Metallothioneins and renal ageing

Area of Science:

• Nephrology
• Gerontology
• Molecular Biology

Background:

• Human lifespan is increasing, leading to a higher prevalence of chronic kidney disease in older adults.
• The mechanisms underlying age-related decline in kidney function remain largely unknown.

Purpose of the Study:

• To investigate age-associated gene expression changes in healthy donor kidneys.
• To explore the functional role of identified genes in kidney aging.

Main Methods:

• Microarray analysis of kidney biopsies from different age groups.
• Quantitative PCR, in situ hybridization, and immunohistochemistry for gene validation and localization.
• In vitro studies using renal proximal tubular cells (RPTEC/TERT1) to assess gene function.

Main Results:

• Significant upregulation of metallothionein (MT) isoforms, particularly MT2A, in older donor kidneys (>59 years).
• MTs were localized to renal proximal tubular cells.
• Overexpression of MT2A in RPTEC/TERT1 cells conferred resistance to cadmium chloride-induced cytotoxicity and hypoxia-induced apoptosis, models of oxidative stress.

Conclusions:

• Increased MT expression in aging kidneys may serve as a protective mechanism against oxidative stress.
• MTs are functionally implicated in the pathophysiology of kidney aging.