LC-MS-based rheumatoid arthritis serum metabolomics reveals the role of deoxyinosine in attenuating collagen-induced arthritis in mice.

Rheumatoid arthritis (RA) is a persistent autoimmune condition with no identified cure currently. Recently, scientists have applied metabolomics to investigate altered metabolic profiles and unique diseases-associated metabolic signatures. Herein, we applied metabolomics approach to analyze serum samples of 41 RA patients and 42 healthy controls (HC) with the aim to characterize RA patients' metabolic profile, investigate related underlying pathological processes, and identify target metabolites. By utilizing ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry, we found 168 proposed metabolites and 45 vital metabolic pathways. Our analysis revealed that deoxyinosine (DI), a metabolite of the purine metabolic pathway, was the most significant reduced metabolite in RA patients. Furthermore, through targeted detection, we confirmed lower concentration of DI in RA patients' peripheral blood. Moreover, DI inhibited lipopolysaccharide-induced inflammation both in vitro and in vivo. We further assessed DI's therapeutic potential in a collagen-induced arthritis (CIA) murine model. The results revealed that DI attenuated CIA, as evidenced by significantly lowered clinical scores of arthritis, alleviated joint swelling, and mitigated bone destruction. Moreover, we elucidated the underlying mechanism by which DI increased the population of myeloid-derived suppressor cells (MDSCs) and suppressed the proliferation of induced T cells. Collectively, these findings suggested that DI potentially ameliorated RA by inducing immunosuppressive MDSCs. The study provides key observations on RA pathogenesis and may contribute to developing novel therapeutic strategies for this debilitating condition.

Nontargeted metabolomics reveals sequential changes in amino acid and ferroptosis-related metabolism in Parkinson's disease.

Parkinson's disease (PD) is inseparable from metabolic disorders but lacks assessment of specific metabolite alteration. To explore the sequential metabolic changes in PD progression, we evenly divided 78 C57BL/6 mice (10 weeks) into six groups (one control group and five experimental groups) and collected the hippocampus tissue of mice after treating with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, and probenecid (twice a week) at five periods (1, 2, 3, 4, and 5 weeks) for metabolome analysis. Our study identified 567 differentially abundant metabolites (DAMs) (total 4348 metabolites). Compared with controls, 145, 146, 171, 208, and 213 DAMs were obtained from the five experimental groups, respectively. Notably, 40 shared DAMs were present in five experimental groups, of which 22 shared DAMs formed a new metabolic network based on amino acid metabolism. Compared with group W3, 84 DAMs were identified in group W5, including 12 unique DAMs. DAMs in different stages of PD were significantly enriched in amino acid metabolism pathway, lipid metabolism pathway, and ferroptosis pathway. l-Glutamine, spermidine, and l-tryptophan were the key hubs in the whole metabolic process of PD. N-Formyl-l-methionine gradually increased in abundance with PD progression, whereas 5-methylcytosine gradually decreased. The study emphasized the sequential changes in DAMs in PD progression, stimulating subsequent studies.

The Efficacy and Safety of Nirmatrelvir/Ritonavir Against COVID-19 in Elderly Patients.

Objective: To assess the key factors influencing the effectiveness of nirmatrelvir/ritonavir in treating elderly patients with COVID-19. Methods: This study was conducted on patients aged ≥60 who were admitted to the Second Affiliated Hospital of Soochow University for COVID-19 infection and were treated with nirmatrelvir/ritonavir. Clinical information was collected from patients and steady-state blood concentrations of nirmatrelvir and ritonavir were measured. Factors associated with treatment effects were searched by univariate and multivariate analysis. Results: A total of 68 (51 males and 17 females) patients had a median age of 80 (73.0-84.8) years were enrolled in this study. The blood concentration measurements (trough concentrations) of nirmatrelvir and ritonavir were 5.1 (2.6-7.1) and 0.4 (0.2-0.9) µg/mL, respectively. Adverse drug reaction was reported in 4 (5.9%) patients. Univariate analysis showed that age, clinical classification, APACHE II score, total bilirubin (TBil), aspartate transaminase (AST), lactate dehydrogenase (LDH), and total cholesterol (TC) were significantly associated with the effectiveness of treatment (P value <0.05). Concentration of nirmatrelvir was also associated with treatment outcome (P value <0.1). Based on the results of univariate analysis, the above factors were introduced into the multiple linear regression equation as independent variables, and the results showed that clinical classification was included in the regression equation model and was the most important factor affecting the treatment outcome. By receiver operating characteristic curve analysis, the area under curve of age + biochemical indicators + APACHE II score + clinical classification was 0.968 (95% CI = 0.919-1.000; P <0.0001). Among the 68 patients included in the study, 4 cases experienced adverse drug reactions. Conclusion: Age, clinical classification, APACHE II score, TBil, AST, LDH, and TC were significantly associated with the effectiveness of treatment in elderly patients with COVID-19.

