Hyperibone J exerts antidepressant effects by targeting ADK to inhibit microglial P2X7R/TLR4-mediated neuroinflammation.

INTRODUCTION: The antidepressant properties of Hypericum species are known. Hyperibone J, a principal component found in the flowers of Hypericum bellum, exhibited in vitro anti-inflammatory effects. However, the antidepressant effects and mechanisms of Hyperibone J remain to be elucidated. Adenosine kinase (ADK) is upregulated in epilepsy and depression and has been implicated in promoting neuroinflammation. OBJECTIVES: This study aimed to explore the impact of Hyperibone J on neuroinflammation-mediated depression and the mechanism underlying this impact. METHODS: This study employed acute and chronic in vivo depression models and an in vitro LPS-induced depression model using BV-2 microglia. The in vivo antidepressant efficacy of Hyperibone J was assessed through behavioral assays. Techniques such as RNA-seq, western blot, qPCR and ELISA were utilized to elucidate the direct target and mechanism of action of Hyperibone J. RESULTS: Compared with the model group, depression-like behaviors were significantly alleviated in the Hyperibone J group. Furthermore, Hyperibone J mitigated hippocampal neuroinflammation and neuronal damage. RNA-seq suggested that Hyperibone J predominantly influenced inflammation-related pathways. In vitro experiments revealed that Hyperibone J reversed the LPS-induced overexpression and release of inflammatory factors. Network pharmacology and various molecular biology experiments revealed that the potential binding of Hyperibone J at the ASN-312 site of ADK diminished the stability and protein expression of ADK. Mechanistic studies revealed that Hyperibone J attenuated the ADK/ATP/P2X7R/Caspase-1-mediated maturation and release of IL-1ß. The study also revealed a significant correlation between Tlr4 expression and depression-like behaviors in mice. Hyperibone J downregulated ADK, inhibiting Tlr4 transcription, which in turn reduced the phosphorylation of NF-κB and the subsequent transcription of Nlrp3, Il-1b, Tnf, and Il-6. CONCLUSION: Hyperibone J exerted antineuroinflammatory and antidepressant effects by binding to ADK in microglia, reducing its expression and thereby inhibiting the ATP/P2X7R/Caspase-1 and TLR4/NF-κB pathways. This study provides experimental evidence for the therapeutic potential of Hypericum bellum.

Genome-Wide Identification and Expression Analysis of ADK Gene Family Members in Cotton under Abiotic Stress.

Adenosine kinase (ADK) is a key enzyme widely distributed in plants, playing an important role in maintaining cellular energy homeostasis and regulating plant growth, development, and responses to environmental stresses. However, research on ADK genes in cotton (Gossypium hirsutum), an economically significant crop, has been limited. This study identified 92 ADK genes from four cotton species (G. arboreum, G. raimondii, G. hirsutum, and G. barbadense) using HMMER and Local BLASTP methods and classified them into six groups. Chromosomal localization revealed a random distribution of ADK genes in G. hirsutum, with 13 genes located on the At subgenome and 14 genes on the Dt subgenome. Gene structure analysis showed consistency in exon-intron organization within subgroups, while conserved motif analysis identified subgroup-specific motifs, indicating functional diversity. Synteny and collinearity mapping analysis revealed that the primary expansion mechanisms of the ADK gene family in cotton are polyploidy and segmental duplication. Cis-regulatory elements in GhADK promoters were classified into light response, hormone response, developmental regulation, and stress response. We also analyzed the expression patterns of GhADK genes under a low temperature (4 °C) and drought conditions. Most GhADK genes responded to cold stress with different expression patterns, indicating their roles in rapid response and long-term cold adaptation. Under drought stress, expression patterns varied, with some genes showing sustained high expression levels. The qRT-PCR validation of transcriptomic data confirmed the stress-induced expression patterns of selected GhADK genes. Functional analysis through the VIGS silencing of GhADK25 demonstrated its importance in cold and drought stress responses, with silencing resulting in poor growth under stress, highlighting its significance in stress tolerance. This study provides a basis for further understanding the evolutionary relationships and functions of the cotton ADK gene family.

Diabetes and the fabkin complex: A dual-edged sword.

