Search for a command to run...
Tau protein was initially described as a microtubule-associated protein, predominantly expressed in neurons, that facilitates microtubule assembly and stabilization within the neuronal cytoskeleton. Alterations in the phosphorylated state of tau, as well as other post-translational modifications could have pathological effects including its auto-aggregation, which characterizes a group of neurodegenerative diseases known as tauopathies. Even though tau is abundant in neurons, it is also present in peripheral tissue (kidney, testis and pancreas). However, the physiological mechanisms of tau in non-neuronal tissues, have received less attention. Here, we analyze the distribution and phosphorylations along tau protein in pancreatic tissue, an organ that plays an essential role in human metabolism. Human pancreas tissue samples were obtained from 5 patients with no neurodegenerative diseases. After a 7 days fixation in paraformaldehyde (4% in Phosphate Buffered Saline, PBS), several pancreas sections of 50 μm thick were cut and processed for double and triple immunofluorescence, which were performed using specific antibodies as follows: pT231/PHF1, MC1/pS262 and AT100/pS416/TG-3 in order to track tau phosphorylation. Lastly, the samples were observed through a confocal microscope. Immunohistochemical studies evidenced phosphorylated tau predominantly in the Langerhans islets cells cytoplasm. We observed with a diffuse granular appearance phosphorylated tau protein in S416 and S262. According to its distribution, we suggest phosphorylated tau corresponds to the beta cells of the pancreatic islets. With these findings we infer that phosphorylated tau protein, present in pancreatic islets, plays an important role in hormone vesicles motility. Hence, it is necessary to expand our knowledge about the specific function of tau in hormone excretion under physiological conditions and the relevance of its phosphorylation state. Authors want to express their gratitude to Dr. P. Davis (Albert Einstein College of Medicine, Bronx, NY, USA) for the generous gift of mAb (TG-3) and Tec. M. in C. Ivan J. Galván-Mendoza for his support in confocal microscopy LaNSE-CINVESTAV. We also want to express our gratitude to the Mexican families who donated the pancreatic tissue from their loved ones and made possible our research. This work is dedicated to the memory of Professor Dr. José Raúl Mena López.