Ovarian Estrogen Synthesis Reduced by Peritoneal Endometriosis in Rat Autologous Transplantation Model

OBJECTIVE: To investigate the effects of peritoneal endometriosis on rat ovaries. METHODS: A rat model of peritoneal endometriosis was established by autologous transplantation. qPCR was performed to measure mRNA levels of steroid hormone and steroid synthesis-related genes in the ovaries of endometriosis rats. Immunohistochemistry was performed to characterize the distribution of FSHR in the ovaries of endometriosis rats. RNAseq was performed to find pathological changes in the ovaries of endometriosis rats. RESULTS: By qPCR, it was revealed that mRNA levels of steroid hormone synthesis-related genes were decreased in the ovaries of rats with endometriosis; With IHC, observed that FSHR expression was significantly decreased in the antral follicles of rats with endometriosis. RNAseq revealed that endometriosis affected transcription of the genes related to the microtubule structure and tight junctions of rat ovarian cells. CONCLUSION: Peritoneal endometriosis decreased the genic expression of ovarian steroid hormone synthetases and FSHR protein level in granulosa cells of antral follicles, and reduced the mRNA levels of the microtubule structure and tight junctions in rat ovarian cells, which contribute to the impairment of ovarian function.

Modeling of Microtubule Structure and Dynamics: Concepts and Mechanism of Reactions Inside a Microtubule

Via docking energy and interactions inside microtubules, TXL and stathmin molecules have been studied, and it has been shown that better binding capabilities in TXL are related to the environment of neighbor amino acids compared to other toxoids. Molecular dynamics simulation of the best-docked complexes of several ligands has been done for presenting the new concepts and mechanism of reactions inside a microtubule complex

Microtubular structure impairment after GSM-modulated RF radiation exposure

The objective of the study was to investigate whether low-level 915 MHz GSM-modulated radiofrequency (RF) radiation impairs microtubular structure and affects normal cell growth. V79 cells were exposed to a GSM-modulated field in a Gigahertz Transversal Electromagnetic Mode cell (GTEM cell) for 1, 2, and 3 h. Signal generator combined with power and chip modulator generated the electromagnetic field (EMF). The electric field strength was adjusted to 10, 20, and 30 V/m, and the average specific absorption rate (SAR) was calculated to be 0.23, 0.8, and 1.6 W/kg. The structure of microtubule proteins was assessed by indirect immunocytochemistry, and cell growth was determined based on cell counts taken every day over six post-exposure days. Three-hour radiation exposure significantly altered microtubule structure regardless of the electric field strength. Moreover, on the third post-exposure day, three-hour radiation significantly reduced cell growth, regardless of field strength. The same was observed with two-hour exposure at 20 and 30 V/m. In conclusion, 915 MHz GSM-modulated RF radiation affects microtubular proteins in a time-dependent manner, which, in turn, affects cell proliferation. Our future research will focus on microtubule structure throughout the cell cycle and RF radiation effects on mitotic spindle.

Expansion Microscopy provides new insights into the cytoskeleton of malaria parasites including the conservation of a conoid

Malaria is caused by unicellular Plasmodium parasites. Plasmodium relies on diverse microtubule cytoskeletal structures for its reproduction, multiplication or dissemination. Due to the small size of this parasite, its cytoskeleton has been primarily observable by electron microscopy. Here, we demonstrate that the nanoscale cytoskeleton organization is within reach using ultrastructure expansion microscopy (U-ExM). In developing microgametocytes, U-ExM allows to monitor the dynamic assembly of axonemes and concomitant tubulin polyglutamylation in whole cells. In the invasive merozoite and ookinete forms, U-ExM unveils the subpellicular microtubule arrays that confer cell rigidity. In ookinete, we additionally identify an apical tubulin ring above the subpellicular microtubules that colocalises with markers of the conoid in related Apicomplexa parasites. This microtubule structure was presumed to be lost in Plasmodium despite its crucial role in both motility and invasion in most apicomplexans. Here, U-ExM reveals that a divergent and reduced form of the conoid is actually conserved in the Plasmodium genus.

