Trisomy 16鼠结肠和人先天性巨结肠蛋白基因产物9.5的表达

目的：研究Ｄｏｗｎ’ｓ 综合征动物模型ｔｒｉｓｏｍｙ １６ 结肠神经系发育和先天性巨结肠（ＨＤ） 病变肠管蛋白基因产物９－５（ｐｒｏｔｅｉｎ ｇｅｎｅ ｐｒｏｄｕｃｔ９ ．５ ,ＰＧＰ９－５） 的神经表达。方法：Ｔｒｉｓｏｍｙ １６ 鼠培育;细胞遗传学分析;Ｔｒｉｓｏｍｙ １６ 鼠结肠和ＨＤＰＧＰ９－５ 免疫组织化学。结果：（１）Ｔｒｉｓｏｍｙ １６ 鼠结肠神经系发育异常,肌间神经丛发育迟缓,粘膜下神经丛缺失,结肠末端有５ ｍｍ 的无神经节区,但结肠系膜神经发育良好;（２）ＨＤ狭窄段肠管ＰＧＰ９－５ 阳性神经纤维大量增生,神经节细胞缺如。结论：（１）Ｔｒｉｓｏｍｙ １６ 鼠具有稳定的遗传学特征,可能伴先天性巨结肠。（２） 由于ＨＤ 狭窄段肠管神经节细胞缺失,增生的ＰＧＰ９－５ 阳性神经纤维是肠道外源性神经的代偿,对其神经元的性质尚有待确定。（３）ＨＤ有遗传倾向     

先天性巨结肠病肠壁NOS阳性神经元光镜和电镜观察

目的：探讨NOS阳性神经元与先天性巨结肠病病因及病理机制的关系。方法：对扩张段和移行段肠壁分别作全层铺片,NADPH－d酶组织化学染色,光镜和扫描电镜下观察NOS阳性神经结构。结果：扩张肠段光镜下肠肌丛神经节和神经元均较大,节内神经元染色深数量多,沿神经节周边及神经纤维发出处排列。扫描电镜下神经元胞体较大,排列较密,发出的神经纤维较多,在各个方向上相互连接。沿肌纤维排列的神经元之间有较多的横向连接纤维,肠肌丝社会元还通过穿行于环行肌层的神经纤维和粘膜下层神经元相连接,移行段光镜下节内神经元胞浆染色较淡,深浅不一,神经节和神经元均较小,发现的纤维细且染色较淡,扫描电镜下神经元胞形较小,且大小不等,密较较小,神经元间的纤维联系及神经纤维攀附于肌纤维表面的现象均较少,神经元和神经纤维呈沿纵行肌长轴线性分布。结论：先天性巨结肠病的发生及发展可与NOS阳性神经元在肠壁的分布与代谢异常有关关。     

Altered cytoskeleton in smooth muscle of aganglionic bowel

CONTEXT: Intestinal motility is under the control of smooth muscle cells, enteric plexus, and hormonal factors. In Hirschsprung disease (HD), the aganglionic colon remains spastic or tonically enhanced and unable to relax. The smooth muscle cell's cytoskeleton consists of proteins or structures whose primary function is to link or connect protein filaments to each other or to the anchoring sites. Dystrophin is a subsarcolemmal protein with a double adhesion property, one between the membrane elements and the contractile filaments of the cytoskeleton and the other between the cytoskeletal proteins and the extracellular matrix. Desmin and vinculin are functionally related proteins that are present in the membrane-associated dense bodies in the sarcolemma of the smooth muscle cells. OBJECTIVE: To examine the distribution of the cytoskeletal proteins in the smooth muscle of the aganglionic bowel. DESIGN: Bowel specimens from ganglionic and aganglionic sections of the colon were collected at the time of pull-through surgery from 8 patients with HD. Colon specimens collected from 4 patients at the time of bladder augmentation acted as controls. Anti-dystrophin, anti-desmin, and anti-vinculin antibodies were used for fluorescein immunostaining using confocal laser scanning microscopy. RESULTS: Moderate to strong dystrophin immunoreactivity was observed at the periphery of smooth muscle fibers in normal bowel and ganglionic bowel from patients with HD, whereas dystrophin immunoreactivity was either absent or weak in the smooth muscle of aganglionic colon. Moderate to strong cytoplasmic immunostaining for vinculin and desmin was seen in the smooth muscle of normal bowel and ganglionic bowel from patients with HD, whereas vinculin and desmin staining in the aganglionic colon was absent or weak. CONCLUSION: This study demonstrates that the cytoskeletal proteins are abundant in the smooth muscle of normal bowel, but are absent or markedly reduced in the aganglionic bowel of HD. As cytoskeletal proteins are required for the coordinated contraction of muscle cells, their absence may be responsible for the motility dysfunction in the aganglionic segment.     

