Efeito da redução da função colinérgica na mecânica pulmonar e na histopatologia pulmonar em modelo experimental de inflamação aguda induzida por instilação de LPS em camundongos geneticamente modificados / Cholinergic function reduction effect of pulmonary mechanics and pulmonary histopathology acute inflammation model of experimental induced by LPS in mice genetically modified

A lesão pulmonar aguda (LPA) é caracterizada por inflamação pulmonar de início súbito com recrutamento de polimorfonucleares e liberação de mediadores próinflamatórios. É uma condição grave que evolui com óbito em aproximadamente 40% dos casos. Diversos estudos que elucidaram a fisiopatologia da LPA, o tratamento ainda é insatisfatório. O sistema colinérgico anti-inflamatório foi descrito no pulmão e está relacionado a um reflexo via nervo vago que inibe a liberação de citocinas inflamatórias por efeitos relacionados a ação da acetilcolina em receptores nicotínicos. Nossa hipótese é de que a redução de VAChT, que está relacionada ao déficit na liberação de ACh, module a resposta inflamatória pulmonar em modelo de LPS. Objetivo: 1. Avaliar se a deficiência de VAChT modula a resposta pulmonar em animais geneticamente modificados; 2. Avaliar se a deficiência colinérgica induzida por redução de VAChT está envolvida na resposta pulmonar ao LPS e elucidar alguns mecanismos envolvidos; 3. Avaliar o potencial terapêutico do PNU, um agonista de alfa7nAChR nas alterações funcionais e histopatológicas em modelo de LPA em animais C57Bl6. Metodologia: Foram utilizados camundongos machos geneticamente modificados mutante (VAChT KDHOM) ou selvagem (WT) e C57BL/6. Inicialmente avaliamos a função pulmonar e a histopatologia pulmonar em animais VAChT KDHOM. Após, animais WT e VAChT KDHOM receberam instilação intranasal de LPS ou salina e a resposta inflamatória foi avaliada de 1,5h até 72 horas após. Ainda, foi avaliado a resposta pulmonar em VAChT KDHOM e WT após a instilação de LPS intraperitoneal. Por fim, animais C57BL/6 instilados com LPS intranasal, receberam tratamento prévio ou após com PNU, agonista do receptor nicotínico alfa7. Resultados: Animais mutante apresentaram maior quantidade de células recuperadas no lavado bronco alveolar (LBA) e aumento de citocinas próinflamatórias, aumento de edema peribrônquico e piora da função pulmonar. Ainda,...

Acute lung injury (ALI) is characterized by acute lung inflammation with recruitment of polymorphonuclear and release of proinflammatory mediators. It is a severe condition since leads to death 40% of the cases. Several studies have elucidated the pathophysiology of ALI, however the treatment is still unsatisfactory. The anti-inflammatory cholinergic system was described in the lung and is related to a vagal nerve reflex that inhibits the release of inflammatory cytokines by the action o ACh on nicotinic receptors. Our hypothesis is that the VAChT reduction, which is related to the deficit in the release of ACh, modulates the pulmonary inflammatory response in a model of LPS. Aim: 1. To assess whether VAChT deficiency modulates the pulmonary response in genetically modified animals; 2. Assess whether cholinergic deficiency induced reduction VAChT is involved in pulmonary response to LPS and elucidate some mechanisms involved; 3. To evaluate the therapeutic potential of PNU, an agonist alfa7nAChR, in functional and histological changes in C57BL6 mice with LPA. Methods: Mutant genetically modified male mice (VAChT KDHOM) or wild (WT) and C57BL/6 were used. First, we evaluated lung function and lung histopathology in VAChT KDHOM animals. After, WT animals and VAChT KDHOM received intranasal instillation of LPS or saline and the inflammatory response was assessed 1.5 hours to 72 hours. Moreover, the pulmonary response was evaluated in WT and VAChT KDHOM after instillation of LPS intraperitoneally. Finally, C57BL6 instilled with intranasal LPS received prior or post-treatment with PNU, an alfa7 nicotinic receptor agonist. Results: Mutant animals had higher number of cells recovered in brochoalveolar lavage (BAL) and increased pro-inflammatory cytokines, peribronchial edema and worsening of lung function. Still, there was an increase of NF_kB expression and reduction of JAK2. The VAChT deficiency induced increase in inflammatory cells...

Expression of non-neuronal cholinergic system in maxilla of rat in vivo

BACKGROUND: Acetylcholine (ACh) is known to be a key neurotransmitter in the central and peripheral nervous systems, which is also produced in a variety of non-neuronal tissues and cell. The existence of ACh in maxilla in vivo and potential regulation role for osteogenesis need further study. RESULTS: Components of the cholinergic system (ACh, esterase, choline acetyltransferase, high-affinity choline uptake, n- and mAChRs) were determined in maxilla of rat in vivo, by means of Real-Time PCR and immunohistochemistry. Results showed RNA for CarAT, carnitine/acylcarnitine translocase member 20 (Slc25a20), VAChT, OCTN2, OCT1, OCT3, organic cation transporter member 4 (Slc22a4), AChE, BChE, nAChR subunits α1, α2, α3, α5, α7, α10, ß1, ß2, ß4, γ and mAChR subunits M1, M2, M3, M4, M5 were detected in rat's maxilla. RNA of VAChT, AChE, nAChR subunits α2, ß1, ß4 and mAChR subunits M4 had abundant expression (2(-ΔCt) > 0.03). Immunohistochemical staining was conducted for ACh, VAChT, nAChRα7 and AChE. ACh was expressed in mesenchymal cells, chondroblast, bone and cartilage matrix and bone marrow cells, The VAChT expression was very extensively while ACh receptor α7 was strongly expressed in newly formed bone matrix of endochondral and bone marrow ossification, AchE was found only in mesenchymal stem cells, cartilage and bone marrow cells. CONCLUSIONS: ACh might exert its effect on the endochondral and bone marrow ossification, and bone matrix mineralization in maxilla.

