Identification of leptin gene expression in sinusoidal endothelial rat liver cells.

Sinusoidal endothelial liver cells (SECs) have a key role in the pathophysiology of chronic liver disease. Leptin is an important profibrogenic and proinflammatory cytokine whose expression in sinusoidal endothelial liver has not been documented. The authors studied the potential of rat SECs to express the leptin and leptin receptor genes. Two cell lines of rat SECs were generated from a male rat liver by pronase-collagenase perfusion and dilution cloning. They were characterized according to morphology, ploidy, von Willebrand antigen immunoreactivity, CD31 transcription, matrix metalloproteinase secretion, and pseudocapillary formation. Expression of the leptin and leptin receptor genes was studied using qualitative reverse transcriptase-polymerase chain reaction. Both cell lines fulfilled the accepted criteria for consideration as being derived from the liver sinusoidal endothelium. Confluent monolayers of both cell lines transcribed leptin and leptin receptor genes. This work demonstrated that SECs can transcribe the leptin gene in vitro, cotranscribing with the leptin receptor gene. Leptin production and signaling at this level could be of paramount importance in liver physiopathology; further studies of this issue are warranted because it represents a potential intervention point during chronic liver diseases.

Aortic preadipocyte differentiation into adipocytes induced by rosiglitazone in an in vitro model.

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a key transcription factor for adipocyte differentiation. Preadipocyte differentiation into adipocytes from precursors in blood vessels is an important issue related to atherosclerotic cardiovascular disease; however, it has been poorly studied because of lack of experimental models. Our aim was to evaluate the potential of primary outgrowths derived from rat aortic rings as a model for studying the preadipocyte differentiation from aortic precursors induced by thiazolidinediones, which are exogenous ligands for PPARgamma. Cell outgrowths derived from rat aortic rings were cultured and incubated with rosiglitazone at 1-1,000 nM; presence of lipid droplets was evaluated by oil red O staining. Rosiglitazone at 100 nM exerted a clear adipogenic effect inferred from the cells filled with fine and medium size lipidic droplets; this effect was extreme at 1,000 nM with cells showing lipidic macrodroplets. These results showed that cultures derived from aortic rings are a useful model for studying arterial preadipocyte differentiation.

[Prevalence of osteoporosis and osteopenia among women over fifty years of age, from the city of Durango, Mexico, diagnosed by forearm-DEXA]. / Prevalencia de osteoporosis y osteopenia en mujeres oriundas de la ciudad de Durango, México, de 50 y más años de edad diagnosticadas por DEXA en antebrazo.

OBJECTIVE: To estimate the prevalence of osteopenia and osteporosis using distal forearm dual-energy X-ray absorptiometry among a random sample of women of 50 years or older living in the city of Durango, Mexico. MATERIAL AND METHODS: 258 women participated in a cross-sectional study fielded at the Osteoporosis Clinic of Durango. Bone mineral density was determined by dual-energy X-ray absorptiometry. Scanning was performed on the distal third of the dominant forearm. Diagnosis of osteopenia and osteoporosis was based on the WHO criteria. RESULTS: Osteoporosis was diagnosed in 13.65% (95%CI: 9.6-18.5) and osteopenia in 30.12% (95% CI: 24.5-36.2) of participants. Mean age, weight, height and body mass index were 65 years, 60.5 kg, 147.8 cm and 28.3 kg/m2 respectively. CONCLUSIONS: Osteoporosis and osteopenia were a common diagnosis given the mean age of our sample. These results can be extrapolated to the general population thereby suggesting the need for preventive measures to decrease disease prevalence, especially considering the increase in life expectancy.

Estrogens are potentially the only steroids with an antioxidant role in pregnancy: in vitro evidence.

BACKGROUND: Pregnancy is a condition that favors oxidative stress by reactive oxygen species. Oxidative stress is involved in the etiopathogenesis of disorders of pregnancy such as pre-eclampsia. An antioxidant effect of estrogens has been described and a putative role of them as antioxidants has been proposed. The aim of this work was to evaluate in vitro the antioxidant properties of dehydroepiandrosterone sulfate, estradiol, estriol, progesterone, and testosterone, five steroid hormones present in the maternofetal circulation. METHODS: The antioxidant properties of the hormones were evaluated by two methods: 1. their antioxidant effect on the auto-oxidation of linoleic acid, a hydrogen atom transfer reaction; 2. diphenylpicrylhydrazyl-scavenging capacity, a single electron transfer reaction. RESULTS: Of the five hormones tested, only estradiol and estriol at 10 microM concentration exerted a strong antioxidant effect of 81.73 and 70.97% respectively on linoleic acid auto-oxidation, at the end-point of the reaction. Likewise, only these two hormones showed radical-scavenging activity on diphenylpicrylhydrazyl, noticeable only at supraphysiological concentrations of 1 mM. CONCLUSIONS: Estradiol and estriol could play a role as antioxidants for maternofetal autoprotection in addition to their hormonal activity, but this role could be preferentially exerted by estriol due to its higher concentrations exhibited during pregnancy. In vivo studies are necessary to shed light on this issue.

Cell growth in vitro directed by handmade patterns.

In this report, we show how the in vitro model of mechanically injured confluent monolayers of cultured mammalian cells, consisting in denudation by gentle scraping of areas in the monolayer, can be extended to obtain patterned cell cultures without using preadded attaching matrices. This work was done with a sinusoidal endothelial liver cell line. Patterns for cell growth were drawn in confluent monolayers by cell detaching with the aid of pipette tips followed by reincubation of the culture. In one or some d, acellular patterns were closed by cell migration and proliferation. For unveiling the pattern formed by migration and cell duplication, an enzymatic digestion with trypsin-collagenase solution was applied; after some min, only the migrating and younger cells filling the previous acellular pattern remained attached to the dish, and the now cellular pattern was clearly depicted. After stopping and recovering from the enzymatic treatment, the culture was ready for starting studies such as those related to migration, proliferation, cell-cell interactions. This method allows us to create simple and complex patterns, does not require preparation of the dishes with attaching matrices, and extracellular matrices in acellular areas are absent because of the enzymatic treatment, thus, potentially having many applications in cell culture techniques.