Κυριακή 17 Νοεμβρίου 2019

Structural organization, GABAergic and tyrosine hydroxylase expression in the striatum and globus pallidus of the South American plains vizcacha, Lagostomus maximus (Rodentia, Caviomorpha)

Abstract

The striatum is an essential component of the basal ganglia that regulatessensory processing, motor, cognition, and behavior. Depending on the species, the striatum shows a unique structure called caudate–putamen as in mice, or its separation into two regions called caudate and lenticular nuclei, the latter formed by putamen and globus pallidus areas, as in primates. These structures have two compartments, striosome and matrix. We investigated the structural organization, GABAergic and tyrosine hydroxylase (TH) expression in the striatum and globus pallidus of the South American plains vizcacha, Lagostomus maximus. Its striatum showed regionalization arising from the presence of an internal capsule, and a similar organization to a striosome–matrix compartmentalization. GABAergic neurons in the matrix of caudate exhibited parvalbumin, calretinin, calbindin, GAD65, and NADPH-d-immunoreactivity. These were also expressed in cells of the putamen with the exception of calretinin showing neurofibers localization. Globus pallidus showed parvalbumin- and GAD65-immunoreactive cells, and calretinin- and calbindin-immunoreactive neuropil, plus GABA-A-immunoreactive neurofibers. NADPH-d-, GAD65- and GABA-A-immunoreactive neurons were larger than parvalbumin-, calretinin-, and calbindin-immunoreactive cells, whereas calbindin-immunoreactive cells were the most abundant. In addition, TH-immunoreactive neuropil was observed in the matrix of the striatum. A significant larger TH-immunoreactive area and neuron number was found in females compared to males. The presence of an internal capsule suggests an adaptive advantage concerning motor and cognitive abilities favoring reaction time in response to predators. In an anatomy-evolutive perspective, the striatum of vizcacha seems to be closer to that of humans than to that of laboratory traditional models such as mouse.

Periostin-modified bone marrow mesenchymal stem cells from osteoporotic rats promote alveolar bone regeneration

Abstract

Bone regeneration is impaired in patients with osteoporosis. Previous studies have shown that periostin (Postn) shows great potential in bone regeneration treatments. However, the role of Postn in bone marrow mesenchymal stem cells (BMMSCs) remains to be elucidated. In this study, we isolated BMMSCs from ovariectomized rats (OVX-BMMSCs) and normal rats. Then, the expression levels of Postn and osteogenesis in OVX-BMMSCs were detected by alizarin red and alkaline phosphatase substrate staining, qPCR, and western blotting. We found that the levels of Postn in OVX-BMMSCs were significantly reduced. Furthermore, Postn overexpression in OVX-BMMSCs using recombinant lentivirus could improve the expression of alkaline phosphatase, runt-related transcription factor 2, and osteocalcin and reduce the expression of sclerostin. Besides, micro-computed tomography analysis, hematoxylin-eosin, and Masson’s staining showed that the healing of the alveolar bone defect in osteoporotic rats could be promoted using Postn-modified OVX-BMMSC sheets. In conclusion, Postn-modified OVX-BMMSCs might restore the osteogenic capacity and promote alveolar bone regeneration, which may serve as a new therapeutic approach for bone regeneration in osteoporosis.

Localization of Mucin 1 in endometrial luminal epithelium and its expression in women with reproductive failure during implantation window

Abstract

Pinopode and Mucin 1 (MUC1) have both been proposed as morphological and molecular markers of endometrial receptivity for implantation. However, their spatial relationship in luminal epithelium and its association with reproductive failure are still unclear. This was a prospective cohort study conducted at a university assisted reproductive unit including 9 receptive control women, 18 infertile women, and 22 women with recurrent implantation failure (RIF) and 22 women with recurrent miscarriage (RM). Endometrial tissues were obtained at 7 days after luteinizing hormone surge during implantation window. Luminal epithelium was examined by scanning electron microscopy (SEM). MUC1 localization in luminal epithelium was detected by scanning immunoelectron microscopy (SIM) and compared by modified double immunofluorescence (mIF) staining without antigen retrieval. SEM did not show any significant difference in percentage of secretory cells, any stage of pinopodes, and ciliated cells between control, infertility, RIF and RM groups. SIM identified MUC1 was mainly localized on surface of ciliated cells and at the bottom of cilia, not secretory cells and pinopodes, and its specific localization was validated by mIF staining. MUC1 expression in ciliated cells in control women was significantly higher than those women with reproductive failure, but there was no significant difference between RIF and RM. In conclusion, MUC1 is mainly expressed in ciliated cells, not secretory cells and pinopodes, of the endometrial luminal epithelium during implantation window. The specific expression of MUC1 in the ciliated cells in receptive control women is higher than that of women with reproductive failure during implantation window.

