Histochemistry and Cell Biology最新文献

Hematopoietic stem cells (HSCs) reside in a milieu that supports their functions, differentiation, and survival. This niche consists of several types of cells, including mesenchymal stem/stromal cells, endothelial cells, osteoblasts, megakaryocytes, macrophages, adipocytes, lymphoid cells, and nerve fibers. The interactions between these cells and HSCs have a role in HSC fate. Several studies have focused on identification of the biological and cellular mechanisms contributing to the establishment of this niche. However, the exact mechanisms of the interaction between HSCs and the bone marrow niche have not been elucidated yet. Unraveling these mechanisms would help in the design of effective methods for maintenance and multiplication of HSCs in clinical settings, in addition to establishment of novel therapies for hematopoietic diseases. The current review summarizes the effects of the niche cells on HSC function and underlying mechanisms of interplay between HSCs and their niche.

The damaged organ may experience severe pathological alterations as a result of tissue ischemia-reperfusion (I/R). The study of stem cell-based repair therapies is actively being conducted, and the outcomes and therapeutic potential of these cells are both promising. Autophagy checks protein homeostasis by breaking down huge damaged proteins or organelles. The study's objective was to assess how ADSCs impact the autophagic process after testicular ischemia/reperfusion. In our investigation, 30 male rats were divided into five groups: control, ADSC, ischemia, I/R, and I/R + ADSC (n = 6). Hematoxylin-eosin (HE) was used to stain the testes, and histological changes were assessed. The immunoexpression of androgen receptor (AR), Beclin1, protein light chain 3B (LC3B), and p62 were examined. The seminiferous epithelium in the testis from the ischemia and I/R groups revealed significant degeneration with disorganized morphology, damaged spermatogenic cells, and interstitial space congestion, according to HE stain results. Johnsen's score were significantly better in I/R + ADSC group than in ischemia and I/R groups. We demonstrated that in rat testes from the I/R groups, immunostaining of Beclin 1 (p = 0.042) and LC3B (p = 0.011) were raised, and p62 (p = 0.047) and AR (p = 0.049) were decreased. Ischemia and I/R promoted testicular autophagy, therefore we can conclude that ADSCs prevent excessive autophagy. Additionally, these results show that the use of ADSCs cures testicular injury and dysfunction associated with I/R injury in rats even a little.

Abstarct: Blood plasma therapy, a new treatment method to eliminate the damage and deterioration caused by aging in many organ systems, has attracted increasing attention. The digestive tract, which cooperates with many different systems, has strong effects on our health. In the present study, the effects of plasma therapy on the ileum of elderly rats were investigated. Wistar rats (n = 7; 12-15 months old) were given pooled plasma collected from middle-age rats (6 months, n =28) (for 30 days, 0.3 ml daily, intravenously into the tail vein). At the end of the experiment, villus height, crypt depth, total mucosal thickness and surface absorption area were evaluated. In addition, the effects of IgA, which plays a role in the digestive system's defense against microorganisms, were examined. Both the cell proliferation intensity and proliferation index were evaluated in crypt cells. An increase was determined in all morphological parameters in the experimental group. Similarly, plasma application decreased IgA expression and numbers in the experimental groups. Contrarily, cell proliferation parameters showed a significant increase in the experimental groups' crypt cells. Therefore, we found that the treatment supports the digestive system in terms of both nutrient utilization and absorption-related parameters and has a protective effect on intestinal immune system parameters.

The intercommunication between nerves and muscles plays an important role in the functioning of our body, and its failure leads to severe neuromuscular disorders such as spinal muscular atrophy and amyotrophic lateral sclerosis. Understanding the cellular and molecular mechanisms underlying nerve-muscle interactions and mediating their mutual influence is an integral part of strategies aimed at curing neuromuscular diseases. Here, we propose a novel ex vivo experimental model for the spinal cord (SC) and skeletal muscle interactions which for the first time utilizes only fully formed (but not yet quite functional) postnatal tissues. The model represents an organotypic co-culture comprising a longitudinal slice of the mouse postnatal SC and an extensor digitorum longus (EDL) muscle explant placed in the "damage zone" of transversally dissected longitudinal slice of the SC. Using this model, we have shown that SC tissue stimulates muscle contractions and reduces the area occupied by acetylcholine receptors on muscle surface. In turn, EDL muscles stimulate the growth of SC-derived neurites. Thus, our organotypic model allows one to assess the mutual influence of neurons and muscles in a nearly natural setting which maintains the architecture and cellular composition of intact tissues. Therefore, this model may provide an effective platform for studying molecular and cellular mechanisms linked to defective neuromuscular interactions in associated pathologies.

