Developmental sex differences in the peri-pubertal pattern of hypothalamic reproductive gene expression, including Kiss1 and Tac2, may contribute to sex differences in puberty onset.

The mechanisms regulating puberty still remain elusive, as do the underlying causes for sex differences in puberty onset (girls before boys) and pubertal disorders. Neuroendocrine puberty onset is signified by increased pulsatile GnRH secretion, yet how and when various upstream reproductive neural circuits change developmentally to govern this process is poorly understood. We previously reported day-by-day peri-pubertal increases (Kiss1, Tac2) or decreases (Rfrp) in hypothalamic gene expression of female mice, with several brain mRNA changes preceding external pubertal markers. However, similar pubertal measures in males were not previously reported. Here, to identify possible neural sex differences underlying sex differences in puberty onset, we analyzed peri-pubertal males and directly compared them with female littermates. Kiss1 expression in male mice increased over the peri-pubertal period in both the AVPV and ARC nuclei but with lower levels than in females at several ages. Likewise, Tac2 expression in the male ARC increased between juvenile and older peri-pubertal stages but with levels lower than females at most ages. By contrast, both DMN Rfrp expressionand Rfrp neuronal activation strongly decreased in males between juvenile and peri-pubertal stages, but with similar levels as females. Neither ARC KNDy neuronal activation nor Kiss1r expression in GnRH neurons differed between males and females or changed with age. These findings delineate several peri-pubertal changes in neural populations in developing males, with notable sex differences in kisspeptin and NKB neuron developmental patterns. Whether these peri-pubertal hypothalamic sex differences underlie sex differences in puberty onset deserves future investigation.

Identification of hub genes associated with cognition in the hippocampus of Alzheimer's Disease.

Alzheimer's Disease (AD) is a neurodegenerative disease featured by cognitive impairment. This bioinformatic analysis was used to identify hub genes related to cognitive dysfunction in AD. The gene expression profile GSE48350 in the hippocampus of AD patients aged >70 years was obtained from the Gene Expression Omnibus (GEO) database. A total of 96 differentially expressed genes (DEGs) were identified, and subjected to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses; a protein-protein interaction (PPI) network was constructed. The DEGs were enriched in synapse-related changes. A protein cluster was teased out of PPI. Furthermore, the cognition ranked the first among all the terms of biological process (BP). Next, 4 of 10 hub genes enriched in cognition were identified. The function of these genes was validated using APP/PS1 mice. Cognitive performance was validated by Morris Water Maze (MWM), and gene expression by RT-qPCR, Cholecystokinin (CCK), Tachykinin precursor 1 (TAC1), Calbindin 1 (CALB1) were downregulated in the hippocampus. These genes can provide new directions in the research of the molecular mechanism of AD.

Effects of in vitro exposure of perfluorooctanoic acid and monocrotophos on astroglia SVG p12 cells.

Glia cells provide supportive functions to the central nervous system and can be compromised by environmental contaminants. The primary objective of this study was to characterize the effects of in vitro exposure to perfluorooctanoic acid, a persistent environmental contaminant and/or monocrotophos (MCP), a neurotoxic organophosphate that is rapidly metabolized, to astroglia SVG p12 cells. The endpoints evaluated include cell viability, intracellular glutamate levels as a marker of astrocyte homeostasis function, differential gene expression for selected proteins, which include inflammatory markers (tachykinin), astrocytosis (nestin), S100B, and metabolism enzymes (CYP1A1). The results from cell viability revealed significant differences from the controls at some of the concentrations tested. Also, intracellular glutamate levels were elevated at the 10-µM concentration for perfluorooctanoic acid (PFOA) as well as the 10-µM PFOA/5-µM MCP concentration. Gene expression results at 80-µM PFOA concentration revealed a significant increase in the expression of S100B, tachykinin and CYP1A1. A combination of 10-µM PFOA/20-µM MCP caused a significant decrease in the expression of tachykinin. Gene expression for MCP exposures produced a decrease at the 20-µM MCP concentration. Immunofluorescence results indicated an increase in nestin protein expression for the 20-µM concentration of MCP, which contradicted the gene expression at the same concentration tested. The results indicate that toxicity to glia cells can compromise critical glia functions and could be implicated in neurodegenerative diseases.

