Metallothionein Gene Expression in Human Adipose Tissue from Lean and Obese Subjects

Abstract

Expression of the gene encoding metallothionein, a low molecular-weight cysteine-rich, stress-response and metal-binding protein was examined in human adipose tissue. The mRNA for MT-2A, a major metallothionein isoform in humans, was detected in subcutaneous fat using a specific antisense oligonucleotide probe. The level of MT-2A mRNA was significantly higher in a group of obese subjects than in a lean group, paralleling a similar increase in ob mRNA. A two-week period on a diet of 800 calories/day did not lead to any significant change in MT-2 mRNA levels. Separation of mature adipocytes from the cells of the stromal vascular fraction indicated that in human adipose tissue the metallothionein (MT-2A) gene is expressed both in adipocytes and in other cells of the tissue.

Response of the adipose tissue transcriptome to dihydrotestosterone in mice

“…Under cold exposure and induction by catecholamines, the MT1 gene is abundantly detected in brown adipose tissue of rats (4,6). Secretion or expression of MT protein is also observed in white adipose tissue from mice (46), dogs (14), and humans (12). All these observations indicate that expression of MT genes is linked to the regulation of energy balance.…”

“…Male and female, 14-to 15-wk-old, C57BL/6 mice were obtained from Charles River Canada (St-Constant, Québec, Canada). Fourteen animals were pooled for one replica at each time point (1,3,6,12,18, and 24 h), and fourteen mice were pooled to generate two replica of the control group in each sex. A total of 196 animals were used in our study.…”

“…Bilateral gonadectomy (castration for male mice and ovariectomy for female mice) were performed under isoflurane-induced anesthesia 7 days prior to death and organ collection for the seven gonadectomized groups (n ϭ 14 mice per group). DHT (0.1 mg) was injected subcutaneously 1,3,6,12,18, and 24 h prior to death in DHT-treated groups. One group was retained as control and received a vehicle solution [0.4% (wt/vol) Methocel A15LV Premium; 5% ethanol].…”

Association of anti-obesity activity of N-acetylcysteine with metallothionein-II down-regulation

“…In addition, accumulating evidence indicates that MTs may play a role in adipocyte differentiation, and are induced in 3T3L1 mouse fibroblasts during adipocyte differentiation (Schmidt and Beyersmann, 1999;Trathurn et al, 2000a;. The level of MT-2A mRNA in subcutaneous fat tissues was found to be significantly higher in obese subjects (Do et al, 2000). However, roles of MTs during adipocyte differentiation and of their regional preferences for omental and subcutaneous adipose tissues are not understood.…”

Expression of the Zinc Transporters Genes and Metallothionein in Obese Women

“…These women had high BMIs and waist circumference values greater than 88 cm, which could have contributed to the secretion of inductors of metallothionein expression (cortisol and proinflammatory cytokines). Do et al [25] compared the genetic expression of metallothionein between obese and control patients and identified higher expression of the protein in the adipose tissue of the obese group. The high expression of metallothionein induced by the factors mentioned above can facilitate the reduction of the zinc serum concentrations and the redistribution of this mineral among different tissues, especially in the liver [26,27].…”