Although bulk endocytosis has been found in a number of neuronal and endocrine cells, the molecular mechanism and physiological function of bulk endocytosis remain elusive. In pancreatic beta cells, we have observed bulk-like endocytosis evoked both by flash photolysis and trains of depolarization. Bulk-like endocytosis is a clathrin-independent process that is facilitated by enhanced extracellular Ca(2+) entry and suppressed by the inhibition of dynamin function. Moreover, defects in bulk-like endocytosis are accompanied by hyperinsulinemia in primary beta cells dissociated from diabetic KKAy mice, which suggests that bulk-like endocytosis plays an important role in maintaining the exo-endocytosis balance and beta cell secretory capability.
Animals ; Calcium ; metabolism ; Cytoplasmic Granules ; metabolism ; Diabetes Mellitus ; metabolism ; pathology ; Disease Models, Animal ; Dynamins ; metabolism ; Electric Capacitance ; Endocytosis ; physiology ; Insulin ; metabolism ; Insulin-Secreting Cells ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Patch-Clamp Techniques ; Photolysis ; Primary Cell Culture

Caenorhabditis elegans hid-1 gene was first identified in a screen for mutants with a high-temperature-induced dauer formation (Hid) phenotype. Despite the fact that the hid-1 gene encodes a novel protein (HID-1) which is highly conserved from Caenorhabditis elegans to mammals, the domain structure, subcellular localization, and exact function of HID-1 remain unknown. Previous studies and various bioinformatic softwares predicted that HID-1 contained many transmembrane domains but no known functional domain. In this study, we revealed that mammalian HID-1 localized to the medial- and trans- Golgi apparatus as well as the cytosol, and the localization was sensitive to brefeldin A treatment. Next, we demonstrated that HID-1 was a peripheral membrane protein and dynamically shuttled between the Golgi apparatus and the cytosol. Finally, we verified that a conserved N-terminal myristoylation site was required for HID-1 binding to the Golgi apparatus. We propose that HID-1 is probably involved in the intracellular trafficking within the Golgi region.
Animals ; Brefeldin A ; pharmacology ; Cell Line, Tumor ; Cytosol ; drug effects ; metabolism ; Humans ; Intracellular Space ; drug effects ; metabolism ; Membrane Proteins ; metabolism ; Protein Transport ; drug effects ; Rats ; Vesicular Transport Proteins ; metabolism ; trans-Golgi Network ; drug effects ; metabolism

Objective:To investigate the clinicopathological features, immunohistochemical phenotypes and molecular characteristics of adenosquamous carcinoma of the lung(ASC)in elderly patients.Methods:Clinical data of 72 ASC patients in the Department of Pathology, The Second Affiliated Hospital of Soochow University from January 2009 to December 2020 were retrospectively analyzed, and 48 patients aged ≥60 years were selected.Clinical manifestations, imaging findings, histopathological and immunohistochemical characteristics were collected, and gene mutations were detected by the amplification refractory mutation system(ARMS-PCR).Results:There were 48 patients including 32 males and 16 females with a mean age of 70 years(range: 60-84 years). The maximum diameters of the tumors ranged from 0.3 to 9.0 cm(mean: 2.8 cm). Microscopically, the tumors contained two components, squamous cell carcinoma and adenocarcinoma, with the squamous cell carcinoma tissue showing intercellular bridges and the adenocarcinoma tissue showing papillary, acinar or tubular structures.Immunohistochemistry assays detected varying expression levels of CK7(30/31), CK5/6(20/28), TTF1(12/31), P40(15/17), and P63(12/13). Molecular testing showed that the EGFR mutation rate was 58.8%(10/17)and the ALK fusion mutation rate was 5.9%(1/17), while ROS1 and MET mutations were not detected.All 48 patients underwent surgical resection.Conclusions:ASC cases are relatively rare and prone to misdiagnosis.The diagnosis requires the combination of HE morphology, immunohistochemistry and imaging examination, and surgery is the main treatment option.The mutation rate of the EGFR gene is relatively high in ASC patients.

OBJECTIVE To investigate the inhibitory effect of berberine （BER） on the invasion and migration of human renal carcinoma cells and its potential mechanism. METHODS Using human renal carcinoma OSRC-2 cell as object， alamarBlue assay was adopted to detect the inhibitory effects of 0 （control group）， 25， 50， 75， 100， 125， 150， 175 and 200 μmol/L BER on the proliferation of OSRC-2 cell after treatment for 24 h and 48 h. After treated with 0（control group）， 50， 100 μmol/L BER for 48 h， the effect of BER on cell cycle was analyzed by flow cytometry. The migration of OSRC-2 cells in 24 h and 36 h was observed by cell scratch test， and the invasion ability of OSRC-2 cells in 24 h was detected by Transwell assay. The protein expression of methyltransferase-like 3 （METTL3） was detected by Western blot after treatment for 48 h， and RNA methylation quantification kit was used to detect the levels of N6-methyladenosine （m6A） in OSRC-2 cells. RESULTS Compared with control group， BER at different concentrations could significantly decrease the survival rate of OSRC-2 cells （P＜0.01）， and showed a dose-dependent and time-dependent manner. After 48 h of BER treatment at 50， 100 μmol/L， the cell was arrested in G0/G1 phase （P＜0.01）. Compared with control group， the migration and invasion abilities of cells in 50， 100 μmol/L BER group were significantly decreased （P＜0.05 or P＜0.01）； the protein expression of METTL3 and the level of m6A in RNA were significantly decreased （P＜0.01）. CONCLUSIONS BER can inhibit level of m6A by down-regulating the expression of METTL3， thereby inhibiting the invasion and metastasis of human renal carcinoma cells.

Cell Membrane ; metabolism ; Clathrin ; metabolism ; DNA-(Apurinic or Apyrimidinic Site) Lyase ; metabolism ; Endocytosis ; HeLa Cells ; Humans ; Interleukin-2 Receptor alpha Subunit ; metabolism