Differential expression and signaling activation of insulin receptor isoforms A and B: A link between breast cancer and diabetes

We showed that when insulin-like growth factor II (IGF-II) is highly expressed in breast tissues and cell lines, the IGF-I receptor signaling pathway is highly activated. Since IGF-II activates the insulin receptor (INSR), we propose that the INSR signaling is also activated in this system. We examined the expression of both INSR isoforms, insulin receptor A (INSR-A) and insulin receptor B (INSR-B), and the downstream signaling pathways in breast cancer (BC) cells and in paired (normal/tumor) breast tissues from 100 patients. Analysis was performed by real-time PCR, Western blot, immunohistochemistry, and phospho-ELISA techniques. Tumor tissues and cell lines from African-American patients expressed higher levels of INSR-A, but lower levels of INSR-B. Accordingly, insulin receptor substrate 1 and focal adhesion kinase activation were significantly increased in these women. We conclude that higher INSR-A and lower INSR-B contribute to higher proliferation and lower metabolic response. Thus, differential expression of INSR isoforms represents a potential biological link between BC and diabetes.

Insulin-like growth factors I and II receptors in the breast cancer survival disparity among African-American women

OBJECTIVE

African-American (AA) women with breast cancer are more likely to have advanced disease at diagnosis, higher risk of recurrence and poorer prognosis than Caucasian (CA) women. We have recently shown higher insulin-like growth factor II (IGF-II) expression in paired breast tissue samples from AA women as compared to CA women. IGF-II is a potent mitogen that induces cell proliferation and survival signals through activation of the IGF-I and Insulin receptors (IGF-IR, IR) while IGF-II circulating levels are regulated by cellular uptake through the IGF2 receptor. We hypothesize that differential expression of the IGF1R and IGF2R among AA and CA women potentiates IGF-II mitogenic effects, thus contributing to the health disparity observed between these ethnic groups.

DESIGN

We examined IGF-IR and IGF2R mRNA, protein expression and IGF1R phosphorylation in paired breast tissue samples from AA and CA women by Real Time-PCR, Western blot analysis, immunohistochemistry and ELISA techniques.

RESULTS

Our results showed significantly increased expression of IGF1R in AA normal tissues as compared to CA normal tissues. IGF1R expression was similar between AA normal and malignant tissues, while IGF1R, IRS-1 and Shc phosphorylation was significantly higher in AA tumor samples. Significantly higher levels of IGF2R were found in CA tumor samples as compared to AA tumor samples.

CONCLUSIONS

We conclude that IGF1R and IGF2R differential expression may contribute to the increased risk of malignant transformation in young AA women and to the more aggressive breast cancer phenotype observed among AA breast cancer patients and represent, along with IGF-II, potential therapeutic targets in breast cancer.

Differential insulin-like growth factor II (IGF-II) expression: A potential role for breast cancer survival disparity

OBJECTIVE

Increased risk of cancer and other adult diseases have been associated with perinatal exposure to adverse conditions such as stress and famine. Recently, Insulin-like growth factor II (IGF-II) was identified as the first gene associated with altered expression caused by fetal exposure to poor nutrition. IGF-II regulates fetal development and breast cancer cell survival, in part, by regulating anti-apoptotic proteins through activation of the IGF-I and insulin receptors. African-American (AA) women have a lower overall breast cancer (BC) incidence, however, they present with advanced disease at diagnosis, poorer prognosis and lower survival than Caucasian (CA) women. The reasons for the BC survival disparity are not well understood. We hypothesize that IGF-II plays a role in the survival disparity observed among AA breast cancer patients by stimulating rapid tumor growth, inhibiting apoptosis, and promoting metastasis.

DESIGN

This study examines IGF-II expression and regulation of the anti-apoptotic proteins Bcl-2, Bcl-X(L), and survivin in Hs578t (ER-), CRL 2335 (ER-), and CRL 2329 (ER+) breast cancer cells and compares with the expression of these proteins in paired breast tissue samples from AA and CA women by qRT-PCR and Western blotting.

RESULTS

IGF-II expression was significantly higher in AA cell lines and tissue samples when compared to Caucasians. IGF-II siRNA treatment decreased anti-apoptotic protein levels in all cell lines (regardless of ER status). These effects were blocked by the addition of recombinant IGF-II. Of significance, IGF-II expression and regulation of Bcl-X(L) and survivin in cell lines correlated with their expression in paired breast tissues.

CONCLUSIONS

IGF-II and the anti-apoptotic proteins differential expression among AA and CA patients may contribute to the breast cancer survival disparities observed between these ethnic groups.

