Molecular cloning and expression analysis of ADAMs and cadherins during chicken embryonic development

Introduction: Cell adhesion molecules (CAMs) play various roles during embryonic development. Cadherins are a large superfamily of CAMs that mediate cell-cell adhesion and signaling transduction by a calcium-dependent mechanism. The ADAM family of genes can also be considered a family of CAMs, because their disintegrin domain binds integrin to mediate cell-cell or cell-matrix interactions, and their cysteine-rich domain and epidermal growth factor-like domain both are able to modify cell-cell adhesion. Moreover, many ADAMs are metalloproteases that shed different trans-membrane proteins, such as cadherins. However, the expression patterns and potential functions of most ADAMs and some cadherins remain poorly understood. In the present thesis, I cloned seven members of the ADAM family and a multiple cadherins from the chicken embryo, and investigated their molecular characteristics and expression profiles during chicken embryonic development. Methods: Fertilized eggs were incubated in a forced-draft incubator at 37°C and 65% humidity until the embryos reached the desired stage. Total RNA was isolated from different stages and partial or full-length cDNAs of the ADAMs and cadherins of interest were cloned by RT-PCR or RACE. The temporal expression profiles of each gene were analyzed with semi-quantitative RT-PCR during chicken embryonic development. Northern blot was performed to determine the amount and size of chicken cadherin-8 isoforms as well. Results from semi-quantitative RT-PCR and Northern blot were further analyzed by appropriate statistic methods. The temporal and spatial expression patterns of the cloned molecules were investigated using in situ hybridization of sections or whole mount specimens. Appropriate protein markers helped to confirm the identity of expression areas by immunostaining. To investigate the function of chicken ADAM17, an overexpression (gain-of-function) experiment was performed using in vivo (ex ovo) electroporation of the embryonic chicken tectum. Results: I obtained the novel full-length sequences of chicken ADAM12, ADAM13, ADAM22, Cdh8 and Cdh19. The expression pattern of ADAM13 was investigated in detail in the chicken embryo throughout the developing organism. The expression patterns of eight chicken cadherins (N-Cdh, R-Cdh, Cdh6, Cdh7, Cdh8, Cdh11, Cdh18 and Cdh20) were analyzed in the developing cochlea at older embryonic stages. I confirmed that 6. Summary 123 chicken Cdh8 possesses three isoforms from mRNA alternative splicing and analyzed their temporal and spatial expression in the chicken embryonic brain. Five ADAMs investigated (ADAM9, ADAM10, ADAM12, ADAM22, ADAM23) show different types of expression patterns in the developing chicken brain. Finally, ADAM17 overexpression (gain-offunction) resulted in a morphological change of the blood vessels in the developing tectum. This change coincided with an increase in the number of pericytes

Targeting Lung Cancer Stem Cells: Research and Clinical Impacts

Lung cancer is the most common cancer worldwide, accounting for 1.8 million new cases and 1.6 million deaths in 2012. Non-small cell lung cancer (NSCLC), which is one of two types of lung cancer, accounts for 85–90% of all lung cancers. Despite advances in therapy, lung cancer still remains a leading cause of death. Cancer relapse and dissemination after treatment indicates the existence of a niche of cancer cells that are not fully eradicated by current therapies. These chemoresistant populations of cancer cells are called cancer stem cells (CSCs) because they possess the self-renewal and differentiation capabilities similar to those of normal stem cells. Targeting the niche of CSCs in combination with chemotherapy might provide a promising strategy to eradicate these cells. Thus, understanding the characteristics of CSCs has become a focus of studies of NSCLC therapies

Conditioned Medium of Human Menstrual Blood-Derived Endometrial Stem Cells Protects Against MPP+-Induced Cytotoxicity in vitro