Protein gene-product 9.5 in developing mouse circumvallate papilla: comparison with neuron-specific enolase and calcitonin gene-related peptide

The present study was made to investigate the ontogeny of protein gene-product 9.5 (PGP 9.5)-like immunoreactivity (-LI) in the developing mouse circumvallate papilla (CVP), and its distribution was compared to that of neuron-specific enolase (NSE) and calcitonin gene-related peptide (CGRP). In adult CVP, PGP 9.5-LI was observed in the subgemmal nerve plexus; some thin PGP 9.5-like immunoreactive (-IR) nerve fibers penetrated taste buds and apical epithelium. PGP 9.5-LI was also observed in the spindle-shaped cells in taste buds, and a small number of round- or oval-shaped ganglionic cells in the lamina propria. The distribution of NSE-LI was comparable to that of PGP 9.5-LI. CGRP-LI was observed in the nerve fibers only; distribution of CGRP-IR nerve fibers was similar to that of PGP 9.5-IR nerve fibers, although the number of CGRP-IR nerve fibers was smaller than that of PGP 9.5-IR nerve fibers. At least six developmental stages were defined with regard to the developmental changes in the distribution of PGP 9.5-LI from embryonic day (E) 12 to adulthood: Stage I (E12–13) — a dense nerve plexus of PGP 9.5-IR nerve fibers was detected in the lamina propria beneath the core of newly-formed papilla. Stage II (E14–16) — thin PGP 9.5-IR nerve fibers penetrated the apical epithelium, and a few round-shaped cells in the apical epithelium also displayed PGP 9.5-LI. Stage III (E17–18) — thin PGP 9.5-IR nerve fibers penetrated the inner lateral epithelium of the trench. Stage IV [Postnatal day (P) 0–3] many PGP 9.5-IR nerve fibers penetrated the outer lateral epithelium of the trench; later in this stage, taste buds appeared. Stage V (P5–10) — a small number of PGP 9.5 IR cells in the taste buds appeared, and their number increased gradually. Stage VI (PI4-adult) — the number of PGP 9.5-IR taste cells increased and reached the adult level, while the number of PGP 9.5-IR nerve fibers decreased. The development of NSE-LI was similar to that of PGP 9.5-LI. CGRP-IR nerve fibers were detected at E12 in the lamina propria, and the development of the intraepithelial CGRP-IR nerve fibers was similar to that of PGP 9.5-IR nerve fibers. The present results indicate that invasion by nerve fibers of the epithelium of lingual papillae occurs in a complex manner, and that these nerve fibers may participate in the formation of the taste buds.     

