Kinase Activity Research Articles

Isoform-specific C-terminal phosphorylation drives autoinhibition of Casein kinase 1

Casein kinase 1δ (CK1δ) controls essential biological processes including circadian rhythms and wingless-related integration site (Wnt) signaling, but how its activity is regulated is not well understood. CK1δ is inhibited by autophosphorylation of its intrinsically disordered C-terminal tail. Two CK1 splice variants, δ1 and δ2, are known to have very different effects on circadian rhythms. These variants differ only in the last 16 residues of the tail, referred to as the extreme C termini (XCT), but with marked changes in potential phosphorylation sites. Here, we test whether the XCT of these variants have different effects in autoinhibition of the kinase. Using NMR and hydrogen/deuterium exchange mass spectrometry, we show that the δ1 XCT is preferentially phosphorylated by the kinase and the δ1 tail makes more extensive interactions across the kinase domain. Mutation of δ1-specific XCT phosphorylation sites increases kinase activity both in vitro and in cells and leads to changes in the circadian period, similar to what is reported in vivo. Mechanistically, loss of the phosphorylation sites in XCT disrupts tail interaction with the kinase domain. δ1 autoinhibition relies on conserved anion-binding sites around the CK1 active site, demonstrating a common mode of product inhibition of CK1δ. These findings demonstrate how a phosphorylation cycle controls the activity of this essential kinase.

Strategies for enhanced acetone-butanol-ethanol production by Clostridium beijerinckii Y10 from glucose and xylose and exploration of its physiological mechanisms

To enhance the production of butanol and its ratio to the total solvent, the impacts of exogenous amino acids supplementation on acetone-butanol-ethanol (ABE) fermentation were studied. With this effort, the highest butanol and total solvent production of 14.18 ± 0.24 g/L and 16.29 ± 0.31 g/L were achieved when 5.0 mg/L of phenylalanine was added at 18 h. Additionally, to explore the physiological reasons for the efficient synthesis of butanol under the optimal condition, the changes of key enzyme activities in the butanol synthesis pathway and the intracellular microenvironment were investigated. The findings show that phenylalanine addition could enhance crude enzyme activities of acetate kinase and butyrate kinase activities, strengthen NADH synthesis and expend more ATP to promote the growth of Clostridium beijerinckii Y10. This study suggests that the method of a tiny amount of amino acid addition was a simple and efficient approach to enhance bio-butanol production, thus providing a new strategy to improve the performance of other similar fermentation.

Vitamin D3 mitigates myopathy and metabolic dysfunction in rats with metabolic syndrome: the potential role of dipeptidyl peptidase-4.

Metabolic syndrome is associated with vitamin D3 deficiency. This work aims to examine the efficacy of vitamin D3 in inhibiting MetS-induced myopathy and to determine whether the beneficial effects of vitamin D3 are mediated by the inhibition of dipeptidyl peptidase-4 (DPP-4). An in silico study investigated the potential effectiveness of vitamin D3 on the inhibition of the DPP-4 enzyme. An in vitro assay of the DPP-4 inhibitory effect of vitamin D3 was performed. In vivo and over 12 weeks, both diet (with 3% salt) and drinking water (with 10% fructose) were utilized to induce MetS. In the seventh week, rats received either vitamin D3, vildagliptin, a combination of both, or vehicles. Serum lipids, adipokines, glycemic indices, and glucagon-like peptide-1 (GLP-1), muscular glucose transporter type-4 (GLUT-4) content, DPP-4, adenosine monophosphate kinase (AMPK) activities, and Sudan Black B-stained lipids were assessed. Muscular reactive oxygen species (ROS), caspase-3, and desmin immunostaining were used to determine myopathy. MetS-induced metabolic dysfunction was ameliorated by vitamin D3, which also reduced intramuscular glycogen and lipid accumulation. This is demonstrated by the attenuation of MetS-induced myopathy by vitamin D3, decreased oxidative stress, increased desmin immuno-expression, and caspase-3 activity. Our in silico data demonstrated that vitamin D3 is capable of inhibiting DPP-4, which is further supported by biochemical findings. Vitamin D3 increased serum GLP-1, muscular AMPK activity, and GLUT-4 content, whereas the levels of muscular ROS were decreased in MetS. Vildagliptin and its combination with vitamin D3 yielded comparable results. It is suggested that the DPP-4 inhibitory potential of vitamin D3 is responsible for the amelioration of MetS-induced metabolic changes and myopathy.

