Obesity and cortisol status.

The fact, that obesity is a prominent feature of hypercortisolism (Cushing's syndrome) has stimulated investigation on the possible existence of the reverse relationship, namely that hypercortisolism is a feature of obesity. We have reviewed half a century of literature on this question, and have found out the following: (1) Hypercortisolism can exist in two forms: systemic hypercortisolism, in which there is an overall bodily excess of cortisol, and tissue, or intracellular, hypercortisolism, in which there is increased intracellular concentration of cortisol without an overall bodily excess. (2) There are two parameters of systemic hypercortisolism: CPR and plasma cortisol concentration. Proper evaluation of the first parameter requires correction for the active metabolic mass, which is best performed by expressing CPR per gram of urinary creatinine. The second parameter can be confounded by the marked moment-to-moment fluctuations in plasma cortisol concentrations due to cortisol's episodic secretion. Proper evaluation requires measuring the 24-hour mean concentration. Of these two parameters of systemic cortisol status, the plasma concentration is the more critical and accurate. (3) Corrected CPR is normal in obese individuals, and 24-hour mean plasma cortisol concentrations are slightly but definitely subnormal. This combination of findings indicates diminished stimulability of the hypothalamic-pituitary-adrenal (HPA) axis, which normally regulates bodily cortisol status. This deduction is supported by empirical studies on HPA reactivity. (4) Tissue hypercortisolism, due to increased intracellular activity of 11beta-HSD-1, which catalyzes reduction of cortisone to cortisol, has been reported in obese mice and humans. The findings of various studies are not consistent, and whether the enzymatic overactivity is a cause or a result of obesity is still unclear.     

Induction of two cyclotide-like genes <Emphasis Type="Italic">Zmcyc1</Emphasis> and <Emphasis Type="Italic">Zmcyc5</Emphasis> by abiotic and biotic stresses in <Emphasis Type="Italic">Zea mays</Emphasis>

Cyclotides are small plant disulfide-rich and cyclic proteins with a diverse range of biological activities. Cyclotide-like genes show key sequence features of cyclotides and are present in the Poaceae. In this study the cDNA of the nine cyclotide-like genes were cloned and sequenced using 3′RACE from Zea mays. The gene expression of two of these genes (Zmcyc1 and Zmcyc5) were analyzed by real-time PCR in response to biotic (Fusarium graminearum, Ustilago maydis and Rhopalosiphum maydis) and abiotic (mechanical wounding, water deficit and salinity) stresses, as well as in response to salicylic acid and methyl jasmonate elicitors to mimic biotic stresses. All isolated genes showed significant similarity to other cyclotide-like genes and were classified in two separate clusters. Both Zmcyc1 and Zmcyc5 were expressed in all studied tissues with the highest expression in leaves and lowest expression in roots. Wounding, methyl jasmonate and salicylic acid significantly induced the expression of Zmcyc1 and Zmcyc5 genes, but the higher expression was observed for Zmcyc1 as compared with Zmcyc5. Expression levels of these two genes were also induced in inoculated leaves with F. graminearum, U. maydis and also in response to insect infestation. In addition, the 1000-base-pairs (bp) upstream of the promoter of Zmcyc1 and Zmcyc5 genes were identified and analyzed using the PlantCARE database and consequently a large number of similar biotic and abiotic cis-regulatory elements were identified for these two genes.     

Efficient tRNA degradation and quantification in Escherichia coli cell extract using RNase‐coated magnetic beads: A key step toward codon emancipation

Emancipating sense codons toward a minimized genetic code is of significant interest to science and engineering. A key approach toward sense codon emancipation is the targeted in vitro removal of native tRNA. However, challenges remain such as the insufficient depletion of tRNA in lysate‐based in vitro systems and the high cost of the purified components system (PURE). Here we used RNase‐coated superparamagnetic beads to efficiently degrade E. coli endogenous tRNA. The presented method removes >99% of tRNA in cell lysates, while partially preserving cell‐free protein synthesis activity. The resulting tRNA‐depleted lysate is compatible with in vitro‐transcribed synthetic tRNA for the production of peptides and proteins. Additionally, we directly measured residual tRNA using quantitative real‐time PCR. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1401–1407, 2017     

Effect of testosterone replacement on feeding behaviors after acute and chronic stress in gonadectomized male NMRI mice

Background

We study the role of gonadectomy on the response to unavoidable stress and the role of testosterone replacement on gonadectomy in the male Naval Medical Research Institute mice (30±5 g) were studied. For this purpose, the hormonal and metabolic changes were investigated.