Resolvin D1/N-formyl peptide receptor 2 ameliorates paclitaxel-induced neuropathic pain through the activation of IL-10/Nrf2/HO-1 pathway in mice.

Introduction: Paclitaxel is a chemotherapy drug that is commonly used to treat cancer, but it can cause paclitaxel-induced neuropathic pain (PINP) as a side effect. Resolvin D1 (RvD1) has been shown to be effective in promoting the resolution of inflammation and chronic pain. In this study, we evaluated the effects of RvD1 on PINP and its underlying mechanisms in mice. Methods: Behavioral analysis was used to assess the establishment of the PINP mouse model and to test the effects of RvD1 or other formulations on mouse pain behavior. Quantitative real-time polymerase chain reaction analysis was employed to detect the impact of RvD1 on 12/15 Lox, FPR2, and neuroinflammation in PTX-induced DRG neurons. Western blot analysis was used to examine the effects of RvD1 on FPR2, Nrf2, and HO-1 expression in DRG induced by PTX. TUNEL staining was used to detect the apoptosis of DRG neurons induced by BMDM conditioned medium. H2DCF-DA staining was used to detect the reactive oxygen species level of DRG neurons in the presence of PTX or RvD1+PTX treated BMDMs CM. Results: Expression of 12/15-Lox was decreased in the sciatic nerve and DRG of mice with PINP, suggesting a potential involvement of RvD1 in the resolution of PINP. Intraperitoneal injection of RvD1 promoted pain resolution of PINP in mice. Intrathecal injection of PTX-treated BMDMs induced mechanical pain hypersensitivity in naïve mice, while pretreatment of RvD1 in BMDMs prevented it. Macrophage infiltration increased in the DRGs of PINP mice, but it was not affected by RvD1 treatment. RvD1 increased IL-10 expression in the DRGs and macrophages, while IL-10 neutralizing antibody abolished the analgesic effect of RvD1 on PINP. The effects of RvD1 in promoting IL-10 production were also inhibited by N-formyl peptide receptor 2 (FPR2) antagonist. The primary cultured DRG neurons apoptosis increased after stimulation with condition medium of PTX-treated BMDMs, but decreased after pretreatment with RvD1 in BMDMs. Finally, Nrf2-HO1 signaling was additionally activated in DRG neurons after stimulation with condition medium of RvD1+PTX-treated BMDMs, but these effects were abolished by FPR2 blocker or IL-10 neutralizing antibody. Discussion: In conclusion, this study provides evidence that RvD1 may be a potential therapeutic strategy for the clinical treatment of PINP. RvD1/FPR2 upregulates IL-10 in macrophages under PINP condition, and then IL-10 activates the Nrf2- HO1 pathway in DRG neurons, relieve neuronal damage and PINP.

Anti-proliferation and apoptosis-inducing effects of dihydroartemisinin on SH-SY5Y cells and metabolomic analysis.

Background: In childhood, metastatic neuroblastoma (NB) is the most common extracranial solid tumor, but there are no appropriate drugs for its treatment. Dihydroartemisinin (DHA), a drug for malaria treatment, has therapeutic potential in several cancers; however, its mechanisms remain unclear. This study aimed to investigate the anti-proliferation effect of DHA on SH-SY5Y cells and to explore its mechanism in vitro. Methods: We used 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to measure the half-maximal inhibitory concentration (IC50) of DHA; western blot was used to determine protein levels; propidium iodide (PI) staining was used to determine apoptotic cells; JC-1 staining to measure mitochondrial membrane potential; and dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining was used to determine reactive oxygen species (ROS). Metabonomic analysis was performed by using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)-based untargeted metabolomics. Multivariate statistical analysis was performed to screen potential metabolites associated with DHA treatment in SH-SY5Y cells. Results: It was shown that DHA inhibited SH-SY5Y cell proliferation and increased poly (ADP-ribose) polymerase (PARP-1) and caspase 3 in a dose-dependent manner. In Further, DHA promoted ROS generation and γH2AX expression. In addition, a total of 125 proposed metabolites in SH-SY5Y cells and 45 vital metabolic pathways were identified through UHPLC-MS/MS-based untargeted metabolomic analysis. Conclusions: These data suggest that DHA could regulate taurine, linoleic acid, phenylalanine metabolism, and tryptophan metabolism, which are involved in the anti-proliferation effect of DHA in SH-SY5Y cells.