Precursor IGF-II (proIGF-II) and mature IGF-II (mIGF-II) induce Bcl-2 And Bcl-X L expression through different signaling pathways in breast cancer cells

IGF-II plays a crucial role in fetal and cancer development by signaling through the IGF-I receptor. We have shown that inhibition of IGF-II by resveratrol (RSV) induced apoptosis and that proIGF-II (highly expressed in cancer) was more potent than mIGF-II in inhibiting this effect. Thus, we hypothesized that IGF-II differentially regulates the signaling cascade of the IGF-I receptor to stimulate the anti-apoptotic proteins Bcl-2 and Bcl-X(L) to prevent apoptosis. RSV treatment to breast cancer cells inhibited Bcl-2 and Bcl-X(L) expression and induced mitochondrial membrane depolarization. ProIGF-II was more potent than mIGF-II in: (1) activating the PI3/Akt pathway, (2) regulating Bcl-2 and Bcl-X(L) expression, and (3) inducing phosphorylation/nuclear translocation of Cyclic AMP-responsive element binding protein. Furthermore, IGF-II differentially regulated the intracellular translocation of Bcl-2 and Bcl-X(L), a critical process in breast cancer progression to hormone-independence. Our study provides a novel mechanism of how proIGF-II promotes progression and chemoresistance in breast cancer development.

Differential effect of proIGF-II and IGF-II on resveratrol induced cell death by regulating survivin cellular localization and mitochondrial depolarization in breast cancer cells

Insulin-like growth factor II (IGF-II) plays a pivotal role in fetal and cancer development by signaling through the IGF-I and insulin receptors and activating the estrogen signaling cascade. We previously showed that precursor IGF-II (proIGF-II, the predominant form expressed in cancer) and not mature IGF-II (mIGF-II) blocks resveratrol (RSV) (a phytoalexin/anticancer agent)-induced cell death in MCF-7 cells. We hypothesize that proIGF-II regulates antiapoptotic proteins and/or the mitochondria to inhibit RSV actions and promote cell survival. This study examines the effect of mIGF-II and proIGF-II on survivin expression and mitochondrial polarization in response to RSV. RSV inhibits survivin expression and stimulates mitochondrial depolarization, caspase 7 activation and cell death. These effects were completely blocked by the addition of proIGF-II. RSV treatment had no effect on transfected MCF-7 cells constitutively expressing proIGF-II, while IGF-II siRNA transfection decreased survivin levels. Our results provide new insights for the potential use of proIGF-II as target for new anticancer therapies.

Induction and axonal localization of epithelial/epidermal fatty acid-binding protein in retinal ganglion cells are associated with axon development and regeneration

Epithelial/epidermal fatty acid-binding protein (E-FABP) is induced in peripheral neurons during nerve regeneration and is found at high levels in central neurons during neuronal migration and development. Furthermore, E-FABP expression is required for normal neurite outgrowth in PC12 cells treated with nerve growth factor (NGF). The present study examined whether E-FABP plays a role in retinal ganglion cell (RGC) differentiation and axon growth. Rat retinal tissues from embryonic (E) and postnatal (P) development through adulthood were examined using immunocytochemical labeling with E-FABP and growth-associated protein 43 (GAP-43) antibodies. E-FABP colocalized with GAP-43 at E14 through P10. At E14, E-FABP immunoreactivity was confined to the somas of GAP-43-positive cells in the ganglion cell layer, but it was localized to their axons by E15. The axons in the optic nerve were GAP-43-positive and E-FABP-negative on E15, but the two proteins were colocalized by E18. Retinal cultures at E15 confirmed that E-FABP and GAP-43 colocalize in RGCs. Postnatally, labeling was present between P1 and P10 but decreased at older ages and was minimally present or absent in adult animals. Western immunoblotting revealed that at E18, P1, and P10 E-FABP levels were at least fourfold greater than those in the adult. By P15, protein levels were only twofold greater, with adult levels reached by P31. Furthermore, E-FABP could be reinduced during axon regeneration. Dissociated P15 retinal cells cultured in the presence of brain-derived neurotrophic factor, ciliary neurotrophic factor, and basic fibroblast growth factor exhibited sixfold more GAP-43 and E-FABP double-positive RGCs (cell body and axons) than controls. Moreover, all GAP-43-immunoreactive RGCs were also positive for E-FABP. Taken together, these results indicate the following: 1) E-FABP is expressed in RGCs as they reached the ganglion cell layer and 2) E-FABP plays a functional role in the elaboration of RGC axons in both development and regeneration.

