Search

Purpose: Anemia is relatively common in cancer patients, and is associated with poor survival in patients with various malignancies. However, how anemia would affect prognosis and response to neoadjuvant chemotherapy (NAC) in osteosarcoma (OS) is still without substantial evidence. Methods: We retrospectively analysed 242 patients with stage II OS around the knee joint in our institute. Changed hemoglobin (Hb) levels (before and after NAC) were recorded to assess the prognostic value in DFS (disease-free survival) and tumor response to NAC. Univariate and multivariate analyses were conducted to identify prognostic factors related with outcome in OS patients. Results: The mean Hb level significantly decreased after NAC (134.5 ± 15.3 g/L vs. 117.4 ± 16.3 g/L). The percentage of mild (21%), moderate (4.2%) and severe (0%) anemia patients markedly increased after NAC: 41%, 24% and 4.1% respectively. There was higher percentage of ≥ 5% Hb decline in patients with tumor necrosis rate < 90% (141 out of 161), compared with those with tumor necrosis rate ≥ 90% (59 out of 81). Further univariate and survival analysis demonstrated that Hb decline had a significant role in prediction survival in OS patients. Patients with ≥ 5% Hb decline after NAC had an inferior DFS compared with those with < 5% Hb decline. Conclusion: In osteosarcoma, patients with greater Hb decrease during neoadjuvant treatment were shown to have worse DFS and a poorer response to NAC than those without. Attempts to correct anemia and their effects on outcomes for osteosarcoma patients should be explored in future studies. [ABSTRACT FROM AUTHOR]

Objective: De novo mutations of the voltage‐gated sodium channel gene SCN8A cause developmental and epileptic encephalopathy (DEE). Most pathogenic variants result in gain‐of‐function changes in activity of the sodium channel Nav1.6, poorly controlled seizures, and significant comorbidities. In previous work, an antisense oligonucleotide (ASO) reduced Scn8a transcripts and increased lifespan after neonatal administration to a mouse model. Here, we tested long‐term ASO treatment initiated after seizure onset, as required for clinical application. Methods: ASO treatment was initiated after observation of a convulsive seizure and repeated at 4 to 6 week intervals for 1 year. We also tested the long‐term efficacy of an AAV10‐short hairpin RNA (shRNA) virus administered on P1. Results: Repeated treatment with the Scn8a ASO initiated after seizure onset provided long‐term survival and reduced seizure frequency during a 12 month observation period. A single treatment with viral shRNA was also protective during 12 months of observation. Interpretation: Downregulation of Scn8a expression that is initiated after the onset of seizures is effective for long‐term treatment in a model of SCN8A‐DEE. Repeated ASO administration or a single dose of viral shRNA prevented seizures and extended survival through 12 months of observation. ANN NEUROL 2024;95:754–759 [ABSTRACT FROM AUTHOR]

Purpose: Domain knowledge (DK) acquired from prior studies is important for medical diagnosis. This paper leverages the population‐level DK using an optimality design criterion to train a deep learning model in an end‐to‐end manner. In this study, the problem of interest is at the patient level to diagnose a subject with idiopathic pulmonary fibrosis (IPF) among subjects with interstitial lung disease (ILD) using a computed tomography (CT). IPF diagnosis is a complicated process with multidisciplinary discussion with experts and is subject to interobserver variability, even for experienced radiologists. To this end, we propose a new statistical method to construct a time/memory‐efficient IPF diagnosis model using axial chest CT and DK, along with an optimality design criterion via a DK‐enhanced loss function of deep learning. Methods: Four state‐of‐the‐art two‐dimensional convolutional neural network (2D‐CNN) architectures (MobileNet, VGG16, ResNet‐50, and DenseNet‐121) and one baseline 2D‐CNN are implemented to automatically diagnose IPF among ILD patients. Axial lung CT images are retrospectively acquired from 389 IPF patients and 700 non‐IPF ILD patients in five multicenter clinical trials. To enrich the sample size and boost model performance, we sample 20 three‐slice samples (triplets) from each CT scan, where these three slices are randomly selected from the top, middle, and bottom of both lungs respectively. Model performance is evaluated using a fivefold cross‐validation, where each fold was stratified using a fixed proportion of IPF vs non‐IPF. Results: Using DK‐enhanced loss function increases the model performance of the baseline CNN model from 0.77 to 0.89 in terms of study‐wise accuracy. Four other well‐developed models reach satisfactory model performance with an overall accuracy >0.95 but the benefits brought on by the DK‐enhanced loss function is not noticeable. Conclusions: We believe this is the first attempt that (a) uses population‐level DK with an optimal design criterion to train deep learning‐based diagnostic models in an end‐to‐end manner and (b) focuses on patient‐level IPF diagnosis. Further evaluation of using population‐level DK on prospective studies is warranted and is underway. [ABSTRACT FROM AUTHOR]