A simple, web-based repository for the management, access and analysis of micrographic images

Abstract

Microscopy is advancing at a rapid pace, enabling high-speed, high-resolution analyses to be conducted in a wide range of cellular contexts. For example, the capacity to quickly capture high-resolution images from multiple optical sections over multiple channels with confocal microscopy has allowed researchers to gain deeper understanding of tissue morphology via techniques such as three-dimensional rendering, as have more recent advances such as lattice light sheet microscopy and superresolution structured illumination microscopy. With this, though, comes the challenge of storing, curating, analysing and sharing data. While there are ways in which this has been attempted previously, few approaches have provided a central repository in which all of these different aspects of microscopy can be seamlessly integrated. Here, we describe a web-based storage and analysis platform called Microndata, that enables relatively straightforward storage, annotation, tracking, analysis and multi-user access to micrographs. This easy to use tool will simplify and harmonise laboratory work flows, and, importantly, will provide a central storage repository that is readily accessed, even after the researcher responsible for capturing the images has left the laboratory. Microndata is open-source software, available at http://www.microndata.net/.

Immunohistochemical localization and possible functions of nesfatin-1 in the testis of mice during pubertal development and sexual maturation

Abstract

The study was aimed to address the role of nesfatin-1 on the sexual maturation of testis during the pubertal transition. The immunostaining of testis suggested nesfatin-1 is expressed in Leydig cells with pubertal maturation. The pre-pubertal mice for in vivo study were randomly divided in three groups; (a) control-saline (b) treated with low (0.25 nM) dose of nesfatin-1/gbw/day and (c) treated with high (1.25 nM) dose nesfatin-1/gbw/day. Histological analysis showed that nesfatin-1 loaded mice showed facilitated maturation of testis. Western blot analysis on various protein expressions upon injection of nesfatin-1 into pre-pubertal mice suggested that expressions of proteins involving steroid hormone production, spermatogenic markers (PCNA, Bcl2, AR), glucose uptake-related proteins (GLUT8 and insulin receptor) and GnRH-R and GPR-54 proteins were facilitated. Both of lactose dehydrogenase activity and lactate levels were increased. The treatment with nesfatin-1 also reduced oxidative stress, which further facilitates testicular functions during puberty. The treatment of nesfatin-1 on cultured testis also supports in vivo findings as evident by the increased testosterone production and StAR protein expression as well as increased glucose and lactate production. In sum, our data report for the first time the accelerative role of nesfatin-1 on spermatogenesis and steroidogenesis of pre-pubertal male mice by directly acting on the testis coupled with the advancement of puberty.

Smad interacting protein 1 influences transforming growth factor-β 1 /Smad signaling in extracellular matrix protein production and hypertrophic scar formation

Abstract

The transforming growth factor (TGF)-β/Smad signal transduction pathway is closely associated with hypertrophic scar (HS) formation. Smad interacting protein 1 (SIP1) is a cytoplasmic protein that efficiently regulates Smad2-/3-dependent signaling within the TGF-β1 pathway. SIP1 influences collagen synthesis in the HS through a heretofore unknown mechanism. This study investigated the role of the SIP1-mediated TGF-β1/Smad signaling pathway in extracellular matrix (ECM) protein production and hypertrophic scarring. SIP1 expression was markedly lower in HS vs. normal skin (NS) tissue, and α-smooth muscle actin (α-SMA) content and collagen I/III (Col I/III) synthesis were inversely correlated with SIP1 expression. Furthermore, SIP1 inhibited Smad2/3 phosphorylation in vitro, and improved the collagen-based architecture of the scar while reducing collagen expression and overall scar formation in a rabbit ear model of HS. Based on these findings, we propose that SIP1 acts as a molecular modulator capable of altering Smad2-/3-facilitated signaling through the control of Smad phosphorylation, thus inhibiting α-SMA and collagen upregulation in fibroblasts and, ultimately, HS formation. The low SIP1 content in scar tissue also suggests that SIP1 (and positive regulation thereof) is a prospective target for selective HS drug therapy.