A-170 Hypereosinophilic Syndrome and t(5;15): Case Report and Literature Review

Abstract Background Hypereosinophilic syndrome (HES) is a myeloproliferative disorder characterized by persistent eosinophilia (absolute eosinophil count >1,500/mm3), classified into primary/clonal, reactive and idiopathic. After ruling out secondary causes of eosinophilia (parasitic infections, allergic conditions, vasculitis and collagenosis, drugs, eosinophilic lung disease, allergic gastroenteritis and metabolic conditions such as adrenal insufficiency), the main hypotheses become oncohematological diseases. Main entities to consider are myeloid/lymphoid neoplasms associated with eosinophilia and rearrangement of PDGFRA, FDGFRB, FGFR1 or PCM1-JAK2 and chronic eosinophilic leukemia. Conventional and molecular cytogenetics are the basis for classification and diagnosis of various hematological malignancies. This report describes a rare case of HES with t(5;15) (q33;q22). Methods A 29-year-old male patient was admitted with leukocytosis with the following exams: hemoglobin 6.5g/dL, hematocrit 21.7%, platelets 71,000/mm3, leukocytes 56,190/mm3 (60% neutrophils with a left shift to pro-myelocyte; 6% monocytes and 24% eosinophils), DHL 277 U/L, B12 vitamin 932 pg/mL, folic acid 1.72ng/mL, ferritin 913ng/mL. Non-reactive results were detected for antinuclear antibody, rheumatoid Factor, HIV, hepatitis B and C, syphilis and chagas disease. Bone marrow was hypercellular for age with absolute granulocytic predominance (G:E ratio 64:1) and eosinophilia (38%) in all maturational stages without dysplasia. Bone marrow flow cytometry did not detect neither increases in blasts nor anomalous immunophenotype. Bone marrow biopsy demonstrated 99% cellularity with normal blasts. Cytogenetics with translocation between the long arms of chromosome 5 and 15 in 15 of 20 metaphases analyzed - 46,XY,t(5;15)(q33;q22). No other molecular tests were available for this patient. Results In the case described t(5;15)(q33;q22) was found, which may be related to the TP53BP1::PDGFRB gene rearrangement. This breakpoint generates a chimeric oncoprotein similar to other tyrosine kinase fusions responsive to Imatinib. 53BP1 is a cellular DNA damage response component that binds wild type (non-mutant) p53. Oncogenesis occurs since the coiled-coil domains of TP53BP1 can mediate the homodimerization of PDGFRB and the constitutive activation of its tyrosine kinase activity; on the other hand, the DNA damage response of TP53BP1 may be disrupted. Gene rearrangements involving PDGFRA and FDGFRB are associated with response to tyrosine kinase inhibitors. Elevated vitamin B12 is a common finding in myeloproliferations with eosinophilia due to the increased production of haptocorrins, which binds to vitamin B12 in serum and in other tissues. Conclusions To our knowledge, in the literature there is only one described case of Myeloproliferative Neoplasia with Eosinophilia related to t(5;15)(q33;q22).

Enhanced kinase translocation reporters for simultaneous real-time measurement of PKA, ERK, and Ca2.

Kinase translocation reporters (KTRs) are powerful tools for single-cell measurement of time-integrated kinase activity but suffer from restricted dynamic range and limited sensitivity, particularly in neurons. To address these limitations, we developed enhanced KTRs (eKTRs) for protein kinase A (PKA) and extracellular signal-regulated kinase (ERK) that display high sensitivity, rapid response kinetics, broad dynamic range, cell type-specific tuning, and an ability to detect PKA and ERK activity in primary sensory neurons. Moreover, co-expression of optically separable eKTRs for PKA and ERK revealed the kinetics of expected and unexpected crosstalk between PKA, ERK, protein kinase C, and calcium signaling pathways, demonstrating the utility of eKTRs for live cell monitoring of diverse and interacting signaling pathways. These results open the door to improved live-cell and in vivo measurements of key signaling pathways in neurons, while at the same time demonstrating the importance of KTR size and NLS strength to KTR dynamics.