Analysis on interrelation between electroacupuncture-induced cumulative analgesic effect and hypothalamic cholinergic activities in chronic neuropathic pain rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the effects of repeated electroacupuncture (EA) of Zusanli (ST36)- Yanglingquan (GB34) on hypothalamic acetylcholinesterase (AchE) and vesicular acetylcholine (ACh) transporter (VAChT) activities and choline acetyltransferase (ChAT) mRNA and muscarinic M1 receptor (M1R) mRNA expression in chronic constrictive injury (CCI) and/or ovariectomy (OVX) rats so as to reveal its underlying mechanism in cumulative analgesia.</p><p><b>METHODS</b>A total of 103 female Wistar rats were randomly divided into normal control (n =15), CCI (n =15), CCI+EA2d (n =15), CCI+EA2W (n =15), OVX+CCI =13), OVX+CCI+EA2d (n =15), and OVX+CCI+EA2W groups (n =15). CCI model was established by ligature of the unilateral sciatic nerve with surgical suture. Memory impairment model was established by removal of the bilateral ovaries. Morris water test was conducted to evaluate the OVX rats' memory learning ability, and the thermal pain threshold (PT) of the bilateral paws was detected the next morning after EA. EA (2/15 Hz, 1 mA) was applied to bilateral ST36-GB34 for 30 min, once daily for 2 days or 2 weeks, respectively. Hypothalamic AChE activity was detected by histochemistry, VAChT immunoactivity was determined by immunohistochemistry, and ChAT mRNA and M1R mRNA expressions were assayed by reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>In comparison with the normal control group, the AChE activity in hypothalamic arcuate nucleus (ARC) and supraoptic nucleus (SON) regions of CCI group, AChE activity in paraventricular nucleus (PVN), ARC, and SON regions of OVX+CCI group, and hypothalamic muscarinic M1R mRNA expression levels in both CCI and OVX+CCI groups were down-regulated significantly (P <0.05). Compared with the CCI group, the AChE activities in hypothalamic ARC and SON regions of CCI+EA2d and CCI+EA2W groups and PVN region of CCI+EA2W group and hypothalamic ChAT mRNA and M1R mRNA expression levels in CCI+EA2W group were up-regulated considerably (P <0.05). In comparison with the OVX+CCI group, the AChE activities in PVN, ARC, and SON regions and the expressions of hypothalamic ChAT mRNA and VAChT in ARC region of OVX+CCI+EA2W group were up-regulated remarkably (P <0.05). The effects in rats of CCI+EA2W group were evidently superior to those of OVX+CCI+EA2d group in up-regulating AChE activities in PVN, ARC, and SON regions, VAChT immunoactivity in ARC region, and expression levels of hypothalamic ChAT mRNA and M1R mRNA (P <0.05). Similar situations were found in OVX+CCI rats after EA2W. It suggested a cumulative effect after repeated EA of ST36-GB34. Comparison between CCI+EA2W and OVX+CCI+EA2W groups showed that the effects in rats of the former group were evidently better than those of the latter group in up-regulating AChE activity in ARC and SON regions and the expressions of hypothalamic ChAT mRNA and M1 mRNA (P <0.05), suggesting a reduction of EA2W effects after OVX.</p><p><b>CONCLUSION</b>Repeated EA can significantly up-regulate AChE and VAChT activities and ChAT mRNA and M1R mRNA expressions in the hypothalamus of CCI and OVX+CCI rats, which may contribute to the cumulative analgesic effects of repeated EA and be closely related to the animals' neuromemory ability.</p>

Effects of training in the Morris water maze on the spatial learning acquisition and VAChT expression in male rats

It has been well established that cholinergic pathway plays an important role in learning and memory processes. The present study was designed to evaluate the effects of Morris water maze [MWM] training on spatial memory acquisition and expression of the vesicular acetylcholine transporter [VAChT] in male rats. Methods: In this study, training trials of all groups of animals were conducted in the MWM task. Rats received one training session consisting of four trials per day which continued for another four consecutive days. Controls received visible platform MWM training. The escape latency, the traveled distance and swimming speed for each rat were recorded and used to evaluate the performance of the animal during training period. For evaluation of expression of VAChT protein levels, brain tissues from animals in each experiment were obtained immediately after the last trial on the related experimental day and processed for immunohistochemistry staining and western blotting analysis. There was a significant difference between animals subjected to one day training and those receiving four days of training in escape latency and travel distance. There were an apparent increase in VAChT immunoreactivity in the medial septal area [MSA] and CA1 region of the hippocampus in one day and four day trained animals compared with controls [visible group]. Quantitative immunostaining analysis by optical density measurements in the CA1 region and evaluation of immunopositive neurons in medial septal area of brain sections confirmed qualitative findings. Assessment of VAChT protein level expression in hippocampus by western blotting evaluation showed the same pattern of immunohistochemistry results. Overall, results of this study reveal changes in cholinergic neuron activity in different stages of training in the MWM task. Data suggest that there is a significant level of cholinergic neuronal activity during early stages of the training especially in the hippocampus region that may contribute to the apparent increase in VAChT expression