Tac1-Expressing Neurons in the Periaqueductal Gray Facilitate the Itch-Scratching Cycle via Descending Regulation.

Uncontrollable itch-scratching cycles lead to serious skin damage in patients with chronic itch. However, the neural mechanism promoting the itch-scratching cycle remains elusive. Here, we report that tachykinin 1 (Tac1)-expressing glutamatergic neurons in the lateral and ventrolateral periaqueductal gray (l/vlPAG) facilitate the itch-scratching cycle. We found that l/vlPAG neurons exhibited scratching-behavior-related neural activity and that itch-evoked scratching behavior was impaired after suppressing the activity of l/vlPAG neurons. Furthermore, we showed that the activity of Tac1-expressing glutamatergic neurons in the l/vlPAG was elevated during itch-induced scratching behavior and that ablating or suppressing the activity of these neurons decreased itch-induced scratching behavior. Importantly, activation of Tac1-expressing neurons induced robust spontaneous scratching and grooming behaviors. The scratching behavior evoked by Tac1-expressing neuron activation was suppressed by ablation of spinal neurons expressing gastrin-releasing peptide receptor (GRPR), the key relay neurons for itch. These results suggest that Tac1-expressing neurons in the l/vlPAG promote itch-scratching cycles.

Expression and functional characterization of tachykinin-related peptides in the blood-feeding bug, Rhodnius prolixus.

Tachykinins (tachykinin-related peptides, TRPs) are multifunctional neuropeptides that have widespread distribution in the central nervous system (CNS) and in the gastrointestinal tract of many insects, and most have been shown to stimulate contractions of visceral muscles. Invertebrate TRPs carry a characteristic conserved C-terminal pentapeptide (FXGXR-amide) and most of them share some amino acid sequence similarities (approx. 45%) with the vertebrate and mammalian tachykinin family. We have functionally characterized the tachykinins in R. prolixus (Rhopr-TKs) and partially cloned the transcript that encodes for the peptide precursor. The transcript encodes 8 Rhopr-TKs, 7 of which are unique with Rhopr-TK 5 having 2 copies. The spatial distribution analysis of the Rhopr-TK transcript indicates that the highest expression levels are in the CNS, but transcript expression is also associated with salivary glands, fat body, dorsal vessel, and the various gut compartments. Rhopr-TK 1, 2 and 5 significantly increase the frequency and amplitude of peristaltic contractions of the salivary glands. Hindgut muscle also displayed a dose-dependent increase in basal tonus in response to Rhopr-TK1, 2 and 5. TK-like immunoreactivity was seen in a small group of processes that are situated on the lateral margins of the hindgut. Interestingly, kinin-like immunoreactivity is seen in immunoreactive processes on the lateral margin of the hindgut as well as fine processes covering the entire hindgut. Co-localization studies show that TK-like staining is always co-localized with kinin-like immunoreactivity, whereas kinin-like staining is seen in the fine processes that are devoid of TK-like immunoreactivity indicating that TKs are most likely released together with kinins to act on the hindgut. Rhopr-Kinin 2 is a potent stimulator of hindgut muscle contraction in R. prolixus. Addition of Rhopr-Kinin 2 and Rhopr-TK 2 to the hindgut leads to a contraction that was additive of the effects of Rhopr-Kinin 2 and Rhopr-TK 2 alone.

[CLINICAL AND ENDOSCOPIC, MORPHOLOGIC AND IMMUNOHISTOCHEMICAL FEATURES OF GASTRIC ULCER IN H. PYLORI-INFECTED INDIVIDUALS RECEIVING CYTOTOXIC THERAPY].