Insight in the (Phospho)proteome of Vascular Smooth Muscle Cells Derived From Patients With Abdominal Aortic Aneurysm Reveals Novel Disease Mechanisms.

Abdominal aortic aneurysm (AAA) is characterized by weakening and dilatation of the aortic wall in the abdomen. The aim of this study was to gain insight into cell-specific mechanisms involved in AAA pathophysiology by analyzing the (phospho)proteome of vascular smooth muscle cells derived from patients with AAA compared with those of healthy donors. A (phospho)proteomics analysis based on tandem mass spectrometry was performed on vascular smooth muscle cells derived from patients with AAA (n=24) and healthy, control individuals (C-SMC, n=8). Following protein identification and quantification using MaxQuant, integrative inferred kinase activity analysis was used to calculate kinase activity scores. Expression differences between vascular smooth muscle cells derived from patients with AAA and healthy, control individuals were predominantly found in proteins involved in ECM (extracellular matrix) remodeling (THSD4 [thrombospondin type-1 domain-containing protein 4] and ADAMTS1 [A disintegrin and metalloproteinase with thrombospondin motifs 1]), energy metabolism (GYS1 [glycogen synthase 1] and PCK2 [phosphoenolpyruvate carboxykinase 2, mitochondrial]), and contractility (CACNA2D1 [calcium voltage-dependent channel subunit α-2/δ-1] and TPM1 [tropomyosin α-1 chain]). Phosphorylation patterns on proteins related to actin cytoskeleton organization dominated the phosphoproteome of vascular smooth muscle cells derived from patients with AAA . Besides, phosphorylation changes on proteins related to energy metabolism (GYS1), contractility (PARVA [α-parvin], PPP1R12A [protein phosphatase 1 regulatory subunit 12A], and CALD1 [caldesmon 1]), and intracellular communication (GJA1 [gap junction α-1 protein]) were seen. Kinase activity of NUAK1 (NUAK family SNF1-like kinase 1), FYN (tyrosine-protein kinase Fyn), MAPK7 (mitogen-activated protein kinase 7), and STK10 (serine/threonine kinase 10) was different in vascular smooth muscle cells derived from patients with AAA compared with those from healthy, control individuals. This study revealed changes in expression and phosphorylation levels of proteins involved in various processes responsible for AAA progression and development (eg, energy metabolism, ECM remodeling, actin cytoskeleton organization, contractility, intracellular communication, and cell adhesion). These newly identified proteins, phosphosites, and related kinases provide further insight into the underlying mechanism of vascular smooth muscle cell dysfunction within the aneurysmal wall. Our omics data thereby offer the opportunity to study the relevance, either as drug target or biomarker, of these proteins in AAA development.

Ligand-induced CaMKIIα hub Trp403 flip, hub domain stacking, and modulation of kinase activity.