Depletion of a fatty acid-binding protein impairs neurite outgrowth in PC12 cells

Epithelial fatty acid-binding protein (E-FABP) is up-regulated in rat dorsal root ganglia after sciatic nerve crush and in differentiating neurons during development. The present study investigates the role of E-FABP during nerve growth factor (NGF)-mediated neurite outgrowth in PC12 cells. Undifferentiated PC12 cells express low levels of E-FABP, while NGF triggers a 6- and 8-fold induction of E-FABP mRNA and protein, respectively. Up-regulation of E-FABP mRNA occurs as early as 24 h after NGF treatment and remains highly expressed over the course of several days, corresponding to NGF-mediated neurite outgrowth. Withdrawal of NGF leads to down-regulation of E-FABP mRNA and retraction of neurites. Immunofluorescence microscopy reveals E-FABP immunoreactivity in the perinuclear cytoplasm, neurites and growth cones of NGF-differentiated cells. To examine the role of E-FABP during neurite outgrowth, PC12 cells were transfected with a constitutive antisense E-FABP vector to create the E-FABP-deficient line PC12-AS. By morphometric analysis, PC12-AS cells treated for 2, 4, and 7 days with NGF exhibited significantly decreased neurite expression relative to control (mock-transfected) cells. Taken together, these data indicate that E-FABP is important in normal NGF-mediated neurite outgrowth in PC12 cells, a finding that is consistent with a potential role in axonal development and regeneration.

In situ and immunocytochemical localization of E-FABP mRNA and protein during neuronal migration and differentiation in the rat brain

The present study compares the temporal-spatial expression and tissue localization of the rat epidermal type fatty acid binding protein (E-FABP) (DA11/C-FABP/S-FABP/LEBP/KLBP) in the developing rat central nervous system (CNS). In situ hybridization (ISH) and immunocytochemistry (ICC) studies demonstrate that mRNA E-FABP and protein are expressed at high levels during neurogenesis, neuronal migration, and terminal differentiation. Migrating pyramidal cells in the cerebral cortex, Purkinje cells and deep nuclear neurons in the cerebellum, and neurons in the olfactory bulb and retina exhibited a strong E-FABP-like immunoreactivity (E-FABP-LI) throughout the entire process of differentiation and migration. The levels of E-FABP mRNA and protein were dramatically higher in prenatal and early postnatal neurons, as compared to adult neurons. The E-FABP antibody immunoreacted with growing neurites, and nuclear and cytoplasmic regions of neurons. The intracellular multiregional pattern of localization of E-FABP and its differential temporal expression during development, are consistent with its proposed role in transporting long chain free fatty acids and/or other hydrophobic ligands during neuronal differentiation and axon growth.

Fatty acid binding protein is induced in neurons of the dorsal root ganglia after peripheral nerve injury

Peripheral nerve trauma induces the expression of genes presumed to be involved in the process of nerve degeneration and repair. In the present study, an in vivo paradigm was employed to identify molecules which may have important roles in these processes. A cDNA library was constructed with RNA extracted from rat dorsal root ganglia (DRG) 3 days after a sciatic nerve crush. After differential hybridization to this library, several cDNAs were identified that encoded mRNAs that were upregulated in the DRG ipsilateral to the crush injury, as opposed to the contralateral or naive DRG. Approximately 0.15% of all the clones screened were found to be induced. This report presents the types of induced sequences identified and characterizes one of them, DA11. The 0.7 kb DA11 full length cDNA clone contains a 405 nucleotide open reading frame that encodes a putative protein of 15.2 kDa (135 amino acid residues) and is a member of the family of fatty acid binding proteins (FABP). The DA11 protein differs by one amino acid residue from the sequence of the C-FAPB protein and by eight residues from the sequence of mal1, proteins found in rat and mouse skin, respectively. Northern and Western blot analyses showed that the DA11 mRNA and protein were induced in the injured DRG. Furthermore, studies using antibodies generated against DA11 found that the DA11-like immunoreactivity was more pronounced in the nuclei of neurons located in the DRG ipsilateral to the sciatic cut than those located in the contralateral DRG. The induction of DA11 mRNA and protein in DRG neurons suggests, for the first time, the involvement of a neuronal FABP in the process of degeneration and repair in the nervous system.