Objective: SCN8A encephalopathy is a developmental epileptic encephalopathy typically caused by de novo gain‐of‐function mutations in Nav1.6. Severely affected individuals exhibit refractory seizures, developmental delay, cognitive disabilities, movement disorders, and elevated risk of sudden death. Patients with the identical SCN8A variant can differ in clinical course, suggesting a role for modifier genes in determining disease severity. The identification of genetic modifiers contributes to understanding disease pathogenesis and suggesting therapeutic interventions. Methods: We generated F1 and F2 crosses between inbred mouse strains and mice carrying the human pathogenic variants SCN8A‐R1872W and SCN8A‐N1768D. Quantitative trait locus (QTL) analysis of seizure‐related phenotypes was used for chromosomal mapping of modifier loci. Results: In an F2 cross between strain SJL/J and C57BL/6J mice carrying the patient mutation R1872W, we identified a major QTL on chromosome 5 containing the Gabra2 gene. Strain C57BL/6J carries a splice site mutation that reduces expression of Gabra2, encoding the α2 subunit of the aminobutyric acid type A receptor. The protective wild‐type allele of Gabra2 from strain SJL/J delays the age at seizure onset and extends life span of the Scn8a mutant mice. Additional Scn8a modifiers were observed in the F2 cross and in an F1 cross with strain C3HeB/FeJ. Significance: These studies demonstrate that the SJL/J strain carries multiple modifiers with protective effects against seizures induced by gain‐of‐function mutations in Scn8a. Homozygosity for the hypomorphic variant of Gabra2 in strain C57BL/6J is associated with early seizure onset and short life span. GABRA2 is a potential therapeutic target for SCN8A encephalopathy. [ABSTRACT FROM AUTHOR]

De novo methotrexate (MTX)‐resistance, whose underlying mechanism remains largely unknown, usually leads to very poor prognosis in patients with osteosarcoma (OS). In this study, we established the de novo MTX‐resistant OS cell line SF‐86 and identified the candidate gene spindle and kinetochore associated complex subunit 1 (SKA1) as potentially related to de novo MTX‐resistance. Analysis of a cohort of 95 OS patients demonstrated that SKA1 overexpression significantly correlated with de novo MTX‐resistance and poor 5‐year survival. Mechanistically, SKA1 overexpression lead to a downregulation of folylpoly‐γ‐glutamate synthetase (FPGS), a key enzyme that converts MTX into its active form, MTX‐PG. We further demonstrated that SKA1 interacts with DNA‐directed RNA polymerase II subunit RPB3. ChIP analysis revealed that RPB3 binds the promoter region of the FPGS gene and triggers FPGS transcription upon MTX treatment in SW1353, a MTX‐sensitive OS cell line lacking endogenous SKA1 expression. On the contrary, this process is blocked in SF‐86 cells due to the formation of an inhibitory SKA1‐RPB3 complex. Furthermore, downregulation of SKA1 levels restores MTX sensitivity in SF‐86. Collectively, our study has established the de novo MTX‐resistant cell line SF‐86 and identified SKA1 as a novel regulator of FPGS, playing a key role in the development of de novo MTX‐resistance in OS. [ABSTRACT FROM AUTHOR]