Methods

In the experimental group, the gonads were surgically removed, and a cannula was inserted into the left lateral ventricle. For acute and chronic stress induction, animals were placed in the communication box for 30 min for one day and four consecutive days, respectively. The animals received different doses of intraventricular (ICV) testosterone (0.01, 0.05, 0.1 μg/mouse) 5 minutes or intraperitoneal (IP) testosterone (0.05, 0.01, 0.1 mg/kg) 30 minutes before the stress induction.

Results

The results showed that acute and chronic stress increases plasma cortisol concentration. IP testosterone injections of testosterone did not decrease cortisol concentrations in response to acute stress, whereas ICV injections did reduce cortisol concentrations. The stress reduced anorexia time, while the administration of testosterone increased anorexia time. In addition, acute stress reduced food intake in the gonadectomized mice. IP testosterone at 0.01 and 0.05 mg/kg increased food intake. Additionally, stress in gonadectomized mice reduced water intake, while the IP injection of testosterone in chronic stress further reduced water intake. Also, stress reduced the animals’ brain/adrenal volumes, while the IP and ICVinjection of testosterone at 0.01 mg/kg inhibited this effect.

Conclusion

The results showed that the IP (0.05, 0.01, 0.1 mg/kg) and ICV (0.01, 0.05, 0.1 μg/mouse) administration of testosterone in the gonadectomized mice can modulate hormonal and metabolic changes induced by stress.

     

High prevalence of mouse mammary tumor virus-like gene sequences in breast cancer samples of Iranian women

Mouse mammary tumor virus (MMTV) is considered to be responsible for breast tumor development in mice. In several instances sequences homologous to the genome of this virus have been reported in human breast cancer samples.

Here we aimed to evaluate MMTV involvement in human breast cancer development. DNA was extracted from 118 formalin fixed and paraffin embedded malignant (n = 59) and benign (n = 59) breast lesions. Using two sets of outer and inner MMTV-like envelope specific primers, in a nested PCR setup, MMTV genome was detected in 19 samples out of 59 (%32.2) cases of breast carcinomas, while in non-malignant breast tissue samples, only 3 samples out of 59 (%5) were positive. The difference was statistically highly significant (p < 0.001). Alignment of PCR amplified sequences with BR6, GR and C3H mouse mammary tumor virus strains emerged to be around 99% identical which is indicative of tumor tissue infection by an exogenous mouse MMTV genome.     

Mitochondrial DNA deletion Δ4977 in peptic ulcer disease

Reactive oxygen species (ROS) play a critical role in peptic ulcer disease (PUD). Due to the high rate of ROS production and limited capacity for DNA repair within mitochondria, mtDNA is susceptible to oxidative damage and mutations. mtDNA deletion Δ4977 is one of the most common deletion events identified in mitochondria. We examined the association of 4977-bp mtDNA deletion with PUD. Genotypes were determined in bioptic samples of 150 PUD patients and 190 controls. The 4977-bp mtDNA deletion was found more frequently among patients with PUD (52%) than among controls (22.63%). The strong association between the mtDNA 4977-bp deletion and PUD was confirmed (OR = 3.7; 95% CI, 2.32–5.91; P = 0.0001). The 4977-bp deletion in mitochondrial DNA may be a risk factor for PUD, or may reflect an increase in oxidative stress that commonly accompanies underlying PUD disease. Larger population-based studies are needed to uncover the possible causal relationship between this deletion and peptic ulcer disease.