De novo engineering riboflavin production Bacillus subtilis by overexpressing the downstream genes in the purine biosynthesis pathway.

BACKGROUND: Bacillus subtilis is widely used in industrial-scale riboflavin production. Previous studies have shown that targeted mutagenesis of the ribulose 5-phosphate 3-epimerase in B. subtilis can significantly enhance riboflavin production. This modification also leads to an increase in purine intermediate concentrations in the medium. Interestingly, B. subtilis exhibits remarkable efficiency in purine nucleoside synthesis, often exceeding riboflavin yields. These observations highlight the importance of the conversion steps from inosine-5'-monophosphate (IMP) to 2,5-diamino-6-ribosylamino-4(3 H)-pyrimidinone-5'-phosphate (DARPP) in riboflavin production by B. subtilis. However, research elucidating the specific impact of these reactions on riboflavin production remains limited. RESULT: We expressed the genes encoding enzymes involved in these reactions (guaB, guaA, gmk, ndk, ribA) using a synthetic operon. Introduction of the plasmid carrying this synthetic operon led to a 3.09-fold increase in riboflavin production compared to the control strain. Exclusion of gmk from the synthetic operon resulted in a 36% decrease in riboflavin production, which was further reduced when guaB and guaA were not co-expressed. By integrating the synthetic operon into the genome and employing additional engineering strategies, we achieved riboflavin production levels of 2702 mg/L. Medium optimization further increased production to 3477 mg/L, with a yield of 0.0869 g riboflavin per g of sucrose. CONCLUSION: The conversion steps from IMP to DARPP play a critical role in riboflavin production by B. subtilis. Our overexpression strategies have demonstrated their effectiveness in overcoming these limiting factors and enhancing riboflavin production.

Higher infection risk for JAK inhibitors tofacitinib and baricitinib compared to subcutaneous biological DMARDs.

INTRODUCTION: Rheumatoid arthritis (RA) is usually treated with disease modifying antirheumatic drugs (DMARDs), including biological DMARDs (bDMARDs) and more recently, Janus kinase inhibitors (JAKi). Randomized trials suggest similar infection risks for JAKi and bDMARDs, but real-world data are scarce. METHODS: From a nationally representative prescription database, adult RA patients starting a new JAKi or bDMARD between August 1st, 2018, and January 31st, 2021, were included. Prescriptions of antibiotic, antiviral or antifungal medication were used as proxy for infections. Infection incidence rates (IR) were compared between JAKi and bDMARDs and infection risks were estimated using multilevel Poisson regression adjusted for follow-up time and potential confounders and stratified for age < 65 and ≥ 65 years. RESULTS: In 14,989 patients, we identified 20,050 treatment episodes with either JAKi or bDMARDs. The infection IR was significantly higher in JAKi (48/100 patient years) compared bDMARDs (35/100 patient years, adjusted incidence rate ratio (IRR) 1.22, 95% CI 1.12-1.33). More herpes zoster infections were seen in JAKi compared to bDMARDs (adjusted IRR 2.65, 95% CI 1.94-3.60). No significant differences in infection IRs were found comparing JAKi baricitinib and tofacitinib. In older patients, infection IRs were higher, but IRRs were similar between age groups. CONCLUSION: In comparison to bDMARDs, JAKi are associated with a slightly higher infection risk and a higher risk of herpes zoster specifically. In older patients, infection IRs are higher but similar infection risks for JAKi and bDMARDs are observed. No differences in infection risk between tofacitinib and baricitinib were found. Key Points • Compared to bDMARDs, JAKi are associated with a slightly higher infection risk for all ages • An increased risk of herpes zoster in patients who use JAK inhibitors was confirmed • No significant differences in infection incidence were found between tofacitinib and baricitinib.

Comparison of the therapeutic effects of febuxostat combined with a low-purine diet and allopurinol combined with a low-purine diet on the improvement of gout patients.