Mesenchymal stem cells (MSCs) showed the potential to treat Parkinson’s disease (PD). However, it is unknown whether the conditioned medium of human menstrual blood-derived endometrial stem cells (MenSCs-CM) has the function to alleviate syndromes of PD. In this study, human neuroblastoma SH-SY5Y cells were exposed to neurotoxicant 1-methyl-4-phenylpyridinium (MPP+) for inducing a range of response characteristics of PD. After culturing this cell model with 24 h/48 h collected MenSCs-CM for different days, cell viability, pro-inflammation cytokines, mitochondrial membrane potential (ΔΨm), oxidative stress, and cell apoptosis were detected. Finally, protein assay was performed to detect 12 kinds of neurotrophic factors inside MenSCs-CM. Our results showed that MPP+ caused SH-SY5Y cell viability reduction as an increasing dose and time dependent manner. MPP+ treatment resulted in inflammation, mitochondrial dysfunction, reactive oxygen species (ROS) production accumulation, and apoptosis of SH-SY5Y at its IC50 concentration. Forty-eight hours-collected MenSCs-CM and culturing with the MPP+-treated SH-SY5Y for 2 days are the optimized condition to increase cell viability. Besides, MenSCs-CM was efficacious against MPP+ induced inflammation, ΔΨm loss, ROS generation, and it could significantly decrease cells numbers in late apoptosis stage. What’s more, protein assay showed that MenSCs-CM contained various neuroprotective factors. Our study provided the first evidence that MenSCs-CM has a protective effect on MPP+-induced cytotoxicity in various aspects, and firstly showed that MenSCs can release at least 12 kinds of neurotrophic factors to medium, which may contribute to the protective function of MenSCs-CM to treat PD. This research enlightening that MenSCs-CM is beneficial in the therapy for PD and probably also for other neurodegenerative diseases

Modulation of hippocampal gamma oscillations by dopamine in heterozygous Reeler mice In vitro

The reelin haploinsufficient heterozygous reeler mouse (HRM), an animal model of schizophrenia, has altered mesolimbic dopaminergic pathways, shares similar neurochemical, and behavioral properties with the patients with schizophrenia. Dysfunctional neural circuitry with impaired gamma (γ) oscillation (30–80 Hz) has been implicated in abnormal cognition in patients with schizophrenia. However, the function of neural circuitry in terms of γ oscillation and its modulation by dopamine has not been reported in HRM. In this study, first, we recorded γ oscillations in CA3 from wide type (WT) mice and HRM hippocampal slices, and studied the effects of dopamine (DA) on γ oscillations. We found that there was no difference in γ power between WT mice and HRM and that dopamine increased γ power of WT mice but not HRM, suggesting that dopamine modulations of network oscillations in HRM are impaired. Second, we found that N-methyl-D-aspartate receptor (NMDAR) antagonist itself increased γ power and occluded DA-mediated enhancement of γ power in WT mice but partially restored DA modulation of γ oscillations in HRM. Third, inhibition of phosphoinositide 3-kinase (PI3K), a downstream molecule of NMDAR, increased γ power and blocked the effects of DA on γ oscillation in WT mice and had no significant effect on γ power but largely restored DA modulation of γ oscillations in HRM. Our results reveal that impaired DA function in HRM is associated with dysregulated NMDAR-PI3K signaling, a mechanism that may be relevant in the pathology of schizophrenia

Advances in organic–inorganic nanocomposites for cancer imaging and therapy

“All in one” organic–inorganic nanocomposites with high biocompatibility and excellent physicochemical properties have recently attracted special attention in cancer imaging and therapy. Combination of organic and inorganic materials confers the nanocomposites with superior biocompatibility and biodegradability of organic materials, as well as magnetic, mechanical, and optical properties of inorganic materials. Increased endeavors have been made to produce diverse organic–inorganic nanocomposites and investigate their potential applications in cancer treatment. Thus, a systematic review of research progresses of diverse organic–inorganic nanocomposites in cancer imaging and therapy is indispensable. Following a brief overview of nanocomposites synthesis, classification, and functionalization, the current review is focused on comprehensively summarizing representatives of both organic–inorganic nanoscale nanocomposites (including organic-silica, organic-carbon, organic-quantum dots, organic-platinum family metals, organic-gold, organic metal oxides, and other nanocomposites) and organic–inorganic molecular nanocomposites (including metal-organic frameworks, organosilica nanoparticles, and amorphous metal coordination polymer particles), and further analyzing their working mechanism in cancer imaging and therapy. Finally, the challenges and future perspectives of organic–inorganic nanocomposites are addressed for promoting their developments and clinical application in cancer treatment

Altered myelination in the Niemann-Pick type C1 mutant mouse

Niemann–Pick type C1 (NPC1) disease is a lysosomal storage disorder caused by mutation of Npc1 or Npc2 gene, resulting in various progressive pathological features. Myelin defection is a major pathological problem in Npc1 mutant mice; however, impairment of myelin proteins in the developing brain is still incompletely understood. In this study, we showed that the expression of myelin genes and proteins is strongly inhibited from postnatal day 35 onwards including reduced myelin basic protein (MBP) expression in the brain. Furthermore, myelination characterized by MBP immunohistochemistry was strongly perturbed in the forebrain, moderately in the midbrain and cerebellum, and slightly in the hindbrain. Our results demonstrate that mutation of the Npc1 gene is sufficient to cause severe and progressive defects in myelination in the mouse brain