Blockade of endoplasmic reticulum stress-induced cell death by Ureaplasma parvum vacuolating factor

Identification of an endonuclease and N6-adenine methyltransferase from Ureaplasma parvum SV3F4 strain

Here, we report a novel endonuclease and N6-adenine DNA methyltransferase (m6A methyltransferase) in the Ureaplasma parvum SV3F4 strain. Our previous study found that the SV3F4 strain carries 17 unique genes, which are not encoded in the two previously reported U. parvum serovar 3 strain, OMC-P162 and ATCC 700970. Of these 17 unique genes, UP3_c0261 and UP3_c0262, were originally annotated as encoding hypothetical proteins. Comparative genomics analyses more recently indicated they encode a Type II restriction endonuclease and an m6A methyltransferase, respectively. The UP3_c0261 and UP3_c0262 genes were individually expressed and purified in Escherichia coli. The UP3_c0261 recombinant protein showed endonuclease activity on the pT7Blue vector, recognizing and cleaving a GTNAC motif, resulting in a 5 base 5' extension. The UP3_c0261 protein digested a polymerase chain reaction (PCR) product harboring the GTNAC motif. The endonuclease UP3_c0261 was designated as UpaF4I. Treatment of the PCR product with the recombinant protein UP3_c0262 completely blocked the restriction enzyme activity of UpaF4I. Analysis of the treated PCR product harboring a modified nucleotide by UP3_c0262 with HPLC-MS/MS and MS/MS showed that UP3_c0262 was an m6A methyltransferase containing a methylated A residue in both DNA strands of the GTNAC motif. Whole genome methylation analysis of SV3F4 showed that 99.9 % of the GTNAC motif was m6A modified. These results suggest the UP3_c0261 and UP3_c0262 genes may act as a novel Type II restriction-modification system in the Ureaplasma SV3F4 strain.

Ureaplasma infections: update on epidemiology, antimicrobial resistance, and pathogenesis

Human Ureaplasma species are being increasingly recognized as opportunistic pathogens in human genitourinary tract infections, infertility, adverse pregnancy, neonatal morbidities, and other adult invasive infections. Although some general reviews have focused on the detection and clinical manifestations of Ureaplasma spp., the molecular epidemiology, antimicrobial resistance, and pathogenesis of Ureaplasma spp. have not been adequately explained. The purpose of this review is to offer valuable insights into the current understanding and future research perspectives of the molecular epidemiology, antimicrobial resistance, and pathogenesis of human Ureaplasma infections. This review summarizes the conventional culture and detection methods and the latest molecular identification technologies for Ureaplasma spp. We also reviewed the global prevalence and mechanisms of antibiotic resistance for Ureaplasma spp. Aside from regular antibiotics, novel antibiotics with outstanding in vitro antimicrobial activity against Ureaplasma spp. are described. Furthermore, we discussed the pathogenic mechanisms of Ureaplasma spp., including adhesion, proinflammatory effects, cytotoxicity, and immune escape effects, from the perspectives of pathology, related molecules, and genetics.

Minimal Bacterial Cell JCVI-syn3B as a Chassis to Investigate Interactions between Bacteria and Mammalian Cells

Mycoplasmas are atypical bacteria with small genomes that necessitate colonization of their respective animal or plant hosts as obligate parasites, whether as pathogens, or commensals. Some can grow axenically in specialized complex media yet show only host-cell-dependent growth in cell culture, where they can survive chronically and often through interactions involving surface colonization or internalization. To develop a mycoplasma-based system to identify genes mediating such interactions, we exploited genetically tractable strains of the goat pathogen Mycoplasma mycoides (Mmc) with synthetic designer genomes representing the complete natural organism (minus virulence factors; JCVI-syn1.0) or its reduced counterpart (JCVI-syn3B) containing only those genes supporting axenic growth. By measuring growth of surviving organisms, physical association with cultured human cells (HEK-293T, HeLa), and induction of phagocytosis by human myeloid cells (dHL-60), we determined that JCVI-syn1.0 contained a set of eight genes (MMSYN1-0179 to MMSYN1-0186, dispensable for axenic growth) conferring survival, attachment, and phagocytosis phenotypes. JCVI-syn3B lacked these phenotypes, but insertion of these genes restored cell attachment and phagocytosis, although not survival. These results indicate that JCVI-syn3B may be a powerful living platform to analyze the role of specific gene sets, from any organism, on the interaction with diverse mammalian cells in culture.