Membrane properties and innervation of smooth muscle cells in Hirschsprung's disease

Mechanical and membrane properties of smooth muscle cells and/or neuroeffector transmission in the aganglionic segment of the large intestine (Hirschsprung's disease) were compared with findings in the ganglionic segment. Tension-recording, microelectrode, and double sucrose gap methods were used. There was no difference in resting membrane potential of the longitudinal or circular muscle cell in these two segments, which were obtained at biopsy in Japanese children. In the ganglionic preparations, generations of regular prepotentials, with or without the spike, correlated well to the rhythmic contractions. However, in the aganglionic segment, irregular spike and contraction only were observed. In the circular or longitudinal muscle of the ganglionic segments, field stimulations evoked inhibitory junction potentials, excitatory junction potentials, or both and triggered initial relaxation and then a contraction of the tissue. In the aganglionic segment, however, field stimulation evoked only excitatory junction potentials followed by contraction. These results indicate that, in cases of Hirschsprung's disease, there may be a deficiency in the nonadrenergic inhibitory pathways. This is the first evidence for a lack of spasticity in muscle from the aganglionic segment of the large intestine obtained from children with Hirschsprung's disease.     

Immunohistochemical study of neuron specific enolase and S-100 protein in Hirschsprung's disease

Summary The distribution of whole differentiated neurons in the intestines from 15 children with Hirschsprung's disease was investigated using neuron specific enolase (NSE) and the perineuronal elements were studied using S-100 protein immunostaining.In aganglionic segments, NSE immunoreactive ganglion cells and S-100 positive satellite cells were absent, but the hypertrophic nerve trunks did show a markedly positive NSE and S-100 immunoreactivity.Two different forms of aganglionic segment were present. One was the middle aganglionic segment of long segment aganglionosis which was almost completely dennervated. In the other type, there were several NSE positive nerve fibers in the muscularis propria of both the aganglionic segment of short segment aganglionosis and the distal aganglionic segment of long segment aganglionosis. These latter two aganglionic segments seemed to be innervated by extrinsic nerves.     

Evaluation of PGP9.5 in the diagnosis of Hirschsprung's disease.

The ability of an acetylcholinesterase-stained frozen section to detect an increase in large cholinergic nerve fibres within the muscularis mucosae and extending into the lamina propria was a significant step forward in the diagnosis of Hirschsprung's disease (HD). However, such frozen section diagnosis is not always possible. The purpose of this study was to assess the ability of PGP9.5 to detect this pattern of mucosal nerve fibre staining immunohistochemically. Sixty-four specimens were included in the study. Twenty-six of these had been diagnosed as HD by conventional means. All cases were stained immunohistochemically with PGP9.5, S100, and anti-neurofilaments (NF). Twenty-four cases of HD were also stained with neurone-specific enolase (NSE). PGP9.5 reliably stained fibres in the mucosal and submucosal plexuses, and ganglion cells, when the latter were present. This positive staining of ganglion cells was more intense than that seen with NSE, and the positive fibre staining was more intense than that seen with NF. Increased lamina propria fibres were detected with PGP9.5 in only 37 per cent of HD cases compared with S100 positive staining in 60 per cent of cases. However, when S100 staining was assessed alone, it gave a higher false-negative rate in diagnosing HD than PGP9.5 used alone. Therefore we would recommend the use of PGP9.5 and S100 together for the immunohistochemical diagnosis of HD in formalin-fixed biopsies.     

Delayed expression of calbindin D28k during regeneration of the periodontal Ruffini endings of the rat incisor following injury to the inferior alveolar nerve

