Vanilloid receptor 1-like receptor-immunoreactive primary sensory neurons in the rat trigeminal nervous system

Immunohistochemistry for vanilloid receptor 1-like receptor (VRL-1), a candidate transducer for high-threshold noxious heat, was performed on rat trigeminal primary sensory neurons. The immunoreactivity was detected in 14% of the trigeminal ganglion cell bodies, while the neurons in the mesencephalic trigeminal tract nucleus were almost devoid of it (0.5%). The immunoreactive neurons in the trigeminal ganglion were mostly of medium to large size (mean+/-S.D. of 956+/-376microm(2)). Nerve bundles in the tooth pulp, periodontal ligament, facial skin and oral mucosa contained VRL-1-positive smooth nerve fibers. The immunoreactivity could not be traced to the isolated nerve fibers, except in the tooth pulp. In the brainstem trigeminal nuclear complex, a notable concentration of the immunoreactivity was seen in laminae I and II of the medullary dorsal horn. Thirty-seven per cent of the trigeminal ganglion neurons retrogradely labeled from the tooth pulp exhibited VRL-1 immunoreactivity, while the immunoreactivity was detected in only 9% of those labeled from the skin. Co-expression of calcitonin gene-related peptide was common among the VRL-1-immunoreactive tooth pulp neurons (45%) and cutaneous neurons (25%). Moreover, as many as 41% of the VRL-1-immunoreactive tooth pulp neurons co-expressed parvalbumin immunoreactivity. Parvalbumin immunoreactivity was never detected in the VRL-1-immunoreactive cutaneous neurons.From the findings of the present study, we propose that large primary neurons responding to high-threshold noxious heat are abundant in the tooth pulp, but not in the facial skin.     

Toll-like receptor 4 expression and cytokine responses in the human urinary tract mucosa

Mucosal pathogens trigger a local innate host response by activating epithelial cells. Bacterial adherence and Toll-like receptor 4 (TLR4) signaling have been implicated as key events in this process. This study addressed the molecular basis of the epithelial response to gram-negative infection in the human urinary tract. Mucosal biopsies were obtained from kidneys, ureters, and bladders of patients undergoing urinary tract surgery, and epithelial TLR4 and CD14 expression was examined by immunohistochemistry. TLR4 was detected in epithelial cells lining the entire urinary tract and in the renal tubular epithelium. CD14, in contrast, was completely absent from the epithelial tissue. The response of the epithelial cells to infection was studied by in vitro challenge of the biopsies with uropathogenic Escherichia coli bacteria. A rapid cytokine response was observed, with production of interleukin-1beta (IL-1beta), IL-6, and IL-8 but not of IL-4 or gamma interferon. Adhering, P- or type 1-fimbriated E. coli activated IL-6 and IL-8 production more efficiently than the nonfimbriated control, as shown by cellular staining and analysis of secreted cytokines. The results demonstrate that human uroepithelial cells possess the molecular machinery needed to respond to uropathogenic E. coli. This includes recognition receptors for fimbriae and TLR4 for transmembrane signaling. We speculate that the lack of membrane-bound CD14 allows the epithelium to regulate its sensitivity to lipopolysaccharide and to discriminate between more-virulent and less-virulent strains.     

Increased expression of metabotropic glutamate receptor subtype 1 on spinothalamic tract neurons following spinal cord injury in the rat

Spinal cord injury (SCI) leads to an increase in metabotropic glutamate receptor subtype 1 (mGluR1) immunoreactivity in the peri-lesion area. The increased expression of mGluR1 parallels the development of thermal hyperalgesia and mechanical allodynia and has been suggested to contribute to the development and maintenance of chronic central pain (CCP) syndromes resulting from SCI. However, expression of mGluR1 has not been directly shown to increase on cells in the pain pathway. Therefore, the expression of mGluR1 on spinothalamic tract (STT) neurons was quantified using confocal imaging and densiometric analysis in normal, sham, and SCI rats. Contusion SCI produced an increase in mGluR1 expression on STT cells in both the cervical enlargement and the spinal section just rostral to contusion SCI. These results suggest that mGluR1 is expressed on neurons that modulate pain transmission and expression on these cells increases following injury, supporting the hypothesis that mGluR1 contributes to CCP following SCI.     