HPV-associated cervicovaginal microbiome and host metabolome characteristics

BACKGROUND

Cervicovaginal microbiome plays an important role in the persistence of HPV infection and subsequent disease development. However, cervicovaginal microbiota varied cross populations with different habits and regions. Identification of population-specific biomarkers from cervicovaginal microbiota and host metabolome axis may support early detection or surveillance of HPV-induced cervical disease at all sites. Therefore, in the present study, to identify HPV-specific biomarkers, cervicovaginal secretion and serum samples from HPV-infected patients (HPV group, n = 25) and normal controls (normal group, n = 17) in Xichang, China were collected for microbiome (16S rRNA gene sequencing) and metabolome (UHPLC-MS/MS) analysis, respectively.

RESULTS

The results showed that key altered metabolites of 9,10-DiHOME, α-linolenic acid, ethylparaben, glycocholic acid, pipecolic acid, and 9,12,13-trihydroxy-10(E),15(Z)-octadecadienoic acid, correlating with Sneathia (Sneathia_amnii), Lactobacillus (Lactobacillus_iners), Atopobium, Mycoplasma, and Gardnerella, may be potential biomarkers of HPV infection.

CONCLUSION

The results of current study would help to reveal the association of changes in cervicovaginal microbiota and serum metabolome with HPV infections.

Reduction-to-synthesis: the dominant approach to genome-scale synthetic biology

Advances in systems and synthetic biology have propelled the construction of reduced bacterial genomes. Genome reduction was initially focused on exploring properties of minimal genomes, but more recently it has been deployed as an engineering strategy to enhance strain performance. This review provides the latest updates on reduced genomes, focusing on dual-track approaches of top-down reduction and bottom-up synthesis for their construction. Using cases from studies that are based on established industrial workhorse strains, we discuss the construction of a series of synthetic phenotypes that are candidates for biotechnological applications. Finally, we address the possible uses of reduced genomes for biotechnological applications and the needed future research directions that may ultimately lead to the total synthesis of rationally designed genomes.

Effects of Ureaplasma parvum infection in the exosome biogenesis-related proteins in ectocervical epithelial cells

Ureaplasma parvum is a mycoplasma commonly associated with female reproductive pathologies, such as preterm birth and infertility. It can survive intracellularly and utilize exosomes to propagate infection and its virulence factors. This study explored the differential protein composition of exosomes derived from normal and U. parvum-infected cells. We also investigated the impact of U. parvum on exosome biogenesis in ectocervical epithelial cells. Ectocervical epithelial (ECTO) cells were infected with U. parvum, and immunocytochemical staining was performed using U. parvum-specific marker multiple banded antigen (mba) and exosome marker CD9. NanoLC-MS/MS analysis was conducted to identify differentially expressed proteins in exosomes. Ingenuity Pathway Analysis (IPA) was performed to identify affected canonical pathways and biological functions associated with the protein cargo of exosomes. Western blot analysis of ECTO cells validated the proteomic findings in ECTO cells. U. parvum exhibited colonization of ECTO cells and colocalization with CD9-positive intraluminal vesicles. Proteomic analysis revealed decreased protein abundance and distinct protein profiles in exosomes derived from U. parvum-infected ECTO cells. Differentially expressed proteins were associated with clathrin-mediated endocytosis and various signaling pathways indicative of infection, inflammation, and cell death processes. Additionally, U. parvum infection altered proteins involved in exosome biogenesis. In ECTO cells, U. parvum infection significantly decreased clathrin, ALIX, CD9, and CD63 and significantly increased TSG101, Rab5, Rab35, and UGCG. These findings contribute to our understanding of the infection mechanism and shed light on the importance of exosome-mediated communication in the pathophysiology of diseases affecting the cervix, such as cervicitis and preterm birth.

