SummaryDue to differences across species, the mechanisms of cell fate decisions determined in mice cannot be readily extrapolated to humans. In this study, we developed a feeder- and xeno-free culture protocol that efficiently induced human pluripotent stem cells (iPSCs) into PLZF+/GPR125+/CD90+ spermatogonium-like cells (SLCs). These SLCs were enriched with key genes in germ cell development such as MVH, DAZL, GFRα1, NANOS3, and DMRT1. In addition, a small fraction of SLCs went through meiosis in vitro to develop into haploid cells. We further demonstrated that this chemically defined induction protocol faithfully recapitulated the features of compromised germ cell development of PSCs with NANOS3 deficiency or iPSC lines established from patients with non-obstructive azoospermia. Taken together, we established a powerful experimental platform to investigate human germ cell development and pathology related to male infertility.
Chronic inflammation, which is regulated by overactivated microglia in the brain, accelerates the occurrence and development of Alzheimer's disease (AD). Gx-50 has been investigated as a novel drug for the treatment of AD in our previous studies. Here, we investigated whether gx-50 possesses anti-inflammatory effects in primary rat microglia and a mouse model of AD, amyloid precursor protein (APP) Tg mice. The expression of TNF-α, IL-1β, NO, prostaglandin E2, and the expression of iNOS and COX2 were inhibited by gx-50 in amyloid β (Aβ) treated rat microglia; additionally, microglial activation and the expression of IL-1β, iNOS, and COX2 were also significantly suppressed by gx-50 in APP + transgenic mice. Furthermore, gx-50 inhibited the activation of NF-κB and MAPK cascades in vitro and in vivo in APP-Tg mice. Moreover, the expression of TLR4 and its downstream signaling proteins MyD88 and tumor necrosis factor receptor associated factor 6 (TRAF6) was reduced by gx-50 in vitro and in vivo. Interestingly, silencing of TLR4 reduced Aβ-induced upregulation of IL-1β and TRAF6 to levels similar to gx-50 inhibition; moreover, overexpression of TLR4 increased the expression of MyD88 and TRAF6, which was significantly reduced by gx-50. These findings provide strong evidence that gx-50 has anti-inflammatory effects against Aβ-triggered microglial overactivation via a mechanism that involves the TLR4-mediated NF-κBB/MAPK signaling cascade. Keywords:Alzheimer's disease r APP-Tg mice r gx-50 r inflammation r microglia r NF-κB Additional supporting information may be found in the online version of this article at the publisher's web-site IntroductionAlzheimer's disease (AD) is one of the most common dementias and is characterized by cognitive deficits and neuron loss. Although the neuropathologic hallmarks of AD are well known, these features do not necessarily reflect the fundamental cause of the disease in which many factors and pathways are involved, and complex mechanisms continue to be elucidated. Among the mechanisms, neuroinflammation is now thought to contribute and exacCorrespondence: Prof. Zhongdong Qiao e-mail: zdqiao@sjtu.edu.cn erbate AD pathology and has been studied extensively in recent years [1]. Although acute neuroinflammatory responses are generally beneficial to the CNS, chronic neuroinflammation is most often detrimental to the host tissue [2]. Microglia are the most abundant resident immune cells in the brain and have a central role in the pathophysiology of AD due to their rapid activation in response to brain injury and disease, including nearly every type of brain pathology (e.g., trauma, infection, neoplasm, infarction, and neurodegeneration) [3]. Amyloid precursor protein (APP) and amyloid β (Aβ) can directly active microglia and initiate the local inflammatory response in the AD brain [4], which is followed bywww.eji-journal.eu 666Shi Shi et al. Eur. J. Immunol. 2016. 46: 665-676 the production of excessive proinflammatory and neurotoxic factors, including the cytokines TNF-α, IL-1β, IL-6, a...
