S-Protein of the Probiotic Strain Lactobacillus crispatus 2029 Prevents the Growth of Permeability of the Caco-2 Monolayer of Human Enterocytes Induced by Intestinal Infections

The use of a biomodel of the confluent monolayer Caco-2 of enterocytes allowed us to reveal the ability of the S-protein isolated from strain LC2029 to prevent permeability disorders resulting from intestinal infections induced by pathogens (E. coli O157: H7, C. jejuni ATCC 33291, S. enteritidis ATCC 25928). This is important for maintaining the efficiency of the intestinal barrier.

Ultraviolet-A light increases mitochondrial anti-viral signaling protein in confluent human tracheal cells even at a distance from the light source

Mitochondrial antiviral signaling (MAVS) protein mediates innate antiviral responses, including responses to certain coronaviruses such as severe acute respiratory syndrome coronavirus-2 ( SARS-CoV-2 ). We have previously shown that ultraviolet-A (UVA) therapy can prevent virus-induced cell death in human ciliated tracheal epithelial cells (HTEpC) infected with coronavirus-229E, and that UVA treatment results in an increase in intracellular levels of MAVS. In this study, we set out to determine the mechanisms by which UVA light can activate MAVS, and whether local UVA light application can activate MAVS at locations distant from the light source (such as via cell-to-cell communication). MAVS levels were compared in HTEpC exposed to 2 mW/cm 2 narrow band (NB)-UVA for 20 minutes and in unexposed controls, at 30-40% and at 100% confluency. MAVS levels were also compared in unexposed HTEpC treated with supernatants or lysates from UVA-exposed cells or from unexposed controls. Also, MAVS was assessed in different sections of confluent monolayer plates where only one section was exposed to NB-UVA. The results show that UVA increases the expression of MAVS protein. Cells in a confluent monolayer exposed to UVA were able to confer an elevation in MAVS in cells adjacent to the exposed section, and even cells in the most distant sections not exposed to UVA. In this study, human ciliated tracheal epithelial cells exposed to UVA demonstrate increased MAVS protein, and also appear to transmit this influence to distant confluent cells not exposed to light.

Unusual characteristics of opaque Ishikawa endometrial cells include the envelopment of chromosomes with material containing endogenous biotin in the latter stages of cytokinesis

We have identified a small dynamic population of opaque cells in Ishikawa endometrial cultures whose unusual characteristics include the fact that chromosomes become enveloped during the final stages of cytokinesis by material staining for endogenous biotin. Endogenous biotin, ultimately shown to be due to mitochondrial carboxylases, was detected in a membrane that wraps around aggregated nuclei in syncytia that develop as part of the differentiation of domes in Ishikawa cells. (Fleming H et al. 1998). The “wrapped chromosomes” in individual opaque Ishikawa cells stain similarly suggesting a similar origin. We were able to show that opaque cells form from transparent monolayer cells, can be polyploid, and often appear to be detaching from the colony and from the underlying substrate. We were also able to show an opaque cell fissioning asymmetrically, to give rise to a monolayer cell whose nucleus appeared to be wrapped. We believe that the cycle of differentiation of monolayer cells into opaque, polyploid cells and depolyploidization back into monolayer cells is involved in the spatial extension of cells as they develop from discrete colonies into a confluent monolayer. Wrapping of chromosomes may ensure that complete genomes are inherited by daughter cells during depolyploidization.

Unusual characteristics of opaque Ishikawa endometrial cells include the envelopment of chromosomes with material containing endogenous biotin in the latter stages of cytokinesis

We have identified a small dynamic population of opaque cells in Ishikawa endometrial cultures whose unusual characteristics include the fact that chromosomes become enveloped during the final stages of cytokinesis by material staining for endogenous biotin. Endogenous biotin, ultimately shown to be due to mitochondrial carboxylases, was detected in a membrane that wraps around aggregated nuclei in syncytia that develop as part of the differentiation of domes in Ishikawa cells. (Fleming H et al. 1998). The “wrapped chromosomes” in individual opaque Ishikawa cells stain similarly suggesting a similar origin. We were able to show that opaque cells form from transparent monolayer cells, can be polyploid, and often appear to be detaching from the colony and from the underlying substrate. We were also able to show an opaque cell fissioning asymmetrically, to give rise to a monolayer cell whose nucleus appeared to be wrapped. We believe that the cycle of differentiation of monolayer cells into opaque, polyploid cells and depolyploidization back into monolayer cells is involved in the spatial extension of cells as they develop from discrete colonies into a confluent monolayer. Wrapping of chromosomes may ensure that complete genomes are inherited by daughter cells during depolyploidization.