RESUMO
Telocytes (TCs), novel interstitial cells, have been identified in various organs of many mammals. However, information about TCs of lower animals remains rare. Herein, pancreatic TCs of the Chinese giant salamanders (Andrias davidianus) were identified by CD34 immunohistochemistry (IHC) and transmission electron microscopy (TEM). The IHC micrographs revealed CD34+ TCs with long telopodes (Tps) that were located in the interstitium of the pancreas. CD34+ TCs/Tps were frequently observed between exocrine acinar cells and were close to blood vessels. The TEM micrographs also showed the existence of TCs in the interstitium of the pancreas. TCs had distinctive ultrastructural features, such as one to three very long and thin Tps with podoms and podomers, caveolae, dichotomous branching, neighbouring exosomes and vesicles. The Tps and exosomes were found in close proximity to exocrine acinar cells and α cells. It is suggested that TCs may play a role in the regeneration of acinar cells and α cells. In conclusion, our results demonstrated the presence of TCs in the pancreas of the Chinese giant salamander. This finding will assist us in a better understanding of TCs functions in the amphibian pancreas.
Assuntos
Pâncreas/citologia , Telócitos/citologia , Urodelos/anatomia & histologia , Animais , Antígenos CD34/metabolismo , Imuno-Histoquímica , Pâncreas/ultraestrutura , Telócitos/ultraestruturaRESUMO
Telocytes (TCs) and their telopodes (Tps) have been found in various organs of many mammals, including in lower animals. However, knowledge of TCs in lower animals is still very limited. This study identified TCs and their Tps in the ileum of the Chinese giant salamander, Andrias davidianus (Amphibia: Caudata), by transmission electron microscopy. The TCs/Tps were found near epithelial cells, glandular cells and unmyelinated nerve fibres. Moreover, exosomes were also found to be present in between TCs/Tps and these cells.
Assuntos
Íleo/ultraestrutura , Telócitos/fisiologia , Urodelos/anatomia & histologia , Animais , Axônios/ultraestrutura , Feminino , Masculino , Microscopia Eletrônica de Transmissão , Vesículas Transportadoras/ultraestruturaRESUMO
INTRODUCTION: The intestinal structure is the foundation for various activities and functions in poultry. An important question concerns the changes in the intestinal status under endotoxin stimulation. This study aimed to investigate the mechanism of intestinal injury induced by lipopolysaccharide (LPS) in Wahui pigeons. METHODS: Thirty-six 28-day-old healthy Wahui pigeons were randomly divided into two groups. The experimental group was injected with LPS (100 µg/kg) once per day for five days, and the control group was treated with the same amount of sterile saline. Blood and the ileum were collected from pigeons on the first, third, and fifth days of the experiment and used for oxidative stress assessment, inflammatory factor detection, histopathological examination, and positive cell localization. In addition, intestinal injury indices and mRNA expression levels (tight junction proteins, inflammatory cytokines, and factors related to autophagy and apoptosis) were evaluated. RESULTS: Villi in the ileum were shorter in the LPS group than in the control group, and D-lactic acid levels in the serum were significantly increased. Glutathione and catalase levels significantly decreased, but the malondialdehyde content in the serum increased. TNF-α and IL-10 were detected at higher levels in the serum, with stronger positive signals and higher mRNA expression levels, in the LPS group than in the control group. In addition, the levels of TLR4, MyD88, NF-κB, and HMGB1 in the inflammatory signaling pathway were also upregulated. Finally, the mRNA expression of Claudin3, Occludin, and ZO-1 was significantly decreased; however, that of Beclin1 and Atg5 was increased in the LPS group. CONCLUSION: Ileal pathological changes and oxidative stress were caused by LPS challenge; it is proposed that this triggering regulates the inflammatory response, causing excessive autophagy and apoptosis, promoting intestinal permeability, and leading to intestinal injury in Wahui pigeons.
Assuntos
Autofagia/efeitos dos fármacos , Íleo/efeitos dos fármacos , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Columbidae , Citocinas/metabolismo , Íleo/metabolismo , Interleucina-10/metabolismo , Mucosa Intestinal/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo/fisiologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
In this study, we attempt to identify gastric telocytes (TCs) of the Chinese giant salamander Andrias davidianus, by light microscopy, immunohistochemistry and transmission electron microscopy (TEM) methods. Toluidine blue staining showed TCs with one to two very thin and long telopodes (Tps) that were located in gastric lamina propria. Tps had characteristic structures, including podoms, podomers and dichotomous branching. Immunohistochemistry showed the existence of CD34(+)/PDGFRα(+) TCs with moniliform Tps in stroma and were close to gastric glands and blood vessels. TEM micrographs also demonstrated the presence of TCs in interstitium between gastric glands. TCs/Tps were located in close proximity to gastric glands, blood vessels, endocrine cells and stem cells. In particular, Tps frequently surrounded stem cells. TCs and Tps, Tps and stem cells established close contacts. Moreover, the exosomes were also found near TCs/Tps. Our data confirmed the presence of TCs in gastric lamina propria of the amphibian, and suggested that TCs cooperate with resident stem cells to regulate endocrine cells and gastric glands regeneration and homeostasis.