Vanilloid receptor loss in rat sensory ganglia associated with long term desensitization to resiniferatoxin.

A dose-dependent loss of vanilloid receptors (specific [3H]resiniferatoxin binding sites) was found in sensory ganglia of rats 24 h after s.c. administration of resiniferatoxin (RTX), an ultrapotent capsaicin analog. This receptor loss displayed an ED50 of 30 micrograms/kg both in dorsal root and trigeminal ganglia; the ED50 was 6-fold higher than the ED50 for loss of the neurogenic inflammatory response and 30-60-fold higher than the ED50 for desensitization in the standard eye-wiping (chemogenic pain) response. The receptor loss appeared later (24 h) than the loss of the physiological responses (6 h) and showed modest recovery (to 20-30% of control levels) over the following 4 weeks. This vanilloid receptor loss may represent a novel, specific mechanism for vanilloid-induced chronic desensitization.     

Differential expression of COX-1 and COX-2 in the gastrointestinal tract of the rat

The aim of this study was to use immunohistochemistry with morphometry to investigate COX-1 and COX-2 expression in the normal rat gastrointestinal (GI) tract and examine if sites of ulceration previously observed with long-term COX-2 inhibitor administration in mice correlate with differential COX-1/COX-2 expression. COX-2 positive cells were observed predominantly in the apical lamina propria of intestinal villi with fewer cells in the mucosal epithelium. The highest level of COX-2 expression was observed at the ileocaecal junction (ICJ). COX-2 expression was also present in parasympathetic ganglia of the submucosa and muscularis. In the stomach, the highest grade of COX-2 expression was observed in the apical lamina propria of the fundus adjacent to the junctional ridge. In contrast, COX-1 positive cells within the lamina propria were evenly distributed along the GI tract but were present in higher numbers than COX-2 positive cells. The mean level of COX-1 expression at the ICJ was not significantly different from the ileum and caecum. Evidence that the highest level of COX-2 expression in normal rats is located on the ileal side of the ICJ provides the first mechanism to explain spontaneous ulceration and perforation of the distal ileum in COX-2 -/- animals.     

Brain angiotensin type 1 receptor expression and function in the Zucker obese rat

The Zucker obese rat is a model with predisposition for hypertension. There is evidence that angiotensin II (ANG II) may play a role in the maintenance of this hypertension. However, the potential role of brain ANG II in this regard has been largely unexplored. The aim of the present study was to compare the pressor response produced by i. c.v. injection of ANG II in Zucker obese and lean rats, and to determine if functional differences could be correlated to changes in brain AT1 receptor protein and/or mRNA expression. The Zucker obese rat had a significantly greater increase in blood pressure after i.c.v. injection of ANG II compared to the lean rat. AT1 receptor protein expression was greater in the brainstem, but not the hypothalamus, of the obese rat. These data raise the possibility that increased central responsiveness to ANG II may play a role in the predisposition of the Zucker obese rat to hypertension.     

Impact of caveolin-1 expression on the prognosis of transitional cell carcinoma of the upper urinary tract

This study aimed to investigate the relationship of caveolin-1 expression with prognosis in patients with transitional cell carcinoma of the upper urinary tract (TCCUUT). Formalin-fixed, paraffin-embedded tissue sections of TCC-UUT from 98 patients, who had undergone radical nephroureterectomy, were stained immunohistochemically using antibodies against caveolin-1. The expression pattern of caveolin- 1 was compared with the clinicopathological variables. The caveolin-1 expression was significantly correlated with T stage (p<0.001) and grade (p=0.036). The survival rate of patients with caveolin-1 positive tumors was significantly lower than that of patients with caveolin-1 negative tumors (p<0.0001). The univariate analyses identified T stage, grade, and caveolin-1 expression as significant prognostic factors for cancer-specific survival, whereas the multivariate analyses indicated that T stage and caveolin-1 expression were independent prognostic factors. These results show that the increased expression of caveolin-1 is associated with tumor progression and poor prognosis in TCC-UUT, suggesting that caveolin-1 may play an important role in the progression of TCC-UUT.     