THE PURPOSE OF THE STUDY: To determine the prognostic significance of the expression of molecules of PCNA, Bcl-2, NF-Kb and tachykinins (substance P, neurokinin A) in patients with gastric ulcer (CU) receiving cytotoxic therapy. MATERIALS AND METHODS: Total surveyed 90 patients divided into 3. equal groups. The first comparison group consisted of patients with chronic atrophic H. pylori-associated gastritis (CAG) (30 pers.). A second control group consisted of patients with gastric ulcer (30 pers.). Third, the study group consisted of 30 people. with CU suffering from hematological malignancies, in a period of complete clinical remission of the disease and receiving supportive polychemotherapy (PCT). Patients underwent endoscopy, morphological and immunohistochemical study of the mucous membrane of the antrum and body of the stomach to detect the expression of molecules of PCNA, Bcl-2, neurokinin A, substance P and factor Nf-Kb. RESULTS: The total level of dyspeptic syndrome on visual scale analogue in patients receiving chemotherapy and GU (GUpct) was significantly higher (p < 0.05) compared with patients with GU. It should be noted that patients with GUpct reducing clinical symptoms is much slower (p < 0.05). At the same time in 13 (43.3%) patients with GUpct determines the duration of ulcer healing, whereas in patients with GU in only 4 (13.3%) patients. Patients with GUpct more frequently (p < 0.05) were verified II and stage Ill chronic gastritis (CG), while Stage I--less (p < 0.05). Patients with GUpct significantly more often (p<0.05) was determined by the II degree of CG and significantly less (p < 0.05)--IV degree. Patients with GUpct determined significantly lower (p < 0.05), the expression performance PCNA, substance P and neurokinin A and higher (p < 0.05)--Bcl-2 and factor Nf-kB. CONCLUSION: GU in patients receiving chemotherapy, dyspeptic syndrome is characterized by severe, advanced stage of CG on the background of relatively low severity of CG in accordance with the classification of OLGA (2008). Patients with GUpht have a significant level of violation of regeneration changes how is this atrophy, intestinal metaplasia, dysplasia of gastric mucosa association with gross violations of the processes of epithelial cell homeostasis of epithelial cells regulation after molecules PCNA, Bcl-2, NF-kB and tachykinins (substation P, neurokinin A).

Analysis of the Expression of Tachykinins and Tachykinin Receptors in the Rat Uterus During Early Pregnancy.

The peptides of the tachykinin family participate in the regulation of reproductive function acting at both central and peripheral levels. Our previous data showed that treatment of rats with a tachykinin NK3R antagonist caused a reduction of litter size. In the present study, we analyzed the expression of tachykinins and tachykinin receptors in the rat uterus during early pregnancy. Uterine samples were obtained from early pregnant rats (Days 1-9 of pregnancy) and from nonpregnant rats during the proestrus stage of the ovarian cycle, and real-time quantitative RT-PCR, immunohistochemistry, and Western blot studies were used to investigate the pattern of expression of tachykinins and tachykinin receptors. We found that all tachykinins and tachykinin receptors were locally synthesized in the uterus of early pregnant rats. The expression of substance P, neurokinin B, and the tachykinin receptors NK1R and NK3R mRNAs and proteins underwent major changes during the days around implantation and they were widely distributed in implantation sites, being particularly abundant in decidual cells. These findings support the involvement of the tachykinin system in the series of uterine events that occur around embryo implantation in the rat.

Expression of miR-206 during the initiation of mammary gland development.

MicroRNAs (miRNAs) are a class of small noncoding RNAs that control gene expression by targeting mRNAs and triggering either translational repression or RNA degradation. The aberrant expression of miRNAs might be involved in human diseases, including cancer. The expression of miR-206 in estrogen receptor alpha (ER-α)-positive human breast cancer tissues is well known. However, the expression and regulation of miR-206 in the developing mammary gland has not yet been studied. To understand the effects of miR-206 on mammary gland development, we have profiled gene expression in scramble-transfected and miR-206-overexpressing developing mammary buds. The genes that are potentially regulated by miR-206 in the mammary epithelium and/or mesenchyme, such as Tachykinin1 and Gata3, are known to be breast cancer markers. The expression of Wnt, which is involved in gland positioning, and of the transcription factors Tbx3 and Lef1, which are essential for mammary gland development, changes after miR-206 overexpression. Using a mammary bud in vitro culture system, we have demonstrated that miR-206 acts downstream of ER-α during mammary gland growth. Thus, miR-206 might be a novel candidate for morphogenesis during the initiation of mammary gland formation and the regulation of genes related to mammary gland development and breast cancer.

Bilateral increase in expression and concentration of tachykinin in a unilateral rabbit muscle overuse model that leads to myositis.