OBJECTIVE: To compare the clinical efficacy of febuxostat combined with a low-purine diet versus allopurinol combined with a low-purine diet in the treatment of gout. METHODS: In this prospective controlled trial, 98 gout patients admitted to our hospital from February 2021 to December 2022 were enrolled as study subjects. Patients were randomly assigned to the study group (febuxostat combined with a low-purine diet) and the control group (allopurinol combined with a low-purine diet), with 49 patients in each group. The therapeutic effect was evaluated based on joint function and serum uric acid levels after treatment, and classified into three levels: markedly effective, effective, and ineffective. The levels of inflammatory factors, including tumor necrosis factor-a (TNF-a), cytokine interleukin-1beta (IL-1ß), and interleukin (IL)-18 (IL-18), were collected. The Numeric Rating Scale (NRS) was used to assess the degree of pain in patients. Clinical indicators before and 6 months after treatment were compared between the two groups. RESULTS: There was no statistically significant difference in age and gender between the two groups. After 6 months of treatment, the effective rate in the study group (48 cases, 97.96%) was higher than that in the control group (42 cases, 85.71%), with a statistically significant difference (p = .027). At the same time, the study group had significantly lower levels of serum uric acid (162.39 µmol/L ± 17.23 µmol/L vs. S198.32 µmol/L ± 18.34 µmol/L, p < .001), creatinine (87.39 mmol/L ± 9.76 mmol/L vs. 92.18 mmol/L ± 9.27 mmol/L, p = .014), total cholesterol (3.65 mmol/L ± 0.65 mmol/L vs. 4.76 mmol/L ± 0.73 mmol/L, p < .001), and triglycerides (1.76 mmol/L ± 0.32 mmol/L vs. 2.28 mmol/L ± 0.41 mmol/L, p < .001) compared to the control group, with statistically significant differences (p < .05). After treatment, the levels of inflammatory factors and degree of pain in the study group were significantly lower than those in the control group (all p < .05). During the treatment process, the incidence of adverse reactions in the study group (2 cases, 4.08%) was lower than that in the control group (9 cases, 18.37%), with a statistically significant difference (p = .025). CONCLUSION: Febuxostat combined with a low-purine diet can reduce inflammatory factors and alleviate the degree of pain in gout patients, significantly improving their clinical symptoms.

Pioglitazone-induced alterations of purine metabolism in healthy male subjects.

Pioglitazone is class of thiazolidinediones that activates peroxisome proliferator-activated receptors (PPARs) in adipocytes to improve glucose metabolism and insulin sensitivity and has been used as a treatment for type 2 diabetes. However, the underlying mechanisms of associated pioglitazone-induced effects remain unclear. Our study aimed to investigate endogenous metabolite alterations associated with pioglitazone administration in healthy male subjects using an untargeted metabolomics approach. All subjects received 30 mg of pioglitazone once daily in the assigned sequence and period. Urine samples were collected before pioglitazone administration and for 24 h after 7 days of administration. A total of 1465 compounds were detected and filtered using a coefficient of variance below 30% and 108 metabolites were significantly altered upon pioglitazone administration via multivariate statistical analysis. Fourteen significant metabolites were identified using authentic standards and public libraries. Additionally, pathway analysis revealed that metabolites from purine and beta-alanine metabolisms were significantly altered after pioglitazone administration. Further analysis of quantification of metabolites from purine metabolism, revealed that the xanthine/hypoxanthine and uric acid/xanthine ratios were significantly decreased at post-dose. Pioglitazone-dependent endogenous metabolites and metabolic ratio indicated the potential effect of pioglitazone on the activation of PPAR and fatty acid synthesis. Additional studies involving patients are required to validate these findings.

Molecular docking approach for the design and synthesis of new pyrazolopyrimidine analogs of roscovitine as potential CDK2 inhibitors endowed with pronounced anticancer activity.