WT1 expression in the female genital tract

The Wilms tumor gene 1 (WT1) has been reported in normal tissues and many neoplasms of the female genital tract. This review discusses WT1 expression in the female genital tract and its potential utility in the differential diagnosis of neoplasms that occur at this location. WT1 is of value in the differential diagnosis of synchronous serous carcinomas arising in the ovary/fallopian tube/peritoneum and endometrium, as strong WT1 positivity in both tumors points toward an extrauterine origin. In addition, WT1 can be used to distinguish sex cord stromal tumors (WT1 positive) from endometrioid carcinomas (OECs). WT1 expression is not helpful in the differential diagnosis of ovarian serous carcinomas (OSCs) and transitional carcinomas, as both are typically positive and has limited value in the distinction of serous tumors arising in the ovary/fallopian tube/peritoneum from mesotheliomas. WT1 is also not helpful to differentiate small cell carcinoma of hypercalcemic type from juvenile granulosa cell tumor, a common diagnostic problem. Intra-abdominal desmoplastic round cell tumor reacts to WT1 (C-terminal) in contrast to all other tumors discussed which helps to separate this rare tumor from most other small round cell tumors that may involve, primarily or secondarily, the ovary with the exception of small cell carcinoma of hypercalcemic type that typically reacts with the N-terminal of WT1.     

Glutamate receptor expression in the rat retina.

The expression of five genes (GluR A; B; C; D; GluR 5) encoding functional subunits of glutamate receptors was investigated in the rat retina using in situ hybridization with oligonucleotide probes. All five genes are expressed in the retina. All probes label cell bodies in the ganglion cell layer as well as somata in the inner third of the inner nuclear layer (INL), where the amacrine cells are located. In addition GluR 5, B and D, and to a lesser extent also GluR A are found in the middle and outer part of the INL, where bipolar and horizontal cells reside. Different subsets of retinal neurons may thus use glutamate receptors of different subunit composition.     

Relationship of type 1 pilus expression in Escherichia coli to ascending urinary tract infections in mice.

The role of type 1 pili and P adhesins during the in vivo growth of Escherichia coli inoculated into the urethras of BALB/c mice was studied. Strains which produced type 1 pili when grown in broth but lost this trait when grown on agar (regulated variants) were tested. Broth-grown organisms colonized the bladder of every animal tested, with counts of 10(3) to 10(4) viable organisms recovered from bladder homogenates. Agar-grown organisms gave lower rates of infection and the number of viable organisms recovered from bladders was significantly reduced. The degree of inoculum piliation influenced bladder colonization in a direct way: as piliation increased, the number of bacteria recovered from bladders also increased. After intraurethral inoculation, all of the bladders and 44% of the kidneys were colonized on day 1, and by day 5, 94% of the bladders and 16% of the kidneys were positive. Hemagglutination titers remained high for the bladder isolates, but the organisms colonizing the kidneys became significantly less piliated with time. Bacteriuria was unrelated to bladder or renal colonization. Strains that demonstrated random phase variation of type 1 pili during growth on agar produced similar colonizations of the urinary tract with broth- and agar-grown inocula. Strains that produced only P adhesins were less effective in colonizing the urinary tract than were type 1 piliated organisms. Other strains which did not produce pili only minimally colonized the bladder. The results suggest that type 1 pili play an essential role in ascending infections of the urinary tract.     

