Adenosine Triphosphate Protects from Elevated Extracellular Calcium-Induced Damage in Human Proximal Kidney Cells:...

Area of Science:

• Nephrology
• Cell Biology
• Biochemistry

Background:

• Extracellular calcium ([Ca2+]) is critical for kidney cell function.
• Maintaining extracellular [Ca2+] within a narrow range is essential for cellular processes.
• Dysregulation of extracellular [Ca2+] can lead to kidney cell injury.

Purpose of the Study:

• To investigate the effect of extracellular adenosine triphosphate (ATP) on human proximal tubule (HK-2) cell viability under high calcium conditions.
• To assess the modulation of intracellular calcium levels and calcium-binding protein (CaBP) expression.
• To develop an artificial intelligence (AI)-enabled deep learning model for predicting calcium-induced injury and protection in HK-2 cells.

Main Methods:

• HK-2 cells were cultured in DMEM with varying CaCl2 concentrations.
• Cell viability was assessed using MTT assays.
• Intracellular [Ca2+] was measured via fluorescence microscopy.
• A Convolutional Neural Network (CNN) was developed for image-based classification of cell injury.
• mRNA levels of CaBPs were quantified using real-time PCR.

Main Results:

• Elevated extracellular [Ca2+] decreased HK-2 cell viability, an effect reversed by ATP.
• High extracellular [Ca2+] increased intracellular calcium, which was reduced by ATP.
• A CNN model achieved 98% accuracy in classifying calcium-induced HK-2 cell injury.
• ATP enhanced the expression of CaBPs such as calmodulin, S100A8, S100A14, and CaBP28k.

Conclusions:

• ATP confers protection to HK-2 cells against detrimental effects of high extracellular calcium.
• A CNN model provides a user-friendly tool for studying calcium-dependent injury in kidney cells.
• ATP-mediated protection is associated with increased expression of calcium-binding proteins.