The Fabkin complex, composed of FABP4, ADK, and NDPKs, emerges as a novel regulator of insulin-producing beta cells, offering promising prospects for diabetes treatment. Our approach, which combines literature review and database analysis, sets the stage for future research. These findings hold significant implications for both diabetes treatment and research, as they present potential therapeutic targets for personalized treatment, leading to enhanced patient outcomes and a deeper comprehension of the disease. The multifaceted role of the Fabkin complex in glucose metabolism, insulin resistance, anti-inflammation, beta cell proliferation, and vascular function underscores its therapeutic potential, reshaping diabetes management and propelling advancements in the field.

Novel homozygous ADK out-of-frame deletion causes adenosine kinase deficiency with rare phenotypes of sepsis, metabolites disruption and neutrophil dysfunction.

Adenosine kinase deficiency (OMIM #614300) is a type of inborn errors of metabolism with multiorgan symptoms primarily neurological disorders, hepatic impairment, global developmental delay, and mild dysmorphism. The genetic causes of adenosine kinase deficiency are homozygous or compound heterozygous loss-of-function variants of ADK. To date, fewer than 25 cases of adenosine kinase deficiency have been reported worldwide and none have been reported in China. In this research, trio whole-exome sequencing (Trio-WES) identified a novel homozygous ADK (NM_001123.4) out-of-frame deletion, c.518_519delCA (p.Thr173Serfs*15), in a Chinese patient with rare phenotypes of sepsis, metabolites disruption and neutrophil dysfunction. This variant was dysfunctional, with marked reduction of ADK level in both the patient's peripheral blood and cells transfected with the corresponding variant. Additionally, metabolomics detected by high-throughput mass spectrometry showed disturbances in the methionine (Met) and energy pathway. RNA sequencing (RNA-seq) of the patient's peripheral blood suggested a defective anti-inflammatory response characterized by impaired neutrophil activation, migration, and degranulation, which might be the primary cause for the sepsis. To our knowledge, we identified the first Chinese patient of adenosine kinase deficiency with a novel homozygous out-of-frame deletion in ADK causing multiorgan disorders, metabolites disruption, rare phenotypes of sepsis, and neutrophil dysfunction. Our findings broaden the genetic spectrum and pathogenic mechanisms of adenosine kinase deficiency.

The Interaction between ADK and SCG10 Regulate the Repair of Nerve Damage.

The cytoskeleton must be remodeled during neurite outgrowth, and Superior Cervical Ganglion 10 (SCG10) plays a critical role in this process by depolymerizing Microtubules (MTs), conferring highly dynamic properties to the MTs. However, the precise mechanism of action of SCG10 in the repair of injured neurons remains largely uncertain. Using transcriptomic identification, we discovered that SCG10 expression was downregulated in neurons after Spinal Cord Injury (SCI). Additionally, through mass spectrometry identification, immunoprecipitation, and pull-down assays, we established that SCG10 could interact with Adenosine Kinase (ADK). Furthermore, we developed an excitotoxicity-induced neural injury model and discovered that ADK suppressed injured neurite re-growth, whereas, through overexpression and small molecule interference experiments, SCG10 enhanced it. Moreover, we discovered ADK to be the upstream of SCG10. More importantly, the application of the ADK inhibitor called 5-Iodotubercidin (5-ITu) was found to significantly enhance the recovery of motor function in mice with SCI. Consequently, our findings suggest that ADK plays a negative regulatory role in the repair of injured neurons. Herein, we propose a molecular interaction model of the SCG10-ADK axis to regulate neuronal recovery.

Accumulation of endogenous adenosine improves cardiomyocyte metabolism via epigenetic reprogramming in an ischemia-reperfusion model.