Research progress on the GRP78 gene in the diagnosis, treatment and immunity of cervical cancer

BACKGROUND

GRP78 is a molecular chaperone protein in the endoplasmic reticulum that is involved in protein assembly and quality control, and it participates in ER stress regulation of endoplasmic reticulum stress pathways. Studies have confirmed that GRP78 gene is highly expressed in a variety of tumors and is involved in different biological functions.

PURPOSE

The present review highlights the involvement of the GRP78 gene in regulating the development of cervical cancer by promoting the proliferation and invasion of cervical cancer cells as well as by inhibiting apoptosis and promoting the Warburg effect. High expression of GRP78 is positively correlated with chemotherapy resistance in cervical cancer. GRP78 plays an anticancer role in cervical cancer by regulating autophagy and apoptosis. Mediated immune CD8 + T cells regulate tumor cell immunity and play a role in the application of the HPV vaccine.

CONCLUSIONS

GRP78 plays a multifunctional role in cervical cancer and has important therapeutic and diagnostic value.

Small molecule '4ab' induced autophagy and endoplasmic reticulum stress-mediated death of aggressive cancer cells grown under adherent and floating conditions

Metastasis is the leading cause of death in cancer patients and a major challenging aspect of cancer biology. Various adaptive molecular signaling pathways play a crucial role in cancer metastasis and later in the formation of secondary tumors. Aggressive cancer cells like triple negative breast cancer (TNBCs) are more inclined to undergo metastasis hence having a high recurrence rate and potential of micro-metastasis. Tumor cells in circulation known as circulating tumor cells (CTCs) offer an attractive drug target to treat metastatic disease. Cell cycle regulation and stress response of CTCs in blood has a crucial role in their survival and progression and thus may be considered therapeutically active hotspots. The cyclin D/cyclin-dependent kinase (CDK) pathway regulates cell cycle checkpoints, a process that is frequently dysregulated in cancer cells. Selective CDK inhibitors can limit the phosphorylation of cell cycle regulatory proteins by inducing cell cycle phase arrest, and thus may be an effective therapeutic strategy for aggressive cancer cells in their dividing phase at the primary or secondary site. However, during the floating condition, cancer cells halt their multiplication process and proceed through the various steps of metastasis. Current study showed that a novel CDK inhibitor 4ab induced autophagy and endoplasmic reticulum (ER) stress in agressive cancer cells grown under adherent and floating conditions resulting in paraptosis. Further, our results showed that 4ab efficiently induced cell death in aggressive cancer cells through ER stress-mediated activation of JNK signaling. Additionally, was observed that treatment of 4ab in tumor-bearing mice displayed a significant reduction in tumor burden and micro-metastasis. The outcome of these studies showed that 4ab can be a potential anti-tumor and anti-metastatic agent. Graphical representation of 4ab: image representing the effect of 4ab on death-inducing pathways in aggressive cancer cells. 4ab induces ER stress and activates autophagy leading to vacuolation of there by causing apoptosis in aggressive cancer cells.

Reconstitution of a minimal motility system based on Spiroplasma swimming by two bacterial actins in a synthetic minimal bacterium

Motility is one of the most important features of life, but its evolutionary origin remains unknown. In this study, we focused on Spiroplasma, commensal, or parasitic bacteria. They swim by switching the helicity of a ribbon-like cytoskeleton that comprises six proteins, each of which evolved from a nucleosidase and bacterial actin called MreB. We expressed these proteins in a synthetic, nonmotile minimal bacterium, JCVI-syn3B, whose reduced genome was computer-designed and chemically synthesized. The synthetic bacterium exhibited swimming motility with features characteristic of Spiroplasma swimming. Moreover, combinations of Spiroplasma MreB4-MreB5 and MreB1-MreB5 produced a helical cell shape and swimming. These results suggest that the swimming originated from the differentiation and coupling of bacterial actins, and we obtained a minimal system for motility of the synthetic bacterium.

