Kisspeptin Cells in the Ewe Brain Respond to Leptin and Communicate with Neuropeptide Y and Proopiomelanocortin Cells

Kisspeptin stimulates reproduction, and kisspeptin cells in the arcuate nucleus (ARC) express Ob-Rb in the mouse. Herein we report studies in ewes to determine whether kisspeptin cells express Ob-Rb and respond to leptin and whether reciprocal connections exist between kisspeptin cells and proopiomelanocortin (POMC) or neuropeptide Y (NPY) cells to modulate reproduction and metabolic function. Kiss1 mRNA was measured by in situ hybridization in ovariectomized ewes that were normal body weight, lean, or lean with leptin treatment by intracerebroventricular (icv) infusion (4 μg/h, 3 d). Kiss1 expression in the ARC and the preoptic area was lower in hypogonadotropic lean animals than animals of normal weight, and icv infusion of leptin partially restored Kiss1 expression in lean animals. Single-cell laser capture microdissection coupled with real-time PCR showed that Kiss1 cells in the preoptic area and ARC express Ob-Rb. Double-label fluorescent immunohistochemistry showed that reciprocal connections exist between kisspeptin cells and NPY and POMC cells. Accordingly, we treated ovariectomized ewes with kisspeptin (5 μg/h, icv) or vehicle for 20 h and examined POMC and NPY gene expression by in situ hybridization. Kisspeptin treatment reduced POMC and increased NPY gene expression. Thus, kisspeptin neurons respond to leptin and expression of Kiss1 mRNA is affected by leptin status. Kisspeptin cells communicate with NPY and POMC cells, altering expression of the relevant genes in the target cells; reciprocal connections also exist. This network between the three cell types could coordinate brain control of reproduction and metabolic homeostatic systems.

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Methods to Enhance Signal Using Isotopic In Situ Hybridization

Journal of Histochemistry & Cytochemistry ◽

10.1177/002215540205000805 ◽

2002 ◽

Vol 50 (8) ◽

pp. 1031-1037 ◽

Cited By ~ 13

Author(s):

Betty Ky ◽

Paul J. Shughrue

Keyword(s):

Gene Expression ◽

In Situ Hybridization ◽

Cell Types ◽

Oxytocin Receptor ◽

Specific Cell ◽

Rat Hypothalamus ◽

Low Levels ◽

Tuberoinfundibular Peptide ◽

Cryostat Sections

Isotopic in situ hybridization (ISH) has been established as a uniquely powerful tool for the study of gene expression in specific cell types. This technique allows the visualization and quantification of gene expression and gene expression changes in cells. In our study of biological and molecular phenomena, we have increasingly encountered the need to detect small changes in gene expression as well as genes of low abundance, such as the oxytocin receptor (OTR) and the tuberoinfundibular peptide of 39 residues (Tip39). To increase the sensitivity of isotopic ISH for detection of rare mRNAs, we performed ISH on cryostat sections of rat hypothalamus and thalamus with 35S-labeled riboprobes and amplified the signal by hybridizing over 2 nights as well as labeling the probe with both [35S]-UTP and [35S]-ATP. These two methods of enhancement independently and in combination demonstrated a dramatic increase in signal, allowing the visualization of low levels of gene expression previously undetectable by conventional methods.

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Effect of Immune and Metabolic Challenges on the Luteinizing Hormone-Releasing Hormone Neuronal System in Cycling Female Rats: An Evaluation at the Transcriptional Level*

Endocrinology ◽

10.1210/endo.138.4.5044 ◽

1997 ◽

Vol 138 (4) ◽

pp. 1374-1384 ◽

Cited By ~ 26

Author(s):

Rossella E. Nappi ◽

Serge Rivest

Keyword(s):

