TSH Cells Research Articles

Early Serum Markers for Immune Checkpoint Inhibitor Induced Hypophysitis in Melanoma Patients.

Immune checkpoint inhibitors (ICIs) have shown promising anti-tumor activities and are widely used for the treatment of advanced cancers. However, they may lead to immune-related adverse events (irAEs) and some of them, such as hypophysitis, can be life-threatening. Here, early diagnosis is critical. We retrospectively analyzed 40 melanoma patients who developed hypophysitis during ICI treatment with either ipilimumab and/or anti-PD1 therapy and compared them to 40 control patients who did not develop hypophysitis during the ICI treatment, matched for age, gender, type of immunotherapy, and stage. Clinical data and blood values such as LDH, CRP, TSH, T3, T4, and absolute immune cell counts were retrieved from the medical records. Patient characteristics, laboratory values, progression-free survival, and overall survival were compared between the two groups. Patients with ir-hypophysitis had a median age of 59 years, and most of them were male. Clinically, frequent symptoms were fatigue, headache, dizziness, and gastrointestinal symptoms such as nausea or abdominal pain. The onset of ir-hypophysitis differed much between ipilimumab- (median 8 weeks) and anti-PD1 (median 40 weeks)-induced hypophysitis (p < 0.001). At baseline, besides a slightly increased CRP level (p = 0.06), no differences were observed in patients who later developed hypophysitis compared to the control. After treatment started, hypophysitis patients showed a constant and significant decline in T4 levels from the start of therapy until diagnosis (p < 0.05), independent of the ICI treatment regime. However, a decline in T3 and TSH was only noted in patients with ipilimumab-induced ir-hypophysitis. Furthermore, serum sodium levels declined rapidly at the diagnosis of hypophysitis (p < 0.001). In addition, there was a constant increase in the absolute counts of eosinophils and lymphocytes from baseline in hypophysitis patients (p < 0.05). Ir-hypophysitis reveals different clinical pictures and onset times depending on the ICI regime used. Whereas a drop in T4 levels was indicative of developing hypophysitis independent of the ICI regime, TSH levels only declined in patients under ipilimumab-based ICI regimes. To best monitor our patients, it is important to recognize these differences.

Seasonality of Reproduction in a Subtropical Free-Living Finch Amandava amandava: Plasticity of Adenohypophyseal Gonadotropes, Lactotropes, and Thyrotropes

Introduction: This study sought to decipher the mechanism of transitions between life-history stages in a seasonally reproducing subtropical finch, Amandava amandava delineating the plasticity of the gonadotropes (LH cells), lactotropes (PRL cells), and thyrotropes (TSH cells) in the pituitary gland including the pars tuberalis, with regard to the in situ expression, morphological characteristics, and alteration in the plasma levels of hormones. Methods: Immunohistochemistry of LH, PRL, TSH cells, morphometry and densitometry of expressed hormones (Image J software analysis), and ELISA for plasma hormonal levels were performed. Results: LH, PRL, and TSH cells showed remarkable plasticity during the annual seasonal reproductive cycle. In the PT, all the 3 cell types were detected during the breeding phase, with additional detection of the TSH immunoreactivity during the pre-breeding and the PRL immunoreactivity during post-breeding phases. Pars distalis (PD) expressions and the plasma levels of the LH and TSH were at the peak during the breeding phase, but the PRL peak was during the post-breeding phase. In addition to PRL in the neurohypophysis and in the median eminence, hypothalamic PRL, and TSH were also elucidated. Conclusions: This study suggests activation of the gonadal axis by the PT TSH which might transduce seasonal cues, but not specifically photoperiod, in the birds of the tropics/subtropics. Post-breeding phase sustained high plasma TSH and peak plasma PRL might coordinate the transition to the non-breeding phase including the trigger of parental care as the later hormone assigned with. Hypothalamic TSH and PRL might influence events of seasonality through central modulation.