Abstract Resistance to Inhibitors of Cholinesterase-8 (Ric-8) proteins are molecular chaperones that fold heterotrimeric G protein α subunits shortly after biosynthesis. Ric-8 proteins also act as test tube guanine nucleotide exchange factors (GEF) that promote Gα subunit GDP for GTP exchange. The GEF and chaperoning activities of Ric-8A are regulated by phosphorylation of five serine and threonine residues within protein kinase CK2 consensus sites. The traditional way that Ric-8A proteins have been purified is from Spodoptera frugiperda (Sf 9) or Trichoplusia ni (Tni) insect cells. Endogenous insect cell kinases do phosphorylate the critical regulatory sites of recombinant Ric-8A reasonably well, but there is batch-to-batch variability among recombinant Ric-8A preparations. Additionally, insect cell-production of some Ric-8 proteins with phosphosite alanine substitution mutations is proscribed as there seems to be interdependency of multi-site phosphorylation for functional protein production. Here, we present a method to produce wild type and phosphosite mutant Ric-8A proteins that are fully occupied with bound phosphate at each of the regulatory positions. Ric-8A proteins were expressed and purified from E. coli. Purified Ric-8A was phosphorylated in vitro with protein kinase CK2 and then re-isolated to remove kinase. The phosphorylated Ric-8A proteins were ∼99% pure and the completeness of phosphorylation was verified by chromatography, phos-tag SDS-PAGE mobility shifts, immunoblotting using phospho-site specific antibodies, and mass spectrometry analysis. E. coli -produced Ric-8A that was phosphorylated using this method promoted a faster rate of Gα subunit guanine nucleotide exchange than Ric-8A that was variably phosphorylated during production in insect cells. Highlights • Optimized production of phosphosite mutant Ric-8A proteins with high purity. • Produce homogenous and fully phosphorylated Ric-8A proteins. • Ric-8A-5PO 4 produced by this method has higher Gαq guanine nucleotide exchange activity than insect cell-produced Ric-8A. [ABSTRACT FROM AUTHOR]

Autonomous vehicles typically transmit information over wireless communication network, which is vulnerable to malicious cyber attacks and poses huge security threats for autonomous vehicles. To address these challenges, this paper is concerned with resilient H ∞ path-following control problem for autonomous vehicles under false data injection (FDI) attacks and denial-of-service (DoS) attacks, simultaneously. Firstly, a novel observer is constructed to estimate both sensor FDI attack signal and system state. An attack parameter dependent time-varying piecewise Lyapunov function is constructed to ensure stability of the underlying system. Then, a resilient H ∞ path-following control scheme is developed to suppress the impact of FDI attacks and external interference despite the presence of intermittent DoS attacks. The design criterion of resilient controller is derived to assure the exponential stability of the closed-loop system and maintain the desired H ∞ performance. Finally, simulation studies are carried out to verify the efficiency and merits of the developed results. [ABSTRACT FROM AUTHOR]

Myo-inositol, the precursor of all inositol compounds, is essential for the viability of eukaryotes. Identifying the factors that regulate inositol homeostasis is of obvious importance to understanding cell function and the pathologies underlying neurological and metabolic resulting from perturbation of inositol metabolism. The current study identifies Mck1, a GSK3 homolog, as a novel positive regulator of inositol de novo synthesis in yeast. Mck1 was required for normal activity of myo-inositol phosphate synthase (MIPS), which catalyzes the rate-limiting step of inositol synthesis. mck1Δ cells exhibited a 50% decrease in MIPS activity and a decreased rate of incorporation of [13C6]glucose into [13C6]-inositol-3-phosphate and [13C6]-inositol compared to WT cells. mck1Δ cells also exhibited decreased growth in the presence of the inositol depleting drug valproate (VPA), which was rescued by supplementation of inositol. However, in contrast to wild type cells, which exhibited more than a 40% decrease in MIPS activity in the presence of VPA, the drug did not significantly decrease MIPS activity in mck1Δ cells. These findings indicate that VPA-induced MIPS inhibition is Mck1-dependent, and suggest a model that unifies two current hypotheses of the mechanism of action of VPA—inositol depletion and GSK3 inhibition. [ABSTRACT FROM AUTHOR]

