Histochemistry and Cell Biology最新文献

Mott cells are plasma cells that have multiple spherical Russell bodies packed in their cytoplasm. Russell bodies are dilated endoplasmic reticulum cisternae filled with aggregates of immunoglobulins that are neither secreted nor degraded. Mott cells were observed in our study by light and electron microscope in the lymph nodes of rats with experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Mott cells were detected on hematoxylin and eosin (HE)-stained lymph node sections as vacuolated cells with eccentrically positioned nuclei and large number of faint blue spherical inclusions in the cytoplasm. Electron microscopic investigation revealed the presence of Russell bodies of the "medusa" form inside Mott cells in lymph node ultra-thin sections of EAE animals. Mott cells expressed the plasma cell marker CD138 and either kappa or lambda immunoglobulin light chains, indicating their origin from polyclonally activated B cells. Finally, Mott cells were associated with active EAE, as they were not found in the lymph nodes of EAE-resistant Albino Oxford rats. The presence of Russell bodies implies an excessive production of immunoglobulins in EAE, thus further emphasizing the role of B cells, and among them Mott cells, in the pathogenesis of this animal model of multiple sclerosis.

Diabetes mellitus is a chronic metabolic disease characterized by persistent hyperglycemia, revealing a decrease in insulin efficiency. The sustained glucotoxic pancreatic microenvironment increases reactive oxygen species generation, resulting in chronic oxidative stress responsible for massive DNA damage. This triggers PARP-1 activation with both NAD⁺ and ATP depletion, affecting drastically pancreatic beta cells' energy storage and leading to their dysfunction and death. The aim of the present study is to highlight the main histological changes observed in pancreatic islets pre-treated with a unique NADH intraperitoneal injection in a streptozotocin-(STZ)-induced diabetes model. In order to adjust NADH doses, a preliminary study with three different doses, 500 mg/kg, 300 mg/kg, and 150 mg/kg, respectively, was conducted. Subsequently, and on the basis of the results of the aforementioned study, Wistar rats were randomly divided into four groups: non-diabetic control group, diabetics (STZ 45 mg/kg), NADH-treated group (150 mg/kg) 15 min before STZ administration, and NADH-treated group (150 mg/kg) 15 min after STZ administration. The effect of NADH was assessed by blood glucose level, TUNEL staining, histo-morphological analysis, and immunohistochemistry. The optimum protective dose of NADH was 150 mg/kg. NADH effectively decreased hyperglycemia and reduced diabetes induced by STZ. Histologically, NADH pre-treatment revealed a decrease in beta cell death favoring apoptosis over necrosis and therefore preventing inflammation with further beta cell destruction. Our data clearly demonstrate that NADH prior or post-treatment could effectively prevent the deleterious loss of beta cell mass in STZ-induced diabetes in rats and preserve the normal pancreatic islet's function.

We recently reported that phogrin, also known as IA-2β or PTPRN2, forms a complex with the insulin receptor in pancreatic β cells upon glucose stimulation and stabilizes insulin receptor substrate 2. In β cells of systemic phogrin gene knockout (IA-2β^-/-) mice, impaired glucose-induced insulin secretion, decreased insulin granule density, and an increase in the number and size of lysosomes have been reported. Since phogrin is expressed not only in β cells but also in various neuroendocrine cells, the precise impact of phogrin expressed in β cells on these cells remains unclear. In this study, we performed a comprehensive analysis of morphological changes in RIP-Cre^+/-Phogrin^flox/flox (βKO) mice with β cell-specific phogrin gene knockout. Compared to control RIP-Cre^+/- Phogrin^+/+ (Ctrl) mice, aged βKO mice exhibited a decreased density of insulin granules, which can be categorized into three subtypes. While no differences were observed in the density and size of lysosomes and crinosomes, organelles involved in insulin granule reduction, significant alterations in the regions of lysosomes responding positively to carbohydrate labeling were evident in young βKO mice. These alterations differed from those in Ctrl mice and continued to change with age. These electron microscopic findings suggest that phogrin expression in pancreatic β cells plays a role in insulin granule homeostasis and crinophagy during aging, potentially through insulin autocrine signaling and other mechanisms.

