Endoplasmic reticulum (ER) stress is a common cellular stress response that is triggered by a variety of conditions that disturb cellular homeostasis, and induces cell apoptosis. Autophagy, an important and evolutionarily conserved mechanism for maintaining cellular homeostasis, is closely related to the apoptosis induced by ER stress. There are common upstream signaling pathways between autophagy and apoptosis induced by ER stress, including PERK/ATF4, IRE1α, ATF6, and Ca . Autophagy can not only block the induction of apoptosis by inhibiting the activation of apoptosis-associated caspase which could reduce cellular injury, but also help to induce apoptosis. In addition, the activation of apoptosis-related proteins can also inhibit autophagy by degrading autophagy-related proteins, such as Beclin-1, Atg4D, Atg3, and Atg5. Although the interactions of different autophagy- and apoptosis-related proteins, and also common upstream signaling pathways have been found, the potential regulatory mechanisms have not been clearly understood. In this review, we summarize the dual role of autophagy, and the interplay and potential regulatory mechanisms between autophagy and apoptosis under ER stress condition.

Endoplasmic reticulum (ER) stress, a common cellular stress response, is closely related to the activation of autophagy that is an important and evolutionarily conserved mechanism for maintaining cellular homeostasis. Autophagy induced by ER stress mainly includes the ER stress-mediated autophagy and ER-phagy. The ER stress-mediated autophagy is characterized by the generation of autophagosomes that include worn-out proteins, protein aggregates, and damaged organelles. While the autophagosomes of ER-phagy selectively include ER membranes, and the double membranes also derive, at least in part, from the ER. The signaling pathways of IRE1α, PERK, ATF6, and Ca are necessary for the activation of ER stress-mediated autophagy, while the receptor-mediated selective ER-phagy degrades the ER is Atg40/FAM134B. The ER stress-mediated autophagy and ER-phagy not only have differences, but also have connections. The activation of ER-phagy requires the core autophagy machinery, and the ER-phagy may be a branch of ER stress-mediated autophagy that selectively targets the ER. However, the determined factors that control the changeover switch between ER stress-mediated autophagy and ER-phagy are largely obscure, which may be associated with the type of cells and the extent of stimulation. This review summarized the crosstalk between ER stress-mediated autophagy and ER-phagy and their signaling networks. Additionally, we discussed the possible factors that influence the type of autophagy induced by ER stress.

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Silent information regulator factor 2-related enzyme 1 (sirtuin 1, Sirt1) is a nicotinamide adenine dinucleotide-dependent deacetylase, which can deacetylate histone and non-histone proteins and other transcription factors, and is involved in the regulation of many physiological functions, including cell senescence, gene transcription, energy balance, and oxidative stress. Ischemia/hypoxia injury remains an unresolved and complicated situation in the diseases of ischemia stroke, heart failure, and coronary heart disease, especially among the old folks. Studies have demonstrated that aging could enhance the vulnerability of brain, heart, lung, liver, and kidney to ischemia/hypoxia injury and the susceptibility in old folks to ischemia/hypoxia injury might be associated with Sirt1. In this review, we mainly summarize the role of Sirt1 in modulating pathways against energy depletion and its involvement in oxidative stress, apoptosis, and inflammation under the condition of ischemia/hypoxia.

Abstract Background We aimed to evaluate the antiviral activity and safety of darunavir/cobicistat (DRV/c) in treating COVID-19 patients. Methods In this single-center, randomized, and open-label trial, mild patients with polymerase chain reaction (PCR)–confirmed COVID-19 were enrolled in Shanghai, China. Participants were randomized to receive DRV/c for 5 days on the top of interferon alpha 2b inhaling or interferon alpha 2b inhaling alone. The primary end point was the virological clearance rate of oropharyngeal swabs at day 7 after randomization in the intention-to-treat population (clinicaltrials.gov: NCT04252274). Results From January 30, 2020, to February 6, 2020, a total of 30 patients were enrolled, of whom 18 (60%) were male, aged 47.2 ± 2.8 years; 63.3% (19/30) of the participants had fever, and 46.7% (14/30) had cough at enrollment. The participants were randomized (range) at 4 (2–5) days after onset of symptoms. The proportion of negative PCR results at day 7 was 46.7% (7/15) and 60.0% (9/15) in the DRV/c and control groups (P = .72), respectively. The viral clearance rate at day 3 was 20% (3/15) in both study groups, while the number increased to 26.7% (4/15) in the DRV/c group and remained 20% (3/15) in the control group at day 5. Fourteen days after randomization, 1 participant in the DRV/c group progressed to critical illness and discontinued DRV/c, while all the patients in the control group were stable (P = 1.0). The frequencies of adverse events in the 2 groups were comparable. Conclusions Five days of DRV/c did not increase the proportion of negative conversion vs standard of care alone, although it was well tolerated.