Abstract: Osteosarcoma (OS) is the most common primary malignant tumour of bone. Nearly 30–40% of OS patients have a poor prognosis despite multimodal treatments. Because the carcinogenesis of OS remains unclear, the identification of new oncogenes that control the tumourigenesis and progression of OS is crucial for developing new therapies. Here, we found that the expression of Mediator of RNA polymerase II transcription subunit 19 (Med19) was increased in OS samples from patients compared to normal bone tissues. Cyclin D1 and cyclin B1 are upregulated in Med19 positive OS tissues. Importantly, among 97 OS patients of Enneking stage IIB or IIIB, Med19 expression was correlated with metastasis (P <0.05) and poor prognosis (P <0.01). Med19 knockdown significantly induced growth inhibition, reduced colony-forming ability and suppressed migration in the OS cell lines Saos-2 and U2OS, along with the downregulated expression of cyclin D1 and cyclin B1. Med19 knockdown also induced apoptosis in Saos-2 cells via induction of caspase-3 and poly ADP-ribose polymerase (PARP). In addition, Med19 knockdown significantly suppressed tumour growth in an OS xenograft nude mouse model via suppression of cyclin D1 and cyclin B1. Simultaneously, Med19 downregulation decreased the expression of Ki67 and proliferating cell nuclear antigen (PCNA) in tumour samples from OS xenograft nude mice. Med19 depletion remarkably reduced tumour metastasis in a model of OS metastatic spreading. Taken together, our data suggest that Med19 acts as an oncogene in OS via a possible cyclin D1/cyclin B1 modulation pathway. [Copyright &y& Elsevier]

Exogenous nitrogen and carbon can affect plant cell walls, which are composed of structural carbon. Sucrose synthase (SUS), invertase (INV), hexokinase (HXK), phosphoglucomutase (PGM), and UDP-glucose pyrophosphorylase (UGP) are the key enzymes of sucrose metabolism involved in cell wall synthesis. To understand whether these genes are regulated by carbon and nitrogen to participate in structural carbon biosynthesis, we performed genome-wide identification, analyzed their expression patterns under different carbon and nitrogen treatments, and conducted preliminary functional verification. Different concentrations of nitrogen and carbon were applied to poplar (Populus trichocarpa Torr. and Gray), which caused changes in cellulose, lignin, and hemicellulose contents. In poplar, 6 SUSs, 20 INVs, 6 HXKs, 4 PGMs, and 2 UGPs were identified. Moreover, the physicochemical properties, collinearity, and tissue specificity were analyzed. The correlation analysis showed that the expression levels of PtrSUS3/5, PtrNINV1/2/3/5/12, PtrCWINV3, PtrVINV2, PtrHXK5/6, PtrPGM1/2, and PtrUGP1 were positively correlated with the cellulose content. Meanwhile, the knockout of PtrNINV12 significantly reduced the cellulose content. This study could lay the foundation for revealing the functions of SUSs, INVs, HXKs, PGMs, and UGPs, which affected structural carbon synthesis regulated by nitrogen and carbon, proving that PtrNINV12 is involved in cell wall synthesis. [ABSTRACT FROM AUTHOR]