Cyclin-dependent kinase 2 (CDK2) is a vital protein for controlling cell cycle progression that is critically associated with various malignancies and its inhibition could offer a convenient therapeutic approach in designing anticancer remedies. Consequently, this study aimed to design and synthesize new CDK2 inhibitors featuring roscovitine as a template model. The purine ring of roscovitine was bioisosterically replaced with the pyrazolo[3,4-d]pyrimidine scaffold, in addition to some modifications in the side chains. A preliminary molecular docking study for the target chemotypes in the CDK2 binding domain revealed their ability to accomplish similar binding patterns and interactions to that of the lead compound roscovitine. Afterwards, synthesis of the new derivatives was accomplished. Then, the initial anticancer screening at a single dose by the NCI revealed that compounds 7a, 9c, 11c, 17a and 17b achieved the highest GI% values reaching up to 150 % indicating their remarkable activity. These derivatives were subsequently selected to undertake five-dose testing, where compounds 7a, 9c, 11c and 17a unveiled the most pronounced activity against almost the full panel with GI50 ranges; 1.41-28.2, 0.116-2.39, 0.578-60.6 and 1.75-42.4 µM, respectively and full panel GI50 (MG-MID); 8.24, 0.6, 2.46 and 6.84 µM, respectively. CDK2 inhibition assay presented compounds 7a and 9c as the most potent inhibitors with IC50 values of 0.262 and 0.281 µM, respectively which are nearly 2.4 folds higher than the reference ligand roscovitine (IC50 = 0.641 µM). Besides, flow cytometric analysis on the most susceptible and safe cell lines depicted that 7a caused cell cycle arrest at G1/S phase in renal cancer cell line (RXF393) while 9c led to cell growth arrest at S phase in breast cancer cell line (T-47D) along with pronounced apoptotic induction in the mentioned cell lines. These findings afforded new anticancer pyrazolo[3,4-d]pyrimidine, roscovitine analogs, acting via CDK2 inhibition.

Metabolic and neurobehavioral disturbances induced by purine recycling deficiency in Drosophila.

Adenine phosphoribosyltransferase (APRT) and hypoxanthine-guanine phosphoribosyltransferase (HGPRT) are two structurally related enzymes involved in purine recycling in humans. Inherited mutations that suppress HGPRT activity are associated with Lesch-Nyhan disease (LND), a rare X-linked metabolic and neurological disorder in children, characterized by hyperuricemia, dystonia, and compulsive self-injury. To date, no treatment is available for these neurological defects and no animal model recapitulates all symptoms of LND patients. Here, we studied LND-related mechanisms in the fruit fly. By combining enzymatic assays and phylogenetic analysis, we confirm that no HGPRT activity is expressed in Drosophila melanogaster, making the APRT homolog (Aprt) the only purine-recycling enzyme in this organism. Whereas APRT deficiency does not trigger neurological defects in humans, we observed that Drosophila Aprt mutants show both metabolic and neurobehavioral disturbances, including increased uric acid levels, locomotor impairments, sleep alterations, seizure-like behavior, reduced lifespan, and reduction of adenosine signaling and content. Locomotor defects could be rescued by Aprt re-expression in neurons and reproduced by knocking down Aprt selectively in the protocerebral anterior medial (PAM) dopaminergic neurons, the mushroom bodies, or glia subsets. Ingestion of allopurinol rescued uric acid levels in Aprt-deficient mutants but not neurological defects, as is the case in LND patients, while feeding adenosine or N6-methyladenosine (m6A) during development fully rescued the epileptic behavior. Intriguingly, pan-neuronal expression of an LND-associated mutant form of human HGPRT (I42T), but not the wild-type enzyme, resulted in early locomotor defects and seizure in flies, similar to Aprt deficiency. Overall, our results suggest that Drosophila could be used in different ways to better understand LND and seek a cure for this dramatic disease.

One-carbon unit supplementation fuels purine synthesis in tumor-infiltrating T cells and augments checkpoint blockade.

Nucleotides perform important metabolic functions, carrying energy and feeding nucleic acid synthesis. Here, we use isotope tracing-mass spectrometry to quantitate contributions to purine nucleotides from salvage versus de novo synthesis. We further explore the impact of augmenting a key precursor for purine synthesis, one-carbon (1C) units. We show that tumors and tumor-infiltrating T cells (relative to splenic or lymph node T cells) synthesize purines de novo. Shortage of 1C units for T cell purine synthesis is accordingly a potential bottleneck for anti-tumor immunity. Supplementing 1C units by infusing formate drives formate assimilation into purines in tumor-infiltrating T cells. Orally administered methanol functions as a formate pro-drug, with deuteration enabling kinetic control of formate production. Safe doses of methanol raise formate levels and augment anti-PD-1 checkpoint blockade in MC38 tumors, tripling durable regressions. Thus, 1C deficiency can gate antitumor immunity and this metabolic checkpoint can be overcome with pharmacological 1C supplementation.

Baricitinib protects ICIs-related myocarditis by targeting JAK1/STAT3 to regulate Macrophage polarization.