BACKGROUND: Tachykinins can have pro-inflammatory as well as healing effects during tissue reorganization and inflammation. Recent studies report an up-regulation in the expression of the substance P (SP)-preferred receptor, the neurokinin-1 receptor, in marked muscle inflammation (myositis). There is, however, only very little information on the expression patterns and levels of tachykinins in this situation. METHODS: The tachykinin system was analyzed using a rabbit experimental model of muscle overuse, whereby unilateral muscle exercise in combination with electrical stimulation led to muscle derangement and myositis in the triceps surae muscle (experimental length 1-6 weeks). Evaluations were made for both parts of the muscle (soleus and gastrocnemius muscles) in experimental and non-experimental (contralateral) sides. Morphologic evaluation, immunohistochemistry, in situ hybridization and enzyme immunoassay (EIA) analyses were applied. RESULTS: Myositis and muscle derangement occurred focally not only in the experimental side but also in the non-experimental side. In the inflammatory areas (focal myositis areas), there were frequent nerve fibers showing tachykinin-like immunoreactivity and which were parts of nerve fascicles and which were freely dispersed in the tissue. Cells in the inflammatory infiltrates showed tachykinin-like immunoreactivity and tachykinin mRNA expression. Specific immunoreactivity and mRNA expression were noted in blood vessel walls of both sides, especially in focally affected areas. With increasing experimental length, we observed an increase in the degree of immunoreactivity in the vessel walls. The EIA analyses showed that the concentration of tachykinin in the tissue on both sides increased in a time-dependent manner. There was a statistical correlation in the concentration of tachykinin and the level of tachykinin immunoreactivity in the blood vessel walls between experimental and non-experimental sides. CONCLUSIONS: The observations show an up-regulation of the tachykinin system bilaterally during muscle derangement/myositis in response to pronounced unilateral muscle overuse. This up-regulation occurred in inflammatory areas and was related not only to increased tachykinin innervation but also to tachykinin expression in blood vessel walls and inflammatory cells. Importantly, the tachykinin system appears to be an important factor not only ipsilaterally but also contralaterally in these processes.

Cloning and expression of tachykinins and their association with kisspeptins in the brains of zebrafish.

The tachykinins are a family of neuropeptides, including substance P (SP), neurokinin A (NKA), and neurokinin B (NKB), that are encoded by the tac1 (SP and NKA) or tac2/3 (NKB) genes. Tachykinins are widely distributed in the central nervous system and have roles as neurotransmitters and/or neuromodulators. Recent studies in mammals have demonstrated the coexpression of NKB and kisspeptin and their comodulatory roles over the control of reproduction. We have recently identified two kisspeptin-encoding genes, kiss1 and kiss2, in teleosts. However, such relationship between tachykinins and kisspeptins has not been demonstrated in non-mammalian species. To determine the involvement of tachykinins in the reproduction in teleosts, we identified tac1 and two tac2 (tac2a and tac2b) sequences in the zebrafish genome using in silico data mining. Zebrafish tac1 encodes SP and NKA, whereas the tac2 sequences encode NKB and an additional peptide homologous to NKB (NKB-related peptide). Digoxigenin in situ hybridization in the brain of zebrafish showed tac1 mRNA-containing cells in the olfactory bulb, telencephalon, preoptic region, hypothalamus, mesencephalon, and rhombencephalon. The zebrafish tac2a mRNA-containing cells were observed in the preoptic region, habenula, and hypothalamus, whereas the tac2b mRNA-containing cells were predominantly observed in the dorsal telencephalic area. Furthermore, we examined the coexpression of tachykinins and two kisspeptin genes in the brain of zebrafish. Dual fluorescent in situ hybridization showed no coexpression of tachykinins mRNA with kisspeptins mRNA in hypothalamic nuclei or the habenula. These results suggest the presence of independent pathways for kisspeptins and NKB neurons in the brain of zebrafish.

Hemokinin-1 gene expression is upregulated in microglia activated by lipopolysaccharide through NF-κB and p38 MAPK signaling pathways.

