Search Results (2,673)

Spastic paraplegia 80 (SPG80), caused by mutations in ubiquitin-associated protein 1 (UBAP1), is a pure form of juvenile-onset hereditary spastic paraplegia (HSP) and leads to progressive motor dysfunction. Despite recent advances in the molecular analyses of HSP, disease-modifying therapy has not been established for HSP including SPG80. In the present study, we evaluated the therapeutic potential of 4-phenylbutyric acid (4-PBA), a chemical chaperone and histone deacetylase inhibitor, in Ubap1 knock-in (KI) mice expressing a disease-associated truncated UBAP1 variant. We found that 4-PBA administration significantly improved the motor performance of KI mice in the rotarod and beam walk tests, with maximal benefits achieved when given during pre- or early-symptomatic stages. Partial efficacy was also observed when treatment began after symptom onset in KI mice. Furthermore, 4-PBA attenuated spinal microglial activation and partially restored microglial morphology, although astrocytic reactivity remained unchanged. These findings support 4-PBA as a candidate therapeutic compound for SPG80 and highlight the potential of proteostasis-targeted interventions in HSPs. Full article

Background. MiR-218 is a micro-RNA expressed in two isoforms (miR-218-1 and miR-218-2) in the brain and, within the mesencephalic area, it represents a specific regulator of differentiation and functional maturation of the dopamine-releasing neurons (DAn). Deletion of miR-218 isoforms within the midbrain alters the expression of synaptic mRNAs, the neuronal excitability of DAn of the substantia nigra pars compacta (SNpc), and their ability to release dopamine (DA) within the dorsal striatum. Objectives. Here we have investigated if miR-218 impacts the function of the DAn population adjacent to SNpc, the mesencephalic ventral tegmental area (VTA) innervating the nucleus accumbens (NAcc), and the medial prefrontal cortex. Methods. With the use of miR-218-1, miR-218-2, and double conditional knock-out mice (KO1, c-KO2, c-dKO), we performed electrophysiological recordings in VTA DAn to investigate firing activity, measurements of DA release in NAcc slices by constant potential amperometry (CPA), and in vivo behavioral analysis. Results. We find that KO1 VTA neurons display hyperexcitability in comparison with c-KO2, c-dKO, and wild type (WT) neurons. DA efflux in the NAcc core and shell is reduced in all single- and double-conditional KO striatal slices in comparison with controls. The KO1 mice display a tendency toward an anxiety-like trait, as revealed by the elevated plus maze test. Conclusions. Our data indicate that miR-218-1 is the isoform that mainly regulates VTA DA neuron excitability whereas both miR-218-1 and miR-218-2 impair DA release in the mesoaccumbens pathway. Full article

This paper investigates the effects of using 10% v/v (E10) and 30% v/v (E30) ethanol–gasoline blends on spark ignition (SI) engine fuel consumption, brake-specific fuel consumption, brake thermal efficiency, combustion parameters and exhaust gas temperature. The 30% v/v ethanol–gasoline blend was designed not to exceed the octane number (RON and MON) of the regular commercially available reference fuel (E10); therefore, the knock resistance of the reference and research fuel does not differ significantly. The tests were conducted on an AVL internal combustion engine test cell using a four-stroke, four-cylinder, turbocharged SI engine with direct injection and a compression ratio of 12.2:1. The engine was manufactured in 2022, and it is the latest commercially available version currently in production. Engine tests were conducted under stoichiometric conditions (when possible) at loads ranging from 2–20 bar brake mean effective pressure and engine speeds ranging from 1000–6000 rpm, and the fuel consumption, brake-specific fuel consumption, combustion parameters, exhaust gas temperature and brake thermal efficiency were measured using the two different ethanol–gasoline blends. Test results showed that the higher concentration ethanol–gasoline blend—due to its lower density, lower heating value and higher latent heat of vaporization—had increased fuel consumption, brake-specific fuel consumption and decreased brake thermal efficiency, while exhaust gas temperature also decreased (at 2500 rpm 12 bar BMEP, the differences were 11%, 6.6%, −0.78% and −3.7%, respectively). Peak combustion pressures were identical under the same operating conditions, but the peak combustion temperature of E30 was on average 3% lower. Full article

