Kidney Week

Abstract: TH-PO885

The Effect of Kidney Cell Sex and Sex Hormone Stimulation on Kidney Metabolism: Implications for Diabetic Kidney Disease

Session Information

• Diabetic Kidney Disease: Basic - I
  November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Diabetic Kidney Disease

• 601 Diabetic Kidney Disease: Basic

Authors

• Clotet Freixas, Sergi, University Health Network, Toronto, Toronto, Ontario, Canada

Sergi Clotet Freixas,

• Van, Julie Anh Dung, University Health Network, Toronto, Toronto, Ontario, Canada

Julie Anh Dung Van,

• Mehrotra, Aman, University Health Network, Toronto, Toronto, Ontario, Canada

Aman Mehrotra,

• Gehring, Adam J., University Health Network, Toronto, Toronto, Ontario, Canada

Adam J. Gehring,

• Woo, Minna, University Health Network, Toronto, Toronto, Ontario, Canada

Minna Woo,

• Caudy, Amy A., University Health Network, Toronto, Toronto, Ontario, Canada

Amy A. Caudy,

• Konvalinka, Ana, University Health Network, Toronto, Toronto, Ontario, Canada

Ana Konvalinka,

Background

Male sex predisposes to diabetic kidney disease (DKD). We uncovered androgen-induced proteome perturbations in renal metabolism that may drive faster DKD progression in men. Our goal is to study cell sex- and sex hormone-specific metabolic alterations in human primary proximal tubule epithelial cells (PTEC).

Methods

PTEC from 3 male and 3 female donors were stimulated with control, dihydrotestosterone (DHT), or estradiol (EST) for 16h/24h. Chronic hyperglycemia was simulated by exposing sex hormone-treated PTEC to high glucose (25mM) for 96h. We assessed glycolysis (extracellular acidification rate, ECAR) and oxygen consumption rate (OCR) in a Seahorse analyzer. We measured extracellular glucose, intracellular ATP, oxidative stress (O₂⁻), and apoptosis (phosphatidilserine). IL-6 and MCP1 were quantified by a Multiplex Assay.

Results

Male PTEC showed significantly higher ECAR and OCR, ATP-linked respiration, maximal glycolitic and respiratory capacity, superoxide levels and apoptosis compared to female PTEC (p<0.05). In male PTEC, ECAR was increased by DHT stimulation, whereas OCR was increased by DHT and EST. In male PTEC, media glucose levels were reduced by DHT. DHT-induced increase in glycolysis, OCR, oxidative stress and glucose consumption was prevented by androgen receptor (AR) inhibitors. ATP, O₂⁻, apoptosis and secretion of IL-6 and MCP1 were increased by DHT, especially in male PTEC. Under hyperglycemia, DHT increased O₂⁻ and ATP. Promoter analysis revealed that 46/60 of our DHT-upregulated proteins may be regulated by MYC and/or SRY transcription factors (involved in glucose/glutamine metabolism and in male sex determination). Male sex and DHT were associated with increased AR and SRY gene levels (p<0.05). MYC was upregulated by DHT in male PTEC and by EST in female PTEC (p<0.05).

Conclusion

The metabolic function of PTEC and their response to sex hormones are influenced by cell sex. Male PTEC show higher glycolysis, oxygen consumption, and respiratory capacity than female PTEC. These differences are related to increased oxidative stress and apoptosis, and to enhanced AR and SRY expression. In male PTEC, DHT-induced protein changes are linked to a more glycolytic and oxidative phenotype, higher glucose consumption, oxidative stress, apoptosis, and IL-6/MCP1 secretion.