Background: Cell-based immunotherapy shows the therapeutic potential in sarcomas, in addition to angiogenesis-targeted tyrosine kinase inhibitor (TKI) and immune checkpoint inhibitor (ICI). Multi-antigen stimulated cell therapy-I (MASCT-I) technology is a sequential immune cell therapy for cancer, which composes of multiple antigen-loaded dendritic cell (DC) vaccines followed by the adoptive transfer of anti-tumor effector T-cells. Methods: In this phase 1 study, we assessed MASCT-I plus camrelizumab (an ICI against PD-1) and apatinib (a highly selective TKI targeting VEGFR2) in patients with unresectable recurrent or metastatic bone and soft-tissue sarcoma after at least one line of prior systemic therapy. One MASCT-I course consisted of 3 DC subcutaneous injections, followed by 3 active T cell infusions administered 18–27 days after each DC injection. In schedule-I group, 3 DC injections were administered with a 28-day interval in all courses; in schedule-II group, 3 DC injections were administered with a 7-day interval in the first course and with a 28-day interval thereafter. All patients received intravenous camrelizumab 200 mg every 3 weeks and oral apatinib 250 mg daily. Results: From October 30, 2019, to August 12, 2021, 19 patients were enrolled and randomly assigned to schedule-I group (n = 9) and schedule-II group (n = 10). Of the 19 patients, 11 (57.9%) experienced grade 3 or 4 treatment-related adverse events. No treatment-related deaths occurred. Patients in schedule-II group showed similar objective response rate (ORR) with those in schedule-I group (30.0% versus 33.3%) but had higher disease control rate (DCR; 90.0% versus 44.4%) and longer median progression-free survival (PFS; 7.7 versus 4.0 months). For the 13 patients with soft-tissue sarcomas, the ORR was 30.8%, DCR was 76.9%, and median PFS was 12.9 months; for the 6 patients with osteosarcomas, the ORR was 33.3%, the DCR was 50.0%, and median PFS was 5.7 months. Conclusions: Overall, MASCT-I plus camrelizumab and apatinib was safe and showed encouraging efficacy in advanced bone and soft-tissue sarcoma, and schedule-II administration method was recommended. Trial registration: ClinicalTrials.gov, NCT04074564. [ABSTRACT FROM AUTHOR]

For microscopic polarization imaging of tissue slices, two types of samples are often prepared: one unstained tissue section for polarization imaging to avoid possible influence from staining dyes quantitatively and one hematoxylin-eosin (H&E) stained adjacent tissue section for histological diagnosis and structural feature identification. However, this sample preparation strategy requires high-quality adjacent tissue sections, and labeling the structural features on unstained tissue sections is impossible. With the fast development of data driven-based polarimetric analysis, which requires a large amount of pixel labeled images, a possible method is to directly use H&E stained slices, which are standard samples archived in clinical hospitals for polarization measurement. We aim to study the influence of hematoxylin and eosin staining on the linear birefringence measurement of fibrous tissue structures. We examine the linear birefringence properties of four pieces of adjacent bone tissue slices with abundant collagen fibers that are unstained, H&E stained, hematoxylin (H) stained, and eosin (E) stained. After obtaining the spatial maps of linear retardance values for the four tissue samples, we carry out a comparative study using a frequency distribution histogram and similarity analysis based on the Bhattacharyya coefficient to investigate how H&E staining affects the linear birefringence measurement of bone tissues. Linear retardance increased after H&E, H, or E staining (41.7%, 40.8%, and 72.5% increase, respectively). However, there is no significant change in the imaging contrast of linear retardance in bone tissues. The linear retardance values induced by birefringent collagen fibers can be enhanced after H&E, H, or E staining. However, the structural imaging contrasts based on linear retardance did not change significantly or the staining did not generate linear birefringence on the sample area without collagen. Therefore, it can be acceptable to prepare H&E stained slices for clinical applications of polarimetry based on such a mapping relationship. [ABSTRACT FROM AUTHOR]