Cellular mechanics during division of a genomically minimal cell

Genomically minimal cells, such as JCVI-syn3.0 and JCVI-syn3A, offer an empowering framework to study relationships between genotype and phenotype. With a polygenic basis, the fundamental physiological process of cell division depends on multiple genes of known and unknown function in JCVI-syn3A. A physical description of cellular mechanics can further understanding of the contributions of genes to cell division in this genomically minimal context. We review current knowledge on genes in JCVI-syn3A contributing to two physical parameters relevant to cell division, namely, the surface-area-to-volume ratio and membrane curvature. This physical view of JCVI-syn3A may inform the attribution of gene functions and conserved processes in bacterial physiology, as well as whole-cell models and the engineering of synthetic cells.

Differences in the characteristics and pulmonary toxicity of nano- and micron-sized respirable coal dust

BACKGROUND

The characteristics of coal dust (CD) particles affect the inhalation of CD, which causes coal worker's pneumoconiosis (CWP). CD nanoparticles (CD-NPs, < 500 nm) and micron particles (CD-MPs, < 5 μm) are components of the respirable CD. However, the differences in physicochemical properties and pulmonary toxicity between CD-NPs and CD-MPs remain unclear.

METHODS

CD was analyzed by scanning electron microscopy, Malvern nanoparticle size potentiometer, energy dispersive spectroscopy, infrared spectroscopy, and electron paramagnetic resonance spectroscopy. CCK-8 assay, ELISA, transmission electron microscope, JC-1 staining, reactive oxygen species activity probe, calcium ion fluorescent probe, AO/EB staining, flow cytometry, and western blot were used to determine the differences between CD-NPs and CD-MPs on acute pulmonary toxicity. CCK-8, scratch healing and Transwell assay, hematoxylin-eosin and Masson staining, immunohistochemistry, immunofluorescence, and western blot were applied to examine the effects of CD-NPs and CD-MPs on pneumoconiosis.

RESULTS

Analysis of the size distribution of CD revealed that the samples had been size segregated. The carbon content of CD-NPs was greater than that of CD-MPs, and the oxygen, aluminum, and silicon contents were less. In in vitro experiments with A549 and BEAS-2B cells, CD-NPs, compared with CD-MPs, had more inflammatory vacuoles, release of pro-inflammatory cytokines (IL-6, IL-1β, TNFα) and profibrotic cytokines (CXCL2, TGFβ1), mitochondrial damage (reactive oxygen species and Ca2+ levels and decreased mitochondrial membrane potential), and cell death (apoptosis, pyroptosis, and necrosis). CD-NPs-induced fibrosis model cells had stronger proliferation, migration, and invasion than did CD-MPs. In in vivo experiments, lung coefficient, alveolar inflammation score, and lung tissue fibrosis score (mean: 1.1%, 1.33, 1.33) of CD-NPs were higher than those of CD-MPs (mean: 1.3%, 2.67, 2.67). CD-NPs accelerated the progression of pulmonary fibrosis by upregulating the expression of pro-fibrotic proteins and promoting epithelial-mesenchymal transition. The regulatory molecules involved were E-cadherin, N-cadherin, COL-1, COL-3, ZO-1, ZEB1, Slug, α-SMA, TGFβ1, and Vimentin.

CONCLUSIONS

Stimulation with CD-NPs resulted in more pronounced acute and chronic lung toxicity than did stimulation with CD-MPs. These effects included acute inflammatory response, mitochondrial damage, pyroptosis, and necrosis, and more pulmonary fibrosis induced by epithelial-mesenchymal transition.