Histochemistry and Cell Biology最新文献

MOTS-c is a promising regulator of metabolism and energy homeostasis. While its effects have been studied in cell lines, our team aimed to investigate its influence on more complex structures-specifically, isolated pancreatic islets. We used two animal models: the rat, which is commonly studied, and the pig, which shares greater physiological similarities with humans. This study assessed the expression and secretion of insulin and glucagon, the expression of their receptors, cell viability, and cell death following MOTS-c treatment of the islets. Additionally, we examined how MOTS-c secretion is affected by different incubation media, such as the presence of free fatty acids, pancreatic hormones, and different glucose concentrations. The results indicate that MOTS-c impacts pancreatic islet physiology by, for example, reducing insulin and glucagon secretion and enhancing cell viability. Notably, the effects differed between the two species, which may be attributed to anatomical differences in their pancreatic islets or structural variations in rat and pig MOTS-c. These facts may lead to the conclusion that if MOTS-c may be helpful in human medicine, the pig model should be considered another valuable choice.

In cancer tissue diagnostic studies of clinical medicine, cell morphology is a key indicator for assessing the behavior of cellular physiological activities. Currently, the method of using thermotherapy as an adjunct to cancer treatment has gradually become a trend. Assessing the morphological characteristics of wound tissue cells during the hyperthermia process is particularly important for providing feedback on the therapeutic efficacy of hyperthermia-assisted treatment. Among the existing cell observation techniques, optical bright-field microscopy can only perform static observations of cells from a two-dimensional planar perspective. However, fluorescence microscopy suffers from issues such as phototoxicity and low temporal resolution. To address the aforementioned issues, this study introduces a quantitative analysis method based on digital holography to overcome these limitations. According to the mechanism of hyperthermia in cancer treatment, cancer cells exhibit morphological changes when exposed to elevated temperatures. Digital holography technology can effectively utilize light refractive indexes and phase differences to quantify the thickness and volume of cells. This study systematically evaluated the morphological changes in HeLa cells and human cervical epithelial cells (HCECs) under different temperature gradients (37-42 ℃ and 60 ℃). Continuous tracking of cell thickness and volume was achieved. The results revealed a unique morphological thermoresponsive process of the cells. The study determined the temperature threshold and exposure duration for high-temperature-induced effects in HeLa cells. The greater temperature sensitivity of HeLa cells compared with HCECs has been verified. This technology is expected to provide an effective means for evaluating morphological changes in cellular thermoresponses, offering novel insights for optimizing personalized cancer treatment regimens.

Remodeling of the extracellular matrix (ECM) throughout the estrous cycle is one of the most striking features of the uterus. A disintegrin and metalloprotease with thrombospondin type I motifs (ADAMTS-1) is a metalloproteinase responsible for the degradation of some proteoglycans, which are ECM components. In this study, ADAMTS-1 distribution was analyzed in the uterus of ovariectomized rats administered 17β-estradiol (E2) and progesterone (P4) and in the uterus at different estrous stages. Ovariectomized (OVX) rats were subjected to single and combined E2 (0.2 mg/kg) and P4 (10 mg/kg) hormone replacement therapies. E2 was administered for 3 consecutive days, followed by E2, P4, or E2 + P4 for 4 consecutive days. The serum level of E2 decreased from the proestrus phase to the diestrus phase, but that of P4 was the highest in the estrus phase. During the estrus phase, the serum level of luteinizing hormone (LH) was the lowest and that of follicle-stimulating hormone (FSH) was the highest. P4 level increased significantly in the OVX + P4 and OVX + E2 + P4 groups compared with the OVX group. The serum levels of LH and FSH decreased in the OVX + E2 and OVX + P4 groups compared with the OVX group, and were the lowest in the OVX + E2 + P4 group. ADAMTS-1 immunoreactivity in luminal, glandular, and stromal cells of the uterus decreased from proestrus to diestrus. When immunoreactivity in hormone replacement groups was compared, weak immunoreactivity was observed in the OVX group. ADAMTS-1 immunoreactivity gradually increased in OVX + P4 and OVX + E2 groups, and was particularly notable in luminal, glandular, and stromal cells in the OVX + E2 + P4 group. ADAMTS-1 distribution was affected by the estrous cycle process and hormone replacement therapy in the OVX procedure.