Evidence indicates that light can trigger an increase in triacylglycerol (TAG) accumulation in eukaryotic microalgae without reducing cell division. In connection with this, we have recently reported that the expression of the chloroplast enzyme diacylglycerol acyltransferase 3 (DGAT3) is induced by light in concert with TAG accumulation in Chlamydomonas reinhardtii. In this work, we report the identification of two phytyl ester synthases (PES) in C. reinhardtii, named PESα and PESβ. These are homologous to chloroplast PES1 and PES2 of Arabidopsis thaliana, which play a role in the synthesis of fatty acid phytyl esters (FAPEs) and TAGs. We demonstrate that PESα and PESβ transcript levels are transiently induced upon transferring cell cultures from a growth condition of low light to high light, and this occurs in parallel to an increase in TAG levels. In a pesα knockdown mutant, DGAT3 transcripts and TAG levels are significantly higher than in the parental strain at the end of the low-light period, and remain elevated after shifting pesα cells to the high-light condition. On the contrary, in a pesβ knockdown mutant, TAG levels, as well as DGAT3 expression, are similar to those of the control strain. These results suggest that PESα and PESβ are non-redundant in TAG metabolism and that PESα is functionally related to DGAT3. Full article

Lilac (Syringa spp.) is a widely cultivated ornamental plant prized for its fragrant aroma and attractive flower colors. However, the molecular mechanisms governing its flower pigmentation remain poorly understood. In this study, we performed integrated transcriptomic and metabolomic analyses on purple (Syringa oblata) and white (Syringa oblata var. alba) lilacs at the P1 stage, the point of deepest pigmentation. Compared with W1, P1 has a total of 918 differentially expressed genes, including 614 up-regulated genes and 304 down-regulated genes. And S. oblata exhibited significant upregulation of key anthocyanin biosynthesis genes, including the rate-limiting enzyme gene ObDFR, ObF3’H and transcriptional regulators such as ObWPA, which encodes a WD40 repeat protein. This transcriptional activation was accompanied by a substantial accumulation of 27 anthocyanins, including Petunidin Chloride, Cyanidin Chloride, Delphinidin and so on, while the Petunidin-3-O-rutinoside, Petunidin-3-O-(6-O-p-coumaroyl)-glucoside and Malvidin-3-O-sambubioside-5-O-glucoside were only detected in S. oblata. Furthermore, ATAC-seq analysis revealed that, in comparison to white lilac, purple lilac exhibited 3522 and 805 genes with increased and decreased chromatin accessibility, respectively. Integrative analysis with the transcriptome identified 135 genes that were both more accessible and transcriptionally upregulated in purple lilac, including ObWPA, Ob0214386, and Ob0227194 which belong to WD40 members. Subsequent qRT-PCR validation confirmed ObWPA as the most significantly upregulated gene in purple lilac, a finding consistent with the specific chromatin accessibility detected in its promoter region. To validate its function, we knocked down ObWPA expression in purple lilac using Virus-Induced Gene Silencing (VIGS). This intervention resulted in a dramatic color shift from purple to white, concomitant with a significant decrease in key anthocyanin metabolites such as Cyanidin-3-(6-O-p-caffeoyl)-glucoside, Cyanidin Chloride, Pelargonidin, Cyanidin-3-O-rutinoside, Dihydrokaempferol, and Petunidin Chloride. Collectively, our findings demonstrate that ObWPA is an indispensable positive regulator of purple color formation in S. oblata. Full article

Although multimodal therapeutic management has significantly improved outcome in prostate cancer (PCa) patients, treatment options for castrate-resistant disease remain challenging. Plant-derived mistletoe extracts have supported cancer patients and are, therefore, widely used as complementary medicine. However, mechanisms behind possible mistletoe benefits to PCa patients remain to be explored. The present study was designed to evaluate the effect of mistletoe extracts from four different host trees (Tiliae, Populi, Salicis, and Crataegi) on the growth and proliferation of PCa cell lines in vitro. PC3, DU145, and LNCaP cells were used to evaluate tumor cell growth (MTT assay) and proliferation (BrdU incorporation assay). Clonogenicity, apoptosis, cell cycle, and cell-cycle-regulating proteins (cyclin-dependent kinases (CDKs) and cyclins) were investigated, as was CD44 standard and splice variant expression and integrin α and β receptors. SiRNA knockdown studies were employed to investigate the functional relevance of integrins. All mistletoe extracts significantly inhibited cell growth in a dose-dependent manner and cell proliferation and clonogenicity were suppressed. Populi and Salicis induced cell-cycle arrest in the G2/M phase and increased apoptosis. Both extracts down-regulated CDK1 and cyclin A and altered CD44 expression. Integrins α5 in all cell lines and α6 in DU145 and LNCaP were particularly diminished. Knocking down α5 and α6 induced cell growth inhibition in DU145. Mistletoe extracts block the growth and proliferation of PCa cells in vitro and therefore qualify for use in future animal studies to evaluate mistletoe as an adjunct to standard PCa treatment. Full article