Understanding the osteochondral junction, where non-mineralised cartilage and mineralised bone converge, is crucial for joint health. Current sample preparation techniques are insufficient for detailed spatial hyperspectral imaging analysis. Using the enhanced Kawamoto method, we used the super cryo embedding medium's temperature-dependent properties to transfer high-quality tissue samples onto slides for spatial imaging analysis. We transferred osteochondral samples using a tape-free system and successfully tested them in hematoxylin and eosin (HE), Safranin-O, nanomechanical assessments and nano-Fourier transform infrared (FTIR) mapping. This protocol elucidates the structural and elemental gradients, mechanical characteristics and distinctive biochemical layering, making it a useful tool for analysing biochemical properties' co-distribution in healthy and diseased situations.

Isocitrate dehydrogenase 1 (IDH1) is a metabolic enzyme that converts isocitrate to α-ketoglutarate in cells. However, research on IDH1 is more focused on the metabolite D-2-hydroxyglutarate than the cellular roles of the IDH1 protein. Metabolic enzymes can moonlight by participating in diverse cellular processes in cancer cells. This moonlighting function of the metabolic enzymes can contribute to changes in gene expression. It is unknown whether IDH1 associates with any transcription factor. We asked whether IDH1 coordinates with forkhead box protein M1 (FOXM1) in mitotic cells to regulate late genes expression. We found that depletion of IDH1 reduces canonical FOXM1-target expression in mitotic cells. Also, IDH1 binds to FOXM1 and a subset of MuvB proteins, Lin-9 and Lin-54, in mitotic cells. Based on these observations, we suggest that IDH1 coordinates with FOXM1 in mitotic cells to regulate late genes expression.

Metabolic syndrome (MetS) is a condition that includes symptoms, such as obesity, hyperglycemia, and hypertension, which elevate cardiovascular risk. An impaired angiogenic response of endothelial cells (ECs) in heart and peripheral organs has been proposed in MetS, but the mechanisms of this phenomenon have not been thoroughly explored. Results obtained from evaluating the whole myocardium are inconsistent, since different types of cells react differently to MetS environment and a variety of molecular pathways are involved in the angiogenic response. Therefore, the aim of this paper was to study one selected pathway-the VEGF/VEGFR pathway, which regulates the angiogenic response and microvascular permeability in ECs isolated from db/db mouse hearts. The expression of mRNAs for VEGF/VEGFR axis proteins was assessed with RT-PCR in ECs isolated from control and db/db mouse myocardium. The density of CD31-, VEGFR2-, and VE-cadherin-positive cells was examined with confocal microscopy, and the ultrastructure of ECs was analyzed with transmission electron microscopy. The aortic ring assay was used to assess the capacity of ECs to respond to angiogenic stimuli. Our results showed a decreased number of microvessels, diminished expression of VE-cadherin and VEGFR2 and widened gaps between the ECs of microcapillaries. The aortic ring assay showed a diminished number of sprouts in db/db mice. These results may indicate that ECs in MetS enhance the production of mRNA for VEGF/VRGFR axis proteins, yet sprout formation and vascular barrier maintenance are limited. These novel data may provide a foundation for further studies on ECs dysfunction in MetS.