Microtubules are often nucleated at non-centrosomal sites in some differentiated cell types. We previously reported that microtubules are nucleated at the cytoplasm in cultured mouse cortical neurons. It is unclear, however, what organelle is the site of such nucleation. In this study, we examined the possibility that recently discovered neuron-specific Golgi-like structures called Golgi satellites are the nucleation sites. Microtubule nucleation was tested by observing microtubule regrowth after nocodazole depolymerization. First, the spatial association between microtubule nucleation and membrane organelles was investigated. Organelle markers including GM130 (cis Golgi and Golgi outpost marker), Golgin97 (trans-Golgi network marker), transferrin receptor (recycling endosome marker), TOMM40 (mitochondria marker), and syntaxin 6 (early endosome and Golgi satellite marker) were examined. Microtubule regrowth was observed in cytoplasmic regions where TOMM40-positive and syntaxin 6-positive organelles were rich. Triple immunostaining showed that γ-tubulin at one end of regrown microtubules was attached to syntaxin 6-organelles but not to TOMM40-organelles, indicating that syntaxin 6-organelles are the microtubule nucleation sites. To address the possibility that the microtubule-nucleating syntaxin 6-organelles were Golgi satellites, we transfected neurons with plasmid vector caring FLAG-tagged Golt sequence, a marker for Golgi satellites, and subsequently performed microtubule regrowth experiments. We found regrown microtubules on FLAG-positive organelles in dendrites. This observation suggests that Golgi satellites are microtubule nucleation sites. Microtubules from the Golgi satellites might guide transport vesicles generated at rough endoplasmic reticulum in dendrites.

Acute lung injury (ALI) represents a severe respiratory condition. Inflammation is a pivotal factor in the pathogenesis of ALI. Mammalian STE20-like protein kinase 1 (MST1) has emerged as a key regulator of sphingolipid metabolism and a mediator of inflammatory responses. However, the precise role and underlying mechanisms of MST1 in lipopolysaccharide (LPS)-induced ALI remain unclear. This study aimed to investigate the influence of MST1 on the inflammatory response in LPS-induced ALI. An LPS-induced ALI model was established using RAW 264.7 cells and mice. In vivo, lung histopathological changes, wet-to-dry (W/D) weight ratio, myeloperoxidase (MPO) activity, and inflammatory cytokine levels [interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α)] were assessed. Oxidative stress markers, including superoxide dismutase (SOD) activity and malondialdehyde (MDA) content, were measured. In vitro, MST1 overexpression was induced in RAW 264.7 cells via lentiviral transfection. Cell viability and proliferation were evaluated using the CCK-8 assay. The expression levels of NF-κB and NLRP3 signaling pathways in vitro or in vivo were analyzed using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting analysis. The results showed that inhibition of MST1 expression attenuated lung damage, alleviated inflammation, enhanced antioxidant capacity, and inhibited the activation of NF-κB and NLRP3 pathways in vivo. In contrast, MST1 overexpression promoted cell proliferation and inflammation in vitro, accompanied by the activation of NF-κB and NLRP3 signaling pathways. This study demonstrated that MST1 activation contributed to inflammation in LPS-induced ALI by modulating the NF-κB/NLRP3 signaling pathway. Targeting MST1 may represent a novel approach to the treatment of ALI.

Members of the INhibitor of Growth protein family (ING1-5) function as epigenetic regulators by targeting different histone acetyltransferase (HAT) and histone deacetylase (HDAC) complexes to the H3K4Me3 mark of active transcription. The INGs recognize H3K4Me3 by specific interaction with their well-conserved plant homeodomains, and affinity can be increased by interactions between DNA and disordered regions within the ING proteins. They are classified as type II tumor suppressors since they are downregulated in numerous cancer types and knockout of ING family members results in tumorigenesis. ING4 targets the HBO1 HAT complex, which is known to affect acetylation of the H4 core nucleosomal histone, to affect local chromatin structure and knockout results in deficient innate immunity. Reports indicating roles in cell cycle regulation, tumor suppression, and apoptosis suggest that ING4 may be a promising target for cancer treatment by targeting pathways of innate immunity. Given the relatedness between ING4 and the closely related ING5 proteins, we have developed and characterized two mouse monoclonal antibodies to specifically recognize human and mouse ING4, but not ING5, to more accurately characterize ING4 levels by western, immunofluorescence and immunohistochemical assays. Using them, we show that ING4 differentially partitions between the nucleus and cytoplasm in different tissues and localizes largely to the cytoplasm of cells having a secretory role in different tissue types.