Aims: The objective of this study was to investigate the efficacy and toxic side effects of two combinations of methotrexate, cisplatin, doxorubicin and ifosfamide on treating Chinese osteosarcoma patients. Methods: A retrospective analysis was conducted of 185 osteosarcoma patients treated with the four drugs mentioned above. A total of 93 patients received the Italian therapeutic treatment (IOR-OS/N-5: Instituto Ortopedic Rizzoli-Section of Osteosacorma/Neoadjuvant chemotherapy-5) and the remaining 92 patients received the therapeutic treatment optimized by our department. We compared the efficacy and toxic side effects of these two therapies. Results: The limb salvage rates, 3-year recurrence rates and 3-year metastasis rates of IOR-OS/N-5 and our optimized treatment were 52.7 and 58.7%; 20.9 and 11.4% and 44.1 and 27.2%, respectively. The 3-year survival rates and the 3-year disease-free survival rates of IOR-OS/N-5 and our optimized treatments were 62.4 and 78.4%; and 53.6 and 67.8%, respectively. Overall survival and disease-free survival rates were significantly different between these two treatments ( P = 0.032 and 0.024, respectively). Liver function with degree III and IV damage accounted for 35.2 and 16.6% of the total adverse reactions in the IOR-OS/N-5 and our optimized treatment groups, respectively. Degree III-IV neutropenia accounted for 22.6 and 40.0%, respectively, in the IOR-OS/N-5 and optimized treatments. Conclusion: The optimization of MTX, DDP, DOX and IFO based on Chinese patients' physiology increased the tolerance and efficacy for the treatment of osteosarcoma. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease characterized by an unpredictable decline in lung function. Predicting IPF progression from the early changes in lung function tests have known to be a challenge due to acute exacerbation. Although it is unpredictable, the neighboring regions of fibrotic reticulation increase during IPF's progression. With this clinical information, quantitative characteristics of high-resolution computed tomography (HRCT) and a statistical learning paradigm, the aim is to build a model to predict IPF progression. A paired set of anonymized 193 HRCT images from IPF subjects with 6–12 month intervals were collected retrospectively. The study was conducted in two parts: (1) Part A collects the ground truth in small regions of interest (ROIs) with labels of "expected to progress" or "expected to be stable" at baseline HRCT and develop a statistical learning model to classify voxels in the ROIs. (2) Part B uses the voxel-level classifier from Part A to produce whole-lung level scores of a single-scan total probability's (STP) baseline. Using annotated ROIs from 71 subjects' HRCT scans in Part A, we applied Quantum Particle Swarm Optimization–Random Forest (QPSO-RF) to build the classifier. Then, 122 subjects' HRCT scans were used to test the prediction. Using Spearman rank correlations and survival analyses, we ascertained STP associations with 6–12 month changes in quantitative lung fibrosis and forced vital capacity. This study can serve as a reference for collecting ground truth, and developing statistical learning techniques to predict progression in medical imaging. [ABSTRACT FROM AUTHOR]

The widely used mood stabilizer valproate (VPA) causes perturbation of energy metabolism, which is implicated in both the therapeutic mechanism of action of the drug as well as drug toxicity. To gain insight into these mechanisms, we determined the effects of VPA on energy metabolism in yeast. VPA treatment increased levels of glycolytic intermediates, increased expression of glycolysis genes, and increased ethanol production. Increased glycolysis was likely a response to perturbation of mitochondrial function, as reflected in decreased membrane potential and oxygen consumption. Interestingly, yeast, mouse liver, and isolated bovine cytochrome c oxidase were directly inhibited by the drug, while activities of other oxidative phosphorylation complexes (III and V) were not affected. These findings have implications for mechanisms of therapeutic action and toxicity. [ABSTRACT FROM AUTHOR]

Objective: SCN8A encephalopathy is a developmental and epileptic encephalopathy (DEE) caused by de novo gain-of-function mutations of sodium channel Nav 1.6 that result in neuronal hyperactivity. Affected individuals exhibit early onset drug-resistant seizures, developmental delay, and cognitive impairment. This study was carried out to determine whether reducing the abundance of the Scn8a transcript with an antisense oligonucleotide (ASO) would delay seizure onset and prolong survival in a mouse model of SCN8A encephalopathy.Methods: ASO treatment was tested in a conditional mouse model with Cre-dependent expression of the pathogenic patient SCN8A mutation p.Arg1872Trp (R1872W). This model exhibits early onset of seizures, rapid progression, and 100% penetrance. An Scn1a +/- haploinsufficient mouse model of Dravet syndrome was also treated. ASO was administered by intracerebroventricular injection at postnatal day 2, followed in some cases by stereotactic injection at postnatal day 30.Results: We observed a dose-dependent increase in length of survival from 15 to 65 days in the Scn8a-R1872W/+ mice treated with ASO. Electroencephalographic recordings were normal prior to seizure onset. Weight gain and activity in an open field were unaffected, but treated mice were less active in a wheel running assay. A single treatment with Scn8a ASO extended survival of Dravet syndrome mice from 3 weeks to >5 months.Interpretation: Reduction of Scn8a transcript by 25 to 50% delayed seizure onset and lethality in mouse models of SCN8A encephalopathy and Dravet syndrome. Reduction of SCN8A transcript is a promising approach to treatment of intractable childhood epilepsies. Ann Neurol 2020;87:339-346. [ABSTRACT FROM AUTHOR]