Aquaporin-1 expression in visceral smooth muscle cells of female rat reproductive tract.

The aquaporins (AQ-s) are a group of intrinsic membrane proteins which facilitate movement of water across cell membranes; their recent identification in the kidney has led to the reappraisal of the mechanisms and pathways of water movement across epithelia. Aquaporin-1, (CHIP-28) is reported distributed in cardiac myocytes and vascular smooth muscle cells of large arteries. A related protein, AQ-4, has been identified in the sarcolemma of skeletal muscle fibres. We report aquaporin expression in the cell membrane of smooth muscle cells of the rat genital tract; fluorescence immunohistochemistry of rat uterine (fallopian) tube and vagina demonstrated AQ-1 in visceral smooth muscle of these tissues. In the uterine tube, AQ-1 labelling is most pronounced in the innermost longitudinal and the inner cells of the circular muscle layer and is absent from the outer longitudinal muscle layer of the myosalpinx. The possibility of a specific role for AQ-1 in tubal transport by altering the tubal luminal diameter during the estrus cycle is suggested.     

Vanilloid receptor VR1-positive primary afferents are glutamatergic and contact spinal neurons that co-express neurokinin receptor NK1 and glutamate receptors

The vanilloid receptor VR1 (TRPV1) is a temperature- and capsaicin-sensitive cation channel expressed by a class of primary afferents involved in nociception. To confirm the hypothesis that VR1-positive primary afferents are glutamatergic and contact spinal neurons that express the main classes of ionotropic glutamate receptors, we performed multiple immunofluorescent staining for VR1 and the glutamate transporter VGLUT2 (a specific marker for glutamatergic transmission) or AMPA and NMDA receptor subunits. VR1-positive cells in the dorsal root ganglion and boutons of their central afferent fibers in the dorsal horn expressed VGLUT2, and the latter contacted AMPA- or NMDA receptor-positive perikarya. Based on our previous observations of preferential targeting of VR1-positive primary afferents to spinal neurons that express the neurokinin receptor NK1 (Hwang et al., 2003), we further quantified the frequency of termination of VR1-positive afferents onto NK1-positive neurons co-expressing glutamate receptors. A larger fraction of NK1/NMDA receptors-positive than NK1/AMPA receptors-positive sites were contacted by VR1-positive boutons. We conclude that VR1-positive primary afferents in the rat use glutamate as neurotransmitter and contact postsynaptic sites that co-express NK1 and ionotropic glutamate receptors.     

Iatrogenic changes in the urinary tract

A handful of therapeutic procedures are used to treat malignancies of the urinary tract, most frequently intravesical immunotherapy or chemotherapy, but also neoadjuvant systemic chemotherapy. These treatment modalities produce morphological changes in the urothelium that can be mistaken for carcinoma; in particular, these therapies frequently mimic urothelial carcinoma in situ (CIS) urothelial dysplasia or true invasive neoplasia. Drugs such as mitomycin C used after transurethral resection of bladder tumour to reduce recurrences, bacillus Calmette–Guérin (BCG) intravesical immunotherapy to treat high‐risk non‐muscle‐invasive bladder cancer and urothelial CIS and platin‐based systemic chemotherapy to improve postcystectomy disease‐specific survival are examples of therapy‐related atypia seen in the urinary tract. To complicate the pathologist's life, a number of systemic drugs in use to treat other diseases, such cyclophosphamide, used to treat some autoimmune disorders or certain haematological malignancies or, in the case of anaesthetics, ketamine, used increasingly as an illegal recreational drug, may produce similarly relevant atypical changes in the urothelium, and therefore need to be differentiated from intraepithelial neoplasia. Other less frequent procedures, such as photodynamic and laser therapy or the newer gene therapy to treat urothelial neoplasia, remain experimental. An immunohistochemical approach to reactive urothelium versus carcinoma in situ using p53, cytokeratin 20 and CD44 is also valid in the post‐therapy setting. The pathologist should be aware of these novelties, as he or she plays a crucial role in evaluating treatment efficacy, but at the same time needs to avoid misdiagnosing secondary atypia as intraepithelial neoplasia.     