γ-Hydroxybutyric acid (GHB) analogs are small molecules that bind competitively to a specific cavity in the oligomeric CaMKIIα hub domain. Binding affects conformation and stability of the hub domain, which may explain the neuroprotective action of some of these compounds. Here, we describe molecular details of interaction of the larger-type GHB analog 2-(6-(4-chlorophenyl)imidazo[1,2-b]pyridazine-2-yl)acetic acid (PIPA). Like smaller-type analogs, PIPA binding to the CaMKIIα hub domain promoted thermal stability. PIPA additionally modulated CaMKIIα activity under sub-maximal CaM concentrations and ultimately led to reduced substrate phosphorylation. A high-resolution X-ray crystal structure of a stabilized CaMKIIα (6x mutant) hub construct revealed details of the binding mode of PIPA, which involved outward placement of tryptophan 403 (Trp403), a central residue in a flexible loop close to the upper hub cavity. Small-angle X-ray scattering (SAXS) solution structures and mass photometry of the CaMKIIα wild-type hub domain in the presence of PIPA revealed a high degree of ordered self-association (stacks of CaMKIIα hub domains). This stacking neither occurred with the smaller compound 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA), nor when Trp403 was replaced with leucine (W403L). Additionally, CaMKIIα W403L hub was stabilized to a larger extent by PIPA compared to CaMKIIα hub wild type, indicating that loop flexibility is important for holoenzyme stability. Thus, we propose that ligand-induced outward placement of Trp403 by PIPA, which promotes an unforeseen mechanism of hub domain stacking, may be involved in the observed reduction in CaMKIIα kinase activity. Altogether, this sheds new light on allosteric regulation of CaMKIIα activity via the hub domain.

LncRNA MBNL1-AS1 functions as an alternative atherosclerosis biomarker in elderly hypertensive patients and regulates vascular smooth muscle cell function.

The clinical role of long non-coding RNA (MBNL1-AS1) in diagnosing atherosclerosis (AS) risks of hypertensive patients and the effects of MBNL1-AS1 on vascular smooth muscle cells (VSMCs) triggered by angiotensin II (Ang II) were investigated. The hypertensive patients were recruited to assess MBNL1-AS1 expression. The ROC curve and Spearman analysis was performed for the significance of MBNL1-AS1. Human VSMCs were treated with Ang II (10-5 mol/L) to establish a hypertensive cell model. MTT and Transwell chamber were used in proliferative and migratory detection of cell models. Targets of MBNL1-AS1 were verified by luciferase activity. Functional enrichment of shared targets of miR-424-5p was researched by GO and KEGG analysis. An increase of MBNL1-AS1 was observed in patients with increased carotid intima-media thickness (cIMT). MBNL1-AS1 could predict the risk of AS and related to cIMT levels. The knockdown of MBNL1-AS1 mitigated the influence of Ang II on cellular proliferation and migration by inhibiting miR-424-5p. Enrichment analysis corroborated that targets of miR-424-5p were mainly involved in serine/threonine kinase activity, MAPK signaling pathway, and PI3K-Akt signaling pathway. MBNL1-AS1/miR-424-5p axis was connected with the progression of AS induced by hypertension.

Improving sugar and respiratory metabolism in pear wounds by postharvest dipping with chitosan and chitooligosaccharide

Chitosan (CTS) and its degradation product, chitooligosaccharide (COS), promote fruit healing by activating phenylpropanoid metabolism. This study investigates their effects on sucrose metabolism in pear wounds. CTS and COS were found to activate neutral invertase, acid invertase, sucrose synthase, and sucrose phosphate synthase, increasing sucrose, glucose, and fructose levels in fruit wounds. They also enhanced sorbitol dehydrogenase activity and promoted sorbitol accumulation. In addition, CTS and COS improved the activities of hexokinase, phosphofructokinase, and pyruvate kinase, increasing phosphoenolpyruvate and ATP production. They activated glucose-6-phosphate dehydrogenase and increased erythrose-4-phosphate, NADPH, and shikimic acid levels. In conclusion, CTS and COS support the formation of the healing closing layer by supplying carbon skeletons, energy, and reducing power through the activation of sugar and respiratory metabolism during the healing process. Compared to CTS, COS was superior in activating the above metabolisms, which is expected to be widely used as a chitin product in postharvest fruit and vegetable preservation and provide new insights into preserving pear freshness.

A genome-wide CRISPR/Cas9 knockout screen identifies SEMA3F gene for resistanceto cyclin-dependent kinase 4 and 6 inhibitors in breast cancer.