Oocyte meiotic maturation failure and chromosome abnormality is one of the main causes of infertility, abortion, and diseases. The mono-orientation of sister chromatids during the first meiosis is important for ensuring accurate chromosome segregation in oocytes. MEIKIN is a germ cell-specific protein that can regulate the mono-orientation of sister chromatids and the protection of the centromeric cohesin complex during meiosis I. Here we found that MEIKIN is a maternal protein that was highly expressed in mouse oocytes before the metaphase I (MI) stage, but became degraded by the MII stage and dramatically reduced after fertilization. Strikingly, MEIKIN underwent phosphorylation modification after germinal vesicle breakdown (GVBD), indicating its possible function in subsequent cellular event regulation. We further showed that MEIKIN phosphorylation was mediated by PLK1 at its carboxyl terminal region and its C-terminus was its key functional domain. To clarify the biological significance of meikin degradation during later stages of oocyte maturation, exogenous expression of MEIKIN was employed, which showed that suppression of MEIKIN degradation resulted in chromosome misalignment, cyclin B1 and Securin degradation failure, and MI arrest through a spindle assembly checkpoint (SAC)-independent mechanism. Exogenous expression of MEIKIN also inhibited metaphase II (MII) exit and early embryo development. These results indicate that proper MEIKIN expression level and its C-terminal phosphorylation by PLK1 are critical for regulating the metaphase-anaphase transition in meiotic oocyte. The findings of this study are important for understanding the regulation of chromosome segregation and the prevention meiotic abnormality.

Coronavirus disease 2019 (COVID-19) reportedly affects male reproductive function by causing spermatogenesis dysfunction and suppressing testosterone secretion. However, the relationship between COVID-19 and impaired reproductive function, such as whether these effects on reproductive function are a direct effect of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection in male reproductive organs or an indirect effect of high fever, is not known. Here, we examined whether the cell entry molecules of SARS-CoV-2, namely, ACE2, NRP1, TMPRSS2, and FURIN, are expressed in the male reproductive organs using the testes and accessory gonads of macaques during the breeding season. RT-PCR expression analysis showed that the testes alone expressed all four molecules. Immunohistochemical staining of testis tissue sections revealed that ACE2 is expressed in Leydig cells and the apical region of Sertoli cells, whereas NRP1 is expressed in the cell bodies surrounding the Leydig and Sertoli cell nuclei. FURIN is mainly expressed in Leydig cells, secondary spermatocytes, and spermatids. However, TMPRSS2 immunopositive cells were not observed. Therefore, it was not possible to observe cells expressing all four molecules in the gonads and accessory gonads of male primates. These results suggest that SARS-CoV-2 is unlikely to directly affect spermatogenesis in primates or proliferate in cells of the seminiferous tubules and undergo release into the semen through the previously known ACE2-mediated infection route. However, the expression of three molecules, including ACE2, was observed in Leydig cells, suggesting that testosterone synthesis and secretion may be affected when primates, including humans, are infected with SARS-CoV-2.

The use of cold formalin fixation (CFF; i.e., fixating tissue samples with 4 °C precooled formalin) recently attracted further attention owing to its putative improved ability to preserve nucleic acid compared with standard room temperature formalin (SFF). In this study, we aimed to assess the effect of four formalin-based fixation protocols (SFF, CFF, delayed formalin fixation-DFF, and cold formalin hyperfixation; CFH) on both DNA and RNA quality. We collected 97 colorectal cancer (CRC) and analyzed 23 metrics of nucleic acid quantity and quality yield using a multiplatform approach by combining spectrophotometric, fluorimetric, electrophoretic, and polymerase chain reaction (PCR) assays. Following confirmation of fixation-protocol-related different effects via clustering analysis, CFF presented best metrics compared with all protocols, specifically positive coefficients of DV1000-60000, DV2/DV1, DNA λ ratio 260/230, and ABL gene expression absolute copies, and negative coefficient of DV150-1000. The SFF subgroup presented a positive coefficient of DV150-1000 and negative coefficients for DV1000-60000, DV2/DV1, RNA λ ratio 260/230, RNA QuBit concentration, DV100/200, RNA electrophoresis concentration and absolute quantity, and ABL copies. Overall, we confirmed the superior yield performances of CFF preservation for both DNA and RNA compared with the other protocols in our series of CRC samples. Pending further validations and clarification of the specific mechanisms behind these findings, our study supports the implementation of CFF in the pathology unit routine specimen management for tumor tissue molecular profiling.