Cell death is an essential process that occurs during the development of the central nervous system. Despite the availability of a wide range of commercially produced antibodies against various apoptotic markers, data regarding apoptosis in intact spinal cord during postnatal development and adulthood are mostly missing. We investigated apoptosis in rat spinal cord at different stages of ontogenesis (postnatal days 8, 29, and 90). For this purpose, we applied immunofluorescent detection of two widely used apoptotic markers, cleaved caspase-3 (cC3) and cleaved poly(ADP-ribose) polymerase (cPARP). Surprisingly, we found significant discrepancy between the number of cC3⁺ cells and PARP⁺ cells, with a ratio between 500:1 and 5000:1 in rat spinal cord at all postnatal time points. The majority of cC3⁺ cells were glial cells and did not exhibit an apoptotic phenotype. In contrast with in vivo results, in vitro analysis of primary cell cultures derived from neonatal rat spinal cord and treated with the apoptotic inductor staurosporine revealed a similar onset of occurrence of both cC3 and cPARP in cells subjected to apoptosis. Gene expression analysis of spinal cord revealed elevated expression of the Birc4 (XIAP), Birc2, and Birc5 (Survivin) genes, which are known potent inhibitors of apoptosis. Our data indicate that cC3 is not an exclusive marker of apoptosis, especially in glial cells, owing its possible presence in inhibited forms and/or its participation in other non-apoptotic roles. Therefore, cPARP appears to be a more appropriate marker to detect apoptosis.

Given the high prevalence of HIV infection and pre-eclampsia (PE) in South Africa, this study evaluated and compared the placental immunostaining of progesterone (P) and progesterone receptors (PR) in the synergy of HIV-infected PE compared to normotensive pregnant women using immunohistochemistry interfaced with morphometric image analysis. Progesterone immunostaining was expressed widely across exchange and conducting villi within mesenchymal, endothelial, and trophoblast cells. In contrast, PR was expressed within syncytiotrophoblasts and was absent within endothelial cells. In exchange villi, P and PR immuno-expression was significantly lower in PE compared to the normotensive group (p = < 0.0001 and p = < 0.0001, respectively) and within the early-onset pre-eclampsia (EOPE) compared to the late-onset pre-eclampsia (LOPE) group (p = < 0.0001 and p = < 0.0001, respectively). Progesterone immuno-expression was significantly lower in the HIV+ compared to the HIV- group (p = < 0.0001), whilst PR was non-significant. In conducting villi, P and PR immuno-expression was significantly lower in the EOPE compared to the LOPE group (p = < 0.0001 and p = < 0.0001, respectively) and in the HIV+ compared to the HIV- group (p = < 0.0001 and p = 0.0009, respectively). Progesterone immuno-expression was slightly higher in the PE compared to normotensive group, and PR immuno-expression was non-significant. There was a significant difference between P and PR within exchange versus conducting villi regardless of pregnancy type, with villi type accounting for 34.47% and 15.28% of total variance for P and PR, respectively. Placental P and PR immuno-expression is downregulated in the duality of PE and HIV+ infection. The use of combined antiretroviral therapy (cART) may result in defective P synthesis, which causes insufficient binding to its receptors. Consequently, PI3K/AKT, JAK-STAT, and MAPK signalling pathways are affected, impairing trophoblast invasion and leading to pre-eclampsia development. Notably, the decrease in P and PR immuno-expression in EOPE validates their effect on placentation.