Palbociclib is a cell-cycle targeted small molecule agent used as one of the standards of care in combination with endocrine therapy for patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Although several gene alterations such as loss of Rb gene and amplification of p16 gene are known to be conventional resistance mechanisms to cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, the comprehensive landscape of resistance is not yet fully elucidated. The purpose of this study is to identify the novel resistant genes to the CDK4/6 inhibitors in HR-positive HER2-negative breast cancer. The wholegenome knockout screen using CRISPR/Cas9 genome editing was conducted in MCF7 to identify resistant genes to palbociclib. The candidate genes for resistance were selected by NGS analysis and GSEA analysis and validated by cell viability assay and mouse xenograft models. We identified eight genes including RET, TIRAP, GNRH1, SEMA3F, SEMA5A, GATA4, NOD1, SSTR1 as candidate genes from the wholegenome knockout screen. Among those, knockdown of SEMA3F by siRNA significantly and consistently increased the cell viability in the presence of CDK4/6 inhibitors in vitro and in vivo. Furthermore, the level of p-Rb was maintained in the palbociclibtreated SEMA3F-downregulated cells, indicating that the resistance is driven by increased activity of cyclin kinases. Our observation provided the first evidence of SEMA3F as a regulator of sensitivity to CDK4/6 inhibitors in breast cancer. The detailed mechanisms of resistance deserve further functional studies to develop the better strategy to overcome resistance in CDK4/6 inhibitors.

Chronic administration of low dose aspirin alleviates ASD-like behaviors and activates AMPK in valproic acid-exposed rats

BackgroundAutism Spectrum Disorder (ASD) is a neurodevelopmental disorder distinguished by deficits in social communication and the presence of restricted/repetitive behaviors. There has been a global increase in the prevalence of ASD, yet the underlying causes of ASD remain inadequately understood, and there is currently no pharmacological intervention for the core symptoms of ASD. However, recent studies have suggested that aspirin may have the potential for use in the treatment of ASD. MethodPregnant rats were administered either VPA or normal saline on gestational day 12.5. The male pups were administered a low dose of aspirin (1 mg/kg) or a vehicle control daily from postnatal day 23 to day 52. ASD-like behaviors were assessed by social interaction, spontaneous grooming test, open field test and light-dark transitions. The activity of AMP-activated protein kinase (AMPK) was quantified by measuring the level of p-AMPK using an immunoblotting assay. ResultsChronic administration of low dose aspirin resulted in significant improvements in social approach deficits, a reduction in repetitive grooming, and the alleviation of anxiety-like behavior in ASD rats. Furthermore, aspirin administration also led to the activation of AMPK in the hippocampus of rats exposed to VPA. ConclusionsThese results raise the question of the need for further investigation of agents with mechanisms related to aspirin in ASD.

Adiponectin receptor 1 regulates endometrial receptivity via the adenosine monophosphate‑activated protein kinase/E‑cadherin pathway.

Endometrial receptivity is essential for successful embryo implantation and pregnancy initiation and is regulated via various signaling pathways. Adiponectin, an important adipokine, may be a potential regulator of reproductive system functions. The aim of the present study was to elucidate the regulatory role of adiponectin receptor 1 (ADIPOR1) in endometrial receptivity. The endometrial receptivity between RL95‑2 and AN3CA cell lines was confirmed using an in vitro JAr spheroid attachment model. 293T cells were transfected with control or short hairpin (sh)ADIPOR1 vectors and RL95‑2 cells were transduced with lentiviral particles targeting ADIPOR1. Reverse transcription‑quantitative PCR and immunoblot assays were also performed. ADIPOR1 was consistently upregulated in the endometrium during the mid‑secretory phase compared with that in the proliferative phase and in receptive RL95‑2 cells compared with that in non‑receptive AN3CA cells. Stable cell lines with diminished ADIPOR1 expression caused by shRNA showed reduced E‑cadherin expression and attenuated in vitro endometrial receptivity. ADIPOR1 regulated AMP‑activated protein kinase (AMPK) activity in endometrial epithelial cells. Regulation of AMPK activity via dorsomorphin and 5‑aminoimidazole‑4‑carboxamide ribonucleotide affected E‑cadherin expression and in vitro endometrial receptivity. The ADIPOR1/AMPK/E‑cadherin axis is vital to endometrial receptivity. These findings can help improve fertility treatments and outcomes.

