Monte A. Del Monte, MD

Research Areas

• Clinical Trials - Pediatric Ophthalmology
  • An Observational, Multicenter Study of the Prevalence of Cerebrotendinous Xanthomatosis (CTX) in Patient Populations Diagnosed with Early-Onset Idiopathic Bilateral Cataracts

Research Summary

Tissue culture and cell biology of ocular tissue, retinal degeneration, diabetic retinopathy, ocular inborn errors in metabolism, biochemical genetics, surgical and nonsurgical therapy for strabismus, amblyopia, congenital cataract and pediatric glaucoma

Factors Influencing Abnormal Retinal Cell Proliferation in Diabetes, Retinal Detachment and Other Eye Disorders

Abnormal cell growth results in blinding complications associated with certain eye diseases and conditions, including diabetes, retinitis pigmentosa and retinal detachment. Cells may form colonies, change shape, and/or migrate to other parts of the eye, resulting in scarring and poor vision. Surgery can often alleviate the symptoms. Dr. Monte Del Monte investigates ways to find simpler, non-surgical treatments for this problem. Many growth factors influence the extent of cell growth and differentiation in the retina. One of these growth factors is retinoic acid. Although we do not understand how, retinoic acid is known to limit cell growth and differentiation in human retinal pigment epithelium and other retinal tissues. Dr. Del Monte's hypothesis is that cyclic AMP-dependent protein kinase A (PKA) mediates the action of retinoic acid. His experiments involving protein kinase A inhibitors in cell culture substantiate his hypothesis. Fibroblast growth factor (FGF) also stimulates human retinal pigment epithelium proliferation. He has found, however, that in the presence of retinoic acid, this stimulation does not occur. Currently, experiments are under way to determine the role of FGF receptors in retinoic acid-mediated growth stimulation. Understanding this biochemistry may lead to development of drug treatments that target the role of retinoic acid, PKA, FGF, and other growth factors in abnormal ocular tissue development. In addition, collaborating with Dr. Douglas Greene of the Michigan Diabetes Training Center, Dr. Del Monte is investigating the effects of hyperglycemia on aldose reductase and myoinositol metabolism in RPE cell lines in culture. Aldose reductase is induced in the presence of high levels of glucose. The enzyme, which converts glucose to sorbitol, increases cytoplasmic sorbitol levels. There is an associated depletion of myo-inositol. Through phosphoinositide signaling pathways, changes in these metabolites lead to tissue damage due to alterations in membrane function, signal transduction, and nerve conductance. Better understanding of these mechanisms will lay the groundwork for future treatments of diabetic retinopathy and neuropathy.