PURPOSE: The emergence of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, but these drugs can also cause severe immune-related adverse effects (irAEs), including myocarditis. Researchers have become interested in exploring ways to mitigate this side effect, and one promising avenue is the use of baricitinib, a Janus kinase inhibitor known to have anti-inflammatory properties. This study aimed to examine the potential mechanism by which baricitinib in ICIs-related myocarditis. METHODS: To establish an ICIs-related myocarditis model, BALB/c mice were administered murine cardiac troponin I (cTnI) peptide and anti-mouse programmed death 1 (PD-1) antibodies. Subsequently, baricitinib was administered to the mice via intragastric administration. Echocardiography, HE staining, and Masson staining were performed to evaluate myocardial functions, inflammation, and fibrosis. Immunofluorescence was used to detect macrophages in the cardiac tissue of the mice.In vitro experiments utilized raw264.7 cells to induce macrophage polarization using anti-PD-1 antibodies. Different concentrations of baricitinib were applied to assess cell viability, and the release of pro-inflammatory cytokines was measured. The activation of the JAK1/STAT3 signaling pathway was evaluated through western blot analysis. RESULTS: Baricitinib demonstrated its ability to improve cardiac function and reduce cardiac inflammation, as well as fibrosis induced by ICIs. Mechanistically, baricitinib treatment promoted the polarization of macrophages towards the M2 phenotype. In vitro and in vivo experiments showed that anti-PD-1 promoted the release of inflammatory factors. However, treatment with baricitinib significantly inhibited the phosphorylation of JAK1 and STAT3. Additionally, the use of RO8191 reversed the effects of baricitinib, further confirming our findings. CONCLUSION: Baricitinib demonstrated its potential as a protective agent against ICIs-related myocarditis by modulating macrophage polarization. These findings provide a solid theoretical foundation for the development of future treatments for ICIs-related myocarditis.

Janus kinase inhibitors in the treatment of pyoderma gangrenosum: case report and review.

Pyoderma gangrenosum (PG) is a rare inflammatory dermatologic condition with neutrophilic infiltration of the skin that causes pustules and ulcerations. Janus kinase (JAK) inhibitors are immunomodulating agents that have been recently described in the literature as an effective treatment for PG. We describe a patient with PG on the lower extremities successfully treated with baricitinib. We also conducted a narrative review of the literature of PG patients treated with JAK inhibitors who were refractory to other treatments.

Model of Chronic Itch in Aged Mice: Beneficial Effects of Drugs Affecting Descending Modulatory Systems.

Pruritus in the elderly, particularly those cases without skin dryness or other identifiable causes, makes treatment challenging due to the lack of evidence regarding the therapeutic effects of antipruritics. This study proposes an age-related alloknesis mouse model for an evaluation system for such cases, and aimed to investigate the effectiveness and mechanisms of action of several drugs commonly used as antipruritics in Japan, utilizing this model. Mice 69-80 weeks old were used as aged mice, and the level of mechanical alloknesis was counted as the number of scratching behaviours in response to innocuous stimuli. Bepotastine, neurotropin, pregabalin, baricitinib, and abrocitinib were used as antipruritics, and yohimbine and methysergide as inhibitors of the descending inhibitory pathway. The findings suggest that mechanical alloknesis in aged mice is a suitable animal model for assessing pruritus in the elderly without xerosis, and pregabalin, neurotropin, baricitinib, and abrocitinib may be effective antipruritics in the elderly through activating both the noradrenergic and serotonergic descending inhibitory pathways. These findings may be useful for the selection of antipruritics for pruritus in the elderly without skin lesions or dryness.

Endogenous ureides are employed as a carbon source in Arabidopsis plants exposed to carbon starvation conditions.

Ureides, the degraded products of purine catabolism in Arabidopsis, have been shown to act as antioxidant and nitrogen sources. Herein we elucidate purine degraded metabolites as a carbon source using the Arabidopsis Atxdh1, Ataln, and Ataah knockout (KO) mutants vis-à-vis wild-type (WT) plants. Plants were grown under short-day conditions on agar plates containing half-strength MS medium with or without 1% sucrose. Notably, the absence of sucrose led to diminished biomass accumulation in both shoot and root tissues of the Atxdh1, Ataln, and Ataah mutants, while no such effect was observed in WT plants. Moreover, the application of sucrose resulted in a reduction of purine degradation metabolite levels, specifically xanthine and allantoin, predominantly within the roots of WT plants. Remarkably, an increase in proteins associated with the purine degradation pathway was observed in WT plants in the presence of sucrose. Lower glyoxylate levels in the roots but not in the shoot of the Atxdh1 mutant in comparison to WT, were observed under sucrose limitation, and improved by sucrose application in root, indicating that purine degradation provided glyoxylate in the root. Furthermore, the deficit of purine-degraded metabolites in the roots of mutants subjected to carbon starvation was partially mitigated through allantoin application. Collectively, these findings signify that under conditions of sucrose limitation and short-day growth, purines are primarily remobilized within the root system to augment the availability of ureides, serving as an additional carbon (as well as nitrogen) source to support plant growth.