THU095 Multilineage Plurihormonal (FSH LH TSH PRL ACTH) Pituitary Neuroendocrine Tumour: A Case Report

Abstract Disclosure: U.K. Mahfuza: None. V.A. Preda: None. A. Di Ieva: None. M. Rodiguez: None. Plurihormonal pituitary neuroendocrine tumors (PitNETs) are adenomas that produce more than one hormone. This is an uncommon entity. The 2022 WHO classification has differentiated these pitNETs along histological subtyping based on the tumour cell lineage, cell type, and related characteristics1.We present a case of a 48-year-old gentleman, who initially sought attention for visual symptoms with findings of raised intraocular pressure. His ophthalmologist assessment showed temporal disc pallor. Subsequently, the MRI revealed a 30mm pituitary macroadenoma compressing the optic apparatus. He was referred to our Endocrinology service. He had a low testosterone level. He underwent an endoscopic trans-sphenoidal resection. Post-operatively he remained on testosterone replacement, the rest of the pituitary axes were intact. Pre- and post-operative visual assessment showed retinal ganglion cell loss which has negative prognostic implications. Overall, his eye pressure and visual fields improved following surgery. The histopathology diagnosis was a PitNET/adenoma with predominantly gonadotroph SF1, FSH and LH staining. In addition, there were single cells and nests of strongly TSH and PRL-positive cells scattered through the tumour, but no GH staining. There was specific ACTH staining; also in monophenotypic nests. Pit1 positive nuclei present. The TPit was negative within the tumour. There were some residual adenohypophysis cells which is a rare finding deep within a solid tumour. The tumour extended to the inferior surface of the dura. These unique features lead to uncertainty regarding the potential recurrence rate over time. Conclusion: Multilineage PitNETs are uncommon2. The literature reports that the surgical outcome depends on the histopathology characteristics of the immunohistochemistry and transcription factors. However, PitNETs positive for SF1, FSH, LH, PRL,rl and ACTH staining are not widely reported. With the updated WHO classification and consideration of cell lineage and cell type the knowledge of these tumours will eventually improve. Follow-up and tailored management in this patient’s cohort are needed.

Sexually Dimorphic Regulation of Gonadotrope Cell Hyperplasia in Medaka Pituitary via Mitosis and Transdifferentiation.

The 2 pituitary gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), regulate the reproductive function in all vertebrates. While many studies have investigated the regulation of gonadotropin production and release by sex steroid feedback, its role on the regulation of gonadotrope cell number remains unclear. Using medaka as a model and an optimized protocol to restore physiological sex steroids levels following gonadectomy, we show that gonadal sex steroids not only decrease fshb transcript levels, but also Fsh cell number in both sexes. We then investigated the origin of Fsh cell hyperplasia induced by gonadectomy. In both sexes, bromodeoxyuridine incubation shows that this is achieved via Fsh cell mitosis. In situ hybridization reveals that new Fsh cells also originate from transdifferentiating Tsh cells in females, but not in males. Both phenomena are inhibited by sex steroid supplementation via feeding. In males (but not females), gonadectomy (without recovery with sex steroid supplementation) also reduces sox2 transcript levels and Sox2-immunopositive population size, suggesting that Sox2 progenitors may be recruited to produce new Fsh cells. Opposite to Fsh cells, gonadectomy decreases lhb levels in both sexes, and levels are not restored by sex steroid supplementation. In addition, the regulation of Lh cell number also seems to be sex dependent. Removal of gonadal sex steroids stimulates Lh cell mitosis in male (like Fsh cells) but not in females. To conclude, our study provides the first evidence on sexually dimorphic mechanisms used in the fish pituitary to remodel gonadotrope populations in response to sex steroids.

Abstract 6305: Downregulation of glutamine transporter stably and significantly attenuates weight loss by a cachexia-inducing pancreatic cancer xenograft