Expression of calbindin D28k (CB)-like immunoreactivity (-LI) was compared with that of protein gene product 9.5 (PGP 9.5), a general neuronal marker, in the periodontal ligament of the rat lower incisor following resection of the inferior alveolar nerve (IAN). In normal animals, the periodontal nerve fibers showing PGP 9.5-LI formed either Ruffini endings with expanded arborization or thin free nerve endings in the alveolar half of the ligament. Thick CB-like immunoreactive (-IR) nerve fibers terminated in a dendritic fashion in the same region, but thin CB-IR nerve fibers were rarely detected. During the 3 days following resection of the IAN, most of the PGP 9.5-IR and all CB-IR nerve fibers disappeared. Regenerated PGP 9.5-IR nerve fibers appeared around 7 days after resection, in contrast to the very small number of regenerated CB-IR nerve fibers. Around 21-28 days following resection, the number and terminal morphology of regenerated PGP 9.5-IR nerve fibers were comparable to those observed in normal animals, but the number of regenerated CB-IR nerve fibers was still smaller. The terminal morphologies of these regenerated CB-IR nerve fibers showed less expansion compared with normal animals at these post-injured periods. The number of regenerated CB-IR nerve fibers increased gradually to return to normal by 56 days following injury. The delayed expression of CB in the regenerated periodontal Ruffini endings suggests that the functional recovery of periodontal Ruffini endings occurred after the regeneration of periodontal Ruffini endings had been completed.     

Distribution of substance P-, methionine-enkephalin-, somatostatin- and serotonin-immunoreactive nerve elements of the large bowel in Hirschsprung's disease

The distribution of substance P-, methionine-enkephalin-, somatostatin- and 5-hydroxytryptamine-immunoreactive nerve elements in Hirschsprung's disease was studied. It was compared to the distribution of the comparable nerve elements in the sigmoid colon and rectum of control children. A reduction of substance P-, methionine-enkephalin- and 5-hydroxytryptamine-immunoreactive fibers as well as a higher density of somatostatin-immunoreactive fibers were found in the aganglionic segment in Hirschsprung gut as compared to those in the ganglionic segment in Hirschsprung children and the large bowel in control children. The changes in the density of peptide- and 5-hydroxytryptamine-immunoreactive fibers suggest the participation of different transmitters or transmitter candidates in the pathogenesis of Hirschsprung's disease.     

The involvement of brain-derived neurotrophic factor (BDNF) in the regeneration of periodontal Ruffini endings following transection of the inferior alveolar nerve

The present study employed immunohistochemistry for protein gene product 9.5 (PGP 9.5) to examine the regeneration process of Ruffini endings, the primary mechanoreceptor in the periodontal ligament, in heterozygous mice with targeted disruption of the brain-derived neurotrophic factor (BDNF) gene and their littermates, following transection of the inferior alveolar nerve. When immunostained for PGP 9.5, periodontal Ruffini endings appeared densely distributed in the periodontal ligament of the heterozygous mice, but the density of the positively stained nerve fibers in the ligament was 20% lower than that in the control littermates. At 3 days after surgery, the PGP 9.5-positive neural elements had disappeared; they began to appear in the periodontal ligament of both animals at 7 days. However, the recovery pattern of the PGP 9.5-positive nerves differed between heterozygous and wild type mice, typical periodontal Ruffini endings morphologically identical to those in the control group appeared in the wild-type mice at 7 days, whereas such Ruffini endings were detectable in the heterozygous mice at 28 days, though much smaller in number. On day 28, when PGP 9.5-positive nerves were largely regenerated in wild type mice, their distribution was much less dense in the ligament of the heterozygous mice than in the non-treated heterozygous mice. The density of PGP 9.5-positive nerve fibers was significantly lower in the heterozygous mice than in wild type mice at any stage examined. These data showing that a reduced expression of BDNF causes delayed regeneration of the periodontal Ruffini endings suggest the involvement of BDNF in the regeneration process of these mechanoreceptors.     

Validation of endobronchial biopsy specimens for nerve quantitation by computer-assisted image analysis

The aim of this study was to assess the validity of endoscopic bronchial biopsy specimens for the quantitation of nerves. To this end, endobronchial biopsy was simulated ex vivo on surgically resected lung specimens and nerve densities were compared in airway smooth muscle of biopsy and surrounding tissue. Specimens were stained immunohistochemically for the general neural marker protein gene product 9.5 (PGP 9.5) and for vasoactive intestinal peptide (VIP), and nerve densities were quantitated using computer-assisted image analysis. Nerve density for total (PGP 9.5-immunoreactive) nerves was slightly higher in biopsies than in corresponding lung tissue, but this difference did not reach statistical significance (p=0.08). There was also no significant difference in the density of VIP-immunoreactive nerves (p=0.60). These findings support the use of endobronchial biopsy specimens to quantitate nerves in asthma and other airway diseases.     