Gene Expression ◽

In Situ Hybridization ◽

Estrous Cycle ◽

Neuronal Activity ◽

Anterior Pituitary ◽

Preoptic Area ◽

Female Rats ◽

Lamina Terminalis ◽

Ovulatory Cycle

Abstract The purpose of this study was to investigate the influence of immune (systemic endotoxin administration) and metabolic (fasting) challenges on LHRH neuronal activity and transcription in the organum vasculosum of the lamina terminalis/medial preoptic area as well as on the expression of the LHRH receptor (LHRH-R) in the anterior pituitary of cycling female rats. The reproductive stages of adult female rats (200–250 g; 14 h of light; lights on at 0600 h) were verified by daily vaginal smears taken every morning for a minimum of three or four cycles before the experiment. The acute-phase response was induced via an ip injection of lipopolysaccharide (LPS; 200μ g/100 g BW), whereas the metabolic challenge consisted of food deprivation for at least 48 h. Control and challenged rats were killed at specific times in the ovulatory cycle (1200, 1500, and 1800 h on proestrus and diestrous day 2). Frozen brains and pituitaries were mounted on a microtome, cut into 30-μm slices, and then processed for the detection of transcripts encoding either LHRH or LHRH-R by means of in situ hybridization histochemistry using intronic (heteronuclear RNA) and exonic [messenger RNA (mRNA)] riboprobes. Dual immunocytochemistry to detect Fos-immunoreactive (ir) nuclei in LHRH-ir perikarya and colocalization of LHRH mRNA with Fos protein during the day of proestrus were performed by using both in situ hybridization and immunocytochemistry techniques on the same brain sections. The percentage of LHRH-ir and LHRH-expressing neurons displaying positive Fos-ir nuclei during the afternoon of proestrus was significantly inhibited 3 h after endotoxin administration. Rats exhibited an increase in the levels of LHRH primary transcript in the organum vasculosum of the lamina terminalis/medial preoptic area structure at 1500 h on proestrus, a phenomenon significantly attenuated by LPS injection only at this phase of the estrous cycle. On the other hand, fasting did not affect LHRH neuronal activity or gene expression in intact cycling rats, but affected these cells in animals exhibiting a disruption of the ovulatory cycle. Interestingly, LPS caused a profound down-regulation of LHRH-R gene expression in the anterior pituitary throughout the entire estrous cycle. Although food deprivation provoked a more variable pattern of LHRH-R mRNA in cycling rats, the signal for this transcript in the adenohypophysis was deeply altered in those showing a perturbed cycle. These results provide evidence that immune challenge interferes with the LHRH system at both hypothalamic and pituitary levels, whereas alteration of that neuroendocrine system in food-deprived rats seems highly associated with the impairment of reproductive cyclicity.

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Changing Patterns of Gene Expression in Dictyostelium Prestalk Cell Subtypes Recognized by In Situ Hybridization with Genes from Microarray Analyses

Eukaryotic Cell ◽

10.1128/ec.2.3.627-637.2003 ◽

2003 ◽

Vol 2 (3) ◽

pp. 627-637 ◽

Cited By ~ 57

Author(s):

Mineko Maeda ◽

Haruyo Sakamoto ◽

Negin Iranfar ◽

Danny Fuller ◽

Toshinari Maruo ◽

...

Keyword(s):