Peroxisomes are membrane-bounded organelles that contain enzymes involved in multiple lipid metabolic pathways. Several of these pathways require (re-)activation of fatty acids to coenzyme A (CoA) esters by acyl-CoA synthetases, which may take place inside the peroxisomal lumen or extraperoxisomal. The acyl-CoA synthetases SLC27A2, SLC27A4, ACSL1, and ACSL4 have different but overlapping substrate specificities and were previously reported to be localized in the peroxisomal membrane in addition to other subcellular locations. However, it has remained unclear if the catalytic acyl-CoA synthetase sites of these enzymes are facing the peroxisomal lumen or the cytosolic side of the peroxisomal membrane. To study this topology in cellulo we have developed a microscopy-based method that uses the previously developed self-assembling split superfolder (sf) green fluorescent protein (GFP) assay. We show that this self-assembling split sfGFP method can be used to study the localization as well as the topology of membrane proteins in the peroxisomal membrane, but that it is less suited to study the location of soluble peroxisomal proteins. With the method we could demonstrate that the acyl-CoA synthetase domains of the peroxisome-bound acyl-CoA synthetases SLC27A2 and SLC27A4 are oriented toward the peroxisomal lumen and the domain of ACSL1 toward the cytosol. In contrast to previous reports, ACSL4 was not found in peroxisomes.

Mesenchymal stem cells (MSCs) are multipotent cells that have the ability to self-renew and regulate paracrine signalling and immune system processes. MSCs have extensive clinical applications in regeneration, functional reconstruction and cellular therapies. However, studies are needed to discover ways to improve the properties of MSCs, such as differentiation, and prevent senescence in culture, which are both very important for cell therapies. Royal jelly (RJ) is a nutritional substance produced by worker bees that contains a substantial amounts of proteins that are beneficial for cell growth and proliferation. RJ is widely used in traditional medicine today, and due to the specific components in its content, it has been reported to have antioxidant, antiproliferative, antimicrobial, neuroprotective, anti-inflammatory, immunomodulatory and anti-ageing properties. In our study, human Wharton's jelly mesenchymal stem cells (WJ-MSCs) derived from umbilical cord matrix were grown in culture medium supplemented with RJ. The control group comprised minimum essential medium (MEM) and 10% foetal bovine serum (FBS); RJ groups were formed using MEM, 10% FBS and 0.075 mg/ml or 0.150 mg/ml RJ. In our study, we evaluated the effect of RJ on WJ-MSC growth by MTT assay, proliferating cell nuclear antigen ELISA, β-galactosidase activity assay, MitoTracker Green staining and differentiation tests in adipogenic, osteogenic and chondrogenic cell lines. It was observed that the number of mitochondria increased, senescence decreased and osteogenic differentiation increased after differentiation induction after the addition of RJ to MSC culture. In general, the results of this study indicate that WJ-MSCs enhance mitochondrial numbers and important cellular activities, such as antisenescence and osteogenic differentiation, and with increasing evidence from further studies, RJ supplementation may be found beneficial for the use of MSCs in bone engineering regenerative medicine or cell therapy.

Burn injuries pose a significant healthcare burden worldwide, often leading to long-term disabilities and reduced quality of life. To explore the impacts of the transplantation of mesenchymal stem cells (MSCs) on the healing of burns and the levels of serum cytokines, 60 fully grown Sprague-Dawley rats were randomly divided into three groups (n = 20 each): group I (control), group II (burn induction), and group III (burn induction + bone marrow (BM)-MSC transplantation). Groups II and III were further divided into four subgroups (n = 5 each) based on euthanasia duration (7, 14, 21, and 28 days post transplant). The experiment concluded with an anesthesia overdose for rat death. After 7, 14, 21, and 28 days, the rats were assessed by clinical, laboratory, and histopathology investigations. The results revealed significant improvements in burn healing potentiality in the group treated with MSC. Furthermore, cytokine levels were measured, with significant increases in interleukin (IL)-6 and interferon alpha (IFN) observed, while IL-10 and transforming growth factor beta (TGF-β) decreased at 7 days and increased until 28 days post burn. Also, the group that underwent the experiment exhibited increased levels of pro-inflammatory cytokines and the anti-inflammatory cytokine IL-10 when compared to the control group. Histological assessments showed better re-epithelialization, neovascularization, and collagen deposition in the experimental group, suggesting that MSC transplantation in burn wounds may promote burn healing by modulating the immune response and promoting tissue regeneration.