Which of the following is a type of renal tubular epithelial cell?

Proximal convoluted tubule cells are indeed a type of renal tubular epithelial cell. These cells line the proximal convoluted tubule, which is a segment of the nephron in the kidney responsible for the reabsorption of water, ions, and nutrients from the filtrate. They are characterized by their brush border (microvilli), which increases the surface area for reabsorption, as well as their abundant mitochondria that provide the energy needed for active transport processes.

The other options mentioned do not qualify as renal tubular epithelial cells. Glomerular epithelial cells refer to podocytes that are involved in the filtration process at the glomerulus, and they have a distinct structure and function compared to tubular cells. Transitional epithelial cells are found in the urinary bladder and are specialized for stretching, while squamous epithelial cells are a general type of epithelial cell found in various tissues, including the skin and lining of body cavities, but they do not specifically constitute renal tubular epithelium. Thus, the identification of proximal convoluted tubule cells as a renal tubular epithelial type is accurate.