Abstract Cancer-induced cachexia is commonly observed in pancreatic cancer. The syndrome induces significant weight loss and leads to morbidity, intolerance to chemotherapy, and mortality. While performing metabolic characterization of the brain and plasma of mice with a cachexia-inducing human pancreatic cancer xenograft we identified significant changes in glutamine metabolism [1] that led us to investigate the effects of altering tumor glutamine metabolism on weight loss. We genetically engineered cachexia inducing Pa04C cells to express shRNA downregulating the glutamine transporter SLC1A5. Tumors derived from Pa04C cells with downregulated SLC1A5 (CSh cells and tumors) exhibited significantly delayed tumor growth compared to empty vector (EV) or wild type (WT) tumors, but escaped growth delay approximately 60 days after inoculation, although SLC1A5 mRNA and protein remained significantly downregulated. Despite tumor growth, mouse weight reduction was significantly attenuated at matched EV and CSh tumor volumes. We next sought to investigate if tumors derived from cells isolated from escaped CSh tumor (TSh cells and tumors) continued to exhibit growth delay and attenuated weight loss when re-inoculated in mice. Quantitative transcriptome profiling by RNA-seq was performed to determine differentially expressed genes in CSh and TSh cells compared to EV cells. Method: EV, CSh or TSh cells were inoculated subcutaneously in male mice. Tumor volumes and weights of tumor bearing mice were recorded until tumors were harvested at ~ 500 mm3 for molecular characterization. RNA was isolated in triplicate from EV, CSh and TSh cells. Transcriptomic analysis was performed by RNA sequencing on a NovaSeq 6000 PE150 platform. All bioinformatics analysis was performed with assistance from the NOVOGENE informatics group. Results: Tumors derived from TSh cells did not exhibit any growth delay unlike tumors derived from CSh cells. SLC1A5 expression remained downregulated in TSh cells and tumors. Despite the loss of growth delay, mice with TSh tumors continued to exhibit attenuated weight loss identifying, suggesting the glutamine transporter as a potential treatment strategy to reduce cachexia. Transcriptomic analysis allowed us to identify the adaptive changes that occurred in CSh tumors that allowed these tumors to escape growth delay despite SLC1A5 downregulation. Transcriptomic differences between TSh and CSh cells were primarily in pathways related to amino acid metabolism, inflammation and the extracellular matrix. These transcriptomic differences allow the identification of novel targets that can be used in combination with glutamine transporter downregulation to arrest the growth of pancreatic cancer cells in vivo. Supported by NIH R35 CA209960 and R01 CA193365. 1) J Cachexia Sarcopenia Muscle. 2020 Dec; 11(6): 1487-1500. Citation Format: Balaji Krishnamachary, Ishwarya Sivakumar, Yelena Mironchik, Raj Kumar Sharma, Santosh Kumar Bharti, Marie-France Penet, Paul Winnard, Eibhlin Goggins, Jiefu Jin, Anirban Maitra, Michael G. Goggins, Zaver M. Bhujwalla. Downregulation of glutamine transporter stably and significantly attenuates weight loss by a cachexia-inducing pancreatic cancer xenograft [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6305.

An Extremely Low Frequency Magnetic Field and Global Cerebral Ischemia Affect Pituitary ACTH and TSH Cells in Gerbils.

The neuroendocrine system can be modulated by a magnetic field and cerebral ischemia as external and internal stressors, respectively. This study deals with the separate or combined effects of an extremely low frequency (ELF) magnetic field (50 Hz, average magnetic field of 0.5 mT) for 7 days and global cerebral ischemia for 10 min on the morpho-functional features of pituitary adrenocorticotrophic (ACTH) and thyrotrophic (TSH) cells in 3-month-old gerbils. To determine the immediate and delayed effects of the applied stressors, measurements were made on the 7th and 14th days after the onset of the experiment. The ELF magnetic field and 10-min global cerebral ischemia, separately and particularly in combination, decreased (P < 0.05) the volume density of ACTH cells, while only in combination were intracellular ACTH content and plasma ACTH concentration increased (P < 0.05) on day 7. The ELF magnetic field elevated serum TSH concentration on day 7 and intracellular TSHβ content on day 14 (P < 0.05). Also, 10-min global cerebral ischemia alone increased serum TSH concentration (P < 0.05), while in combination with the ELF magnetic field it elevated (P < 0.05) intracellular TSHβ content on day 14. In conclusion, an ELF magnetic field and/or 10-min global cerebral ischemia can induce immediate and delayed stimulation of ACTH and TSH synthesis and secretion. Bioelectromagnetics. 2020;41:91-103. © 2019 Bioelectromagnetics Society.

