Κυριακή 10 Νοεμβρίου 2019

EGFR signaling augments TLR4 cell surface expression and function in macrophages via regulation of Rab5a activation

JMJD3 in the regulation of human diseases

ABSTRACT

In recent years, many studies have shown that histone methylation plays an important role in maintaining the active and silent state of gene expression in human diseases. The Jumonji domain-containing protein D3 (JMJD3), specifically demethylate di- and trimethyl-lysine 27 on histone H3 (H3K27me2/3), has been widely studied in immune diseases, infectious diseases, cancer, developmental diseases, and aging related diseases. We will focus on the recent advances of JMJD3 function in human diseases, and looks ahead to the future of JMJD3 gene research in this review.

Functions of p53 in pluripotent stem cells

Abstract

Pluripotent stem cells (PSCs) are capable of unlimited self-renewal in culture and differentiation into all functional cell types in the body, and thus hold great promise for regenerative medicine. To achieve their clinical potential, it is critical for PSCs to maintain genomic stability during the extended proliferation. The critical tumor suppressor p53 is required to maintain genomic stability of mammalian cells. In response to DNA damage or oncogenic stress, p53 plays multiple roles in maintaining genomic stability of somatic cells by inducing cell cycle arrest, apoptosis, and senescence to prevent the passage of genetic mutations to the daughter cells. p53 is also required to maintain the genomic stability of PSCs. However, in response to the genotoxic stresses, a primary role of p53 in PSCs is to induce the differentiation of PSCs and inhibit pluripotency, providing mechanisms to maintain the genomic stability of the self-renewing PSCs. In addition, the roles of p53 in cellular metabolism might also contribute to genomic stability of PSCs by limiting oxidative stress. In summary, the elucidation of the roles of p53 in PSCs will be a prerequisite for developing safe PSC-based cell therapy.

Contact-dependent delivery of IL-2 by dendritic cells to CD4 T cells in the contraction phase promotes their long-term survival

Abstract

Common γ chain cytokines are important for immune memory formation. Among them, the role of IL-2 remains to be fully explored. It has been suggested that this cytokine is critically needed in the late phase of primary CD4 T cell activation. Lack of IL-2 at this stage sets for a diminished recall response in subsequent challenges. However, as IL-2 peak production is over at this point, the source and the exact mechanism that promotes its production remain elusive. We report here that resting, previously antigen-stimulated CD4 T cells maintain a minimalist response to dendritic cells after their peak activation in vitro. This subtle activation event may be induced by DCs without overt presence of antigen and appears to be stronger if IL-2 comes from the same dendritic cells. This encounter reactivates a miniature IL-2 production and leads a gene expression profile change in these previously activated CD4 T cells. The CD4 T cells so experienced show enhanced reactivation intensity upon secondary challenges later on. Although mostly relying on in vitro evidence, our work may implicate a subtle programing for CD4 T cell survival after primary activation in vivo.

Correction to: Neuroendocrine characteristics of induced pluripotent stem cells from polycystic ovary syndrome women
In the original publication the Fig. 2 and the Supplementary Material 1 was incorrect. The correct version of Fig. 2 and the Supplementary Material are provided in this correction article. NESTIN should be corrected to PAX6 in Fig. 2C legend and at page 528 and Supplementary Material 1. NANOG should be corrected to PAX6 in Fig. 2C picture. Fig. 2. Differentiation and identification of NSCs from PCOS-derived iPSCs. (A) Schematic procedure of NSCs differentiation from iPSCs. NSC: Neural stem cell; EB: embryoid body. (B) The phenotype of specific differentiated NSCs. Scale bars = 100 µm. (C) Immunofluorescence images of the NSC markers SOX2 and PAX6. Scale bars = 50 µm. ZOOM, scale bars = 25 μm. (D) The mitochondrial respiration function of PCOS- and non-PCOS-derived iPSCs and NSCs. (E) Quantitative analysis of basal oxygen consumption, ATP production, maximal respiration, and proton leak. (F) Proposed neuroendocrine state in normal and PCOS patients. In normal patients, the GnRH pulsatile frequency is critical for steroidogenesis and follicular development. Low frequency pulses prefer FSH, and high frequency pulses favour LH. In PCOS, the increased GnRH release led to a high level of LH pulsatility, impairing the preferential release of FSH and follicular maturation, thus leading to polycystic ovaries. Red: increased; Blue: decreased. Solid arrow: up regulated; Dotted arrow: down regulated.

Qi Fang: Affective interweave with patients

Correction to: Developing potent PROTACs tools for selective degradation of HDAC6 protein
In the original publication the title of X axis in figure 1G is incorrectly published as “Compound (µmol/L)”. The correct title of X axis in figure 1G should be read as “Compound (nmol/L)”

Professor Yongjia Duan: a distinguished plant pathologist and agricultural educator

Kuo-Hua Sun: The founder of physiologic psychology and child psychology in China

Inhibition of p53 and/or AKT as a new therapeutic approach specifically targeting ALT cancers

Abstract

While the majority of all human cancers counteract telomere shortening by expressing telomerase, ~15% of all cancers maintain telomere length by a telomerase-independent mechanism known as alternative lengthening of telomeres (ALT). Here, we show that high load of intrinsic DNA damage is present in ALT cancer cells, leading to apoptosis stress by activating p53-independent, but JNK/c-Myc-dependent apoptotic pathway. Notably, ALT cells expressing wild-type p53 show much lower apoptosis than p53-deficient ALT cells. Mechanistically, we find that intrinsic DNA damage in ALT cells induces low level of p53 that is insufficient to initiate the transcription of apoptosis-related genes, but is sufficient to stimulate the expression of key components of mTORC2 (mTOR and Rictor), which in turn leads to phosphorylation of AKT. Activated AKT (p-AKT) thereby stimulates downstream anti-apoptotic events. Therefore, p53 and AKT are the key factors that suppress spontaneous apoptosis in ALT cells. Indeed, inhibition of p53 or AKT selectively induces rapid death of ALT cells in vitro, and p53 inhibitor severely suppresses the growth of ALT-cell xenograft tumors in mice. These findings reveal a previously unrecognized function of p53 in anti-apoptosis and identify that the inhibition of p53 or AKT has a potential as therapeutics for specifically targeting ALT cancers.

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