Knowledge mapping of research on the mitochondrial unfolded protein response: a bibliometric and visual analysis.

Background: The mitochondrial unfolded protein response (UPRmt) is a mitochondria stress response, which exerts a crucial role in maintaining mitochondrial proteostasis during stress. However, there is no bibliometric analyses systematically studied this field which could comprehensively review research trends, evaluate publication performances and provide future perspectives. Methods: Articles investigating UPRmt published between 1994 and 2021 were downloaded from the Core Collection of the Web of Science (WOS). CiteSpace and VOSviewer bibliometric software were applied for bibliometric and visual analyses. Results: A total of 2,073 papers researching UPRmt were retrieved. According to the published number of papers, the field of UPRmt research has gone through its infancy (after 2000) and rapid growth (after 2021) phases. The United States and China contributed the most to UPRmt research. Regarding the distribution of institutions, Harvard University was the most influential institution. The most prolific authors are Johan Auwerx and CM Haynes. PLoS One is the most extensive journal in the field of UPRmt research, while the Cell Death and Differentiation journal had the greatest impact among the most-authored journals. Moreover, biochemistry/molecular biology, and cell biology are the largest subject areas. UPRmt research is mainly categorized as UPRmt, transcription, endoplasmic reticulum (ER) stress, lipotoxicity, mitophagy, inflammation, skeletal muscle, hypoxia, apoptosis, mitochondrial dysfunction, neurodegeneration, mitochondrial permeability transition, and integrated stress response. Conclusions: At present, research on UPRmt is booming. Further strengthening the cooperation and exchanges between countries, institutions, and authors in the future will surely promote the development of this field.

Inhibition of the expression of rgs-3 alleviates propofol-induced decline in learning and memory in Caenorhabditis elegans.

BACKGROUND: Exposure to anesthesia leads to extensive neurodegeneration and long-term cognitive deficits in the developing brain. Caenorhabditis elegans also shows persistent behavioral changes during development after exposure to anesthetics. Clinical and rodent studies have confirmed that altered expression of the regulators of G protein signaling (RGS) in the nervous system is a factor contributing to neurodegenerative and psychological diseases. Evidence from preclinical studies has suggested that RGS controls drug-induced plasticity, including morphine tolerance and addiction. This study aimed to observe the effect of propofol exposure in the neurodevelopmental stage on learning and memory in the L4 stage and to study whether this effect is related to changes in rgs-3 expression. METHODS: Caenorhabditis elegans were exposed to propofol at the L1 stage, and learning and memory abilities were observed at the L4 stage. The expression of rgs-3 and the nuclear distribution of EGL-4 were determined to study the relevant mechanisms. Finally, RNA interference was performed on rgs-3-expressing cells after propofol exposure. Then, we observed their learning and memory abilities. RESULTS: Propofol time- and dose-dependently impaired the learning capacity. Propofol induced a decline in non-associative and associative long-term memory, rgs-3 upregulation, and a failure of nuclear accumulation of EGL-4/PKG in AWC neurons. Inhibition of rgs-3 could alleviate the propofol-induced changes. CONCLUSION: Inhibition of the expression of rgs-3 alleviated propofol-induced learning and memory deficits in Caenorhabditis elegans.

Propofol Inhibits Ferroptotic Cell Death Through the Nrf2/Gpx4 Signaling Pathway in the Mouse Model of Cerebral Ischemia-Reperfusion Injury.

Ferroptosis is characterized by excessive accumulation of iron and lipid peroxides, which are involved in ischemia, reperfusion-induced organ injury, and stroke. Propofol, an anesthetic agent, has neuroprotective effects due to its potent antioxidant, anti-ischemic, and anti-inflammatory properties. However, the relationship between propofol and ferroptosis is still unclear. In the current study, we elucidated the role of ferroptosis in the neuroprotective effect of propofol in mouse brains subjected to cerebral ischemia reperfusion injury (CIRI). Ferroptosis was confirmed by Western blotting assays, transmission electron microscopy, and glutathione assays. Propofol regulated Nrf2/Gpx4 signaling, enhanced antioxidant potential, inhibited the accumulation of lipid peroxides in CIRI-affected neurons, and significantly reversed CIRI-induced ferroptosis. Additionally, Gpx4 inhibitor RSL3 and Nrf2 inhibitor ML385 attenuated the effects of propofol on antioxidant capacity, lipid peroxidation, and ferroptosis in CIRI-affected neurons. Our data support a protective role of propofol against ferroptosis as a cause of cell death in mice with CIRI. Propofol protected against CIRI-induced ferroptosis partly by regulating the Nrf2/Gpx4 signaling pathway. These findings may contribute to the development of future therapies targeting ferroptosis induced by CIRI.