Mapping of alpha-melanocyte-stimulating hormone-like immunoreactivity in the cat diencephalon

Using an indirect immunoperoxidase technique, we studied the location of alpha-melanocyte-stimulating hormone-like fibers and cell bodies in the cat diencephalon. In the thalamus, almost all the immunoreactive fibers were found in the midline region, whereas in the hypothalamus immunoreactive fibers were observed in the whole structure. The hypothalamus showed a higher density of both immunoreactive fibers and cell bodies; no immunoreactive neurons were found in the thalamus. The densest network of immunoreactive fibers was observed in the epithalamus (nucleus periventricularis anterior) and in the hypothalamic nuclei filiformis, hypothalami ventromedialis, arcuatus, periventricularis hypothalami, area hypothalamica dorsalis, and hypothalamus posterior. A high density of immunoreactive neurons was found in the nucleus arcuatus, in the hypothalamus lateralis, and in the area hypothalamica dorsalis; a low density was found in the nucleus hypothalami ventromedialis and in the hypothalamus dorsomedialis. By comparison with the studies of previous researchers, these data showed a more widespread distribution of alpha-melanocyte-stimulating hormone-like immunoreactive fibers and perikarya in the feline hypothalamus. Moreover, our findings indicate that the peptide is widely distributed in the cat diencephalon, suggesting that alpha-melanocyte-stimulating hormone might be involved in several physiological functions.

Comparison of c-jun, junB, and junD mRNA expression and protein in the rat dorsal root ganglia following sciatic nerve transection

The present study was designed to compare the expression of the Jun family of protooncogenes following nerve injury. Adult rats were anesthetized and the sciatic nerve transected. Dorsal root ganglia (DRG) at 1, 2, 3, and 7 days after nerve transection were collected, their total RNA extracted, and Northern blots performed using 32P-labeled oligonucleotide probes. The constitutive expression of c-jun mRNA was very low in DRG. Induction of c-jun mRNA was observed by day 1 after nerve transection, with a sixfold peak at 3 days and a twofold induction still present by day 7. The constitutive expression of junB mRNA was also low in the DRG, and sciatic nerve transection produced only a modest induction (1.7-fold by day 3) in the DRG ipsilateral to the nerve cut. junD mRNA was constitutively expressed at high levels in the DRG, and its level of expression did not in the DRG, and its level of expression did not change after sciatic nerve transection. Immunocytochemistry studies demonstrated a pattern of c-Jun, JunB, and JunD immunoreactivity (IR) associated with the cell nuclei of DRG neurons. c-Jun IR was found at very low levels in the undamaged contralateral DRG neurons, but sciatic nerve transection dramatically increased the number of c-Jun-immunoreactive neurons. Dot blot immunoblotting assay confirmed that the DRG ipsilateral to the sciatic nerve cut contained a higher level of c-Jun protein than the contralateral control DRG. Similar to c-Jun IR, JunB IR was minimal in the undamaged contralateral DRG. However, the DRG ipsilateral to the nerve transection did not show an increase in the number of immunoreactive neurons. JunD protein was expressed at high levels in the contralateral DRG, and this level of expression persisted after sciatic nerve transection in the ipsilateral DRG. DNA gel retardation assay experiments with an AP-1 consensus sequence showed a single DNA-protein complex. This complex was increased in ipsilateral as compared with contralateral DRG extracts. The amount of DNA-protein complex was reduced by c-Jun protein antiserum but was not altered when treated with a Fos antibody. We conclude that c-jun, junB and junD mRNAs and proteins are differentially regulated in the DRG after sciatic nerve transection.

Calbindin D-28K-immunoreactivity in the cat diencephalon: an immunocytochemical study

The distribution of calbindin D-28k-immunoreactive fibers and cell bodies in the cat diencephalon has been analyzed by using the avidin-biotin immunoperoxidase technique. The thalamus showed a higher density of immunoreactive cell bodies than the hypothalamus. A high density of both immunoreactive perikarya and fibers was observed in the nuclei pulvinar, geniculatum mediale and laterale, lateralis posterior and dorsalis, habenularis lateralis and medialis, posterior, subparafascicularis, submedius, centralis medialis, medialis dorsalis, ventralis postero-medialis and postero-lateralis, reticularis, centralis lateralis, rhomboidens, paracentralis, ventralis lateralis, anterior and medialis, reuniens, anterior ventralis and medialis, hypothalamus posterior, corpus mamillare, area hypothalamica dorsalis and in the hypothalami ventromedialis. Moreover, a high density of fibers containing calbindin and a moderate/low density of immunoreactive cell bodies was found in the nuclei periventricularis anterior, parataenialis, hypothalamus lateralis, mamillaris lateralis, filiformis, periventricularis hypothalami, hypothalamus anterior and in the suprachiasmaticus.