Adenosine kinase (ADK) plays the major role in cardiac adenosine metabolism, so that inhibition of ADK increases myocardial adenosine levels. While the cardioprotective actions of extracellular adenosine against ischemia/reperfusion (I/R) are well-established, the role of cellular adenosine in protection against I/R remains unknown. Here we investigated the role of cellular adenosine in epigenetic regulation on cardiomyocyte gene expression, glucose metabolism and tolerance to I/R. Evans blue/TTC staining and echocardiography were used to assess the extent of I/R injury in mice. Glucose metabolism was evaluated by positron emission tomography and computed tomography (PET/CT). Methylated DNA immunoprecipitation (MeDIP) and bisulfite sequencing PCR (BSP) were used to evaluate DNA methylation. Lentiviral/adenovirus transduction was used to overexpress DNMT1, and the OSI-906 was administered to inhibit IGF-1. Cardiomyocyte-specific ADK/IGF-1-knockout mice were used for mechanistic experiments.Cardiomyocyte-specific ADK knockout enhanced glucose metabolism and ameliorated myocardial I/R injury in vivo. Mechanistically, ADK deletion caused cellular adenosine accumulation, decreased DNA methyltransferase 1 (DNMT1) expression and caused hypomethylation of multiple metabolic genes, including insulin growth factor 1 (IGF-1). DNMT1 overexpression abrogated these beneficial effects by enhancing apoptosis and decreasing IGF-1 expression. Inhibition of IGF-1 signaling with OSI-906 or genetic knocking down of IGF-1 also abrogated the cardioprotective effects of ADK knockout, revealing the therapeutic potential of increasing IGF-1 expression in attenuating myocardial I/R injury. In conclusion, the present study demonstrated that cardiomyocyte ADK deletion ameliorates myocardial I/R injury via epigenetic upregulation of IGF-1 expression via the cardiomyocyte adenosine/DNMT1/IGF-1 axis.

Relationship between the Gene Expression of Adenosine Kinase Isoforms and the Expression of CD39 and CD73 Ectonucleotidases in Colorectal Cancer.

Tumor cells have the capacity to create an adenosine-rich immunosuppressive environment, which can interfere with antitumor immunotherapy. Approaches are currently being developed with a view to suppressing the production of adenosine or its signals. Such approaches include the use of antibodies to inhibit CD39, CD73, and adenosine-receptor antagonists. However, the abundance of enzymatic pathways that control the ATP-adenosine balance, as well as the still poorly understood intracellular adenosine regulation, makes the hoped-for success unlikely. In the present study, the enzyme adenosine kinase (ADK) needed to convert adenosine to adenosine monophosphate, thereby regulating its levels, was investigated. To do so, peripheral blood samples from patients with colorectal cancer (CRC) (n = 31) were collected with blood samples from healthy donors (n = 17) used as controls. ADK gene expression levels and those of its long (ADK-L) and short (ADK-S) isoforms were measured. The relationship between the levels of ADK gene expression and that of CD39, CD73, and A2aR genes was analyzed. It turned out that in the group of CRC patients (stages III-IV), the level of ADK-L mRNA was lower (p < 0.0011) when compared to that of the control. For the first time, an average correlation was found between the level of expression of CD39 and ADK-S (r = -0.468 at p = 0.043) and between CD73 and ADK-L (r = 0.518 at p = 0.0232) in CRC patients. Flow cytometry was used to assess the content of CD39/CD73-expressing CD8+, CD4+ and Treg lymphocytes, as well as their relationship with the level of ADK gene expression in CRC patients. But no significant correlations were found.

Corrigendum: Adenosine kinase on deoxyribonucleic acid methylation: Adenosine receptor-independent pathway in cancer therapy.

[This corrects the article DOI: 10.3389/fphar.2022.908882.].

Functional importance of coacervation to convert calcium polyphosphate nanoparticles into the physiologically active state.

Inorganic polyphosphates (polyP) are of increasing medical interest due to their unprecedented ability to exhibit both morphogenetic and ATP-delivering properties. However, these polymers are only physiologically active in the coacervate state, but not as amorphous nanoparticles (NP), the storage form of the polymer. Little is known about the mechanism of formation and interconversion of these two distinct polyP phases in the presence of metal ions. Based on in silico simulation studies, showing a differential clustering of polyP and calcium ions, the pH-dependent NP and coacervate formation of polyP was examined experimentally. Turbidimetric studies showed that Ca-polyP coacervate formation at pH 7 is a slow process compared to NP formation at pH 10. In FTIR spectra, the asymmetric stretching vibration signal of the internal (PO2)- units, which is present in the Ca-polyP coacervate formed at pH 7, disappears in the NP formed at pH 10 using the conventional method (dropping of a CaCl2 solution into a Na-polyP solution). Surprisingly, when reversing the procedure, adding Na-polyP to CaCl2, a coacervate is obtained at both pH 7 and pH 10, as confirmed by SEM and FTIR analyses. The (PO2)- signal also disappears when Ca-polyP-NP are exposed to peptides, leading to the transformation of the NP into the coacervate phase. From these results, a mechanistic model of pH-dependent coacervate and NP formation is proposed that considers not only electrostatic ion-ion but also ion-dipole interactions. Functional studies revealed a delayed polyP release kinetics for Ca-polyP-NP embedded in a hydrogel due to NP/coacervate conversion. Human A549 epithelial cells grown on the coacervate show increased proliferation and ATP production compared to cells cultured on particulate polyP. Ca-polyP NP taken up by endocytosis undergo intracellular coacervate transformation. Understanding the differential expression of the two polyP phases is of functional importance for the potential therapeutic application of this physiological, regeneratively active polymer.

