Effects of homocysteine-induced endoplasmic reticulum protein on endoplasmic reticulum stress, autophagy, and neuronal apoptosis following intracerebral hemorrhage

Untargeted metabolic profiling of high-dose methotrexate toxicity shows alteration in betaine metabolism

Cardiotoxicity is a well-established adverse effect of several drugs across multiple therapeutic indications. It is particularly prevalent following anticancer therapy. In order to evaluate the changes in cellular metabolism associated with methotrexate cardiotoxicity, we treated Wistar rats with a single high dose of methotrexate (HDMTX), and after five days, the animals were sacrificed. We then analyzed the cardiotoxicity parameters in serum like Cardiac enzymes(CK-MB, Troponin T, ALP), Inflammatory markers (TNF-α and IL-6), oxidative stress markers (NO, NOX-2), histopathology and cardiac tissue with the goal of identifying a metabolic signature of cardiotoxicity using discovery-based metabolomics. The biochemical parameters for cardiac enzymes, oxidative stress and inflammatory markers showed a significant increase in all three categories in rats treated with HDMTX. These findings were mirrored in the histopathological analysis confirming cardiotoxicity due to HDMTX. The results showed a total of 95 metabolites that were found to be significantly (p < 0.05) modulated: either up- or downregulated in the HDMTX-treated group when compared with the control group. Using integrated pathway analysis we found these metabolites were associated with many important cardiac tissue metabolic pathways, such as the malate aspartate shuttle, taurine and hypotaurine metabolism, betaine metabolism, spermidine biosynthesis, and homocysteine degradation. Among them, L-arginine, homocysteine, and betaine were significantly upregulated, suggesting their possible association with cardiac tissue injury. Overall, we provided evidence for using untargeted metabolomics to identify novel metabolites associated with HDMTX cardiac toxicity.

Deubiquitylating Enzyme OTUB1 Facilitates Neuronal Survival After Intracerebral Hemorrhage Via Inhibiting NF-κB-triggered Apoptotic Cascades

The deubiquitylase OTU domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1) has been implicated in the pathogenesis of various human diseases. However, the molecular mechanism by which OTUB1 participates in the pathogenesis of intracerebral hemorrhage (ICH) remains elusive. In the present study, we established an autologous whole blood fusion-induced ICH model in C57BL/6 J mice. We showed that the upregulation of OTUB1 contributes to the attenuation of Nuclear factor kappa B (NF-κB) and its downstream apoptotic signaling after ICH. OTUB1 directly associates with NF-κB precursors p105 and p100 after ICH, leading to attenuated polyubiquitylation of p105 and p100. Moreover, we revealed that NF-κB signaling was modestly activated both in ICH tissues and hemin-exposed HT-22 neuronal cells, accompanied with the activation of NF-κB downstream pro-apoptotic signaling. Notably, overexpression of OTUB1 strongly inhibited hemin-induced NF-κB activation, whereas interference of OTUB1 led to the opposite effect. Finally, we revealed that lentiviral transduction of OTUB1 markedly ameliorated hemin-induced apoptotic signaling and HT-22 neuronal death. Collectively, these findings suggest that the upregulation of OTUB1 serves as a neuroprotective mechanism in antagonizing neuroinflammation-induced NF-κB signaling and neuronal death, shed new light on manipulating intracellular deubiquitylating pathways as novel interventive approaches against ICH-induced secondary neuronal damage and death.

Effects of vitamin B12 deficiency on risk and outcome of ischemic stroke

Ischemic stroke is the most prevalent form of stroke and has a high incidence in older adults, characterized by high morbidity, mortality, disability, and recurrence rate. Vitamin B₁₂ deficiency is prevalent in the elderly and has been reported to be associated with ischemic stroke. The mechanisms maybe include the disorder of methylation metabolism, accumulation of toxic metabolites, immune dysfunction, affecting gut microbial composition and gut-brain immune homeostasis, and toxic stress responses to the brain. Vitamin B₁₂ deficiency may lead to cerebral artery atherosclerosis, change myelination, influence the metabolism and transmission between nerve tissue, and ultimately causes the occurrence and development of ischemic stroke. This paper reviews the correlation between vitamin B₁₂ deficiency and ischemic stroke, looking forward to improving clinicians' understanding and providing new therapeutic directions for ischemic stroke.

Individuals with Bipolar Disorder Have a Higher Level of Homocysteine Than Major Depressive Disorder: A Retrospective Chart Review and Observational Study

PURPOSE

Previous studies suggest that homocysteine (Hcy) may be involved in the pathogenesis of bipolar disorder (BD) and major depressive disorder (MDD) by influencing glutamatergic transmission, inflammation, and other mechanisms. There are no established biomarkers to distinguish BD from MDD. This study aims to compare Hcy levels between BD and MDD.