Distribution of parvalbumin immunoreactivity in the cat diencephalon

The distribution of parvalbumin-immunoreactive cell bodies and fibers in the cat diencephalon has been analyzed by using the avidin-biotin immunoperoxidase technique. The thalamus showed a higher density of immunoreactive cell bodies than the hypothalamus. A high or moderate density of perikarya and a high density of fibers containing parvalbumin was observed in the nuclei lateralis posterior, lateralis dorsalis, pulvinar, corpus geniculatum laterale, reticularis, medialis dorsalis, centrum medianum, subparafascicularis, ventralis postero-medialis, ventralis postero-lateralis, habenularis medialis, parafascicularis, corpus geniculatum mediale, centralis lateralis, rhomboidens, reuniens, centralis medialis, ventralis medialis, ventralis lateralis, parataenialis, anterior ventralis, anterior medialis, ventralis anterior, hypothalamus posterior, corpus mamillare, area hypothalamica dorsalis, and in the nucleus suprachiasmaticus. Moreover, a high or moderate density of immunoreactive fibers and a low density of parvalbumin-immunoreactive cell bodies was observed in the nuclei periventricularis anterior, anterior dorsalis, habenularis lateralis, corpus geniculatum laterale (pars ventralis), periventricularis hypothalami, hypothalamus lateralis, hypothalamus anterior, and in the hypothalamus dorsomedialis.

Distribution of calbindin D-28k-immunoreactivity in the cat brainstem

We studied the distribution of calbindin-immunoreactive fibers and cell bodies in the cat brainstem. The densest clusters of immunoreactive perikarya were found in the inferior and superior colliculi, the inferior olive, the periaqueductal gray, the central tegmental field and the substantia nigra, whereas the central linear nucleus, the locus coeruleus, the nucleus incertus, the dorsal and ventral nuclei of the lateral lemniscus, the cuneiform nucleus, the pontine gray, the Kölliker-Fuse nucleus, the dorsal motor nucleus of the vagus and the medial nucleus of the solitary tract had the lowest density. In the lateral tegmental field, the marginal nucleus of the brachium conjunctivum, the superior central nucleus, the nucleus sagulum, the dorsal nucleus of the raphe, the interpeduncular nucleus and the retrorubral nucleus the density of immunoreactive cell bodies was moderate. A high density of immunoreactive fibers was observed in the substantia nigra, the nucleus ruber, the superior and inferior colliculi, the periaqueductal gray, the interpeduncular nucleus, the central, magnocellular and lateral tegmental fields, the marginal nucleus of the brachium conjunctivum, the postpyramidal nucleus of the raphe, the inferior olive, the internal division of the lateral reticular nucleus and the medial and lateral nuclei of the superior olive. A moderate density of calbindin-immunoreactive fibers was found in the retrorubral nucleus, the central linear nucleus, the locus coeruleus, the nucleus sagulum, the dorsal nucleus of the raphe, the cuneiform nucleus, the ventral and dorsal nuclei of the lateral lemniscus, the medial nucleus of the solitary tract, the dorsal motor nucleus of the vagus, and the cuneate nucleus. Other brainstem regions such as the area postrema, the external division of the lateral reticular nucleus, the nucleus ambiguus, the nucleus intercalatus, the nucleus incertus, the pyramidal tract and the trapezoid body had the lowest density of immunoreactive fibers.

SR13/PMP-22 expression in rat nervous system, in PC12 cells, and C6 glial cell lines

SR13/PMP-22 is a protein that was identified after screening a sciatic nerve cDNA library. Our study focused on comparing the level and pattern of expression of SR13/PMP-22 protein and RNA. Northern blot analysis revealed that although SR13/PMP-22 mRNA was present in all nervous tissues and cells studied, levels were at least seven fold higher in the sciatic nerve and the spinal cord. During sciatic nerve postnatal development and maturation, the SR13/PMP-22 mRNA was detected at 2 days after birth, reached a maximal level at day 24, and decreased to 1/3 of the maximum in adult animals. Nerve transection reduced the level of SR13/PMP-22 mRNA to less than 5% in the segment distal to the nerve injury. Experiments using in situ hybridization localized the SR13/PMP-22 mRNA in Schwann cells. Schwann cells present in the vicinity or distal to the nerve cut repressed the signal for the message. In situ hybridization experiments also demonstrated that dorsal root ganglia satellite cells contained the message for SR13/PMP-22. The SR13/PMP-22 antisera used in our study showed a complex pattern of staining. As expected, the SR13/PMP-22 antibody peptide 1 immunoreacted with the sciatic nerve sheath. However, immunocytochemistry of the dorsal root ganglia revealed that the staining was contained in the neuron's cell body and processes and also in satellite cells. We also identified immunoreactive cell bodies and fibers in the spinal cord dorsal horn. Tissue culture studies demonstrated that SR13/PMP-22 mRNA is induced in NGF treated PC12 but not in C6 glioma cell lines grown under experimental conditions that stimulated cell growth arrest. Our experiments suggest that SR13/PMP-22 may have some other function(s) in addition to its hypothesized role in peripheral myelination.