FAM20A is essential for amelogenesis, but is dispensable for dentinogenesis

Abstract

Mutations in the gene encoding family with sequence similarity 20, member A (FAM20A) caused amelogenesis imperfecta (AI), in humans. However, the roles of FAM20A in amelogenesis and dentinogenesis are poorly understood. In this study, we generated a Fam20a knockout (Sox2-Cre;Fam20afl/fl) mouse model by crossing Fam20afl/fl mice with Sox2-Cre transgenic mice, in which Fam20a was ablated in both dental epithelium and dental mesenchyme. We found that these mice developed an enamel phenotype that resembles human AI associated with FAM20A mutations, but did not have apparent dentin defects. The secretory stage ameloblasts in the mandibular incisors from the Sox2-Cre;Fam20afl/fl mice were shorter and detached from the enamel matrix, and subsequently lost their polarity, became disorganized and formed numerous spherical extracellular matrices in place of normal enamel. At the molecular level, the Sox2-Cre;Fam20afl/fl mice displayed dramatically reduced expression levels of the genes encoding the enamel matrix proteins, but unaltered levels of the genes encoding the dentin matrix proteins. Moreover, Fam20a ablation resulted in a great decrease in FAM20C protein level, but it did not alter the intracellular localization of FAM20C protein in ameloblasts and odontoblasts. These results indicate that FAM20A is essential for amelogenesis, but is dispensable for dentinogenesis.

PGE2 facilitates tail regeneration via activation of Wnt signaling in Gekko japonicus

Abstract

Tail regeneration is a distinguishing feature of lizards; however, the mechanisms underlying tail regeneration remain elusive. Prostaglandin E2 (PGE2) is an arachidonic acid metabolite that has been extensively investigated in the inflammatory response under both physiological and pathological conditions. PGE2 also act as a regulator of hematopoietic stem cell homeostasis by interacting with Wnt signaling molecules. The present study aims to identify the effects of PGE2 on tail regeneration and the molecular mechanisms behind it. We initially found that PGE2 levels increased during the early stages of tail regeneration, accompanied by the up-regulated expression of cyclooxygenase 1 and cyclooxygenase 2. Next, we demonstrated that reduced PGE2 production leads to the retardation of tail regeneration. Subsequent experiments demonstrated that this effect is likely mediated by Wnt signaling, which proposing that the activation of the Wnt pathway is essential for the initiation of regeneration. The results showed that inhibition of PGE2 production could suppress Wnt activation and inhibit the proliferation of both epithelial and blastema cells. Furthermore, our findings indicated that forced activation of Wnt signaling could rescue the inhibitory effect of Cox antagonist on regeneration, suggesting a positive role of PGE2 on tail regeneration via a non-inflammatory mechanism.

Investigating time dependent brain distribution of nevirapine via mass spectrometric imaging

Abstract

Central nervous system (CNS) HIV infection causes brain tissue inflammation and tissue deficit that contributes to neuroAIDS. This complication is escalated by the blood–brain barrier (BBB), which prevents easy access to antiretroviral drugs entering the CNS. In this study the aims were to investigate the BBB membrane penetration and brain localization patterns of Nevirapine (NVP) using Imaging Mass Spectrometry (MSI). Sprague–Dawley rats received an intraperitoneal dose of NVP (50 mg kg−1). Plasma and brain samples were harvested, and mass spectrometric methods were then applied to determine the pharmacokinetic properties and localization patterns of NVP in the brain. The pharmacokinetic parameters demonstrated a rapid bio-distribution of NVP in plasma and brain. The plasma Cmax was 6320 ng mL−1 and the brain Cmax was 1923 ng mL−1, both at a Tmax of 0.25 h. MSI of coronal brain sections showed that NVP penetrated and localized in the brain regions implicated with the development of HIV associated neurodegeneration. NVP has great potential to combat neuroAIDS.

Natriuretic peptide system expression in murine and human submandibular salivary glands: a study of the spatial localisation of ANB, BNP, CNP and their receptors

Abstract

The natriuretic peptide (NP) system comprises of three ligands, the Atrial Natriuretic Peptide (ANP), Brain Natriuretic peptide (BNP) and C-type Natriuretic peptide (CNP), and three natriuretic peptide receptors, NPRA, NPRB and NPRC. Here we present a comprehensive study of the natriuretic peptide system in healthy murine and human submandibular salivary glands (SMGs). We show CNP is the dominant NP in mouse and human SMG and is expressed together with NP receptors in ducts, autonomic nerves and the microvasculature of the gland, suggesting CNP autocrine signalling may take place in some of these glandular structures. These data suggest the NP system may control salivary gland function during homeostasis through the regulation of electrolyte re-absorption, neural stimulation and/or blood vessel wall contraction/relaxation. We also show abnormal expression of NPRA in the stroma of a subset of human SMGs resected from patients diagnosed with oral squamous cell carcinoma (OSCC) of non-salivary gland origin. This finding warrants further research to investigate a possible correlation between early OSCC invasion and NPRA overexpression.

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