Postnatal expression of calretinin-immunoreactivity in periodontal Ruffini endings in the rat incisor: a comparison with protein gene product 9.5 (PGP 9.5)-immunoreactivity

The postnatal expression of immunoreactivity for calretinin, one of the calcium binding proteins, and for protein gene product 9.5 (PGP 9.5), a general neuronal marker, was investigated in mechanoreceptive Ruffini endings in the periodontal ligament of the rat incisor. Age-related changes in the expression of these two proteins in periodontal nerves were further quantified with a computerized image analysis. At 1 day after birth, a few PGP 9.5-immunoreactive nerve fibers and a still smaller number of calretinin-positive fibers were found in the periodontal ligament: they were thin and beaded in appearance and no specialized nerve terminals were recognized. Tree-like terminals, reminiscent of immature Ruffini endings, were recognizable in 4-day-old rats by PGP 9.5-immunohistochemistry, while calretinin-immunostaining failed to reveal these specialized endings. At postnatal 7-11 days when PGP 9.5-immunostaining could demonstrate typical Ruffini endings, calretinin-immunopositive nerve fibers merely tapered off without forming the Ruffini type endings. A small number of Ruffini endings showing calretinin-immunoreactivity began to occur in the periodontal ligament at 24-26 days after birth when the occlusion of the first molars had been established. At the functional occlusion stage (60-80 days after birth), the Ruffini endings showing calretinin-immunoreactivity drastically increased in number and density, but less so than those positive for PGP 9.5-immunoreaction. The delayed expression of calretinin suggests that the function of the periodontal Ruffini endings is established after the completion of terminal formation because Ca2+, which binds to calcium binding proteins including calretinin with high affinity, plays an important role in mechano-electric transduction.     

Peptidergic innervation irregularities in Hirschsprung's disease

Summary The distribution of vasoactive intestinal polypeptide (VIP)-containing nerves and the contents of both VIP and substance P (S-P) in the intestines from 12 children with Hirschsprung's disease were examined using immunohistochemical methods and radioimmunoassay. VIP-containing nerve fibers were markedly decreased in number in the true muscle coats of aganglionic segments, while extrinsic hypertrophic nerve bundles in these segments showed positive VIP-immunoreactivities. This finding suggests the existance of extrinsic origins of VIP-containing nerves in the human gut. The contents of VIP were 44.5±8.2 in aganglionic segments and 130 ± 17.1 pg/mg wet tissue weight in normoganglionic segments. The contents of S-P were 0.42 ± 0.18 in aganglionic segments and 6.38 ± 2.3 pg/mg wet tissue weight in normoganglionic segments. Both VIP and S-P contents in aganglionic segments were significantly reduced as assessed by the use of radioimmunoassay (p<0.001 andp<0.05).These abnormal peptidergic patterns of innervation might relate to the non-peristaltic state in Hirschsprung's disease.     

蛋白基因产物9.5与神经丝蛋白标记瘢痕神经效果的比较

目的　比较蛋白基因产物9.5（PGP9.5）与神经丝蛋白（NFP）对瘢痕组织内神经纤维的染色效果。 方法 采取瘢痕组织标本25份,由两实验者分别采用免疫荧光技术以PGP9.5、NFP作为神经标记物进行实验,测量免疫阳性神经纤维灰度并计算神经容积分数NVF,对免疫阳性神经纤维进行半定量分析;比较实验者、标记物对染色以及两标记物染色阳性率的差异。 结果　 ⑴实验者对实验数据没有造成显著差异（F=0.542,P＞0.05）;⑵PGP9.5组的灰度值51.55±41.47,显著低于NFP组的81.38±32.1,(P 　<0.05）;⑶PGP9.5组NVF值为0.57±0.38,显著低于NFP组的NVF0.82±0.28,(P<0.05）;⑷PGP9.5染色阳性率也低于NFP组（P<0.05）。结论　PGP9.5标记人瘢痕神经纤维的效果不如NFP。     