Quantification of axotomy-induced alteration of neuropeptide mRNAs in dorsal root ganglion neurons with special reference to neuropeptide Y mRNA and the effects of neonatal capsaicin treatment

Alteration in mRNA expression in dorsal root ganglia (DRG) neurons encoding 5 neuropeptides was quantitatively compared in normal rats and in those neonatally treated with capsaicin, a selective neurotoxin which destroys a subpopulation of DRG neurons with unmyelinated axons. Adult rats received a unilateral transection of the sciatic nerve and were killed 7 days later. Oligonucleotide probes specific for the genes encoding neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), galanin (GAL), somatostatin (SOM), and calcitonin gene-related peptide (CGRP) were used for in situ hybridization and RNA blot analysis. Following the nerve cut, RNA blot analysis demonstrated a dramatic induction of NPY, VIP, and GAL mRNA levels from the undetectable constitutive level of expression. Conversely, CGRP and SOM mRNAs, which are constitutively expressed, were reduced 55% and 70%, respectively, following the nerve cut. A unimodal size distribution for neurons expressing NPY mRNA was determined, with a mean cross-sectional area of 1700 microns2 representing 24.4% of DRG neurons ipsilateral to the nerve cut. Neurons expressing VIP mRNA were mainly small sized, with a cross-sectional area of approximately 700 microns2, while those expressing GAL mRNA were both small (approximately 700 microns2) and medium (approximately 1,300 microns2) sized. The percentages of neurons expressing VIP or GAL mRNA were 19.9% and 33.7%, respectively. In neonatal capsaicin-treated rats, there was a 10% reduction in neurons expressing NPY mRNA, a 37% reduction for VIP, and a 27% for GAL mRNA compared to vehicle-treated rats after nerve cut. Capsaicin-sensitive neurons comprised 37% of CGRP neurons and 83% of SOM neurons. These observations suggest that NPY is primarily induced in myelinated primary afferent neurons, while VIP and GAL mRNA induction occurs in a mixed population, a sizeable percentage of which has unmyelinated axons. Additionally, SOM mRNA expression is associated mainly with unmyelinated primary afferents.

Distribution of neurokinin A in the cat diencephalon: an immunocytochemical study

The distribution of neurokinin A-like immunoreactive cell bodies and fibers in the diencephalon of the cat was studied using an indirect immunoperoxidase technique. A high or moderate density of immunoreactive neurons was observed in the nuclei habenularis lateralis, medialis dorsalis, parafascicularis, hypothalamus posterior, area hypothalamica dorsalis, hypothalamus lateralis, periventricularis hypothalami, above the corpus mamillare, and in the perifornical area, whereas scarce immunoreactive perikarya were visualized in the nuclei reuniens, hypothalami ventromedialis, hypothalamus dorsomedialis, and mamillaris lateralis. The highest density of fibers containing neurokinin A was found in the nuclei periventricularis anterior, rhomboidens, centralis medialis, periventricularis hypothalami, and supraopticus. In the regio praeoptica, area hypothalamica dorsalis, hypothalamus posterior, and in the perifornical area a moderate density of immunoreactive fibers was observed, whereas the nuclei habenularis lateralis, medialis dorsalis, mamillaris lateralis, parataenialis, reuniens, habenularis medialis, filiformis, hypothalamus dorsomedialis, hypothalami ventromedialis, arcuatus, and suprachiasmaticus showed a low density of neurokinin A immunoreactive fibers.

Distribution of somatostatin-28 (1-12) in the cat brainstem: an immunocytochemical study

We studied the distribution of somatostatin-28 (1-12)-immunoreactive fibers and cell bodies in the cat brainstem. A moderate density of cell bodies containing the peptide was observed in the ventral nucleus of the lateral lemniscus, accessory dorsal tegmental nucleus, retrofacial nucleus and in the lateral reticular nucleus, whereas a low density of such perikarya was found in the interpeduncular nucleus, nucleus incertus, nucleus sagulum, gigantocellular tegmental field, nucleus of the trapezoid body, nucleus praepositus hypoglosii, lateral and magnocellular tegmental fields, nucleus of the solitary tract, nucleus ambiguous and in the nucleus intercalatus. Moreover, a moderate density of somatostatin-28 (1-12)-immunoreactive processes was found in the dorsal nucleus of the raphe, dorsal tegmental nucleus, accessory dorsal tegmental nucleus, periaqueductal gray and in the marginal nucleus of the brachium conjunctivum. Finally, few immunoreactive fibers were visualized in the interpeduncular nucleus, cuneiform nucleus, locus coeruleus, nucleus incertus, superior and inferior central nuclei, nucleus sagulum, ventral nucleus of the lateral lemniscus, nucleus praepositus hypoglosii, medial vestibular nucleus, Kölliker-Fuse area, nucleus ambiguous, retrofacial nucleus, postpyramidal nucleus of the raphe, nucleus of the solitary tract, dorsal motor nucleus of the vagus, lateral reticular nucleus and laminar and alaminar spinal trigeminal nuclei.

