POD-1/Tcf21 overexpression reduces endogenous SF-1 and StAR expression in rat adrenal cells

During gonad and adrenal development, the POD-1/capsulin/TCF21transcription factor negatively regulates SF-1/NR5A1expression, with higher SF-1 levels being associated with increased adrenal cell proliferation and tumorigenesis. In adrenocortical tumor cells, POD-1 binds to the SF-1 E-box promoter region, decreasing SF-1 expression. However, the modulation of SF-1 expression by POD-1 has not previously been described in normal adrenal cells. Here, we analyzed the basal expression of Pod-1 and Sf-1 in primary cultures of glomerulosa (G) and fasciculata/reticularis (F/R) cells isolated from male Sprague-Dawley rats, and investigated whether POD-1 overexpression modulates the expression of endogenous Sf-1 and its target genes in these cells. POD-1 overexpression, following the transfection of pCMVMycPod-1, significantly decreased the endogenous levels of Sf-1 mRNA and protein in F/R cells, but not in G cells, and also decreased the expression of the SF-1 target StAR in F/R cells. In G cells overexpressing POD-1, no modulation of the expression of SF-1 targets, StAR and CYP11B2, was observed. Our data showing that G and F/R cells respond differently to ectopic POD-1 expression emphasize the functional differences between the outer and inner zones of the adrenal cortex, and support the hypothesis that SF-1 is regulated by POD-1/Tcf21 in normal adrenocortical cells lacking the alterations in cellular physiology found in tumor cells.

Effect of induced diabetes mellius on the histological structure of the renal cortex of adult male albino rats and the possible protective role of licorice extract

Diabetes is one of the most common chronic metabolic disorders worldwide. One of the major complications of type 2 diabetes is diabetic nephropathy. The present study was to investigate the effect of type 2 diabetes on the histological structure of the renal cortex of adult male albino rats and the role of licorice ethanolic extract on diabetic renal affection. Forty adult male albino rats were utilized. They were classified into three main groups: the control group [group I], the experimental diabetic group [group II], and the possible protected group [group III]. Type 2 diabetes was induced in rats in groups II and III by giving them a high-fat diet and a single low dose of streptozotocin. Diabetic rats were divided into two subgroups: untreated subgroup IIa and treated subgroup IIb. The possible protected group received licorice ethanolic extract concomitant with the high-fat diet and the single low dose of streptozotocin. At the end of the experiment, the kidneys were dissected out and processed for light and electron microscopic examination. Fasting blood glucose level, fasting insulin level, serum urea, and creatinine were estimated and statistically analyzed. Examination of the renal cortex of untreated diabetic subgroup IIa demonstrated glomerulosclerosis and distorted podocyte foot processes. The cells lining convoluted tubules revealed thick basement membranes, disorganization of basal infoldings, and mitochondrial disarrangement. The area% of positive Bax immunoreaction was significantly increased in subgroup IIa as compared with subgroup IIb and group III. Examination of the renal cortex of the treated diabetic animals [subgroup IIb] revealed little improvement and failure of licorice extract to normalize renal cortical changes, most probably due to late intervention. In contrast, the protected group [group III] revealed a nearly preserved normal architecture. Changes in the renal cortical structure were attenuated with prophylactic therapy of licorice ethanolic extract

Absence of PRKAR1A loss of heterozygosity in laser-captured microdissected pigmented nodular adrenocortical tissue from a patient with Carney complex caused by the novel nonsense mutation p. Y21X / Ausência da perda de heterozigose do PRKAR1A em células capturadas por microdissecção a laser de tecido de nódulo pigmentoso adrenocortical de um paciente com complexo de Carney causado por uma nova mutação nonsense