The mammalian tachykinins, substance P (SP) and hemokinin-1 (HK-1), are widely distributed throughout the nervous system and/or peripheral organs, and function as neurotransmitters or chemical modulators by activating their cognate receptor NK(1). The TAC1 gene encoding SP is highly expressed in the nervous system, while the TAC4 gene encoding HK-1 is uniformly expressed throughout the body, including a variety of peripheral immune cells. Since TAC4 mRNA is also expressed in microglia, the resident immune cells in the central nervous system, HK-1 may be involved in the inflammatory processes mediated by these cells. In the present study, we found that TAC4, rather than TAC1, was the predominant tachykinin gene expressed in primary cultured microglia. TAC4 mRNA expression was upregulated in the microglia upon their activation by lipopolysaccharide, a well-characterized Toll-like receptor 4 agonist, while TAC1 mRNA expression was downregulated. Furthermore, both nuclear factor-κB and p38 mitogen-activated protein kinase intracellular signaling pathways were required for the upregulation of TAC4 mRNA expression, but not for the downregulation of TAC1 mRNA expression. These findings suggest that HK-1, rather than SP, plays dominant roles in the pathological conditions associated with microglial activation, such as neurodegenerative and neuroinflammatory disorders.

Protein kinase A-dependent substance P expression by pituitary adenylate cyclase-activating polypeptide in rat sensory neuronal cell line ND7/23 cells.

The neurotrophic effects of pituitary adenylate cyclase-activating polypeptide (PACAP) on rat sensory neuronal cell line ND7/23 cells were investigated. PACAP caused a concentration-dependent increase in the number of neurite-bearing cells and the expression of the substance P precursor (PPT) mRNA in 24 h. The effects of PACAP were mimicked by vasoactive intestinal polypeptide with lower potency and dibutyryl-cyclic AMP, and inhibited by inhibitors of protein kinase A, ERK kinase or p38 kinase, KT5720, U0126, or SB203580, respectively. In a PPT promoter luciferase reporter assay, the increase of PPT mRNA was the result of an increase in PPT gene transcriptional activity by PACAP. The increasing effects of PACAP on PPT mRNA were similarly observed in primary cultured rat dorsal root ganglion cells. Thus, PACAP could induce differentiation-like phenomena in sensory neurons in a cAMP-, protein kinase A-, ERK kinase-, and p38 kinase-dependent manner. These results provide evidence of the neurotrophic action of PACAP, which may function to rescue damaged neurons or to switch the neuronal phenotype in injured or inflamed sensory neurons.

Early B-cell factor regulates the expression of Hemokinin-1 in the olfactory epithelium and differentiating B lymphocytes.

Hemokinin-1, encoded by the TAC4 gene, is a tachykinin most closely related to substance P. Previous studies have shown that TAC4 distinguishes itself from other tachykinins by its predominantly non-neuronal expression profile, particularly in cells of the immune system. Here we report for the first time that the highest levels of TAC4 expression are found in the olfactory epithelium. Furthermore, we identify olfactory neuron-specific transcription factor (Olf-1), also known as early B-cell factor (EBF), as a novel regulator of TAC4 expression. EBF present in the olfactory epithelium and in B cells binds to two sites in the TAC4 promoter and modulates expression in developing B cells. Our findings suggest a role for TAC4 in cell differentiation, and represent a regulatory bridge between the nervous system and the immune system.

Expression and function of human hemokinin-1 in human and guinea pig airways.

BACKGROUND: Human hemokinin-1 (hHK-1) and endokinins are peptides of the tachykinin family encoded by the TAC4 gene. TAC4 and hHK-1 expression as well as effects of hHK-1 in the lung and airways remain however unknown and were explored in this study. METHODS: RT-PCR analysis was performed on human bronchi to assess expression of tachykinin and tachykinin receptors genes. Enzyme immunoassay was used to quantify hHK-1, and effects of hHK-1 and endokinins on contraction of human and guinea pig airways were then evaluated, as well as the role of hHK-1 on cytokines production by human lung parenchyma or bronchi explants and by lung macrophages. RESULTS: In human bronchi, expression of the genes that encode for hHK-1, tachykinin NK1-and NK2-receptors was demonstrated. hHK-1 protein was found in supernatants from explants of human bronchi, lung parenchyma and lung macrophages. Exogenous hHK-1 caused a contractile response in human bronchi mainly through the activation of NK2-receptors, which blockade unmasked a NK1-receptor involvement, subject to a rapid desensitization. In the guinea pig trachea, hHK-1 caused a concentration-dependant contraction mainly mediated through the activation of NK1-receptors. Endokinin A/B exerted similar effects to hHK-1 on both human bronchi and guinea pig trachea, whereas endokinins C and D were inactive. hHK-1 had no impact on the production of cytokines by explants of human bronchi or lung parenchyma, or by human lung macrophages. CONCLUSIONS: We demonstrate endogenous expression of TAC4 in human bronchi, the encoded peptide hHK-1 being expressed and involved in contraction of human and guinea pig airways.