Extracellular ATP and its derivatives provide spatiotemporal guidance for bone adaptation to wide spectrum of physical forces.

ATP is a ubiquitous intracellular molecule critical for cellular bioenergetics. ATP is released in response to mechanical stimulation through vesicular release, small tears in cellular plasma membranes, or when cells are destroyed by traumatic forces. Extracellular ATP is degraded by ecto-ATPases to form ADP and eventually adenosine. ATP, ADP, and adenosine signal through purinergic receptors, including seven P2X ATP-gated cation channels, seven G-protein coupled P2Y receptors responsive to ATP and ADP, and four P1 receptors stimulated by adenosine. The goal of this review is to build a conceptual model of the role of different components of this complex system in coordinating cellular responses that are appropriate to the degree of mechanical stimulation, cell proximity to the location of mechanical injury, and time from the event. We propose that route and amount of ATP release depend on the scale of mechanical forces, ranging from vesicular release of small ATP boluses upon membrane deformation, to leakage of ATP through resealable plasma membrane tears, to spillage of cellular content due to destructive forces. Correspondingly, different P2 receptors responsive to ATP will be activated according to their affinity at the site of mechanical stimulation. ATP is a small molecule that readily diffuses through the environment, bringing the signal to the surrounding cells. ATP is also degraded to ADP which can stimulate a distinct set of P2 receptors. We propose that depending on the magnitude of mechanical forces and distance from the site of their application, ATP/ADP profiles will be different, allowing the relay of information about tissue level injury and proximity. Lastly, ADP is degraded to adenosine acting via its P1 receptors. The presence of large amounts of adenosine without ATP, indicates that an active source of ATP release is no longer present, initiating the transition to the recovery phase. This model consolidates the knowledge regarding the individual components of the purinergic system into a conceptual framework of choreographed responses to physical forces.

Adenosine Kinase on Deoxyribonucleic Acid Methylation: Adenosine Receptor-Independent Pathway in Cancer Therapy.

Methylation is an important mechanism contributing to cancer pathology. Methylation of tumor suppressor genes and oncogenes has been closely associated with tumor occurrence and development. New insights regarding the potential role of the adenosine receptor-independent pathway in the epigenetic modulation of DNA methylation offer the possibility of new interventional strategies for cancer therapy. Targeting DNA methylation of cancer-related genes is a promising therapeutic strategy; drugs like 5-Aza-2'-deoxycytidine (5-AZA-CdR, decitabine) effectively reverse DNA methylation and cancer cell growth. However, current anti-methylation (or methylation modifiers) are associated with severe side effects; thus, there is an urgent need for safer and more specific inhibitors of DNA methylation (or DNA methylation modifiers). The adenosine signaling pathway is reported to be involved in cancer pathology and participates in the development of tumors by altering DNA methylation. Most recently, an adenosine metabolic clearance enzyme, adenosine kinase (ADK), has been shown to influence methylation on tumor suppressor genes and tumor development and progression. This review article focuses on recent updates on ADK and its two isoforms, and its actions in adenosine receptor-independent pathways, including methylation modification and epigenetic changes in cancer pathology.

Muscle satellite cells are impaired in type 2 diabetic mice by elevated extracellular adenosine.

Muscle regeneration is known to be defective under diabetic conditions. However, the underlying mechanisms remain less clear. Adult quiescent muscle satellite cells (MuSCs) from leptin-receptor-deficient (i.e., db/db) diabetic mice are defective in early activation in vivo, but not in culture, suggesting the involvement of pathogenic niche factors. Elevated extracellular adenosine (eAdo) and AMP (eAMP) are detected under diabetic conditions. eAdo and eAMP potently inhibit cell cycle re-entry of quiescent MuSCs and injury-induced muscle regeneration. Mechanistically, eAdo and eAMP engage the equilibrative Ado transporters (ENTs)-Ado kinase (ADK)-AMPK signaling axis in MuSCs to inhibit the mTORC1-dependent cell growth checkpoint. eAdo and eAMP also inhibit early activation of quiescent fibroadipogenic progenitors and human MuSCs by the same mechanism. Treatment of db/db diabetic mice with an ADK inhibitor partially rescues the activation defects of MuSCs in vivo. Thus, both ADK and ENTs represent potential therapeutic targets for restoring the regenerative functions of tissue stem cells in patients with diabetes.