Gut Microbiota-Mediated Elevated Production of Secondary Bile Acids in Chronic Unpredictable Mild Stress.

A growing body of evidence suggests that gut microbiota could participate in the progression of depression via the microbiota-gut-brain axis. However, the detailed microbial metabolic profile changes in the progression of depression is still not fully elucidated. In this study, a liquid chromatography coupled to mass spectrometry-based untargeted serum high-throughput metabolomics method was first performed to screen for potential biomarkers in a depressive-like state in a chronic unpredictable mild stress (CUMS)-induced mouse model. Our results identified that the bile acid and energy metabolism pathways were significantly affected in CUMS progression. The detailed bile acid profiles were subsequently quantified in the serum, liver, and feces. The results showed that CUMS significantly promoted the deconjugation of conjugated bile acid and secondary bile acid biosynthesis. Furthermore, 16S rRNA gene sequencing revealed that the increased secondary bile acid levels in the feces positively correlated with Ruminococcaceae_UCG-010, Ruminococcus, and Clostridia_UCG-014 abundance. Taken together, our study suggested that changes in family Ruminococcaceae abundance following chronic stress increased biosynthesis of deoxycholic acid (DCA), a unconjugated secondary bile acid in the intestine. Aberrant activation of secondary bile acid biosynthesis pathway thereby increased the hydrophobicity of the bile acid pool, which might, in turn, promoted metabolic disturbances and disease progression in CUMS mice.

Thioredoxin-Interacting Protein (TXNIP) Regulates Parkin/PINK1-mediated Mitophagy in Dopaminergic Neurons Under High-glucose Conditions: Implications for Molecular Links Between Parkinson's Disease and Diabetes.

Patients with diabetes mellitus have a higher risk of developing Parkinson's disease (PD). However, the molecular links between PD and diabetes remain unclear. In this study, we investigated the roles of thioredoxin-interacting protein (TXNIP) in Parkin/PINK1-mediated mitophagy in dopaminergic (DA) cells under high-glucose (HG) conditions. In streptozotocin-induced diabetic mice, TXNIP was upregulated and autophagy was inhibited in the midbrain, while the loss of DA neurons was accelerated by hyperglycemia. In cultured PC12 cells under HG, TXNIP expression was upregulated and the intracellular reactive oxygen species (ROS) levels increased, leading to cell death. Autophagic flux was further blocked and PINK1 expression was decreased under HG conditions. Parkin expression in the mitochondrial fraction and carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-induced co-localization of COX IV (marker for mitochondria) and LAMP1 (marker for lysosomes) were also significantly decreased by HG. Overexpression of TXNIP was sufficient to decrease the expression of both PINK1 and Parkin in PC12 cells, while knockdown of the expression of TXNIP by siRNA decreased intracellular ROS and attenuated cellular injury under HG. Moreover, inhibition of TXNIP improved the CCCP-induced co-localization of COX IV and LAMP1 in PC12 cells under HG. Together, these results suggest that TXNIP regulates Parkin/PINK1-mediated mitophagy under HG conditions, and targeting TXNIP may be a promising therapeutic strategy for reducing the risk of PD under hyperglycemic conditions.

Advances and Application of a Novel Oral Anticoagulant in Specific Populations: Dabigatran Etexilate.

