Change in localization of alkaline phosphatase and mannosidase II by colchicine treatment of primary cultures of fetal rat hepatocytes

Lymphangiogenesis in Odontogenic Keratocysts Compared with Dentigerous Cysts

Statment of the Problem

Podoplanin can indicate the lymphangiogenesis. On the other hand, lymphangiogenesis affects the biological behavior of lesions. The clinical behavior of odontogenic keratocysts (OKC) and dentigerous cysts (DC) is different.

Purpose

This study aimed to evaluate the immunohistochemical expression of podoplanin and to investigate lymphangiogenesis in OKCs as compared to DCs.

Materials and Method

In this experimental laboratory study, sixty paraffined blocks, including 30 OKC and 30 DC samples, were examined in this study, all of which were histopathologically non-inflamed. To evaluate lymphangiogenesis, the immunohistochemical reaction of D2-40 was evaluated via cytoplasmic and membrane staining of lymphatic endothelial cells. The expression of podoplanin in the epithelial cells of two cyst groups was also examined. To analyze the collected data and compare the results between the two groups of cysts, independent samples t-test, Mann-Whitney U test, and Chi-square test were performed in SPSS version 22. The significance level was set at 0.05.

Results

The mean lymph node count and podoplanin expression were significantly higher in the OKC epithelium as compared to DC (p< 0.001). Based on the results, 90% of OKC samples and 43.3% of DC samples showed grade 3 staining.

Conclusion

The rate of lymphangiogenesis and podoplanin expression in the epithelium were higher in OKCs compared to DCs. According to the results, the expression of podoplanin may be a useful marker for determining the invasiveness and proliferation of OKC.

Long-term cell fate and functional maintenance of human hepatocyte through stepwise culture configuration

Human hepatocyte culture system represents by far the most physiologically relevant model for our understanding of liver biology and diseases; however, its versatility has been limited due to the rapid and progressive loss of genuine characteristics, indicating the inadequacy of in vitro milieu for fate maintenance. This study, therefore, is designed to define environmental requirements necessary to sustain the homeostasis of terminally differentiated hepatocytes. Our study reveals that the supplementation of dimethyl sulfoxide (DMSO) is indispensable in mitigating fate deterioration and promoting adaptation to the in vitro environment, resulting in the restoration of tight cell-cell contact, cellular architecture, and polarity. The morphological recovery was overall accompanied by the restoration of hepatocyte marker gene expression, highlighting the interdependence between the cellular architecture and the maintenance of cell fate. However, beyond the recovery phase culture, DMSO supplementation is deemed detrimental due to the potent inhibitory effect on a multitude of hepatocyte functionalities while its withdrawal results in the loss of cell fate. In search of DMSO substitute, our screening of organic substances led to the identification of dimethyl sulfone (DMSO2), which supports the long-term maintenance of proper morphology, marker gene expression, and hepatocytic functions. Moreover, hepatocytes maintained DMSO2 exhibited clinically relevant toxicity in response to prolonged exposure to xenobiotics as well as alcohol. These observations suggest that the stepwise culture configuration consisting of the consecutive supplementation of DMSO and DMSO2 confers the microenvironment essential for the fate and functional maintenance of terminally differentiated human hepatocytes.

Localization of Alkaline Phosphatase and Cathepsin D during Cell Restoration after Colchicine Treatment in Primary Cultures of Fetal Rat Hepatocytes

Localization of alkaline phosphatase (ALP) and cathepsin D (CAPD) in primary cultures of fetal rat hepatocytes was examined using double immunofluorescent staining in order to investigate the relationship between lysosome movement and the fate of ALP during cell restoration after microtubule disruption by colchicine. At 3 hr and 24 hr after colchicine treatment, numerous coarse dots containing ALP were observed throughout the cytoplasm, and some of these showed colocalization with CAPD. At 48 hr and 72 hr after colchicine treatment, although most of the dots containing ALP in the cytoplasm disappeared, dots containing CAPD remained. The present results suggest that the denatured ALP proteins remaining in the cytoplasm of hepatocytes during cell restoration after colchicine treatment are digested by lysosomes.

Effects of colchicine on localization of alkaline phosphatase in McA-RH 7777 rat hepatoma cells

We investigated the changes caused by microtubule disruption in cell contact-induced translocation of alkaline phosphatase (ALP) from the Golgi area to the plasma membrane in McA-RH 7777 cells. When the cells were treated with colchicine, the tubular structure of microtubules in the cytoplasm was lost. Colchicine treatment also resulted in the appearance of numerous dots containing mannosidase II (man II) throughout the cytoplasm. Moreover, ALP was distributed in small dots throughout the cytoplasm, as well as in all regions of the plasma membrane, although it was most concentrated at sites of intercellular contact. On the other hand, when the cells were incubated in basal medium after colchicine treatment, large spots containing ALP reappeared in the perinuclear cytoplasm more quickly than the accumulation of small dots containing man II. These findings suggest that colchicine causes disassembly of the Golgi complex into fragments, which scatter throughout the cytoplasm, but that it does not interfere with translocation of ALP to the plasma membrane. Furthermore, cytoplasmic ALP may be localized at sites other than the Golgi complex.