Functional divergence of thyrotropin beta-subunit paralogs gives new insights into salmon smoltification metamorphosis

Smoltification is a metamorphic event in salmon life history, which initiates downstream migration and pre-adapts juvenile salmon for seawater entry. While a number of reports concern thyroid hormones and smoltification, few and inconclusive studies have addressed the potential role of thyrotropin (TSH). TSH is composed of a α-subunit common to gonadotropins, and a β-subunit conferring hormone specificity. We report the presence and functional divergence of duplicated TSH β-subunit paralogs (tshβa and tshβb) in Atlantic salmon. Phylogeny and synteny analyses allowed us to infer that they originated from teleost-specific whole genome duplication. Expression profiles of both paralogs in the pituitary were measured by qPCR throughout smoltification in Atlantic salmon from the endangered Loire-Allier population raised in a conservation hatchery. This revealed a striking peak of tshβb expression in April, concomitant with downstream migration initiation, while tshβa expression remained relatively constant. In situ hybridization showed two distinct pituitary cell populations, tshβa cells in the anterior adenohypophysis, and tshβb cells near to the pituitary stalk, a location comparable to the pars tuberalis TSH cells involved in seasonal physiology and behaviour in birds and mammals. Functional divergence of tshβ paralogs in Atlantic salmon supports a specific role of tshβb in smoltification.

Cytology of the Pituitary Gonadotrophs, Histological Characteristics of Interrenal and Chromaffin Cells in Relation to Testicular Activities in Mystus Vittatus (Siluriformes, Bagridae) During Growth, Maturation and Spawning Phases

Abstract The histological changes observed in the pituitary corticotrophs, gonadotrophs, adrenocortical tissues and testicular cells in M. vittatus (Bloch, 1794) have been studies during growth, maturation and spawning phases. The studies based on the changes observed in the cell types, shape and size of the cells of the adrenocortical tissues, testes and the overall percentage of gonadotroph (GTH) and thyrotroph (TSH) cells of the pituitary. However, during growth phase, in proximal pars distalis (PPD) the considerable increment of GTH and TSH have been observed having intense aniline blue stain. The corticotrophs (ACTH) also showed significant accumulation of fuchsinophilic cytoplasmic granules. The cytoplasmic features and the architecture of the interrenal cells were well coincident with the increase of different spermatogenic cells. During the maturation phase dense granulation in the GTH and TSH cells appeared to be concomitant with the spermiation. The amount of cytoplasmic granules of the interrenal cells increased than chromaffin cells and was well coincidence with the increase of spermatids and spermatozoa. The hyperactive and vacuolated features of the interrenal cells during spawning phase appeared to be concomitant with the final process of spermiation.

Predictors for Lean Non-alcoholic Fatty Liver Disease: A Real World Experience

Introduction: Non-alcoholic fatty liver disease (NAFLD) is highly prevalent and significant in practice. Recently, NAFLD has been classified as two phenotypically distinct entities: Obese-NAFLD and lean- NAFLD differentiated by patient BMI. It is unclear whether lean-NAFLD is a different disease with unique pathophysiological and disease progression properties as compared to Obese-NAFLD. This study seeks to address this question by comparing various clinical and demographic variables between lean and obese patients presenting with NAFLD in the community setting. Methods: Demographic and clinical parameters were assessed in 199 adults attending Liver Associates of Texas clinics with an established diagnosis of NAFLD seen between April 2015 and April 2016. The subjects were classified into 2 groups based on the World Health Organization (WHO) Body mass index (BMI) Classification: lean-NAFLD (BMI < 25kg/m2) or Obese NAFLD (BMI > 30 kg/m2). A total of 27 lean patients were compared to 116 obese. One-way analysis of variance (ANOVA) was used to compare the mean age, glucose level, hemoglobin A1c (HbA1c), lipid profile, liver profile, TSH and blood cell counts. Pearson's Chi square test was used to discover associations with gender, prevalence of hypertension (HTN), diabetes mellitus (DM), presence of cirrhosis and level of fibrosis. SPSS v19 was used and p value < 0.05 was considered statistically significant. Results: Overall, Obese-NAFLD was significantly associated with HTN compared to Lean-NAFLD (54.8% Vs. 29.6%, p = 0.031). DM and cirrhosis were more prevalent in Obese-NAFLD, but this association didn't reach statistical significance. Mean ages were not significantly different between the two groups. Patients with lean-NAFLD had significantly lower mean triglycerides (p= 0.032), LDL (p= 0.08), TSH (p =0.09), and higher mean HDL (p= 0.025) and albumin (p= 0.02). Conclusion: Lean and Obese NAFLD did show significant differences across some of the measured biochemical and clinical parameters including lipid profiles and hypertension. This may not only provide some prognostic value in the study of NAFLD, but it may also suggest some pathophysiological differences between the lean and obese variations at the hepatic or even molecular level. Our study gives some support to the split classification. Further studies are needed to determine if lean NAFLD is indeed a distinct entity of NAFLD.