Abstract Cardiolipin (CL) is a unique phospholipid localized almost exclusively within the mitochondrial membranes where it is synthesized. Newly synthesized CL undergoes acyl remodeling to produce CL species enriched with unsaturated acyl groups. Cld1 is the only identified CL-specific phospholipase in yeast and is required to initiate the CL remodeling pathway. In higher eukaryotes, peroxidation of CL, yielding CL OX , has been implicated in the cellular signaling events that initiate apoptosis. CL OX can undergo enzymatic hydrolysis, resulting in the release of lipid mediators with signaling properties. Our previous findings suggested that CLD1 expression is upregulated in response to oxidative stress, and that one of the physiological roles of CL remodeling is to remove peroxidized CL. To exploit the powerful yeast model to study functions of CLD1 in CL peroxidation, we expressed the H. brasiliensis Δ12-desaturase gene in yeast, which then synthesized poly unsaturated fatty acids(PUFAs) that are incorporated into CL species. Using LC-MS based redox phospholipidomics, we identified and quantified the molecular species of CL and other phospholipids in cld1 Δ vs. WT cells. Loss of CLD1 led to a dramatic decrease in chronological lifespan, mitochondrial membrane potential, and respiratory capacity; it also resulted in increased levels of mono-hydroperoxy-CLs, particularly among the highly unsaturated CL species, including tetralinoleoyl-CL. In addition, purified Cld1 exhibited a higher affinity for CL OX , and treatment of cells with H 2 O 2 increased CLD1 expression in the logarithmic growth phase. These data suggest that CLD1 expression is required to mitigate oxidative stress. The findings from this study contribute to our overall understanding of CL remodeling and its role in mitigating oxidative stress. Highlights • ∆12-desaturase expression leads to accumulation of peroxidized cardiolipin. • Cld1 has a higher affinity for peroxidized cardiolipin. • cld1 Δ cells expressing Δ12-desaturase exhibit increased peroxidized L 4 CL. • Δ12-desaturase expression in cld1 Δ cells leads to decreased mitochondrial functions. • Δ12-desaturase expression in cld1 Δ cells leads to decreased chronological lifespan. [ABSTRACT FROM AUTHOR]

Valproate (VPA), an FDA approved anti-epileptic drug with a half-life of 12-18 h in humans, has been shown to perturb the vacuolar proton pump (vH+-ATPase) function in yeasts by inhibiting myo-inositol phosphate synthase, the first and rate-limiting enzyme in inositol biosynthesis, thereby resulting in inositol depletion. vH+-ATPase transfers protons (H+) across cell membranes, which help maintain pH gradients within cells necessary for various cellular functions including secretion. This proton pump has a membrane (V0) and a soluble cytosolic (V1) domain, with C-subunit associated with V1. In secretory cells such as neurons and insulin-secreting beta cells, vH+-ATPase acidifies vesicles essential for secretion. In this study, we demonstrate that exposure of insulin-secreting Min6 cells to a clinical dose of VPA results in inositol depletion and loss of co-localization of subunit C of vH+-ATPase with insulin-secreting granules. Consequently, a reduction of glucose-stimulated insulin secretion is observed following VPA exposure. These results merit caution and the reassessment of the clinical use of VPA. [ABSTRACT FROM AUTHOR]