BACKGROUND: Dabigatran etexilate (DE) was approved by the FDA in 2010 to reduce the risk of stroke and systemic embolism in adults with Non-valvular Atrial Fibrillation (NVAF). Compared with warfarin, a traditional anticoagulant drug, DE exhibits a shorter half-life, improved dose-effect relationship, fewer food and drug interactions, and can be taken orally without monitoring the conventional coagulation index. DE can also prevent or reduce the severity of adverse events, such as attenuated drug efficacy or bleeding. It is convenient for patients to take DE due to low levels of individual variation. This review aims to application of Dabigatran etexilate in specific populations. METHODS: Fifty-five papers were included in the review. RESULTS: We review the pharmacological mechanisms, pharmacokinetics and drug interactions, as well as the application of DE for different clinical populations, and provide clinical guidelines. CONCLUSION: When using DE, one should consider the risk of bleeding, age, renal function, drug interactions, and other factors.

Oxidation of multiple MiT/TFE transcription factors links oxidative stress to transcriptional control of autophagy and lysosome biogenesis.

Significant evidences indicate that reactive oxygen species (ROS) can induce macroautophagy/autophagy under both physiological and pathological conditions. Although the relationship between ROS and autophagy regulation has been well studied, the basic mechanism by which ROS affects autophagy and the biological role of this regulation are still not fully understood. In the present study we show that multiple MiT-TFE transcription factors including TFEB, TFE3 and MITF, which are master regulators of autophagy and lysosomal biogenesis, can be activated upon direct cysteine oxidation by ROS. Oxidation promotes the nuclear translocation of these MiT-TFE transcription factors by inhibiting the association of them with RRAG GTPases, which in turn leads to enhanced global gene expression level in autophagy-lysosome system. Our study highlights the role of oxidation of MiT-TFE transcription factors in ROS-linked autophagy, and provides novel mechanism that MiT-TFE transcription factors-mediated transcriptional control of autophagy may govern cell homeostasis in response to oxidative stress, a biological process tightly linked to human diseases including neurodegenerative diseases and cancer. ABBREVIATIONS: Bafi A1: bafilomycin A1; EBSS: Earle's balanced salt solution; EGFP: enhanced green fluorescent protein; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MTORC1: mechanistic target of rapamycin kinase complex 1; ROS: reactive oxygen species; RPS6KB/p70S6K: ribosomal protein S6 kinase B; TFEB: transcription factor EB; WT: wild type.

The tumor suppressor p53 regulates autophagosomal and lysosomal biogenesis in lung cancer cells by targeting transcription factor EB.

The cellular protein degradation system, such as proteasomal or autophagy-lysosomal system plays an important role in the pathogenesis of a variety of human diseases including cancer. Transcription factor EB (TFEB) is a master transcriptional factor in the regulation of autophagy-lysosome pathway (ALP), and it has multiple biological functions including protein degradation, cell homeostasis and cell survival. In the present study we show that the tumor suppressor p53 can regulate TFEB nuclear translocation and activity in lung cancer cells. We found p53 deletion or chemical inhibition of p53 using pifithrin-α could promote the translocation of TFEB from cytoplasm to the nucleus, thus increased the TFEB-mediated lysosomal and autophagosomal biogenesis in lung cancer cells. Moreover, re-expression of p53 could decrease the expression levels of TFEB-targeting genes involved in ALP, and knockdown of TFEB could abolish the effect of p53 on the regulation of ALP gene expression. Taken together, our data indicate that p53 affects ALP through regulating TFEB nuclear translocation in lung cancer cells. Importantly, our study reveals a critical link between two keys factors in tumourigenesis and autophagy, and suggests a potential important role of p53-TFEB signaling axis in lung cancer.

TARDBP/TDP-43 regulates autophagy in both MTORC1-dependent and MTORC1-independent manners.

In a recent paper we addressed the mechanism by which defective autophagy contributes to TARDBP/TDP-43-mediated neurodegenerative disorders. We demonstrated that TARDBP regulates MTORC1-TFEB signaling by targeting RPTOR/raptor, a key component and an adaptor protein of MTORC1. Loss of TARDBP decreased the mRNA stability of RPTOR and this regulation in turn enhanced autophagosomal and lysosomal biogenesis in an MTORC1-dependent manner. Meanwhile, loss of TARDBP could also impair autophagosome-lysosome fusion in an MTORC1-independent manner. Importantly, we found that modulation of MTOR activity by treatment with rapamycin and phosphatidic acid had strong effects on the neurodegenerative phenotypes of TBPH (Drosophila TARDBP)-depleted flies. Taken together, our data reveal that multiple dysfunctions in the autophagic process contribute to TARDBP-linked neurodegeneration and may help to identify potential therapeutic targets in the future.