Thorough investigation of non-volatile substances extractible from inner coatings of metallic cans and their occurrence in the canned vegetables.

Since the decline of the use of bisphenol A, the chemistry of the varnishes and coatings which are applied to the inner surfaces of metallic food contact materials is poorly documented. We hypothesised that can coatings are now diverse and bring forth various non-intentionally added substances (NIAS) to be described. Investigating complex components such as NIAS requires demanding non-targeted approaches. We investigated the coatings of 12 vegetable cans from the French market. More than 125 substances were pinpointed, among them 84 oligoester combinations from 8 diols and 4 diacids. Thus, oligoesters were the dominant family. Additives such as epoxidised soybean oil, bisphenol A diglycidyl ether and benzoguanamine derivatives and phenol-formaldehyde oligomers were also identified. A software for exploring databases of theoretical combinations of polyester and phenol-formaldehyde resin components (NIAS-db 1.0) was made available. The stepwise organic synthesis of native and deuterated combinations of neopentyl glycol and isophthalic acid (4 and 8 units, linear and cyclic) enabled a higher confidence level and monitoring in vegetable extracts. Migration of oligoesters averaged 330 µg/kg in the drained vegetables (43-1600 µg/kg). This study sheds light on the need to fulfil a proper risk assessment on this NIAS family (exposure and hazard characterisation).

Computational studies of the principle of dynamic-change-driven protein interactions.

Dynamic allostery emphasizes a role of entropy change manifested as a sole change in protein fluctuations without structural changes. This kind of entropy-driven effect remains largely understudied. The most significant examples involve protein-ligand interactions, leaving protein-protein interactions, which are critical in signaling and other cellular events, largely unexplored. Here we study an example of how protein-protein interaction (binding of Ras to the Ras binding domain [RBD] of the effector protein Raf) affects a subsequent protein association process (Ras dimerization) by quenching Ras internal motions through dynamic allostery. We also investigate the influence of point mutations or ambient temperature, respectively, on the protein dynamics and interaction of two other systems: in adenylate kinase (ADK) and in the EphA2 SAM:Ship2 SAM complex. Based on these examples, we postulate that there are different ways in which dynamic-change-driven protein interactions are manifested and that it is likely a general biological phenomenon.

Mucoadhesive Nucleoside-Based Hydrogel Delays Oral Leukoplakia Canceration.

Some oral squamous cell carcinomas (OSCCs) originate from preexisting oral potentially malignant disorders (OPMDs). Oral leukoplakia (OLK) is the most common and typical OPMD in the clinic, so treatment for it is essential to reduce OSCC incidence. Local chemotherapy is an option other than surgery considering the superficial site of OLK. However, there are no standardized drugs applied to OLK, and traditionally used chemotherapeutic drugs revealed limited efficacy for lack of adhesion. Hence, there is a growing demand to prepare new agents that combine mucoadhesion with an anti-OLK effect. Here, an isoguanosine-tannic acid (isoG-TA) supramolecular hydrogel via dynamic borate esters was successfully fabricated based on isoG and TA. Previously reported guanosine-TA (G-TA) hydrogel was also explored for an anti-OLK effect. Both gels not only exhibited ideal adhesive properties but also integrated anti-OLK activities in one system. In vitro cell viability indicated that isoG and TA inhibited the proliferation of dysplastic oral keratinocytes (DOKs). The in vivo OLK model evidence revealed that both gels showed potential to prevent OLK canceration. In addition, the probable anti-DOK mechanisms of isoG and TA were investigated. The results indicated that isoG could bind to adenosine kinase (ADK) and then affected the mammalian target of rapamycin (mTOR) pathway to inhibit DOK proliferation. TA could significantly and continuously reduce reactive oxygen species (ROS) in DOKs through its antioxidant effect. ROS plays an important role in the progression of cell cycle. We proved that the low level of ROS may inhibit DOK proliferation by inducing G0/G1 arrest in the cell cycle. Altogether, this study innovatively fabricated an isoG-TA hydrogel with ideal adhesion, and both isoG and TA showed in vitro inhibition of DOKs. Moreover, both isoG-TA and G-TA hydrogels possessed potential in delaying the malignant transformation of OLK, and the G-TA hydrogel showed a better statistical effect, providing an effective strategy for controlling OLK.