Ubiquitin carboxyl terminal hydrolase 1 (UCHL1), a member of the UCH class of DUBs, has been reported as either an oncogene or a tumor suppressor. However, the molecular mechanism underlying the biological function of UCHL1 in osteosarcoma is still unclear. This study was aimed at elucidating the roles of UCHL1 in regulating the biological behavior of osteosarcoma cells. In this study, we found that UCHL1 was elevated in osteosarcoma compared with normal bone tissue. Moreover, UCHL1 expression level was correlated with tumor maximum diameter, high rate of lung metastases and short survival time. Then, we found that knockdown of UCHL1 in osteosarcoma cell MG63 inhibited cell proliferation and significantly increased cell population in the G1 phase. Several cyclins promoting G1/S phase transition were reduced after UCHL1 knockdown, including cell cycle regulator cyclin D1, cyclin E1 and CDK6. Moreover, inhibition of UCHL1 in MG63 cells dramatically induced cell apoptosis. We also found that down-regulation of UCHL1 in MG63 significantly inhibited cell invasion. Then, we found that there was a positive correlation between UCHL1 expression level and the Akt and ERK phosphorylation status. Finally, in vivo data showed that knockdown of UCHL1 inhibited osteosarcoma growth in nude mice. These results indicate that UCHL1 could work as an oncogene and may serve as a promising therapeutic strategy for osteosarcoma. [ABSTRACT FROM AUTHOR]

Aim To investigate prognostic factors for long-term outcomes in Chinese patients with high-grade osteosarcoma of the extremities or trunk treated by multidisciplinary combined therapy. Methods In total, 333 consecutive patients with non-metastatic or primary metastatic high-grade osteosarcoma of the extremities or trunk were retrospectively reviewed to analyze the correlation between survival and sex, age, site, histological type, clinical stage, alkaline phosphatase ( ALP) level, preoperative chemotherapy or not, response to preoperative chemotherapy, postoperative chemotherapy cycles and manner of surgery. The combined therapy included preoperative and postoperative chemotherapy as well as limb salvage surgery or amputation. Results The median survival time was 52 months for all 333 patients. Univariate analysis revealed that sex, ALP level, preoperative chemotherapy and cycle numbers of postoperative chemotherapy may influence the prognosis of high-grade osteosarcoma of the extremities or trunk. Multivariate analysis revealed that the female, a normal ALP level, preoperative chemotherapy with good response and ≥4 cycles of postoperative chemotherapy correlated with a better outcome. Conclusion Preoperative chemotherapy is important in high-grade osteosarcoma treatment and a good response to it is an important marker of prognosis. It should be given with ≥ cycles of postoperative chemotherapy after surgery. [ABSTRACT FROM AUTHOR]

Ric-8A is a 530-amino acid cytoplasmic molecular chaperone and guanine nucleotide exchange factor (GEF) for i, q, and 12/13 classes of heterortrimeric G protein alpha subunits (Gα). We report the 2.2-Å crystal structure of the Ric-8A Gα-binding domain with GEF activity, residues 1–452, and is phosphorylated at Ser435 and Thr440. Residues 1–429 adopt a superhelical fold comprised of Armadillo (ARM) and HEAT repeats, and the C terminus is disordered. One of the phosphorylated residues potentially binds to a basic cluster in an ARM motif. Amino acid sequence conservation and published hydrogen-deuterium exchange data indicate repeats 3 through 6 to be a putative Gα-binding surface. Normal mode modeling of small-angle X-ray scattering data indicates that phosphorylation induces relative rotation between repeats 1–4, 5–6, and 7–9. 2D 1H-15N-TROSY spectra of [2H,15N]-labeled Gαi1 in the presence of R452 reveals chemical shift perturbations of the C terminus and Gαi1 residues involved in nucleotide binding. • The G protein α subunit binding domain of Ric-8A is an Armadillo/HEAT repeat fold • Hydrogen-deuterium exchange data suggest a Gα binding surface on Ric-8A • Ric-8A binds elements of Gα also recognized by G protein-coupled receptors • The Ric-8A fold harbors a putative binding site for its C-terminal phosphoserine Zeng et al. use X-ray crystallography and small-angle scattering, in conjunction with NMR spectroscopy, to reveal the structure of and dynamics of the G protein chaperone and activator Ric-8A and probe its interaction with the G protein alpha subunit i1. [ABSTRACT FROM AUTHOR]