This study investigated the effects of prenatal exposure to pequi oil and 17α-ethinylestradiol (EE2) on the histomorphometry and receptor expression (androgen receptor (AR) and estrogen receptor alpha (ERα) in gerbil ovaries (Meriones unguiculatus) during aging. Experimental groups included: control, vehicle (mineral oil), EE2: 15 µg/kg/day from gestational days 18-22, EE2/Pe: EE2 from days 18-22 and 300 mg/kg of pequi oil from days 18-26, and Pe: pequi oil only, via gavage. Female offspring were euthanized at 12 months, and ovaries were collected, processed histologically, and sectioned. Histological sections were stained with hematoxylin-eosin to analyze the superficial epithelium height and the tunica albuginea thickness. Immunohistochemistry for AR and ERα was performed, and the percentage of positive nuclei for these receptors was quantified in the theca interna, granulosa cells within follicles, and the interstitial gland. Data were analyzed using analysis of variance (ANOVA), Tukey's, and Kruskal-Wallis tests. The data revealed a significant decrease (p < 0.05) in the thickness of the tunica albuginea in the EE2 group, whereas this thickness was increased in the EE2/Pe and Pe groups. Epithelial height was lower in the EE2 group and higher in the EE2/Pe group. No significant changes in AR immunoreactivity were observed. In multilaminar follicles, ERα immunostaining was elevated in granulosa cells in the Pe group and in theca cells of the EE2 group. Additionally, the interstitial gland in the Pe group showed an increase in ERα expression. Pequi oil exposure upregulated ERα more markedly than AR during folliculogenesis and in interstitial cells, suggesting endocrine-modulating potential and relevance for ovarian regulation during aging.

The role of angiogenesis in preeclampsia pathogenesis is widely studied; however, despite the lymphatic vessels' complementary role to the blood vascular system, studies on their morphology in the placenta and placental bed are lacking. In total, 87 placental bed specimens were utilized, which were grouped into normotensive pregnant (n = 28), early-onset preeclampsia (n = 31), and late-onset preeclampsia (n = 28), and further stratified by human immunodeficiency virus (HIV) status. Tissue was immunostained with podoplanin antibody to investigate whether HIV infection affects lymphangiogenesis. The lymphatic capillary density and luminal areas within the placental bed were morphometrically assessed. Lymphatic microvessel density and mean area/lumen in the preeclampsia group were higher and larger than in the normotensive group, respectively (p = 0.01 and p = 0.001). A correlation between blood pressure levels and lymphatic microvessel density was observed (r ≥ 0.272; p ≤ 0.032). Significant differences were observed between the mean microvessel density of normotensive HIV-uninfected and HIV-infected groups (5.9 ± 2.3 versus 7.5 ± 2.8, p = 0.01) and late-onset preeclampsia HIV-uninfected and HIV-infected groups (7.1 ± 3.9 versus 7.8 ± 2.7, p = 0.01). The mean area/lumen between normotensive HIV-uninfected and HIV-infected, and late-onset preeclampsia HIV-uninfected and HIV-infected groups were significantly different (p = 0.03 and p = 0.001). Small lymphatic capillaries were significantly abundant in late-onset preeclampsia HIV-infected (p = 0.03) and normotensive HIV-infected (p = 0.0001) groups compared with uninfected groups. Lymphatic capillary density and area/lumen upregulation was observed in the placental bed of HIV-infected women, with a positive correlation between maternal blood pressure and lymphatic microvessel density, potentially affecting birth weight in the preeclampsia group.