Cholesterol esterification and smooth muscle cell (SMC) proliferation are the crucial events in the development of atherosclerotic lesions. The objective of this study was to analyse cholesterol esterification and the expression of MDR1 (multidrug resistance), ACAT (acyl-CoA:cholesterol acyltransferase) and caveolin-1 genes in atherosclerotic and healthy vascular walls, in SMCs obtained from atherosclerotic lesions and saphenous veins. Results demonstrated higher levels of cholesterol esters, ACAT and MDR1 mRNAs and lower levels of caveolin-1 mRNA in atherosclerotic segments compared to adjacent serial sections of the same artery and the corresponding non-atherosclerotic arteries from cadaveric donors. SMCs isolated from atherosclerotic plaques manifested an increased capacity to esterify cholesterol and to grow at a faster rate than SMCs isolated from saphenous veins. In addition, when SMCs from atherosclerotic plaques were cultured in the presence of progesterone, a potent inhibitor of cholesterol esterification, significant growth suppression was observed. An increase in ACAT and MDR1 expression and a concomitant decrease in caveolin-1 expression were also observed in SMCs isolated from atherosclerotic arteries as early as 12 h after serum stimulation. An opposite pattern was found when SMCs were treated with progesterone. These findings support the idea that cholesterol esterification plays a role both in early atherogenesis and in clinical progression of advanced lesions and raise the possibility that the cholesterol ester pathway might directly modulate the proliferation of SMCs.
Recent studies have shown that a membrane p-glycoprotein, encoded by MDR1 gene, is involved in the transport of free cholesterol from the plasma membrane to endoplasmic reticulum, the site of cholesterol esterification by acyl-CoA:cholesterol acyltransferase (ACAT). Moreover, results deriving from our previous studies have shown that the rate of cell proliferation was positively correlated with cholesteryl ester levels as well as with ACAT and MDR1 gene expression. In this study, lipid content and the expression of the genes involved in cholesterol metabolism such as hydroxy-methylglutaryl coenzyme A reductase (HMGCoA-R), low-density lipoprotein receptor (LDL-R), ACAT and MDR1 have been investigated in control and atherosclerotic arteries. The results have shown that the levels of cholesteryl ester increase with the age of cadaveric donors in arteries prone to atherosclerosis (abdominal aorta, superficial femoral artery) and become predominant in advanced atherosclerotic lesions. The mRNA levels of ACAT and MDR1 showed the same age correlation, reaching the highest values in atherosclerotic specimens. These results suggest that MDR1 may be involved in the accumulation of intracellular cholesterol ester levels found in atherosclerotic lesions. Moreover, the levels of HMGCoA-R, LDL-R and ACAT gene expressions progressively increased with the age of cadaveric donors; conversely, in atherosclerotic specimens, the mRNA levels of HMGCoA-R and LDL-R drastically decreased while ACAT gene expression reached its maximum. These findings suggest a reactivation of normal homeostatic regulation of cholesterol in advanced and complicated lesions.
Hair loss is a common aesthetic disorder that can be triggered by genetic, inflammatory, hormonal, and environmental factors acting on hair follicles and their life cycle. There are several types of hair loss that differ in causes, symptoms, and spatial and temporal progression. Androgenic alopecia, a common form of hair loss, is the consequence of a decreased microcirculation of the scalp as well as the toxic action of elevated dihydrotestosterone levels on the hair bulbs.In the present study, the lotions TRINOV Lozione Anticaduta Uomo and TRINOV Lozione Anticaduta Donna, containing dihomo-γ-linolenic acid (DGLA), S-equol, and propionyl-L-carnitine, were tested on 30 men and 30 women (mean age of men was 46.6 AE 6.4 years; mean age of women was 49.5 AE 9.0) with signs of androgenic alopecia, respectively. DGLA is a precursor of the prostaglandin PGE1, which acts by improving microcirculation; S-equol inhibits 5α-reductases, thus preventing the transformation of testosterone into dihydrotestosterone; and propionyl-L-carnitine promotes lipid metabolism, stimulating energy production. These three molecules are loaded into liposomes for their effective transdermal delivery. Daily topical applications of the lotions resulted in a hair count that significantly increased for women and marginally increased for men after 6 months of treatment. Furthermore, significant increase in anagen hair and a significant decrease in telogen hair were observed starting from 3 months in male and 1 month in female patients. Thus, the formulations under investigation were effective in attenuating androgenic alopecia-related hair loss in men and women.
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