Increased avidity for Dpp/BMP2 maintains the proliferation of progenitors-like cells in the Drosophila eye

During organ development, the progenitor state is transient, and depends on specific combinations of transcription factors and extracellular signals. Not surprisingly, abnormal maintenance of progenitor transcription factors may lead to tissue overgrowth, and the concurrence of signals from the local environment is often critical to trigger this overgrowth. Therefore, identifying specific combinations of transcription factors/signals promoting -or opposing- proliferation in progenitors is essential to understand normal development and disease. We have investigated this issue using the Drosophila eye as model. Transcription factors hth and tsh are transiently expressed in eye progenitors causing the expansion of the progenitor pool. However, if their co-expression is maintained experimentally, cell proliferation continues and differentiation is halted. Here we show that Hth+Tsh-induced tissue overgrowth requires the BMP2 Dpp and the abnormal hyperactivation of its pathway. Rather than using autocrine Dpp expression, Hth+Tsh cells increase their avidity for Dpp, produced locally, by upregulating extracellular matrix components. During normal development, Dpp represses hth and tsh ensuring that the progenitor state is transient. However, cells in which Hth+Tsh expression is forcibly maintained use Dpp to enhance their proliferation.

Ultra structure differentiation of the anterior pituitary cells of the adult female non pregnant carnivore Vulpes zerda

The pituitary gland of carnivore mammals in the world was described, but that of those in Egypt may be low, so the present study is carried out on some carnivore mammals such as Vulpes zerda, to elucidate the similarities and the differences of the pituitary cells between the mammals in the world and those in Egypt. The results indicate that, the gland is pyramidal in shape. The acidophilic cells and the basophilic cells are distributed heterogeneously in the body of the gland. The STH cells are numerous, the nucleus is irregular, lobed and eccentric with the endoplasmic reticulum. The secretory granules are light with a large size. The LTH cells have eccentric nucleus near the plasma membrane, the mitochondrium is spherical or elongated, the endoplasmic reticulum is rough and the granules are collected at the cell periphery.The ACTH cells are found singly, irregular with eccentric nucleus. Its secretory granules are small and spherical shaped, while the TSH cells have very small secretory granules, but the FSH and LH cells are found singly, angular shape with eccentric nuclei and the its secretary granules are spherical or ovoid shaped and exhibit variation in electron density than STH cells. The differences in shape and distribution may be related to the phylogeny.

Screening of New Born Babies for Thyroid Stimulating Hormone, Glucose-6-Phosphate Dehydrogenase, 17-Hydroxyprogesterone and Sickle Cell Disease

BACKGROUND: The expanded newborn screening programme has now initiated worldwide. Many of the countries around the world made this programme mandatory. The effect of such screening system gives the advantage or betterment to the society as well as the nation.METHODS: Samples were collected from babies aged 48-72 hours by heel prick method in a filter paper provided by Bio-Rad. The written consent was taken from the parents before collecting the blood samples. Blood samples were assayed for TSH and17-OHP by Enzyme Immuno Assay (EIA), G-6-PD was estimated by colorimetric assay provided by Bio-Rad Laboratories, USA and Sickle Cell Disease by sickling testRESULTS: A total of 715 newborns were screened for TSH, G-6-PD, 17-OHP and Sickle cell disease. Out of which 1 neonate found abnormal (increased) thyroid stimulating hormone (1/715), and 8 neonates were G-6-PD deficient (8/715). We did not find any cases of congenital adrenal hyperplasia and sickle cell disease.CONCLUSIONS: In this study the prevalence of Congenital Hypothyroidism and Glucose-6-Phosphate dehydrogenase deficiency was found to be 1:715 and 1:89 respectively. No cases of congenital adrenal hyperplasia and sickle cell disease were found.