Reproductive effort affects cellular response in the mantle of Nodipecten subnodosus scallops exposed to acute hyperthermia

In marine ecosystems, temperature regulates the energy metabolism of animals. In the last decades, the temperature increase was related to mass mortality events of marine ectotherms, particularly during high-energy investment for reproduction. In scallops, the mantle has been poorly investigated while this tissue covers more than 40 % of the body mass, contributing to the perception of surrounding environmental stimuli. Our aim was to assess the cellular and molecular responses linked to energy metabolism in the mantle of adult N. subnodosus facing acute hyperthermia during reproductive effort. Scallops collected in spring (late gametogenesis) and summer (ripe gonads) were exposed to a control temperature (22 °C) or acute hyperthermia (30 °C) for 24 h. In spring, increased arginine kinase (AK) activity together with increased pyruvate kinase/citrate synthase ratio (PK/CS) suggested an enhanced carbohydrate, pyruvate, and arginine metabolism to maintain the adenylate energy charge (AEC) in the mantle of scallops coping with acute thermal increase. In summer, animals decreased their AEC (5 %) and arginine phosphate pool (40 %) and increased their anaerobic metabolism as shown by enhanced activities of lactate-dehydrogenase (LDH) and octopine dehydrogenase (ODH), respectively. The abundance of twenty proteins involved in energy metabolism (isocitrate dehydrogenase, ATP synthase subunit β), protein protection (cognates heat shock protein 70), and cytoskeleton (actins and tubulins) were affected only by season. These results underlie the role of the mantle of N. subnodosus in the seasonal responses of this tissue to thermal fluctuations during reproductive effort with possible implications for the physiological performance of scallops under heat waves in wild or harvest conditions.

Ziziphus jujuba (Jujube) in Metabolic Syndrome: From Traditional Medicine to Scientific Validation.

This review evaluates the therapeutic potential of Ziziphus jujuba and its main components in managing complications of metabolic syndrome, including diabetes, dyslipidemia, obesity, and hypertension. The reviewed studies provide evidence supporting the use of Z. jujuba and its main components (lupeol and betulinic acid) as natural treatments for complications of metabolic syndrome. These substances enhance glucose uptake through the activation of signaling pathways such as phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt), reduce hepatic glucose synthesis, and increase glucose uptake by adipocytes and skeletal muscle cells. They also improve insulin sensitivity by modulating AMP-activated protein kinase (AMPK) activity and regulating insulin signaling proteins and glucose transporters. In the field of dyslipidemia, they inhibit triglyceride synthesis, lipid accumulation, and adipogenic enzymes, while influencing key signaling pathways involved in adipogenesis. Z. jujuba and its constituents demonstrate anti-adipogenic effects, inhibiting lipid accumulation and modulating adipogenic enzymes and transcription factors. They also exhibit positive effects on endothelial function and vascular health by enhancing endothelial nitric oxide synthase (eNOS) expression, NO production, and antioxidant enzyme activity. Z. jujuba, lupeol, and betulinic acid hold promise as natural treatments for complications of metabolic syndrome. They improve glucose metabolism, insulin sensitivity, and lipid profiles while exerting anti-adipogenic effects and enhancing endothelial function. However, further research is needed to elucidate the mechanisms and confirm their efficacy in clinical trials. These natural compounds offer potential as alternative therapies for metabolic disorders and contribute to the growing body of evidence supporting the use of natural medicines in their management.