Adenosine-Metabolizing Enzymes, Adenosine Kinase and Adenosine Deaminase, in Cancer.

The immunosuppressive effect of adenosine in the microenvironment of a tumor is well established. Presently, researchers are developing approaches in immune therapy that target inhibition of adenosine or its signaling such as CD39 or CD73 inhibiting antibodies or adenosine A2A receptor antagonists. However, numerous enzymatic pathways that control ATP-adenosine balance, as well as understudied intracellular adenosine regulation, can prevent successful immunotherapy. This review contains the latest data on two adenosine-lowering enzymes: adenosine kinase (ADK) and adenosine deaminase (ADA). ADK deletes adenosine by its phosphorylation into 5'-adenosine monophosphate. Recent studies have revealed an association between a long nuclear ADK isoform and an increase in global DNA methylation, which explains epigenetic receptor-independent role of adenosine. ADA regulates the level of adenosine by converting it to inosine. The changes in the activity of ADA are detected in patients with various cancer types. The article focuses on the biological significance of these enzymes and their roles in the development of cancer. Perspectives of future studies on these enzymes in therapy for cancer are discussed.

NLRP3 Inflammasome Activation Enhances ADK Expression to Accelerate Epilepsy in Mice.

Epilepsy (SE) is a common and serious neurological disease. NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome participates in the pathogenesis of SE, while its underlying mechanism is still unclear. Here, we attempted to explore the mechanism of action of NLRP3 inflammasome in SE. SE mouse model was constructed by administration of kainic acid (KA). Astrocytes were treated with KA to mimic SE cell model. MCC950 (NLRP3 inhibitor) and Z-YVAD-FMK (Caspase-1 inhibitor) were used to treat astrocytes to inhibit the activity of NLRP3 and Caspase-1. Nissl staining was performed to examine the morphology of neuron. Western blot, enzyme-linked immunosorbent assay and immunofluorescence staining were performed to assess protein expression. SE mouse model exhibited an increase of neuronal loss, and an up-regulation of Cleaved-Caspase-1, IL-1ß and IL-18 in hippocampus. The levels of GFAP+ADK+ cells were significantly increased in SE mice. MCC950 or Z-YVAD-FMK abolished these impacts conferred by KA in SE mice. Moreover, KA treatment enhanced the expression of NLRP3, Cleaved-Caspase-1, IL-1ß and IL-18 in astrocytes, which was rescued by knockdown of NLRP3 or Caspase-1. Additionally, CREB, p-CREB, REST were up-regulated, and SP1 was down-regulated in the KA-treated SE mice and KA-treated astrocytes. Inhibition of NLRP3 or Caspase-1 rescued these proteins expression in KA-treated astrocytes. CREB or REST silencing reduced adenosine kinase (ADK) expression, while SP1 knockdown enhanced ADK expression in KA-treated astrocytes. In conclusion, NLRP3 inflammasome activation enhances ADK expression to accelerate SE in mice through regulating CREB/REST/SP1 signaling pathway. Thus, inhibition of NLRP3 inflammasome may be a treatment for SE.

Clinical utility of methionine restriction in adenosine kinase deficiency.