OBJECTIVE: Primary pigmented nodular adrenocortical disease (PPNAD) is the main endocrine manifestation of Carney complex, a multiple neoplasia syndrome caused by PRKAR1A gene mutations. The presence of PRKAR1A loss of heterozygosity (LOH) in adrenocortical tumorigenesis remains controversial. The aim of the present study is to investigate the presence of PRKAR1A LOH in adrenocortical cells in a patient with Carney complex. METHODS: The LOH was investigated using a PRKAR1A informative intragenic marker by GeneScan software analysis in DNA obtained from laser-captured microdissected cells of several adrenal nodules. Patients: A young adult male patient with Carney complex and his family were studied. RESULTS: A novel heterozygous mutation (p. Y21X) was identified at PRKAR1A in blood DNA of the male proband and his relatives. No PRKAR1A LOH was evidenced in the laser-captured microdissected cells from PPNAD tissue by different methodologies. CONCLUSION: We identified a new PRKAR1A nonsense mutation and in addition we did not evidence PRKAR1A LOH in laser-captured nodules cells, suggesting that adrenocortical tumorigenesis in PPNAD may occurs apart from the second hit.

OBJETIVO: A doença adrenocortical nodular pigmentosa primária (PPNAD) é uma das manifestações do complexo de Carney, uma neoplasia endócrina múltipla causada por mutações no PRKAR1A. A perda de heterozigose (LOH) do PRKAR1A na tumorigenese adrenal permanece controversa dada à possibilidade de contaminação com o tecido normal. Nosso objetivo foi investigar a presença de LOH no PRKAR1A a partir de células do nódulo adrenal de um paciente com complexo de Carney. MÉTODOS: A pesquisa da LOH do PRKAR1A foi realizada através do estudo de um marcador intragênico em DNA de células do nódulo adrenal microdissecadas a laser, evitando contaminação com o tecido normal. Pacientes: Um paciente com PPNAD e cinco familiares foram estudados. RESULTADOS: A nova mutação (p. Y21X) foi identificada no PRKAR1A sem evidência de LOH no tecido adrenal. CONCLUSÃO: Identificamos uma nova mutação no PRKAR1A e não evidenciamos LOH nas células dos nódulos adrenocorticais, sugerindo que a PPNAD possa ocorrer na ausência de um segundo evento molecular.

Chronic stress effects on the apoptotic index of the adrenal cortex of pregnant rats

Chronic stress by immobilization during gestation can alter several mechanisms that maintain homeostasis in adrenal gland. The aim of this work was to quantify the apoptotic index of adrenal cortex during mid-pregnancy and to prove cytological characteristics by electron microscopy. The apoptotic index did not present significant differences between the adrenal cortex areas of control and experimental rats in any of the three ages studied. The day of gestation influenced significantly on the apoptotic index in both groups. This index increased as gestation progressed. It may be concluded that chronic stress by immobilization might induce the increase of apoptotic index in adrenal cortex as gestation progresses which might be related variations of plasmatic corticosterone and prolactin, and to the decrease of specific growth factors. On the other hand, it might be concluded that each zone of adrenal cortex behaves independently in regards to apoptosis and cellular proliferation via paracrine and/or autocrine regulatory mechanisms without being affected by other zones.

Proliferative signaling initiated in ACTH receptors

This article reviews recent results of studies aiming to elucidate modes of integrating signals initiated in ACTH receptors and FGF2 receptors, within the network system of signal transduction found in Y1 adrenocortical cells. These modes of signal integration should be central to the mechanisms underlying the regulation of the G0->G1->S transition in the adrenal cell cycle. FGF2 elicits a strong mitogenic response in G0/G1-arrested Y1 adrenocortical cells, that includes a) rapid and transient activation of extracellular signal-regulated kinases-mitogen-activated protein kinases (ERK-MAPK) (2 to 10 min), b) transcription activation of c-fos, c-jun and c-myc genes (10 to 30 min), c) induction of c-Fos and c-Myc proteins by 1 h and cyclin D1 protein by 5 h, and d) onset of DNA synthesis stimulation within 8 h. ACTH, itself a weak mitogen, interacts with FGF2 in a complex manner, blocking the FGF2 mitogenic response during the early and middle G1 phase, keeping ERK-MAPK activation and c-Fos and cyclin D1 induction at maximal levels, but post-transcriptionally inhibiting c-Myc expression. c-Fos and c-Jun proteins are mediators in both the strong and the weak mitogenic responses respectively triggered by FGF2 and ACTH. Induction of c-Fos and stimulation of DNA synthesis by ACTH are independent of PKA and are inhibited by the PKC inhibitor GF109203X. In addition, ACTH is a poor activator of ERK-MAPK, but c-Fos induction and DNA synthesis stimulation by ACTH are strongly inhibited by the inhibitor of MEK1 PD98059.