Distribution of cholecystokinin octapeptide in the cat brainstem: an immunocytochemical study

Using an indirect immunoperoxidase technique, the cell bodies and fibers containing cholecystokinin octapeptide in the brainstem of the cat were located. A high density of immunoreactive perikarya was observed in the lateral tegmental field and retrorubral nucleus, whereas a moderate density was found in the nucleus incertus, periaqueductal gray and dorsal tegmental nucleus. The nuclei coeruleus, sagulum, interpeduncular, motor dorsal nucleus of the vagus and nucleus of the solitary tract had a low density of immunoreactive cell bodies. The densest network of immunoreactive fibers was observed in the interpeduncular nucleus. The nuclei coeruleus, sagulum, praepositus hypoglossi, cuneiform, dorsal and ventral nuclei of the lateral lemniscus, marginal nucleus of the brachium conjunctivum, dorsal motor nucleus of the vagus, lateral tegmental field, inferior colliculus, periaqueductal gray and nucleus of the solitary tract had a moderate density of immunoreactive fibers. Finally, scarce immunoreactive fibers were found in the nucleus of the brachium of the inferior colliculus, inferior central nucleus, nucleus incertus, retrorubral nucleus and dorsal tegmental nucleus.

Distribution of neurotensin-like immunoreactive cell bodies and fibers in the brainstem of the adult male cat

We studied the distribution of cell bodies and fibers containing neurotensin in the brainstem of the cat using an indirect immunoperoxidase technique. A high or moderate density of immunoreactive perikarya was found in the interpeduncular nucleus, inferior colliculus, nucleus of the brachium of the inferior colliculus and in the lateral tegmental field. Moreover, a high density of neurotensin-immunoreactive fibers was observed in the periaqueductal gray, locus coeruleus and in the marginal nucleus of the brachium conjunctivum. The interpeduncular nucleus, nucleus of the solitary tract and the dorsal motor nucleus of the vagus contained a moderate density of immunoreactive fibers.

Differential regulation of S100 beta and mRNAs coding for S100-like proteins (42A and 42C) during development and after lesion of rat sciatic nerve

The changes in the levels of S100 beta (a protein that stimulates neurite extension and neuronal survival) and 42A and 42C (S100-like proteins whose mRNAs are induced in PC12 cells by nerve growth factor) during development and after rat sciatic nerve lesions were analyzed. S100 beta, 42A, and 42C mRNAs showed differential regulation during development. S100 beta mRNA was present both in sciatic nerve and brain, and increased more than 11-fold during the first 3 wk of nerve postnatal development. 42A and 42C mRNAs were essentially restricted to sciatic nerve, with little found in either embryonic or adult brain. The levels of 42C and 42A mRNAs in sciatic nerve increased 4- and 14-fold, respectively, by postnatal day 23 compared to postnatal day 2. 42A, 42C, and S100 beta mRNAs also showed a differential regulation during sciatic nerve degeneration and regeneration. Axotomized and control sciatic nerves were examined by Northern blots at various times after a crush or cut injury. 42A and 42C mRNA levels increased rapidly in the distal segment of axotomized nerve, remained two- to five-fold higher than controls at day 14 after injury but returned to control levels by 40 days. In contrast, S100 beta mRNA showed a three-fold decrease in the axotomized nerve between days 1 and 3 after injury, and slowly returned towards control levels over the next few weeks. The decrease in S100 beta mRNA was reflected by a corresponding decrease in S100 beta protein levels. The induction of 42A and 42C mRNAs and repression of S100 beta mRNA remained if nerve regeneration was prevented.(ABSTRACT TRUNCATED AT 250 WORDS)