Intestinal Flora Dysbiosis Aggravates Cognitive Dysfunction Associated With Neuroinflammation in Heart Failure.

BACKGROUND: Cognitive dysfunction after heart failure (HF) is characterized by neuroinflammation, which plays an important role in the occurrence and development of cognitive dysfunction. Recent studies have shown that an intestinal flora imbalance may also trigger neuroinflammation in Alzheimer's disease. The present study was designed to reveal that intestinal flora dysbiosis caused by HF aggravates neuroinflammation-associated cognitive impairment. METHODS AND RESULTS: Adult male Sprague-Dawley rats were fed daily for 2 weeks with probiotics or placebo until the day of surgery. HF was then triggered by 8 weeks of sustained coronary artery occlusion. 16S rDNA sequencing was used to confirm intestinal flora dysbiosis after HF and demonstrate that the changes paralleled intestinal pathology scores. The permeability of the blood-brain barrier was increased after HF, and such an increase in permeability may increase the levels of inflammatory cytokines caused by intestinal flora disorders. The changes in the intestinal flora caused by probiotics significantly reduced the level of neuroinflammation. In addition, probiotic administration considerably improved the impaired spatial memory in HF rats. CONCLUSIONS: We conclude that intestinal flora dysbiosis plays a potential role in aggravating the impaired cognition associated with neuroinflammation and that these effects may be attenuated by probiotics.

Network and Pathway-Based Integrated Analysis Identified a Novel "rs28457673-miR-15/16/195/424/497 Family-IGF1R-MAPK Signaling Pathway" Axis Associated With Post-stroke Depression.

Single-nucleotide polymorphisms (SNPs) of microRNA (miRNA) (miRSNP) are SNPs located on miRNA genes or miRNA target sites, which have been supposed to be involved in the development of central nervous system diseases by interfering with miRNA-mediated regulatory functions. However, the association of miRSNP with post-stroke depression (PSD) has not been well-investigated. In this study, we collected 54 PSD risk genes via manual literature-mining and integrated PSD-related risk pathways based on multiple public databases. Furthermore, we systematically screened candidate functional miRSNPs for PSD and integrated a miRSNP-based PSD-associated pathway network, which included 99 miRNAs that target 12 PSD risk pathways. We also reviewed the association between three risk pathways and PSD pathogenetic mechanism thoroughly. Combining literature mining and network analysis, our results proposed an underlying mechanism of "miRSNP → miRNA → risk gene → pathway" axis effects on PSD pathogenesis, especially for rs28457673 (miR-15/16/195/424/497 family) → IGF1R → hsa04010 (MAPK signaling pathway). Our studies revealed a functional role in genetic modifier at the system level in the pathogenesis of PSD, which might provide further information for the miRSNP studies in PSD.

Probiotics alleviate cognitive dysfunction associated with neuroinflammation in cardiac surgery.

Neuroinflammation plays a key role in the progression and pathogenesis of postoperative cognitive dysfunction, but it does not always occur in the local response to primary injury. In this study, we revealed that probiotics alleviate cognitive dysfunction associated with neuroinflammation in cardiac surgery. Rats were administered a probiotic or placebo once a day by gavage for 2 weeks until the day of surgery. Cardiac surgery was induced by ischemia/reperfusion of the left coronary artery. Key factors, such as the gut microbiome, the gut barrier and the blood-brain barrier (BBB), were systematically investigated to determine whether changes in the gut microbiome lead to neuroinflammation. We used 16S rDNA sequencing to confirm that cardiac surgery induced intestinal flora dysbiosis by altering the number of organisms rather than the structure in the cecum microbiome, which occurs at the same time as damage to the gut barrier. Cardiac surgery also increased BBB permeability, suggesting that disruption of the microbiome may increase the likelihood of neuroinflammation. Probiotics-induced alterations in the intestinal flora significantly reduced the level of inflammatory cytokines (IL-6 and IL-1ß). Importantly, we found that the administration of probiotics significantly improved spatial memory impairment in rats after cardiac surgery, as measured by the Morris water maze. Overall, dysbiosis of the gut flora may aggravate cognitive impairment associated with neuroinflammation after cardiac surgery, and probiotics may attenuate this effect.