To study the diversity of mRNAs in murine spermatozoa and their potential function during zygotic development, total RNAs in murine spermatozoa were sequenced via RNA-Seq and analyzed through bioinformatics techniques. The delivery and translation of sperm-borne mRNA in fertilized oocyte were detected using RT-PCR (reverse transcription-polymerase chain reaction), Western blot, and immunofluorescence. A total of 35 288 825 reads matching 33 039 transcripts, including 27 310 coding transcripts, were obtained. Based on our analyses, we hypothesized that the transcripts with RPKM (reads per kilobase of exon model per million mapped reads) higher than six may exist in each sperm cell as consistently retained transcripts. There were 4885 consistent transcripts in each sperm, and the remainder were randomly retained. If the baseline RPKM increased, the remaining coding transcripts were more likely related to reproduction and development. The sperm-borne transcripts Wnt4 and Foxg1 were delivered into fertilized oocytes on fertilization. Furthermore, Wnt4 was translated into protein in zygotes, whereas Foxg1 was not translated. In conclusion, approximately 4885 mRNAs were present in each murine spermatozoon, and the spermatozoal mRNAs related to reproduction and development were more likely retained. The sperm-borne mRNA Wnt4 was delivered into the fertilized oocyte and translated, evidence of a paternal effect on zygotic development.
Recent studies have revealed that the α7 nicotinic acetylcholine receptor (α7 nAChR) is a critical link between inflammation and neurodegeneration, which is closely associated with Alzheimer's disease (AD). The JAK2/STAT3 and PI3K/AKT signaling pathways contribute to the neuroprotective and anti-inflammatory effects of α7nAChR. Our previous studies have shown that treatment with gx-50 improves cognitive function and is neuroprotective. Here, we investigated the effect of gx-50 on α7 nAChR and Aβ-induced inflammation in microglia. First, the binding affinity of gx-50 to α7 nAChR was examined using the fluorescence-based Octet RED system, and the expression of α7 nAChR was detected using real-time PCR and western blotting. We also investigated downstream events of α7 nAChR activity, including the translocation of p-STAT3 and the phosphorylation of JAK2, STAT3, PI3K, and AKT. Finally, the effect of gx-50 on Aβ-induced inflammation via α7 nAChR-mediated signaling pathways was investigated using cytokine assays. The results showed that gx-50 is able to act as a specific ligand to activate α7 nAChR, which then upregulates the JAK2/STAT3 and PI3K/AKT signaling pathways to inhibit the secretions of pro-inflammatory cytokines, such as IL-1β. In conclusion, the results suggest that gx-50 could inhibit the Aβ-induced inflammatory response in microglia via α7 nAChR activity, which might be a successful therapeutic target against AD.
Nicotine can induce the abnormal migration and proliferation of vascular smooth muscle cells (VSMCs). We have previously shown that cytoskeletal proteins and RhoGDIA, a negative regulator of the Rho GTPase pathway, are involved in the nicotine-induced dysfunction of VSMCs. Here, we found that nicotine can activate the Rho GTPase pathway and induce the synthesis of the cytoskeletal proteins in VSMCs through the activation of intracellular downstream signaling pathways, including targets such as MYPT1, PAK1 and PI3K/AKT. Upon nicotine treatment, the mRNA level of RhoGDIA is increased but protein level is decreased both in vitro and in vivo, which suggested a mechanism of post-translational regulation. By the dual luciferase reporter assay, we identified the microRNA-200b (miR-200b) as a modulator of the behavioural changes of VSMCs in response to nicotine through targeting RhoGDIA directly. Introducing miR-200b inhibitors into cultured VSMCs significantly attenuated cell proliferation and migration. Additionally, we found that hypomethylation in the CpG island shore region of miR-200b was responsible for the nicotine-induced miR-200b up-regulation in VSMCs. The study demonstrates that nicotine facilitates VSMC dysfunction through a miR-200b/RhoGDIA/cytoskeleton module through the hypomethylation of miR-200b promoter and suggests that epigenetic modifications may play an important role in the pathological progression.
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