Somatostatin-28 (1-12)-like immunoreactivity in the cat diencephalon

Using an indirect immunoperoxidase technique, the location of somatostatin-28 (1-12)-like immunoreactive fibres and cell bodies in the cat diencephalon was studied. The hypothalamus was richer in somatostatin-28 (1-12)-like immunoreactive structures than the thalamus. A high density of immunoreactive fibres was observed in the nuclei habenularis lateralis, paraventricularis anterior (its caudal part), filiformis, hypothalami ventromedialis, and regio praeoptica, whereas a moderate density was found in the nuclei paracentralis, supraopticus, supra chiasmaticus, hypothalamus posterior and area hypothalamica dorsalis. The nuclei lateralis dorsalis, lateralis posterior, medialis dorsalis, rhomboidens, centralis medialis, ventralis medialis, reuniens, anterior dorsalis, parataenialis, interanteromedialis, hypothalamus lateralis, hypothalamus dorsomedialis and arcuatus had the lowest density of immunoreactive fibres. In addition, a high or moderate density of somatostatin-28 (1-12)-like immunoreactive cell bodies was observed in the nuclei paraventricularis hypothalami, supraopticus, supra chiasmaticus, area hypothalamics dorsalis, subparafascicularis, hypothalamus posterior and hypothalamus anterior, whereas scarce immunoreactive perikarya were visualized in the nuclei lateralis dorsalis and parafascicularis. The distribution of somatostatin-28 (1-12)-like immunoreactive structures is compared with the location of other neuropeptides in the cat diencephalon.

Distribution of parvalbumin-immunoreactivity in the rat thalamus using a monoclonal antibody

1. The distribution of parvalbumin cell bodies and fibers in the thalamus of the rat was studied using a monoclonal antibody and the avidin-biotin-peroxidase method. The densest clusters of immunoreactive perikarya were observed in the nuclei ventralis posterior, reticularis, ventralis anterior and zona incerta, whereas the nuclei habenularis lateralis, lateralis posterior, lateralis, centralis lateralis and ventralis lateralis had the lowest density. In the nucleus geniculatum laterale ventralis, the density of parvalbumin cell bodies was intermediate. In all these thalamic nuclei, small, round or fusiform immunoreactive cells with short immunolabeled dendritic processes were observed. 2. The densest network of immunoreactive fibers was observed in the nuclei geniculatum laterale ventralis, reticularis and zona incerta. The nuclei geniculatum laterale dorsalis, ventralis posterior, medialis ventralis, ventralis anterior, anterior ventralis, anterior dorsalis and rhomboidens contained a moderate number of parvalbumin fibers, whereas the nuclei lateralis posterior, habenularis lateralis, parataenialis, centrum medianum, lateralis, centralis lateralis, ventralis lateralis, medialis dorsalis, anterior medialis, ventralis medialis and lateralis anterior had the lowest density of immunoreactive fibers. In addition, a large number of immunoreactive fibers was found in the lemniscus medialis and a scarce number in the stria medullaris. 3. No immunoreactive structure was observed in the nuclei habenularis medialis, paraventricularis, reuniens and geniculatum mediale. 4. Thus, perikarya and fibers containing parvalbumin are widely distributed throughout the thalamus of the rat, suggesting that parvalbumin might play a role, directly or indirectly, in limbic, visual and somatosensory mechanisms.

Neurotensin-like immunoreactivity in the diencephalon of the adult male cat

Using an indirect immunoperoxidase technique, the location of neurotensin-like fibers and cell bodies was studied in the diencephalon of the cat. The findings showed that the hypothalamus is richer in neurotensin-like-immunoreactive structures than the thalamus, and that neurotensin-like-immunoreactive structures are more widely distributed in the hypothalamus than in the thalamus. A high density of immunoreactive fibers was observed in the hypothalamic regions, area hypothalamica dorsalis, hypothalamus posterior, nucleus (n.) filiformis and n. arcuatus, whereas a moderate density was found in the n. parafascicularis, n. paraventricularis anterior, hypothalamus lateralis, median eminence and n. paraventricularis hypothalami. Other diencephalic regions such as n. lateralis posterior, n. lateralis dorsalis, n. medialis dorsalis, n. habenularis lateralis, n. centrum medianum, n. rhomboidens, n. reuniens, hypothalamus anterior, n. supra chiasmaticus, hypothalamus ventromedialis, n. supraopticus and hypothalamus dorsomedialis had the lowest density of immunoreactive fibers. In addition, the densest clusters of neurotensin-like perikarya were found in the n. arcuatus, n. centralis medialis and hypothalamus posterior, whereas the n. medialis dorsalis, n. paraventricularis anterior, n. reuniens, hypothalamus lateralis and hypothalamus ventromedialis had the lowest density. In the n. lateralis dorsalis, n. supraopticus, area hypothalamica dorsalis and n. supra chiasmaticus the density of immunoreactive perikarya was moderate.