Xanthine oxidoreductase inhibition ameliorates high glucose-induced glomerular endothelial injury by activating AMPK through the purine salvage pathway.

Xanthine oxidoreductase (XOR) contributes to reactive oxygen species production. We investigated the cytoprotective mechanisms of XOR inhibition against high glucose (HG)-induced glomerular endothelial injury, which involves activation of the AMP-activated protein kinase (AMPK). Human glomerular endothelial cells (GECs) exposed to HG were subjected to febuxostat treatment for 48 h and the expressions of AMPK and its associated signaling pathways were evaluated. HG-treated GECs were increased xanthine oxidase/xanthine dehydrogenase levels and decreased intracellular AMP/ATP ratio, and these effects were reversed by febuxostat treatment. Febuxostat enhanced the phosphorylation of AMPK, the activation of peroxisome proliferator-activated receptor (PPAR)-gamma coactivator (PGC)-1α and PPAR-α and suppressed the phosphorylation of forkhead box O (FoxO)3a in HG-treated GECs. Febuxostat also decreased nicotinamide adenine dinucleotide phosphate oxidase (Nox)1, Nox2, and Nox4 expressions; enhanced superoxide dismutase activity; and decreased malondialdehyde levels in HG-treated GECs. The knockdown of AMPK inhibited PGC-1α-FoxO3a signaling and negated the antioxidant effects of febuxostat in HG-treated GECs. Despite febuxostat administration, the knockdown of hypoxanthine phosphoribosyl transferase 1 (HPRT1) also inhibited AMPK-PGC-1α-FoxO3a in HG-treated GECs. XOR inhibition alleviates oxidative stress by activating AMPK-PGC-1α-FoxO3a signaling through the HPRT1-dependent purine salvage pathway in GECs exposed to HG conditions.

MGMT inhibition regulates radioresponse in GBM, GSC, and melanoma.

Radiotherapy is the standard treatment for glioblastoma (GBM), but the overall survival rate for radiotherapy treated GBM patients is poor. The use of adjuvant and concomitant temozolomide (TMZ) improves the outcome; however, the effectiveness of this treatment varies according to MGMT levels. Herein, we evaluated whether MGMT expression affected the radioresponse of human GBM, GBM stem-like cells (GSCs), and melanoma. Our results indicated a correlation between MGMT promoter methylation status and MGMT expression. MGMT-producing cell lines ACPK1, GBMJ1, A375, and MM415 displayed enhanced radiosensitivity when MGMT was silenced using siRNA or when inhibited by lomeguatrib, whereas the OSU61, NSC11, WM852, and WM266-4 cell lines, which do not normally produce MGMT, displayed reduced radiosensitivity when MGMT was overexpressed. Mechanistically lomeguatrib prolonged radiation-induced γH2AX retention in MGMT-producing cells without specific cell cycle changes, suggesting that lomeguatrib-induced radiosensitization in these cells is due to radiation-induced DNA double-stranded break (DSB) repair inhibition. The DNA-DSB repair inhibition resulted in cell death via mitotic catastrophe in MGMT-producing cells. Overall, our results demonstrate that MGMT expression regulates radioresponse in GBM, GSC, and melanoma, implying a role for MGMT as a target for radiosensitization.

PERFECTRA: a pragmatic, multicentre, real-life study comparing treat-to-target strategies with baricitinib versus TNF inhibitors in patients with active rheumatoid arthritis after failure on csDMARDs.