Spatial and temporal expression of immunoglobulin superfamily member 1 in the rat.

Loss-of-function mutations in the immunoglobulin superfamily member 1 (IGSF1) gene cause an X-linked syndrome of central hypothyroidism, macroorchidism, variable prolactin and GH deficiency, delayed pubertal testosterone rise, and obesity. To understand the pathophysiology of this syndrome, knowledge on IGSF1's place in normal development is imperative. Therefore, we investigated spatial and temporal protein and mRNA expression of IGSF1 in rats using immunohistochemistry, real-time quantitative PCR (qPCR), and in situ hybridization. We observed high levels of IGSF1 expression in the brain, specifically the embryonic and adult choroid plexus and hypothalamus (principally in glial cells), and in the pituitary gland (PIT1-lineage of GH, TSH, and PRL-producing cells). IGSF1 is also expressed in the embryonic and adult zona glomerulosa of the adrenal gland, islets of Langerhans of the pancreas, and costameres of the heart and skeletal muscle. IGSF1 is highly expressed in fetal liver, but is absent shortly after birth. In the adult testis, IGSF1 is present in Sertoli cells (epithelial stages XIII-VI), and elongating spermatids (stages X-XII). Specificity of protein expression was corroborated with Igsf1 mRNA expression in all tissues. The expression patterns of IGSF1 in the pituitary gland and testis are consistent with the pituitary hormone deficiencies and macroorchidism observed in patients with IGSF1 deficiency. The expression in the brain, adrenal gland, pancreas, liver, and muscle suggest IGSF1's function in endocrine physiology might be more extensive than previously considered.

Pituitary Hormone-producing Cells After Estradiol Application in Rat Models of Menopause

Abstract Female ageing represents the biological process of structural and functional changes in endocrine cells and tissues, as well as in pituitary hormone-producing cells. In addition to the hypothalamic releasing hormones, estradiol plays a significant role in the regulation of the synthesis/secretion of pituitary hormones and is still used therapeutically for menopausal symptoms. The effects of ageing or ovariectomy and synthetic estradiol application under these circumstances were evaluated in pituitary hormone-producing cells of female rats (animal models of menopause); i.e., the following cells were observed: gonadotropes (FSH and LH), thyrotropes (TSH), somatotropes (GH), mammotropes (PRL) and corticotropes (ACTH). The cells were immunostained and histologically analysed. The ELISA method was used for hormonal analyses. Ageing was found to cause diverse, commonly reductive changes regarding the volume, number and secretion of menopausal rat pituitary hormone- producing cells, except for PRL cells that exhibit significantly increased numbers and intensified secretion. After the treatment of middle-aged female rats wiThestradiol, the absolute and relative pituitary weights significantly increased in comparison with the control females. Histological parameters such as the cell and volume density of PRL and ACThcells were significantly increased compared with the control values. The mentioned parameters of FSH, LH, GH, and occasionally TSH cells after estradiol treatment significantly decreased in comparison with the controls. The corresponding hormone levels followed the changes in the histological parameters. These data indicate that the application of estradiol to menopausal females may specifically, in two directions, modify the histological characteristics and secretory activities of different pituitary-hormone producing cells..