Immune defenses in the urinary tract

Recent advances in preclinical modeling of urinary tract infections (UTIs) have enabled the identification of key facets of the host response that influence pathogen clearance and tissue damage. Here, we review new insights into the functions of neutrophils, macrophages, and antimicrobial peptides in innate control of uropathogens and in mammalian infection-related tissue injury and repair. We also discuss novel functions for renal epithelial cells in innate antimicrobial defense. In addition, epigenetic modifications during bacterial cystitis have been implicated in bladder remodeling, conveying susceptibility to recurrent UTI. In total, contemporary work in this arena has better defined host processes that shape UTI susceptibility and severity and might inform the development of novel preventive and therapeutic approaches for acute and recurrent UTI.     

Lithium alters mu-opioid receptor expression in the rat brain

The pretectal nucleus lentiformis mesencephali (LM) receives direct input from the contralateral retina and is dedicated to the analysis of optic flowfields resulting from self-motion. The activity of 126 LM neurons in response to optic flow stimuli was recorded. As with previous studies, it was found that most neurons (approximately 90%) exhibited direction-selectivity to large-field stimuli moving in the contralateral hemifield. However, some neurons (approximately 10%) responded to stimulation of both eyes and had receptive field structures conducive for detection of particular patterns of optic flow resulting from either self-translation or self-rotation. These binocular neurons were maximally responsive to panoramic optic flowfields simulating either translational or rotational optic flow.     

Stress-induced C-fos expression in the rat locus coeruleus is dependent on neurokinin 1 receptor activation

These experiments examined the role of substance P-selective neurokinin 1 receptors in the restraint-induced activation of the rat locus coeruleus. Immunohistochemistry revealed high levels of neurokinin 1 receptor expression in the plasma membrane of tyrosine hydroxylase-positive locus coeruleus neurons. The selective neurokinin 1 receptor antagonists, RP 67580 (5 nmol) and L-760,735 (3.4 nmol), were administered intracerebroventricularly prior to restraint stress, and c-fos protein was measured as an index of locus coeruleus activation. Both antagonists attenuated the restraint-induced increase in locus coeruleus c-fos expression, whereas their inactive enantiomers were ineffective. These results suggest that neurokinin 1 receptors may mediate activation of locus coeruleus neurons during stress. Neurokinin 1 receptor antagonists may prove to be novel therapeutic compounds in the treatment of anxiety and depression.     

Fc-gamma receptor 3A polymorphism predicts the incidence of urinary tract infection in kidney-transplant recipients

We investigated the impact of polymorphisms in host innate immunoregulatory genes on the development of infectious complications after kidney transplantation (KT). The single-nucleotide polymorphisms (SNPs) of C1QA [276 A/G], FCGR2A [131 H/R], and FCGR3A [158 F/V], genes encoding the Fc gamma receptor (FcγR), were analyzed in 81 KT recipients in relation to the occurrences of postoperative infectious complications within 30 days after KT. Consistent with a lower affinity of the isoform encoded by the FCGR3A [158 F] to both IgG1 and IgG3, a significantly higher incidence of urinary tract infections (UTIs) was observed in the FCGR3A [158 F/V or F/F] individuals (65.5%) than in the FCGR3A [158 V/V] individuals (34.5%) following KT. The combination of FCGR2A and FCGR3A SNPs further stratified the incidence of UTIs, regardless of C1QA SNP following KT. No differences were observed in the incidence of fungal or cytomegalovirus infections with respect to the 3 gene polymorphisms.In conclusion, our findings indicate that FcγR SNPs are predisposing factors for UTIs after KT. This study provides a foundation for further prospective studies on a larger scale.