Aging is a physiological decline in both structural homeostasis and functional integrity, progressively affecting organismal health. A major hallmark of aging is the accumulation of senescent cells, which have entered a state of irreversible cell cycle arrest after experiencing inherent or environmental stresses. Although cellular senescence is essential in several physiological events, it plays a detrimental role in a large array of age-related pathologies. Recent biomedical advances in specifically targeting senescent cells to improve healthy aging, or alternatively, postpone natural aging and age-related diseases, a strategy termed senotherapy, have attracted substantial interest in both scientific and medical communities. Challenges for aging research are highlighted and potential avenues that can be leveraged for therapeutic interventions to control aging and age-related disorders in the current era of precision medicine.

Colorectal cancer is one of the leading causes of cancer deaths. It correlates to a high fat diet, which causes an increase of the secondary bile acids including deoxycholate (DOC) in the intestine. We aimed to determine the effects of DOC on intestinal carcinogenesis in Apc (min/+) mice, a model of spontaneous intestinal adenomas. Four-week old Apc (min/+) mice were treated with 0.2 % DOC in drinking water for 12 weeks. The number and size of tumors were measured, and tissue sections were prepared for the evaluation of intestinal carcinogenesis, cell proliferation, and apoptosis. The activation of Wnt signaling was detected in the intestinal tumor cells of the Apc (min/+) mice, and also in the human colon samples. DOC increased the number of intestine tumors by 165.1 % compared with that in untreated Apc (min/+) mice mainly in the middle and distal segments of the small intestine and colon. The numbers of all sizes of tumors in the small intestine were increased. Intestinal carcinogenesis was confirmed in 75 % mice in DOC treated-Apc (min/+) mice compared with 0 % in untreated mice. This was accompanied by promoting tumor cell proliferation and decreasing apoptosis, and increasing the percentage of β-catenin positive cells and its nuclear expression in intestinal tumor cells of Apc (min/+) mice, and also up-regulating the expression of cyclin D1. In addition, the activation of Wnt signaling also played in modulating human colon carcinogenesis. Our studies suggest that DOC enhances the multiplicity of intestinal tumor, and accelerates intestinal adenoma-adenocarcinoma sequence in Apc (min/+) mice mediated by stimulating tumor cell proliferation and decreasing apoptosis through enhancing Wnt signaling.

Leucine-enkephalin (Leu-EK) dose-dependently elicited an increase in cytosolic Ca2+ concentration ([Ca2+]i) with an EC50 of 1.2 microM via the phosphoinositide cascade in NG108-15 cells. Chronic treatment of cells with [D-Ala2,D-Leu5]enkephalin caused time-dependent homologous desensitization. In the presence of extracellular Ca2+, ATP as well as bradykinin stimulated significantly higher increases in inositol 1,4,5-trisphosphate (IP3) generation than did Leu-EK; however, the magnitude of intracellular Ca2+ pools increased after ATP stimulation, whereas bradykinin depleted intracellular pools. Hence, cells lost their [Ca2+]i response to Leu-EK if bradykinin was first added to induce a [Ca2+]i increase, whereas the response was unchanged if Leu-EK was added after addition of ATP. When Leu-EK was added simultaneously with bradykinin or ATP, an additive response was observed in IP3 generation; however, the rise in [Ca2+]i reached the same level as that induced by bradykinin or ATP alone. In the absence of extracellular Ca2+ in which the replenishment of intracellular pools was not possible, ATP displayed an inhibitory effect similar to that of bradykinin on the Leu-EK-induced [Ca2+]i increase. Prior treatment of cells with Leu-EK slightly heterologously desensitized the action of bradykinin, but had no effect on the ATP response. Our results suggest that a shared intracellular Ca2+ pool is sensitive to the opioid, bradykinin and P2-purinoceptor agonists; however, a defined pool of phosphatidylinositol 4,5-bisphosphate or a specific phospholipase C is responsible for each receptor.