Adenosine kinase (ADK) deficiency is a rare autosomal recessive inborn error of metabolism involving the methionine and purine metabolic pathways. Prior reports show that most patients present in infancy with jaundice, hypotonia, developmental delay, and mild dysmorphic features. Characteristic biochemical findings included hypoglycemic hyperinsulinism, cholestasis, elevated liver functions, methionine, S-adenosylhomocysteine, and S-adenosylmethionine, with normal or mildly elevated homocysteine level. Brain imaging demonstrated atrophy, hydrocephalus, and delayed myelination. There are 26 reported patients of ADK deficiency, of which 14 patients were placed on a methionine-restricted diet. Clinical improvement with methionine restriction was not well described. CASE REPORT: We report an infant who presented at birth with persistently elevated ammonia (100-163 µmol/L), hypoglycemia, cholestasis, and liver dysfunction. The initial metabolic and genetic work-up was nondiagnostic, with only a mildly increased plasma methionine level (51 [<38 µmol/L]). Iron depositions in the liver and in lip mucosa led to suspicion of gestational alloimmune liver disease. Immunoglobulin therapy and exchange transfusion treatments demonstrated transient clinical and biochemical improvements. However, subsequent episodes of acute liver failure with development of neurological abnormalities led to further evaluation. Metabolic studies showed a 25-fold increase in plasma methionine level at 8 months of life (1022 [<38 µmol/L]) with white matter abnormalities on brain MRI. Expanded molecular testing identified the disease. Urinary purines profile showed elevations of adenosine and related metabolites. Introduction of a low-methionine diet resulted in rapid clinical amelioration, improvement of brain MRI findings, and normalization of liver functions and methionine levels.

Can remdesivir and its parent nucleoside GS-441524 be potential oral drugs? An in vitro and in vivo DMPK assessment.

Remdesivir (RDV) is the only US Food and Drug Administration (FDA)-approved drug for treating COVID-19. However, RDV can only be given by intravenous route, and there is a pressing medical need for oral antivirals. Significant evidence suggests that the role of the parent nucleoside GS-441524 in the clinical outcomes of RDV could be largely underestimated. We performed an in vitro and in vivo drug metabolism and pharmacokinetics (DMPK) assessment to examine the potential of RDV, and particularly GS-441524, as oral drugs. In our in vitro assessments, RDV exhibited prohibitively low stability in human liver microsomes (HLMs, t 1/2 = âˆ¼1 min), with the primary CYP-mediated metabolism being the mono-oxidation likely on the phosphoramidate moiety. This observation is poorly aligned with any potential oral use of RDV, though in the presence of cobicistat, the microsomal stability was drastically boosted to the level observed without enzyme cofactor NADPH. Conversely, GS-441524 showed excellent metabolic stability in human plasma and HLMs. In further in vivo studies in CD-1 mice, GS-441524 displayed a favorable oral bioavailability of 57%. Importantly, GS-441524 produced adequate drug exposure in the mice plasma and lung, and was effectively converted to the active triphosphate, suggesting that it could be a promising oral antiviral drug for treating COVID-19.

Genome-Wide Identification and Expression Analysis of Tomato ADK Gene Family during Development and Stress.

Adenylate kinase (ADK) is widely distributed in organisms and plays an important role in cellular energy homeostasis. In plants, ADK has important functions in plant growth and development regulation as well as in adaptation to the environment. However, little information is available about the ADK genes in tomato (Solanum lycopersicum), an important economic crop. To investigate the characteristics and functions of ADK genes in tomato, a total of 11 ADK genes were identified and named according to their chromosomal locations. The ADK family in Arabidopsis, tomato, potato, and rice was divided into six groups, and motif analysis revealed that each SlADK protein contained five to eight conserved motifs. A total of 4 to 19 exons were identified in tomato ADK gene family members, and interestingly, most members possessed 4 exons. Several stress response elements were identified in the promoter regions of SlADKs. The 11 SlADKs were randomly distributed on 9 of the 12 tomato chromosomes. Three duplication events were observed between tomato chromosomes, and a high degree of conservation of synteny was demonstrated between tomato and potato. The online TomExpress platform prediction revealed that SlADKs were expressed in various tissues and organs, basically consistent with the data obtained from real-time quantitative PCR (qPCR). The qPCR verification was also performed to determine the expression level of SlADKs and demonstrated that the genes responded to multiple abiotic stresses, such as drought, salt, and cold. Besides, the qPCR results showed that SlADK transcription was responsive to most of the applied hormone treatment. For correlation network analysis under 44 global conditions, the results showed that the number of 17, 3, 4, and 6 coexpressed genes matched with SlADK5, 8, 9, and 11, respectively. For specific gene function analysis, expression of SlADK10 was inhibited using virus-induced gene silencing (VIGS). Compared to wild-type plants, plants with silenced SlADK10 gene had poor drought resistance, indicating SlADK10 regulated drought tolerance of tomato positively. In summary, the information provided in the present study will be helpful to understand the evolutionary relationship and their roles of tomato ADK gene family in further research.