Assuntos
Mucosa Gástrica/citologia , Telócitos/citologia , Urodelos/anatomia & histologia , Animais , Antígenos CD34/metabolismo , Mucosa Gástrica/ultraestrutura , Imuno-Histoquímica , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Telócitos/ultraestruturaRESUMO
In this work, the morphological features of liver in Chinese Taihe black-bone silky Fowl (BSF) were analyzed by light microscope and transmission electron microscopy. The results showed that two kinds of hepatocytes were present in Taihe BSF liver, i.e., the dark and the light hepatocyte. The dark hepatocyte was electron-dense and lager, with many organelles, mitochondria especially. The light hepatocytes were smaller than the dark. They had electron-lucent cytoplasm with a small number of organelles. Furthermore, there were lipolysosomes in the light hepatocyte. The numerous long and serried finger-like microvilli spread into bile canaliculus lumen. The glycogen granules intensely stained, spread in some hepatocytes. Numerous glycogen granules scattered in cytoplasm especially near bile canaliculi. However, lipid droplets were not observed in any hepatocytes. The natural apoptotic hepatocytes were observed in Taihe BSF liver. The hepatocytes which contain abundant uesicae-like endoplasmic reticulum closed the apoptotic hepatocytes and spread the process to approach the cell residual bodies. Besides, there was a macrophage with several phagosomes. In conclusion, the dark and the light hepatocyte were present in Chinese Taihe BSF liver. They were different from electron-dense and organelles. The hepatocytes of Taihe BSF could undergo natural apoptosis, regeneration and renew ability.
Fueron analizadas las características morfológicas ultraestructurales de hígado en la gallina sedosa china de hueso negro por microscopía óptica y microscopía electrónica de transmisión. Los resultados mostraron que se encontraron hepatocitos claros y oscuros en el hígado de la gallina china Taihe. El hepatocito oscuro era denso y de mayor tamaño. Tenía numerosos organelos, especialmente mitocondrias. Los hepatocitos claros eran más pequeños que los oscuros. El citoplasma presentó un pequeño número de organelos. Además, había lipolisosomas en los hepatocitos claros. Numerosas microvellosidades se extendían hacia los canalículos biliares. En algunos hepatocitos se observó una tinción marcada en los gránulos de glucógeno. Sin embargo, no se observaron gotas de lípidos en los hepatocitos. Se observaron los hepatocitos apoptóticos naturales en el hígado de la gallina Silky Taihe. Aquellos hepatocitos que contenían abundante retículo endoplásmico, cerraban los hepatocitos apoptóticos y extendían el proceso de acercamiento a cuerpos residuales celulares. También hubo un macrófago con varios fagosomas. En conclusión, los hepatocitos claros y oscuros estaban presentes en el hígado de la gallina Taihe china. Estos diferían de electrones de alta densidad y organelos. Los hepatocitos de la gallina Taihe presentaron una apoptosis natural y capacidad de regeneración.
Assuntos
Animais , Galinhas/anatomia & histologia , Fígado/ultraestrutura , Hepatócitos/ultraestrutura , MicroscopiaRESUMO
The hornet possesses highly toxic venom, which is rich in toxin, enzymes, and biologically active peptides. Several bradykinin-like peptides, vespakinins, have been found in wasp venoms since 1970s, but the mode of biosynthesis of these peptides is unknown. In the present study, a vespakinin M was purified from venom of Vespa magnifica. Its primary sequence was established as GRPPGFSPFRID. The cDNA encoding the vespakinin M was cloned from the cDNA library of V. magnifica venom gland. The cDNA structure of vespakinin M was found to contain a coding region of 168 nucleotides. The encoded precursor of vespakinin M is composed of a signal peptide, an acidic peptide, and a mature peptide of vespakinin M. This is the first kininogen from insects; it is also the first kininogen from invertebrates. The cDNA structure encoding vespakinin M suggests that the generation mode of bradykinin-related peptides in wasp is different from amphibian skin and mammalian blood system.