Podocytes are cells in the glomerulus that wrap around the glomerular vasculature. Their foot processes inhibit the filtration of proteins from the blood into the urine.
The glomerulus is the first stop in blood filtration in the kidney. This is where factors are filtered out of the blood and into the urine. The amount of blood that is filtered in the glomerulus (glomerular filtration rate - GFR) is regulated by both the input and output of the glomerulus by prostaglandin E (PGE) and angiotensin II (AngII).
The kidneys filter factors out of the blood and into the urine. It also regulates the amount of water and sodium in the body (RAAS) along with aiding in the production of red blood cells by secreting erythropoietin.
Nephrotic syndrome is characterized by podocyte damage and loss of function. This leads to the classic symptoms of swelling, hyperlipidemia, proteinuria, lipiduria, and hypoalbuminemia (loss of albumin in the urine)
Diabetic Kidney Disease
Diabetic kidney disease is a common morbidity of diabetes. High blood sugar levels leads to kidney damage through decreased blood flow to the kidney and microvascular damage in the glomerulus. This leads to scarring (Kimmelstiel-Wilson nodules) and proteinuria.
Nephritis is characterized by glomerular damage where red blood cells (RBCs) leak into the urine. This creates cola-colored urine, red blood cell casts, and dysmorphic red blood cells. A common cause is high levels of IgA. One of the common symptoms is high blood pressure.
Nephrotic Syndrome -> Podocyte
As inflammation plays a large role in the various types of nephrotic syndrome, a common treatment is the use of the anti-inflammatory agent prednisone.
DKD -> Glomerulus
High glucose and blood pressure levels are damaging to the kidney. The diuretic, canagliflozin, inhibits the SGLT2 transporter in the kidney and prevents glucose and water reabsorption. This treats both diabetic and kidney symptoms.
Nephritis -> Kidney
Similar to diabetic kidney disease, high blood pressure is a dangerous symptom of nephritis. The angiotensin receptor blocker (ARB), losartan, can be used to help decrease blood pressure and prevent further kidney damage.