Gene Expression ◽

In Situ Hybridization ◽

Cell Types ◽

Cell Type ◽

Developmentally Regulated ◽

Specific Expression ◽

Cell Type Specific Expression ◽

Changing Patterns ◽

Cell Type Specific

ABSTRACT We used microarrays carrying most of the genes that are developmentally regulated in Dictyostelium to discover those that are preferentially expressed in prestalk cells. Prestalk cells are localized at the front of slugs and play crucial roles in morphogenesis and slug migration. Using whole-mount in situ hybridization, we were able to verify 104 prestalk genes. Three of these were found to be expressed only in cells at the very front of slugs, the PstA cell type. Another 10 genes were found to be expressed in the small number of cells that form a central core at the anterior, the PstAB cell type. The rest of the prestalk-specific genes are expressed in PstO cells, which are found immediately posterior to PstA cells but anterior to 80% of the slug that consists of prespore cells. Half of these are also expressed in PstA cells. At later stages of development, the patterns of expression of a considerable number of these prestalk genes changes significantly, allowing us to further subdivide them. Some are expressed at much higher levels during culmination, while others are repressed. These results demonstrate the extremely dynamic nature of cell-type-specific expression in Dictyostelium and further define the changing physiology of the cell types. One of the signals that affect gene expression in PstO cells is the hexaphenone DIF-1. We found that expression of about half of the PstO-specific genes were affected in a mutant that is unable to synthesize DIF-1, while the rest appeared to be DIF independent. These results indicate that differentiation of some aspects of PstO cells can occur in the absence of DIF-1.

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Pro-opiomelanocortin (POMC) gene expression, as identified by in situ hybridization, in purified populations of interstitial macrophages and Leydig cells of the adult rat testis

Reproduction Fertility and Development ◽

10.1071/rd9930545 ◽

1993 ◽

Vol 5 (5) ◽

pp. 545 ◽

Cited By ~ 3

Author(s):

H Li ◽

GP Risbridger ◽

JA Clements

Keyword(s):

Gene Expression ◽

In Situ Hybridization ◽

Leydig Cells ◽

Cell Types ◽

Rat Testis ◽

Adult Rat ◽

Pomc Gene ◽

Rna Probe ◽

Silver Grains

The presence of testicular pro-opiomelanocortin (POMC) mRNA and POMC-derived peptides has recently been demonstrated in purified preparations of interstitial macrophages and in Leydig cells of the adult rat testis by Northern blot analysis and immunocytochemistry. In the present study, in situ hybridization provided further evidence that the POMC gene is expressed by both purified interstitial macrophages and Leydig cells. The cellular localization of the POMC transcripts was similar for both cell types, silver grains being predominantly located in the cytoplasm. The specificity of the labelling was demonstrated by the lack of silver grains in the preparations pretreated with RNAase or hybridized with an insulin cDNA probe, a gene known not to be expressed in these cell types. An additional control was provided by hybridization with a sense POMC RNA probe, which gave a less intense signal when compared with the antisense RNA probe under the same experimental conditions. The results confirm POMC gene expression in both macrophages and Leydig cells in the adult rat testis.

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Immunolesion of Norepinephrine and Epinephrine Afferents to Medial Hypothalamus Alters Basal and 2-Deoxy-d-Glucose-Induced Neuropeptide Y and Agouti Gene-Related Protein Messenger Ribonucleic Acid Expression in the Arcuate Nucleus

Endocrinology ◽

10.1210/en.2002-220659 ◽

2003 ◽

Vol 144 (1) ◽

pp. 75-83 ◽

Cited By ~ 62

Author(s):

G. S. Fraley ◽

S. Ritter

Keyword(s):