PATIENTS AND METHODS

We collected medical records of patients aged 14-75 admitted to the hospital from January 1 to July 1, 2022 with a discharge diagnosis of MDD or BD, including all examinations of patients at admission (acute phase) and discharge (non-acute phase). We measured Hcy levels in healthy controls (HC).

RESULTS

The analysis included 104 patients with MDD, 103 patients with BD, and 80 HC. Hcy levels were higher in the MDD and BD group than in the HC group and higher in the BD group than in the MDD group, both in the acute and non-acute phases (all P < 0.05). There was no significant difference in Hcy levels between the psychotropic medication users and non-users in the BD or MDD group (all P > 0.05). Multivariate logistic regression analysis only for the MDD and BD group indicated that the likelihood of BD diagnosis was significantly associated with Hcy levels (in the acute phase: OR = 1.052, P = 0.016; in the non-acute phase: OR = 1.101, P < 0.001) after controlling for gender, age, and metabolic indicators.

CONCLUSION

Our study suggests that Hcy levels were elevated in MDD and BD patients and were higher in BD patients than in MDD patients, which provides evidence for a possible relationship between one-carbon metabolism and the pathogenesis of BD. Besides, Hcy may be one of the potential biomarkers to distinguish BD from MDD.

TMT-labeled quantitative proteomic analysis to identify proteins associated with the stability of peanut milk

BACKGROUND

Peanut milk benefits human health mainly due to its high protein content and suitable amino acid composition. To reveal the molecular mechanism affecting the quality of peanut milk, tandem mass tag (TMT)-labeled proteomic analysis was applied to identify the proteome variation between two peanut cultivars that produced peanut milk with the best and worst stability.

RESULTS

A total of 478 differentially abundant proteins (fold change >1.2 or <0.83, P < 0.05) were identified. Most of these proteins were located in the cytoplasm and chloroplasts. Correlation analysis showed that RNA recognition motif (RRM) domain-containing protein (17.1 kDa) had a negative relationship with the sedimentation rate of peanut milk and that 22.0 kDa class IV heat shock protein was negatively correlated with the creaming index (P < 0.05). Bioinformatic analysis showed that the molecular function of RRM domain-containing protein (17.1 kDa) was associated with RNA binding and nucleotide binding, and 22.0 kDa class IV heat shock protein was involved in the pathway of protein processing in the endoplasmic reticulum.

CONCLUSION

Overall, the differentially abundant proteins in the biological metabolic pathway might offer some potential markers to guide future peanut breeding, especially for the production of peanut milk. © 2021 Society of Chemical Industry.

Study of the pathology and the underlying molecular mechanism of tissue injury around hematoma following intracerebral hemorrhage

Intracerebral hemorrhage (ICH) refers to hemorrhage caused by spontaneous rupture of blood vessels in the brain. Brain injury due to ICH leads to catastrophic effects resulting from the formation of hematoma and oxidative stress caused by components of lysed erythrocytes. However, not all neurons in the area surrounding the hematoma die immediately: A number of neurons remain in a critical, but reversible, state; however, the genes involved in this critical state remain poorly understood. Gene chip technology was used identify changes in the area surrounding the hematoma associated with the upregulation of 210 and downregulation of 173 genes. Gene Ontology functional annotation revealed changes in the gene expression profile in the peripheral region of hematoma following ICH, which were primarily associated with the external stimulation received by the organism, the transmission of harmful information to the cell through the transport of cell membrane proteins, and the regulation of a series of biological processes. Protein interaction network analysis revealed that 11 up-[secreted phosphoprotein 1, dual specificity phosphatase 9, catechol-O-methyltransferase, BAR/IMD domain-containing adaptor protein 2-like 1, plakophilin 2, homer scaffold protein 3, ret proto-oncogene (RET), KIT proto-oncogene, receptor tyrosine kinase, hepsin, connector enhancer of kinase suppressor of Ras 2 and kalirin RhoGEF kinase] and four downregulated genes (transcription factor AP-2β, peptidylprolyl isomerase A, SHOC2 leucine rich repeat scaffold protein and synuclein α) may serve a significant role in the area around hematoma following ICH. Reverse transcription-quantitative PCR was used to verify that these genes were differentially expressed in the ICH compared with the control group. Causal network analysis suggested that the Achaete-scute homolog 1-RET signaling axis served a key role in the repair of nerve injury in the peripheral region of hematoma following ICH. Additionally, in vivo experiments revealed that RET expression was upregulated and co-localized with neurons. Taken together, these results suggested that the changes in the gene expression profile in the area around hematoma following ICH were primarily associated with the repair of damage caused to the nervous system.