily through serum creatinine and estimated glomerular filtration rate (eGFR) measurements; however, it is known that serum creatinine and eGFR values typically do not change until the fourth or fifth decade of life. Until recently, therapy only existed to target complications of ADPKD. As therapeutic agents continue to be investigated for use in ADPKD, a suitable biomarker of disease progression in place of serum creatinine is needed.

Sources of information:

This review summarizes recent research regarding the use of total kidney volume as a biomarker in ADPKD, as presented at the Canadian Society of Nephrology symposium held in April 2015.

Findings:

Measurement of patients’ total kidney volume made using ultrasound (US) or magnetic resonance imaging (MRI) has been shown by the Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) study to be directly correlated with both increases in cyst volume and change in glomerular filtration rate (GFR). Additional studies have shown total kidney volume to have an association with complications of ADPKD as well.

Limitations:

Areas for further study continue to exist in comparison of methods of measuring total kidney volume.

Implications:

We believe that the evidence suggests that total kidney volume may be an appropriate surrogate marker for ADPKD disease progression.

Assessing Risk of Disease Progression and Pharmacological Management of Autosomal Dominant Polycystic Kidney Disease: A Canadian Expert Consensus

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited renal disorder worldwide. The disease is characterized by renal cysts and progressive renal failure due to progressive enlargement of cysts and renal fibrosis. An estimated 45% to 70% of patients with ADPKD progress to end-stage renal disease by age 65 years. Although both targeted and nontargeted therapies have been tested in patients with ADPKD, tolvaptan is currently the only pharmacological therapy approved in Canada for the treatment of ADPKD. The purpose of this consensus recommendation is to develop an evidence-informed recommendation for the optimal management of adult patients with ADPKD. This document focuses on the role of genetic testing, the role of renal imaging, predicting the risk of disease progression, and pharmacological treatment options for ADPKD. These areas of focus were derived from 2 national surveys that were disseminated to nephrologists and patients with ADPKD with the aim of identifying unmet needs in the management of ADPKD in Canada. Specific recommendations are provided for the treatment of ADPKD with tolvaptan.