Gene Expression ◽

In Situ Hybridization ◽

Food Intake ◽

Neuropeptide Y ◽

Arcuate Nucleus ◽

Special Importance ◽

Related Protein ◽

Medial Hypothalamus ◽

Agouti Gene

Abstract Neuropeptide Y (NPY) and agouti gene-related protein (AGRP) are orexigenic peptides of special importance for control of food intake. In situ hybridization studies have shown that NPY and AGRP mRNAs are increased in the arcuate nucleus of the hypothalamus (ARC) by glucoprivation. Other work has shown that glucoprivation stimulates food intake by activation of hindbrain glucoreceptor cells and requires the participation of rostrally projecting norepinephrine (NE) or epinephrine (E) neurons. Here we determine the role of hindbrain catecholamine afferents in glucoprivation-induced increase in ARC NPY and AGRP gene expression. The selective NE/E immunotoxin saporin-conjugated antidopamineβ-hydroxylase (anti-dβh) was microinjected into the medial hypothalamus and expression of AGRP and NPY mRNA was analyzed subsequently in the ARC under basal and glucoprivic conditions using 33P-labeled in situ hybridization. Saporin-conjugated anti-dβh virtually eliminated dβh-immunoreactive terminals in the ARC without causing nonspecific damage. These lesions significantly increased basal but eliminated 2-deoxy-d-glucose-induced increases in AGRP and NPY mRNA expression. Results indicate that hindbrain catecholaminergic neurons contribute to basal NPY and AGRP gene expression and mediate the responsiveness of NPY and AGRP neurons to glucose deficit. Our results also suggest that catecholamine neurons couple potent orexigenic neural circuitry within the hypothalamus with hindbrain glucose sensors that monitor brain glucose supply.

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RNA In Situ Hybridization for Detecting Gene Expression Patterns in the Abdomens and Wings of Drosophila Species

Methods and Protocols ◽

10.3390/mps4010020 ◽

2021 ◽

Vol 4 (1) ◽

pp. 20

Author(s):

Mujeeb Shittu ◽

Tessa Steenwinkel ◽

William Dion ◽

Nathan Ostlund ◽

Komal Raja ◽

...

Keyword(s):

Gene Expression ◽

In Situ Hybridization ◽

Expression Patterns ◽

Drosophila Species ◽

Gene Expression Patterns ◽

Probe Design ◽

Tissue Preparation ◽

Design And Synthesis ◽

Rna In Situ Hybridization

RNA in situ hybridization (ISH) is used to visualize spatio-temporal gene expression patterns with broad applications in biology and biomedicine. Here we provide a protocol for mRNA ISH in developing pupal wings and abdomens for model and non-model Drosophila species. We describe best practices in pupal staging, tissue preparation, probe design and synthesis, imaging of gene expression patterns, and image-editing techniques. This protocol has been successfully used to investigate the roles of genes underlying the evolution of novel color patterns in non-model Drosophila species.

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Pituitary adenoma producing growth hormone and adrenocorticotropin: a histological, immunocytochemical, electron microscopic, and in situ hybridization study

Journal of Neurosurgery ◽

10.3171/jns.1998.88.6.1111 ◽

1998 ◽

Vol 88 (6) ◽

pp. 1111-1115 ◽

Cited By ~ 27

Author(s):

Kalman Kovacs ◽

Eva Horvath ◽

Lucia Stefaneanu ◽

Juan Bilbao ◽

William Singer ◽

...

Keyword(s):

Growth Hormone ◽

In Situ Hybridization ◽

Pituitary Adenoma ◽

Immunoelectron Microscopy ◽

Secretory Granules ◽

Cell Types ◽

Content Type ◽

Separate Cell ◽

Fine Print

✓ The authors report on the morphological features of a pituitary adenoma that produced growth hormone (GH) and adrenocorticotropic hormone (ACTH). This hormone combination produced by a single adenoma is extremely rare; a review of the available literature showed that only one previous case has been published. The tumor, which was removed from a 62-year-old man with acromegaly, was studied by histological and immunocytochemical analyses, transmission electron microscopy, immunoelectron microscopy, and in situ hybridization. When the authors used light microscopy, the tumor appeared to be a bimorphous mixed pituitary adenoma composed of two separate cell types: one cell population synthesized GH and the other ACTH. The cytogenesis of pituitary adenomas that produce more than one hormone is obscure. It may be that two separate cells—one somatotroph and one corticotroph—transformed into neoplastic cells, or that the adenoma arose in a common stem cell that differentiated into two separate cell types. In this case immunoelectron microscopy conclusively demonstrated ACTH in the secretory granules of several somatotrophs. This was associated with a change in the morphological characteristics of secretory granules. Thus it is possible that the tumor was originally a somatotropic adenoma that began to produce ACTH as a result of mutations that occurred during tumor progression.

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