Immunocytochemical and ultrastructural identification of adenohypophyseal cells in Ctenopharyngodon idella (Cypriniformes: Cyprinidae) during gonadal differentiation

The adenohypophysis was studied by immunocytochemical and ultrastructural methods in juvenile grass carp (Ctenopharyngodon idella) from natural reproduction in Northern Italian rivers. The adenohypophysis included the rostral pars distalis (RPD), the proximal pars distalis (PPD) and the pars intermedia (PI), all deeply penetrated by branches of the neurohypophysis (Nh). The prolactin (PRL), adrenocorticotropic (ACTH), somatotropic (GH), thyrotropic (TSH), gonadotropic type I (GtH I) and type II (GtH II), somatolactin (SL), melanotropic (MSH) and endorphin (END) cells were identified with antisera raised against piscine and human pituitary hormones. In juveniles of 51-69mm of total body length (TL) with undifferentiated gonads, the PRL cells, arranged in thick strands, occupied most of the RPD. The ACTH and GH cells organized in cords bordering Nh were, respectively, confined to RPD and PPD. The TSH cells were scattered among ACTH cells in RPD and among GH cells in PPD. Cells simultaneously immunoreactive to anti-follicle stimulating hormone and to anti-croaker gonadotropin were intermingled among GH and TSH cells, which were mostly in the dorsal PPD. The SL cells were detected in PI layers bordering the Nh. The MSH and END cells were intermingled in PI and, unlike what observed in other teleosts, their respective antisera did not cross-react. In individuals of 78-112mm TL with gonads at the beginning of differentiation, the GtH II cells were detected in PPD; all other cell types increased in number. These results, supported by ultrastructural investigations, suggest that SL and GtH II cells are directly involved in gonadal differentiation in C. idella.

Somatostatin Receptors Type 2 and 5 Expression and Localization During Human Pituitary Development

Somatostatin (SRIF), by acting mainly through sst2 and sst5 receptors, is a potent inhibitor of hormonal secretion by the human anterior pituitary gland. However, the pattern of protein expression of these SRIF receptors remains unknown during pituitary development. To get further insights into the physiological role of SRIF receptors in human development and pituitary function, the present study examined the developmental expression of the sst2 and sst5 receptors in the individual cell types of the anterior human pituitary. Thirteen fetal human pituitaries were investigated between 13 to 38 weeks of gestation (WG) by double-labeling immunofluorescence with antibodies raised against sst2 or sst5 receptors and GH, LH, FSH, TSH, or pro-opiomelanocortin proteins. SRIF immunoreactivity in the hypothalamus and median eminence was investigated at the same developmental ages. Immunoreactivity for the sst2 receptor was evident as early as 13 to 15 WG and onward mainly in TSH-, LH-, and FSH-expressing cells, whereas sst5 immunoreactivity was apparent at the late development stages (35-38 WG). GH-expressing cells mainly expressed sst5 immunoreactivity. SRIF-positive fibers and cells were detected as soon as 13 to 16 WG in the hypothalamus and median eminence and their densities increased with gestational age. The early appearance of hypothalamic SRIF cells and fibers suggests a physiological link between SRIF and its receptors during pituitary development. Whereas sst2 receptors might play a primary role in the differentiation and regulation of TSH, LH, and FSH cells, sst5 receptors appear to be mainly involved in GH regulation from birth onward.

&lt;i&gt;In Situ&lt;/i&gt; Hybridization Method Reveals (Pro)renin Receptor Expressing Cells in the Pituitary Gland of Rats: Correlation with Anterior Pituitary Hormones

Expression of (pro)renin receptor ((P)RR), a specific receptor for renin and prorenin, was studied in rat pituitary gland. In situ hybridization showed that cells expressing (P)RR mRNA were widely distributed in the anterior lobe and intermediate lobe of the pituitary gland. Double-staining using in situ hybridization for (P)RR mRNA and immunohistochemistry for the pituitary hormones showed that (P)RR mRNA was expressed in most of the GH cells and ACTH cells in the anterior lobe. (P)RR mRNA was also expressed in a few prolactin cells and TSH cells, but not in LH cells. The present study has shown for the first time the distribution of (P)RR mRNA expressing cells in the rat pituitary gland. These findings suggest that (P)RR plays physiological roles in the pituitary gland, such as the modulation of the pituitary hormone secretion.