Functional role of increased acetylated tubulin in porcine oocyte microtubule structure, meiotic maturation and embryogenesis

Acetylated microtubule improves porcine oocyte microtubule structure, meiotic maturation and subsequent embryonic development. HDAC6 can specifically deacetylate α-tubulin in assembled microtubules, increased acetylated microtubule treatment with tubacin, a HDAC6-selective inhibitor, is beneficial for porcine oocytes maturation and early embryogenesis. Here it is shown that α-tubulin acetylation gradually decreased from MI to IVF pronuclear stage. The increased acetylation of α-tubulin significantly reduced the abnormal rate of microtubules, furthermore, the proportion of mitochondria in the vicinity of IVF nucleus was significantly enhanced in MI and MII stages. The expression levels of microtubule assembly genes ( TUBA1A , α TAT1 and MAP2 ) significantly up-regulated in MI and MII stages. In addition, the oocytes with high acetylation level of α-tubulin significantly improved maturation, syngamy and IVF blastocyst formation compared with the control oocytes. In present study, these indicate functional role of increased acetylated α-tubulin advances normal spindle formation and mitochondrial concentration, moreover, improves porcine maturation, syngamy and preimplantation embryo development.

Microtubule destabilization caused by silicate via HDAC6 activation contributes to autophagic dysfunction in bone mesenchymal stem cells

Background Silicon-modified biomaterials have been extensively studied in bone tissue engineering. In recent years, the toxicity of silicon-doped biomaterials has gradually attracted attention but requires further elucidation. This study was designed to explore whether high-dose silicate can induce a cytotoxicity effect in bone mesenchymal stem cells (BMSCs) and the role of autophagy in its cytotoxicity and mechanism. Methods Morphologic changes and cell viability of BMSCs were detected after different doses of silicate exposure. Autophagic proteins (LC3, p62), LC3 turnover assay, and RFP-GFP-LC3 assay were applied to detect the changes of autophagic flux following silicate treatment. Furthermore, to identify the potential mechanism of autophagic dysfunction, we tested the acetyl-α-tubulin protein level and histone deacetylase 6 (HDAC6) activity after high-dose silicate exposure as well as the changes in microtubule and autophagic activity after HDAC6 siRNA was applied. Results It was found that a high dose of silicate could induce a decrease in cell viability; LC3-II and p62 simultaneously increased after high-dose silicate exposure. A high concentration of silicate could induce autophagic dysfunction and cause autophagosomes to accumulate via microtubule destabilization. Results showed that acetyl-α-tubulin decreased significantly with high-dose silicate treatment, and inhibition of HDAC6 activity can restore microtubule structure and autophagic flux. Conclusions Microtubule destabilization caused by a high concentration of silicate via HDAC6 activation contributed to autophagic dysfunction in BMSCs, and inhibition of HDAC6 exerted a cytoprotection effect through restoration of the microtubule structure and autophagic flux.

In situ cryo-electron tomography reveals filamentous actin within the microtubule lumen

Microtubules and filamentous (F-) actin engage in complex interactions to drive many cellular processes from subcellular organisation to cell division and migration. This is thought to be largely controlled by proteins that interface between the two structurally distinct cytoskeletal components. Here, we use cryo-electron tomography to demonstrate that the microtubule lumen can be occupied by extended segments of F-actin in small-molecule induced, microtubule-based cellular projections. We uncover an unexpected versatility in cytoskeletal form that may prompt a significant development of our current models of cellular architecture and offer a new experimental approach for the in-situ study of microtubule structure and contents.

Pathogenic Tau Protein Species: Promising Therapeutic Targets for Ocular Neurodegenerative Diseases

Tau is a microtubule-associated protein, which is highly expressed in the central nervous system as well as ocular neurons and stabilizes microtubule structure. It is a phospho-protein being moderately phosphorylated under physiological conditions but its abnormal hyperphosphorylation or some post-phosphorylation modifications would result in a pathogenic condition, microtubule dissociation, and aggregation. The aggregates can induce neuroinflammation and trigger some pathogenic cascades, leading to neurodegeneration. Taking these together, targeting pathogenic tau employing tau immunotherapy may be a promising therapeutic strategy in fighting with cerebral and ocular neurodegenerative disorders.