The modulatory effects of Lonicera caerulea L. extract and omega-3 on sarcopenia via regulating PI3K and FOXO signaling pathways in rats

Introduction: Sarcopenia is an inflammatory disease caused by a disruption of muscle homeostasis. Lonicera caerulea L. (Haskap berry) (HB) extract and omega-3 (ω−3) possess antioxidant and anti-inflammatory activities. This study assesses the potential ameliorating effects of HB extract and ω−3 supplementation on dexamethasone (DEXA)-induced sarcopenia. Methods: Rats were divided into five groups; the negative control group was injected with saline (i.p.); groups 2, 3, 4, and 5 were injected with DEXA (2 mg/kg/d, i.p.); groups 3 and 4 also received 400 mg/kg/d and 100 mg/kg/d of HB extract and ω−3, respectively, while group 5 received both treatments daily for 21 days. The ameliorative effects of treatments were investigated by measuring lysosomal proteolytic enzyme cathepsin activity, phosphatidylinositol 3 kinase (PI3K) activity, nuclear factor kappa beta (NF-κB) level, and heme oxygenase-1 (HO-1) activity. The gene expression levels of muscle ring-finger protein (MuRF) and forkhead box O (FOXO) transcription factor were also evaluated. Biochemical and histological examinations were done on muscle tissues. Results: DEXA caused a significant elevation (P<0.05) in NF-κβ level and cathepsin activity in muscle tissue. Also, it significantly upregulated the muscle atrophy markers. Meanwhile, PI3K and HO-1 activities were significantly reduced. HB extract and ω−3 administration significantly (P≤0.05) reversed these effects and downregulated the mRNA expression levels of MuRF and FOXO. Also, the histopathological examination confirmed these results. Conclusion: The current study proved the ameliorative effects of HB extract and ω−3 on sarcopenia parameters. Therefore, they might be potential therapeutic agents for myopathy/sarcopenia.

Genetic Insights Into Hypothalamic Hamartoma: Unraveling Somatic Variants.

Hypothalamic hamartomas (HHs) are rare developmental brain lesions associated with drug-resistant epilepsy and often subjected to epilepsy surgery. Brain somatic variants in genes affecting the Sonic hedgehog (Shh) and primary cilia signaling pathways have been implicated in approximately 50% of nonsyndromic HH cases. This study aims to characterize a new cohort of 9 HH cases and elucidate their genetic etiology. We recruited 9 HH cases including 8 nonsyndromic cases of which 4 were type IV HH. Genomic DNA was extracted from peripheral blood and surgical brain tissues, and somatic variants were investigated using high-depth whole-exome sequencing. Pathogenic somatic variants in known HH genes (GLI3, OFD1, and PRKACA) were identified in 7 of the 9 cases. In addition, a 2-hit mutational event comprising a germline variant (predicted to impair kinase activity) and a somatic loss-of-heterozygosity was identified in TNK2, a gene encoding a brain-expressed tyrosine kinase. Our findings reinforce the role of somatic variants in Shh and cilia genes in HH cases while also shedding light on TNK2 as a potential novel disease-causing gene. This study emphasizes the increasing importance of brain mosaicism in epilepsy disorders and underscores the critical role of genetic diagnosis derived from resected brain tissue.

Elucidating enantioselective fate and sensitive biomarkers in zebrafish of chiral pesticide fenpropidin: Insights into metabolic pathways and hazard assessment

Fenpropidin (FPD), a widely utilized chiral fungicide, has been detected in aquatic environments. This study systematically evaluated the bioaccumulation, depuration, biotransformation, and sensitive biomarkers of FPD enantiomers in zebrafish to assess their environmental risks. Compared with S-FPD, R-FPD demonstrated a higher rate of enrichment and an increased level of bioaccumulation. The half-lives of R-FPD and S-FPD were 0.49 ± 0.01 and 0.91 ± 0.02 days at 0.05 mg/L and 1.65 ± 0.01 and 1.85 ± 0.03 days at 0.5 mg/L. Nontarget metabolism analysis identified nine metabolites, primarily formed through hydroxylation, oxidation, dehydration, glutathione conjugation, and glucuronidation pathways. Some metabolites exhibited high toxicity, underscoring the necessity for continuous monitoring of their toxicological effects and environmental fate in risk assessments. The toxicity of S-FPD in zebrafish was 1.21 times greater than that of R-FPD. Furthermore, this study identified sensitive markers for the enantiomers at both protein and transcriptional levels using an integrated biomarker response approach. S-FPD exhibited increased sensitivity to apoptosis and metabolic gene expression, while R-FPD showed greater sensitivity to antioxidant kinase activity. These findings facilitate timely monitoring of environmental pollution caused by FPD enantiomers. This study provides critical insights for assessing potential risks associated with pesticide exposure to human health.