Reassembly of Anterior Pituitary Organization by Hanging Drop Three-Dimensional Cell Culture

The anterior pituitary gland comprises 5 types of hormone-producing cells and non-endocrine cells, such as folliculostellate (FS) cells. The cells form a lobular structure surrounded by extracellular matrix (ECM) but are not randomly distributed in each lobule; hormone-producing cells have affinities for specific cell types (topographic affinity), and FS cells form a homotypic meshwork. To determine whether this cell and ECM organization can be reproduced in vitro, we developed a 3-dimensional (3D) model that utilizes hanging drop cell culture. We found that the topographic affinities of hormone-producing cells were indeed maintained (ie, GH to ACTH cells, GH to TSH cells, PRL to LH/FSH cells). Fine structures in hormone-producing cells retained their normal appearance. In addition, FS cells displayed well-developed cytoplasmic protrusions, which interconnected with adjacent FS cells to form a 3D meshwork. In addition, reassembly of gap junctions and pseudofollicles among FS cells was observed in cell aggregates. Major ECM components—collagens and laminin—were deposited and distributed around the cells. In sum, the dissociated anterior pituitary cells largely maintained their in vivo anterior pituitary architectures. This culture system appears to be a powerful experimental tool for detailed analysis of anterior pituitary cell organization.

Ghrelin Receptor Expression and Colocalization with Anterior Pituitary Hormones Using a GHSR-GFP Mouse Line

Ghrelin is the endogenous ligand for the GH secretagogue receptor (GHSR) and robustly stimulates GH release from the anterior pituitary gland. Ghrelin also regulates the secretion of anterior pituitary hormones including TSH, LH, prolactin (PRL), and ACTH. However, the relative contribution of a direct action at the GHSR in the anterior pituitary gland vs. an indirect action at the GHSR in the hypothalamus remains undefined. We used a novel GHSR-enhanced green fluorescent protein (eGFP) reporter mouse to quantify GHSR coexpression with GH, TSH, LH, PRL, and ACTH anterior pituitary cells in males vs. females and in chow-fed or calorie-restricted (CR) mice. GHSR-eGFP-expressing cells were only observed in anterior pituitary. The number of GHSR-eGFP-expressing cells was higher in male compared with females, and CR did not affect the GHSR-eGFP cell number. Double staining revealed 77% of somatotrophs expressed GHSR-eGFP in both males and females. Nineteen percent and 12.6% of corticotrophs, 21% and 9% of lactotrophs, 18% and 19% of gonadotrophs, and 3% and 9% of males and females, respectively, expressed GHSR-eGFP. CR increased the number of TSH cells, but suppressed the number of lactotrophs and gonadotrophs, expressing GHSR-eGFP compared with controls. These studies support a robust stimulatory action of ghrelin via the GHSR on GH secretion and identify a previously unknown sexual dimorphism in the GHSR expression in the anterior pituitary. CR affects GHSR-eGFP expression on lactotrophs, gonadotrophs, and thyrotrophs, which may mediate reproductive function and energy metabolism during periods of negative energy balance. The low to moderate expression of GHSR-eGFP suggests that ghrelin plays a minor direct role on remaining anterior pituitary cells.

Immunohistochemical Demonstration of Ghrelin in the Nontumorous Human Hypophysis

Ghrelin, a 28 amino acid‐containing orexigenic peptide, is an endogenous ligand of the GH secretagogue receptor. It was extracted from the rat stomach, but is present in other organs. The aim of this work was to localize ghrelin by immunohistochemistry in autopsy‐derived non‐tumorous human pituitaries. Immunohistochemistry was performed using the streptavidin‐biotin‐peroxidase complex method and the results were analyzed independently by 3 of the authors. Double Immunostaining was also undertaken to determine which cell type was expressing both the adenohypophysial hormone and ghrelin.Results showed that ghrelin can be localized in the adenohypophysis. It's immunoexpression being cytoplasmic, weak to moderate, and present in only a subset of cells. The neurohypophysis is immunonegative. Double immunostaining showed that ghrelin is co‐localized with GH, ACTH and LH and is present to 51–90% of such cells. PRL, TSH and FSH cells are consistently non‐reactive. The role of ghrelin in adenohypophysial endocrine activity is not clear. It may well be that ghrelin exerts an autocrine‐paracrine effect and can modulate hormone synthesis and release.