OBJECTIVE: To compare the effectiveness of a strategy administering baricitinib versus one using TNF-inhibitors (TNFi) in patients with rheumatoid arthritis (RA) after conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) failure in a real-life treat-to-target (T2T) setting. METHODS: Patients with biological and targeted synthetic DMARD (b/tsDMARD) naïve RA with disease duration ≤5 years without contraindications to b/tsDMARD were randomised to either TNFi or baricitinib when csDMARD failed to achieve disease control in a T2T setting. Changes in clinical and patient-reported outcome measures (PROMs) were assessed at 12-week intervals for 48 weeks. The primary endpoint was non-inferiority, with testing for superiority if non-inferiority is demonstrated, of baricitinib strategy in the number of patients achieving American College of Rheumatology 50 (ACR50) response at 12 weeks. Secondary endpoints included 28-joint count Disease Activity Score with C reactive protein (DAS28-CRP) <2.6, changes in PROMs and radiographic progression. RESULTS: A total of 199 patients (TNFi, n=102; baricitinib, n=97) were studied. Both study groups were similar. Baricitinib was both non-inferior and superior in achieving ACR50 response at week 12 (42% vs 20%). Moreover, 75% of baricitinib patients achieved DAS28-CRP <2.6 at week 12 compared with 46% of TNFi patients. On secondary outcomes throughout the duration of the study, the baricitinib strategy demonstrated comparable or better outcomes than TNFi strategy. Although not powered for safety, no unexpected safety signals were seen in this relatively small group of patients. CONCLUSION: Up to present, in a T2T setting, patients with RA failing csDMARDs have two main strategies to consider, Janus Kinases inhibitor versus bDMARDs (in clinical practice, predominantly TNFi). The PERFECTRA study suggested that starting with baricitinib was superior over TNFi in achieving response at 12 weeks and resulted in improved outcomes across all studied clinical measures and PROMs throughout the study duration in these patients.

Efficacy and safety study of targeted small-molecule drugs in the treatment of systemic lupus erythematosus.

BACKGROUND: Targeted small-molecule drugs in the treatment of systemic lupus erythematosus (SLE) have attracted increasing attention from clinical investigators. However, there is still a lack of evidence on the difference in the efficacy and safety of different targeted small-molecule drugs. Therefore, this study was conducted to assess the efficacy and safety of different targeted small-molecule drugs for SLE. METHODS: Randomized controlled trials (RCTs) on targeted small-molecule drugs in the treatment of SLE in PubMed, Web of Science, Embase, and Cochrane Library were systematically searched as of April 25, 2023. Risk of bias assessment was performed for included studies using the Cochrane's tool for evaluating the risk of bias. The primary outcome indicators were SRI-4 response, BICLA response, and adverse reaction. Because different doses and courses of treatment were used in the included studies, Bayesian network meta-regression was used to investigate the effect of different doses and courses of treatment on efficacy and safety. RESULTS: A total of 13 studies were included, involving 3,622 patients and 9 targeted small-molecule drugs. The results of network meta-analysis showed that, in terms of improving SRI-4, Deucravacitinib was significantly superior to that of Baricitinib (RR = 1.32, 95% CI (1.04, 1.68), P < 0.05). Deucravacitinib significantly outperformed the placebo in improving BICLA response (RR = 1.55, 95% CI (1.20, 2.02), P < 0.05). In terms of adverse reactions, targeted small-molecule drugs did not significantly increase the risk of adverse events as compared to placebo (P > 0.05). CONCLUSION: Based on the evidence obtained in this study, the differences in the efficacy of targeted small-molecule drugs were statistically significant as compared to placebo, but the difference in the safety was not statistically significant. The dose and the course of treatment had little impact on the effect of targeted small-molecule drugs. Deucravacitinib could significantly improve BICLA response and SRI-4 response without significantly increasing the risk of AEs. Therefore, Deucravacitinib is very likely to be the best intervention measure. Due to the small number of included studies, more high-quality clinical evidence is needed to further verify the efficacy and safety of targeted small-molecule drugs for SLE.

Pronounced benefits of JAK inhibition with baricitinib in COVID-19 pneumonia in obese but not lean subjects.