Probable effect of photoperiod on seasonal variation in the nuclear volume of the adrenal cortex of viscacha (Lagostomus maximus maximus)

The neuroendocrine system regulates several organic functions such as reproduction, metabolism and adaptation to the environment. This system shows seasonal changes linked to the environment. The experimental model used in the present study was Lagostomus maximus maximus (viscacha). The reproduction of males of this species is photoperiod dependent. Twenty-four adult male viscachas were captured in their habitat at different times during one year. The adrenal glands were processed for light microscopy. Serial cuts were stained with hematoxylin-eosin for the morphometric study, and 100 nuclei of each zone of the adrenal cortex were counted per animal. Data were analyzed statistically by ANOVA and the Tukey test. The cells of the glomerulosa zone are arranged in a tube-shaped structure. The fasciculata zone has large cells with central nuclei and clearly visible nucleoli and with a vacuolar cytoplasm. In the reticularis zone there are two of types of cells, one with a nucleus of fine chromatin and a clearly visible nucleolus and the other with nuclear pycnosis. Morphometric analysis showed maximum nuclear volumes during the February-March period with values of 133 percet 7.3 µm3 for the glomerulosa, 286.4 percent 14.72 µm3 for the fasciculata, and 126.3 percent 9.49 µm3 for the reticularis. Minimum nuclear volumes were observed in August with values of 88.24 + or - 9.9 µm3 for the glomerulosa, 163.7 percent 7.78 µm3 for the fasciculata and 64.58 + or - 4.53 µm3 for the reticularis. The short winter photoperiod to which viscacha is subjected could inhibit the adrenal cortex through a melatonin increase which reduces the nuclear volume as well as the cellular activity

Indomethacin, esculetin and nordihydroguaiaretic acid modify arachidonate biosynthesis in rat adrenocortical cells

Se estudio la duración del efecto inhibición que produce la ACTH sobre la incorporación y transformación del ácido [1-14C] eicosatrienoico, en células corticoadrenales aisladas de ratas normales. También se investigó el efecto de la esculetina, indometacina y del ácido nordihidroguaiarético, independientemente o en presencia de ACTH o dibutiril cíclico (diBuAMPc), sobre la biosíntesis de araquidonato. La ACTH y el di BUAMPc produjeron una inhibición significativa en la biosíntese de ácido araquidónico. La depresión producida por la hormona se consideró como un efecto a corto tiempo. El ácido nordihidroguaiarético y la esculetina deprimieron la captación del ácido 20:3 (n=6) en las células corticoadrenales. Este efecto se potenció cuando las células fueron tratadas simultáneamente con ACTH o diBuAMPc. La indometacina no modificó la capacitación del ácido 20:3 (n-6) e incrementó la actividad delta5 desaturante. Este efecto indicaría que, normalmente, los metabolitos producidos por la vía de la negativa sobre la actividad delta5 desaturante producida por la ACTH y el diBuAMPc, y la modulación positiva que se infiere de los resultados obtenidos en el presente trabajo, se puede asumir que existen, por lo menos, dos mecanismos que participan en la formación del ácido 20:4(n-6). Estos mecanismos parecen operar independentemente y probablemente interaccionan produciendo un control bidireccional