bims-ershed 2021-10-03 papers

Issue of 2021‒10‒03
three papers selected by
Matías Eduardo González Quiroz
Worker’s Hospital

Front Pharmacol. 2021 ;12 697360

Regulation of Endoplasmic Reticulum Stress-Autophagy: A Potential Therapeutic Target for Ulcerative Colitis.

Dan Qiao, Ziwei Zhang, Yali Zhang, Qian Chen, Yujun Chen, Yingjue Tang, Xiong Sun, Zhipeng Tang, Yancheng Dai.

Ulcerative colitis (UC) is a chronic nonspecific inflammation that mainly affects the mucosa and submucosa of the rectum and colon. Numerous studies have shown that endoplasmic reticulum stress (ERS)-induced autophagy plays a vital role in the pathogenesis of UC. ERS is the imbalance of internal balance caused by misfolded or unfolded proteins accumulated in the endoplasmic reticulum (ER).Excessive ERS triggers the unfolded protein response (UPR), an increase in inositol-requiring enzyme 1, and a Ca2+ overload, which activates the autophagy pathway. Autophagy is an evolutionarily conserved method of cellular self-degradation. Dysregulated autophagy causes inflammation, disruption of the intestinal barrier, and imbalance of intestinal homeostasis, therefore increasing the risk of colonic diseases. This review summarizes the pathogenesis of ERS, UPR, and ERS-related autophagy in UC, providing potential new targets and more effective treatment options for UC.

Keywords: autophagy; endoplasmic reticulum stress; ulcerative colitis; unfolded protein; unfolded protein response

DOI: https://doi.org/10.3389/fphar.2021.697360

Genes (Basel). 2021 Sep 20. pii: 1446. [Epub ahead of print]12(9):

p53 mRNA Metabolism Links with the DNA Damage Response.

Sivakumar Vadivel Gnanasundram, Ondrej Bonczek, Lixiao Wang, Sa Chen, Robin Fahraeus.

Human cells are subjected to continuous challenges by different genotoxic stress attacks. DNA damage leads to erroneous mutations, which can alter the function of oncogenes or tumor suppressors, resulting in cancer development. To circumvent this, cells activate the DNA damage response (DDR), which mainly involves cell cycle regulation and DNA repair processes. The tumor suppressor p53 plays a pivotal role in the DDR by halting the cell cycle and facilitating the DNA repair processes. Various pathways and factors participating in the detection and repair of DNA have been described, including scores of RNA-binding proteins (RBPs) and RNAs. It has become increasingly clear that p53's role is multitasking, and p53 mRNA regulation plays a prominent part in the DDR. This review is aimed at covering the p53 RNA metabolism linked to the DDR and highlights the recent findings.

Keywords: ATM kinase; DNA damage response; MDM2; RNA metabolism; RNA-binding proteins; mRNA translation; p53

DOI: https://doi.org/10.3390/genes12091446

Biomedicines. 2021 Sep 06. pii: 1166. [Epub ahead of print]9(9):

Association of Caspase 3 Activation and H2AX γ Phosphorylation in the Aging Brain: Studies on Untreated and Irradiated Mice.

Nadia Gionchiglia, Alberto Granato, Adalberto Merighi, Laura Lossi.

Phosphorylation of H2AX is a response to DNA damage, but γH2AX also associates with mitosis and/or apoptosis. We examined the effects of X-rays on DNA integrity to shed more light on the significance of H2AX phosphorylation and its relationship with activation of caspase 3 (CASP3), the main apoptotic effector. After administration of the S phase marker BrdU, brains were collected from untreated and irradiated (10 Gray) 24-month-old mice surviving 15 or 30 min after irradiation. After paraffin embedding, brain sections were single- or double-stained with antibodies against γH2AX, p53-binding protein 1 (53BP1) (which is recruited during the DNA damage response (DDR)), active CASP3 (cCASP3), 5-Bromo-2-deoxyuridine (BrdU), and phosphorylated histone H3 (pHH3) (which labels proliferating cells). After statistical analysis, we demonstrated that irradiation not only induced a robust DDR with the appearance of γH2AX and upregulation of 53BP1 but also that cells with damaged DNA attempted to synthesize new genetic material from the rise in BrdU immunostaining, with increased expression of cCASP3. Association of γH2AX, 53BP1, and cCASP3 was also evident in normal nonirradiated mice, where DNA synthesis appeared to be linked to disturbances in DNA repair mechanisms rather than true mitotic activity.

Keywords: DNA; DNA damage; H2AX; aging; apoptosis; caspase 3; cell proliferation; forebrain; ionizing radiations; neurons

DOI: https://doi.org/10.3390/biomedicines9091166