OBJECTIVE: Obesity and age are strongly linked to severe COVID-19 pneumonia where immunomodulatory agents including Janus kinase inhibitors have shown benefits but the efficacy of such therapy in viral pneumonia is not well understood. We evaluated the impact of obesity and age on survival following baricitinib therapy for severe COVID-19. METHODS: A post hoc analysis of the COV-BARRIER multicentre double-blind randomised study of baricitinib versus placebo (PBO) with an assessment of 28-day mortality was performed. All-cause mortality by day 28 was evaluated in a Cox regression analysis (adjusted to age) in three different groups according to body mass index (BMI) (<25 kg/m2, 25-30 kg/m2 and >30 kg/m2) and age <65 years and ≥65 years. RESULTS: In the high BMI group (>25 kg/m2), baricitinib therapy showed a significant survival advantage compared with PBO (incidence rate ratio (IRR) for mortality by day 28 0.53 (95% CI 0.32 to 0.87)) and 0.66 (95% CI 0.46 to 0.94) for the respective <65 years and ≥65 years, respectively. The 28-day all-cause-mortality rates for BMI over 30 were 5.62% for baricitinib and 9.22% for PBO (HR=0.6, p<0.05). For BMI under 25 kg/m2, irrespective of age, baricitinib therapy conferred no survival advantage (IRR of 1.89 (95% CI 0.49 to 7.28) and 0.95 (95% CI 0.46 to 1.99) for <65 years and ≥65 years, respectively) ((mortality 6.6% baricitinib vs 8.1 in PBO), p>0.05). CONCLUSION: The efficacy of baricitinib in COVID-19 pneumonia is linked to obesity suggesting that immunomodulatory therapy benefit is associated with obesity-associated inflammation.

Bioinformatic validation and machine learning-based exploration of purine metabolism-related gene signatures in the context of immunotherapeutic strategies for nonspecific orbital inflammation.

Background: Nonspecific orbital inflammation (NSOI) represents a perplexing and persistent proliferative inflammatory disorder of idiopathic nature, characterized by a heterogeneous lymphoid infiltration within the orbital region. This condition, marked by the aberrant metabolic activities of its cellular constituents, starkly contrasts with the metabolic equilibrium found in healthy cells. Among the myriad pathways integral to cellular metabolism, purine metabolism emerges as a critical player, providing the building blocks for nucleic acid synthesis, such as DNA and RNA. Despite its significance, the contribution of Purine Metabolism Genes (PMGs) to the pathophysiological landscape of NSOI remains a mystery, highlighting a critical gap in our understanding of the disease's molecular underpinnings. Methods: To bridge this knowledge gap, our study embarked on an exploratory journey to identify and validate PMGs implicated in NSOI, employing a comprehensive bioinformatics strategy. By intersecting differential gene expression analyses with a curated list of 92 known PMGs, we aimed to pinpoint those with potential roles in NSOI. Advanced methodologies, including Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA), facilitated a deep dive into the biological functions and pathways associated with these PMGs. Further refinement through Lasso regression and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) enabled the identification of key hub genes and the evaluation of their diagnostic prowess for NSOI. Additionally, the relationship between these hub PMGs and relevant clinical parameters was thoroughly investigated. To corroborate our findings, we analyzed expression data from datasets GSE58331 and GSE105149, focusing on the seven PMGs identified as potentially crucial to NSOI pathology. Results: Our investigation unveiled seven PMGs (ENTPD1, POLR2K, NPR2, PDE6D, PDE6H, PDE4B, and ALLC) as intimately connected to NSOI. Functional analyses shed light on their involvement in processes such as peroxisome targeting sequence binding, seminiferous tubule development, and ciliary transition zone organization. Importantly, the diagnostic capabilities of these PMGs demonstrated promising efficacy in distinguishing NSOI from non-affected states. Conclusions: Through rigorous bioinformatics analyses, this study unveils seven PMGs as novel biomarker candidates for NSOI, elucidating their potential roles in the disease's pathogenesis. These discoveries not only enhance our understanding of NSOI at the molecular level but also pave the way for innovative approaches to monitor and study its progression, offering a beacon of hope for individuals afflicted by this enigmatic condition.

mSphere of Influence: Deciphering purine auxotrophy in protozoan parasites.

Bruno Martorelli Di Genova works in parasitology, focusing on Toxoplasma gondii metabolism. In this mSphere of Influence article, he reflects on how the articles "Metabolic Reprogramming during Purine Stress in the Protozoan Pathogen Leishmania donovani" and "Yeast-Based High-Throughput Screen Identifies Plasmodium falciparum Equilibrative Nucleoside Transporter 1 Inhibitors That Kill Malaria Parasites" impacted him, informing his research strategies and understanding of metabolic flexibility in Toxoplasma gondii.