Common variants of the neuropeptide expressing tachykinin genes and susceptibility to asthma: a case-control study.

Since tachykinins appear to be involved in the pathogenesis of allergic asthma, we investigated a possible association between 28 single nucleotide polymorphisms of the tachykinin genes TAC1, TAC3 and TAC4, and asthma susceptibility. A case-control study was conducted on 102 patients and 100 healthy subjects from the Canary Islands (Spain). A significant association with asthma was observed for two SNPs: rs2291855 in the TAC3 gene conferring asthma protection (Odds ratio [OR]: 0.46; 95% Confidence Interval [CI]: 0.22-0.97; P=0.038), and rs4794068 in the TAC4 gene associated with an increased risk for asthma (OR: 1.94; 95% CI: 1.06-3.54; P=0.03). The present study represents a preliminary step in elucidating the association between tachykinin gene polymorphisms and asthma susceptibility.

Involvement of substance P and the neurokinin-1 receptor in radiation-induced hair loss in mice.

We investigated the involvement of substance P (SP) and the neurokinin-1 receptor (NK(1)R) in the development of radiation-induced hair loss in mice. A dose of 40 Gy of gamma irradiation induced hair loss from the 10th to at least the 60th day after irradiation. A specific NK(1)R antagonist, CP-99,994, significantly delayed radiation-induced hair loss and reduced its severity. Furthermore, gamma irradiation induced the expression of preprotachykinin-A, a precursor protein of SP, mRNA in irradiated murine skin on the 10th and 30th days after irradiation. These results indicated that gamma irradiation-induced hair loss was mediated by SP via NK(1)R.

The effects of neurokinin B upon gonadotrophin release in male rodents.

Growing evidence suggests the tachykinin neurokinin B (NKB) may modulate gonadotrophin secretion and play a role in sex-steroid feedback within the reproductive axis. NKB signalling has recently been identified as being necessary for normal human reproductive function, although the precise mechanisms underpinning this role remain to be established. We have used rodents to explore further the role of NKB within the reproductive axis. In particular, we have studied its interactions with kisspeptin, a neuropeptide essential for reproductive function in rodent and human with close anatomical links to NKB within the hypothalamus. Intraperitoneal administration of NKB (50 nmol) to male mice had no effect on circulating luteinsing hormone (LH) levels and, although i.p. kisspeptin (15 nmol) increased LH five-fold, co-administration of NKB and kisspeptin was indistinguishable from kisspeptin alone. Intracerebroventricular administration of NKB (10 nmol) to male mice also had no effect on LH levels, with 1 nmol kisspeptin i.c.v. significantly increasing LH compared to control (0.37 +/- 0.18 versus 5.11 +/- 0.28 ng/ml, respectively). Interestingly, i.c.v. co-administration of NKB and kisspeptin caused a significant increase in LH concentrations compared to kisspeptin alone (8.96 +/- 1.82 versus 5.11 +/- 0.28 ng/ml respectively). We used hypothalamic explants from rats to assess the effect of NKB on gonadotrpohin-releasing hormone (GnRH) secretion ex vivo. Doses of NKB up to 1000 nm failed to stimulate GnRH secretion, whereas 100 nm kisspeptin robustly increased GnRH secretion. Of note, co-administration of NKB with kisspeptin abrogated the effect of kisspeptin, producing no GnRH release above basal state. Finally, we analysed the expression of Tac2/Tacr3 (genes encoding NKB and NK3R, respectively) within the arcuate nucleus in different nutritional states. After a 48-h fast, the expression of both Tac2 and Tacr3 showed a significant increase, in contrast to levels of Kiss1 and Kiss1r mRNA, which remained unchanged. In male rodent models, NKB and kisspeptin have different effects upon gonadotrophin release and appear to interact in a complex manner.

Extracellular signal-regulated kinase 1/2 and c-Jun NH2-terminal kinase, through nuclear factor-kappaB and activator protein-1, contribute to caerulein-induced expression of substance P and neurokinin-1 receptors in pancreatic acinar cells.