Distribution of GAP-43 nerve fibers in the skin of the adult human hand

Skin is an important region of somatic sensory input, and is one of the most innervated areas of the human body. In this study, we investigated in human hand skin the distribution of nervous structures immunoreactive for the growth-associated protein 43 (GAP-43) and the protein gene product 9.5 (PGP 9.5). GAP-43 is a neuronal presynaptic membrane protein that is generally considered to be a marker of neuronal plasticity. PGP 9.5 is a neuron-specific soluble protein that is widely used as general marker for the peripheral nervous system. The entire neural network of the dermis and epidermis was stained with antibody to PGP 9.5. In the dermis, there were fewer GAP-43-immunostained nerve fibers than PGP 9.5-immunostained nerve fibers, whereas in the epidermis the numbers were equal. Only some Merkel cells and Meissner corpuscles were GAP-43-immunoreactive. In conclusion, our results show that GAP-43 protein is expressed in a subset of PGP 9.5-immunoreactive nerve structures.     

The expression pattern of laminin isoforms in Hirschsprung disease reveals a distal peripheral nerve differentiation

Hirschsprung disease (HD), a developmental disorder, is associated with failure of enteric ganglia formation. Signaling molecules, including secreted basement membrane molecules, derived from the mesenchyme of the gut wall play an important role in the colonization and/or differentiation of the enteric nervous system. The current study aims to define the possible alterations of laminins involved in the pathogenesis of HD. Expression of the various laminin alpha, beta, and gamma chains, was assessed in the aganglionic, transitional, and ganglionic bowel segments of patients with HD or with other motor disorders. Cytoskeletal, neuronal, and glial markers were also included in this study. The major finding highlighted by the present work concerns the clear identification and location of myenteric aganglionic plexuses in HD with some of the laminin antibodies, which reveal a peripheral nerve type of differentiation. Furthermore, we could show an increase of laminin alpha5 chain immunostaining in the dilated muscle of the ganglionic bowel upstream the distal aganglionic region in a subgroup of patients with HD, as well as a relocalization of laminin alpha2 chain in the subepithelial basement membrane. Overall, these basement membrane molecules could provide useful markers for diagnosis of aganglionosis or hypoganglionosis.     

Ultrastructural localization of acetylcholinesterase activity in Hirschsprung's disease

Localization of acetylcholinesterase activity in congenital megacolon was studied by light and electron microscopy. Acetylcholinesterase activity was strongly positive at the light microscopic level in the Auerbach's plexus of the normal segment and in proliferated nerve fibers of the aganglionic segment. The reaction product observed by electron microscopy was deposited in and between the plasma membranes of the ganglion cells, nerve fibers, and their terminals. The product was also observed in the rough endoplasmic reticulum, nuclear envelope, and Golgi apparatus of the ganglion cells. Acetylcholinesterase activity in the aganglionic segment was observed in and between the plasma membranes of nerve fibers and nerve terminals, which terminated in proximity to smooth muscle cells. Reaction deposits were also observed in the interspace between nerve terminals and smooth muscle cells, suggesting direct innervation of smooth muscles by extrinsic nerve fibers.     