SARS-CoV-2-derived protein Orf9b enhances MARK2 activity via interaction with the autoinhibitory KA1 domain.

Microtubule affinity-regulating kinase 2 (MARK2) is a Ser/Thr protein kinase that regulates cell polarity and immune responses. Here, we report that Orf9b, one of the accessory proteins encoded in the SARS-CoV-2 genome, increases MARK2 activity via interaction with the autoinhibitory KAI domain. We found that co-expression of Orf9b enhances the kinase activity of MARK2 in HEK293 cells. Orf9b does not bind to or enhance the activity of the mutant form of MARK2 lacking the KA1 domain. Orf9b lowers inhibitory phosphorylation of MARK2 at T595 while mutation experiments indicate that this site is dispensable for Orf9b-mediated enhancement of MARK2 activity. Our results suggest that Orf9b enhances MARK2 activity by binding the autoinhibitory KA1 domain, which closely interacts with the kinase domain.

Exonisation of an intronic L1 element in the dystrophin gene associated with X-linked muscular dystrophy in a Border Collie dog.

X-linked recessive dystrophinopathies are the most common muscular dystrophies (MDs) in humans and dogs. To date, 20 breed-specific MD-associated variants are described in the canine dystrophin gene (DMD), including one associated with dystrophin-deficient MD in the Border Collie mixed breed. Here, we report the diagnosis and follow-up of mild dystrophin-deficient MD in a 5-month-old male Border Collie, associated with a novel DMD variant. Diagnosis was based on neurological examination and laboratory evaluations including creatine kinase activity, electromyography and muscle biopsies with immunofluorescent staining. Inspection of the Sashimi plots of the RNA-seq data from the affected muscle biopsy led to the discovery of a 162-bp L1 pseudoexon in DMD intron 63, introducing a frameshift and a premature stop codon (NM_001003343.1: c.9271_9272insN[162] p.(Ala3091fs*21)). Reduced DMD mRNA levels were detected for both the non-pseudoexon (50× less) and pseudoexon (3× less) containing transcripts in the affected muscle, compared with the level of the non-pseudoexon containing transcript in a control muscle, resulting in very low dystrophin protein levels and the upregulation of utrophin. Because the variant was only found in the affected dog, not in the healthy mother and grandmother, or in 108 unrelated Border Collies from the Belgian population (46 males and 62 females), it was considered a de novo variant. Although the prognosis for dystrophinopathy is generally regarded as poor, the dog stabilised at the age of 6 months and is still clinically stable at the age of 2 years.

Paeoniae radix overcomes resistance to EGFR-TKIs via aurora B pathway suppression in lung adenocarcinoma

Targeted therapies using epidermal growth factor receptor (EGFR) inhibitors have markedly improved survival rates and quality of life for patients with EGFR-mutant lung adenocarcinoma (LUAD). Despite these advancements, resistance to EGFR inhibitors remains a significant challenge, limiting the overall effectiveness of the treatment. This study explored the synergistic effects of combining Paeoniae Radix (PR) with first-generation EGFR-tyrosine kinase inhibitors (TKIs), erlotinib and gefitinib, to overcome this resistance. Transcriptomic analysis of EGFR-mutant LUAD cell lines revealed that PR treatment could potentially reverse the gene signatures associated with resistance to EGFR-TKIs, primarily through the suppression of the Aurora B pathway. Experimental validation demonstrated that combining PR with erlotinib and gefitinib enhanced drug responsiveness by inhibiting Aurora kinase activity and inducing apoptosis in LUAD cells. Additionally, gene expression changes confirmed these combined effects, with the suppression of the Aurora B pathway and upregulation of the apoptotic pathway, which was accompanied by increased expression of multiple pro-apoptotic genes. Our findings contribute to the development of natural product-based therapeutic strategies to mitigate drug resistance in LUAD.