The neuropeptide substance P (SP) has emerged to be an important proinflammatory mediator in acute pancreatitis (AP). The presence of substance P and its receptor, neurokinin-1 receptor (NK1R) has been shown in the pancreas and the pancreatic acinar cells. In this study, we investigated the unexplored mechanisms that mediate SP and NK1R expression using an in vitro AP model. Pancreatic acinar cells were obtained from pancreas of male Swiss mice. Isolated cells were treated with caerulein to mimic secretagogue pancreatitis. A concentration-dependent study that subjected the cells to 60 min of stimulation by caerulein showed that SP and the transcript from its gene preprotachykinin-A (PPT-A), and NK1R were up-regulated at a supraphysiological concentration of 10(-7) M. A concentration-dependent study on intracellular kinases, extracellular signal-regulated kinase (ERK1/2), and c-Jun N-terminal kinase (JNK) and also transcription factors nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) showed that they were activated when the caerulein concentration was 10(-7) M. Inhibition of JNK reversed the up-regulation of PPT-A, SP, and NK1R. However, inhibition of ERK1/2 reversed the up-regulation of NK1R but not of PPT-A and SP. Furthermore, we found that specific ERK1/2 and JNK inhibitors reduce NF-kappaB and AP-1 activity. Taken together, our results suggest that supraphysiological concentrations of caerulein up-regulate the expression of SP and NK1R in pancreatic acinar cells, and the signaling molecules that are involved in this up-regulation include ERK1/2, JNK, NF-kappaB, and AP-1.

Increase in hemokinin-1 mRNA in the spinal cord during the early phase of a neuropathic pain state.

BACKGROUND AND PURPOSE: Substance P (SP), a representative member of the tachykinin family, is involved in nociception under physiological and pathological conditions. Recently, hemokinin-1 (HK-1) was identified as a new member of this family. Although HK-1 acts on NK(1) tachykinin receptors that are thought to be innate for SP, the roles of HK-1 in neuropathic pain are still unknown. EXPERIMENTAL APPROACH: Using rats that had been subjected to chronic constrictive injury (CCI) of the sciatic nerve as a neuropathic pain model, we examined the changes in expression of SP- and HK-1-encoding genes (TAC1 and TAC4, respectively) in the L4/L5 spinal cord and L4/L5 dorsal root ganglia (DRGs) in association with changes in pain-related behaviours in this neuropathic pain state. KEY RESULTS: The TAC4 mRNA level was increased on the ipsilateral side of the dorsal spinal cord, but not in DRGs, at day 3 after CCI. In contrast, the TAC1 mRNA level was significantly increased in the DRGs at day 3 after CCI without any changes in the dorsal spinal cord. Analysis of a cultured microglial cell line revealed the presence of TAC4 mRNA in microglial cells. Minocycline, an inhibitor of microglial activation, blocked the increased expression of TAC4 mRNA after CCI and inhibited the associated pain-related behaviours and microglial activation in the spinal cord. CONCLUSIONS AND IMPLICATIONS: The present results suggest that HK-1 expression is increased at least partly in activated microglial cells after nerve injury and is clearly involved in the early phase of neuropathic pain.

Expression of FOXP2 in the developing monkey forebrain: comparison with the expression of the genes FOXP1, PBX3, and MEIS2.

By using the developing monkey brain as a model for human development, we investigated the expression pattern of the FOXP2 gene, a member of the FOX family of transcription factors in the developing monkey brain, and compared its expression pattern with transcription factors PBX3, MEIS2, and FOXP1. We observed FOXP2 mRNA expression in several brain structures, including the striatum, the islands of Calleja and other basal forebrain regions, the cerebral cortex, and the thalamus. FOXP2 mRNA was preferentially expressed in striosomal compartments during striatal development. The striosomal expression was transient and developmentally down-regulated in a topographical order. Specifically, during the perinatal state, striosomal FOXP2 expression was detected in both the caudate nucleus and the putamen, although expression was more prominent in the caudate nucleus than in the putamen. Striosomal FOXP2 expression declined during the postnatal period, first in the putamen and later in the caudate nucleus. During the same period, we also detected PBX3 mRNA in the striosomal compartment of the developing monkey striatum. FOXP2, as well as PBX3 and MEIS2, was expressed in the islands of Calleja and other cell clusters of the basal forebrain. FOXP2, in combination with PBX3 and MEIS2, may play a pivotal role in the development of striosomal neurons of the striatum and the islands of Calleja.