Expression of dishevelled gene in Hirschsprung’s disease

Hirschsprung’s disease (HSCR) is a congenital disorder of the enteric nervous system and is characterized by an absence of enteric ganglion cells in terminal regions of the gut during development. Dishevelled (DVL) protein is a cytoplasmic protein which plays pivotal roles in the embryonic development. In this study, we explore the cause of HSCR by studying the expression of DVL-1 and DVL-3 genes and their proteins in the aganglionic segment and the ganglionic segment of colon in HSCR patients. Materials and Methods: Specimen of aganglionic segment and ganglionic segment of colon in 50 cases of HSCR patients. Expression levels of mRNA and proteins of DVL-1 and DVL-3 were confirmed by quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry staining between the aganglionic segment and the ganglionic segment of colon in HSCR patients. Results: The mRNA expression of DVL-1 and DVL-3 were 2.06 fold and 3.12 fold in the aganglionic segment colon tissues compared to the ganglionic segment, respectively. Similarly, the proteins expression of DVL-1 and DVL-3 were higher (39.71 ± 4.53 vs and 53.90 ± 6.79 vs) in the aganglionic segment colon tissues than in the ganglionic segment (15.01 ± 2.66 and 20.13 ± 3.63) by western blot. Besides, immunohistochemical staining showed that DVL-1 and DVL-3 have a significant increase in mucous and submucous layers from aganglionic colon segments compared with ganglionic segments. Conclusion: The study showed an association of DVL-1 and DVL-3 with HSCR, it may play an important role in the pathogenesis of HSCR.     

Decreased nerve fibers in the oviduct isthmus of women with endometriosis

Oviduct tubal motility is thought to be controlled by hormones and nerves and has been associated with endometriosis. However, it is still not known whether the fallopian tubes in women with endometriosis demonstrate an abnormal distribution of nerve fibers. The objective of this study was to determine the distribution of nerve fibers in the oviduct isthmus in women with and without endometriosis. Histological sections of the oviduct isthmus tissues were obtained from women undergoing hysterectomy for endometriosis (n = 24) and other benign gynecologic diseases (n = 24). The tissues were immunohistochemically stained for protein gene product (PGP) 9.5, substance P (SP), neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP) to reveal all nerve fibers, sensory nerve fibers and sympathetic and parasympathetic nerve fibers. Nerve fibers stained with PGP9.5, VIP and NPY in the oviduct isthmus were all significantly decreased in women with endometriosis as compared with women without endometriosis (P < 0.05). In women with endometriosis, reduced nerve fibers stained with PGP9.5 and SP in the serosal layer, NPY in the muscular and mucosal layers, and VIP in the mucosal layer of the oviduct isthmus were all associated with the severity of the disease (P < 0.05). These results suggest that decreased nerve fibers in the oviduct isthmus in women with endometriosis in comparison to women without may imply a role in the pathogenesis of endometriosis.     

Development of neural tissue and airway smooth muscle in fetal mouse lung explants: a role for glial-derived neurotrophic factor in lung innervation

We have characterized the distribution of neural tissue and its primary target tissue, airway smooth muscle (ASM), in an in vitro mouse model of early lung development comprising left lung lobes at embryonic Day 12, cultured for 2 or 5 d. Neural tissue was detected with antibodies to protein gene product 9.5 (PGP 9.5), synapsin, and p75NTR (the low-affinity neurotrophin receptor), and smooth muscle with an antibody to alpha-actin. Imaging by confocal microscopy revealed few PGP 9.5-positive neurons at the start of culture; after 2 d clusters of neurons and nerve fibers had appeared along the lobar bronchus and after 5 d along the secondary and tertiary branches. Neural tissue did not just follow the smooth muscle-covered tubules, as seen in vivo, but also grew outside the lobes onto a wide layer of alpha-actin-positive cells, suggesting that smooth muscle may express a trophic factor that attracts nerves. Explants cultured with glial-derived neurotrophic factor (GDNF) exhibited a striking increase in the amount of p75NTR- and PGP 9.5-positive tissue outside the lobes, whereas GDNF-impregnated beads attracted neuronal precursors and influenced the direction of neurite extension. We show that the mouse lung explant is suitable for investigating trophic signals involved in pulmonary innervation and that GDNF may have a role in the early innervation of the developing airways.