The Ataxin-2-like (ATXN2L) protein is required to survive embryonic development, as documented in mice with the constitutive absence of the ATXN2L Lsm, LsmAD, and PAM2 domains due to knock-out (KO) of exons 5–8 with a frameshift. Its less abundant paralog, Ataxin-2 (ATXN2), has an extended N-terminus, where a polyglutamine domain is prone to expansions, mediating vulnerability to the polygenic adult motor neuron disease ALS (Amyotrophic Lateral Sclerosis) or causing the monogenic neurodegenerative processes of Spinocerebellar Ataxia Type 2 (SCA2), depending on larger mutation sizes. Here, we elucidated the physiological function of ATXN2L by deleting the LsmAD and PAM2 motifs via loxP-mediated KO of exons 10–17 with a frameshift. Crossing heterozygous floxed mice with constitutive Cre-deleter animals confirmed embryonic lethality among offspring. Crossing with CamK2a-CreERT2 mice and injecting tamoxifen for conditional deletion achieved chimeric ATXN2L absence in CamK2a-positive frontal cortex neurons and reduced spontaneous horizontal movement. Global proteome profiling of frontal cortex homogenate showed ATXN2L levels decreased to 75% and dysregulations enriched in the alternative splicing pathway. Nuclear proteins with Sm domains are critical to performing splicing; therefore, our data suggest that the Like-Sm (Lsm, LsmAD) domains in ATXN2L serve a role in splice regulation, despite their perinuclear location. Full article

TRIM48 is a human-specific tripartite motif (TRIM) family protein with E3 ubiquitin ligase activity that plays a significant role in the oxidative stress response and tumor suppression. However, the mechanisms regulating TRIM48 expression remain unknown. In this study, we demonstrate that TRIM48 is targeted for ubiquitination-dependent degradation by S-phase kinase-associated protein 1 (Skp1)-Cullin1 (Cul1)-F-box protein (SCF) ubiquitin ligase complex, containing F-box protein 22 (FBXO22) as a substrate recognition subunit. We found that TRIM48 is a rapid turnover protein, as evidenced by the fast and drastic decrease in its protein expression level in the presence of a protein synthesis inhibitor cycloheximide, which was suppressed by knocking down either Skp1, Cul1 or FBXO22. Exogenous FBXO22 expression promoted K48-linked polyubiquitination and degradation of TRIM48. FBXO22 deficiency accelerated oxidative stress-induced activation of apoptosis signal-regulating kinase 1 (ASK1) and cell death, which was reversed by additional TRIM48 knockdown. Collectively, our findings identify the FBXO22 SCF complex as a key negative regulator of TRIM48-driven ASK1-activation and cell death under oxidative stress. The dysregulation of this axis may underlie human-specific pathologies, such as tumorigenesis and oxidative stress-associated disorders, highlighting its potential as a target for novel therapeutic interventions. Full article

The increase in the incidence and antibiotic-resistant strains show a need for a broadly protective vaccine to prevent gonorrhea. OMVax has developed a combination vaccine based on native outer membrane vesicles (NOMVs) from two Neisseria meningitidis (Nm) and two Neisseria gonorrhoeae (Ng) strains. The strains had the acyl transferase LpxL1 knocked out to increase safety, and the reduction-modifiable protein was also knocked out in the Ng strains. Factor H binding protein (FHbp) mutants with reduced Factor H (FH) binding from Subfamilies A and B, respectively, were overexpressed in the Nm strains. The Ng strains individually expressed porin outer membrane protein B 1a (PorB.1a) or PorB.1b. Antibodies elicited by the Nm-Ng NOMV vaccine had SBA with a human complement against diverse Nm and Ng strains grown in the presence of Cytidine-5′-monophospho-N-acetylneuraminic acid (CMP-NANA), had no significant reduction in serum bactericidal activity (SBA) compared to the respective individual vaccines, inhibited the adhesion to human cervical and vaginal cells in five out of six Ng strains tested, and inhibited Nm and Ng colonization in a transgenic mouse model. In conclusion, the Nm-Ng NOMV vaccine has the potential to protect against disease and inhibit colonization by diverse Nm and Ng strains, which may be an advantage for controlling the disease through vaccination, particularly in the adolescent/young adult age group. Full article

Ammonia (NH₃) is a promising carbon-free fuel for internal combustion engines, but its low reactivity and poor ignition properties present significant challenges for stable operation. This study presents the development and experimental validation of a spark-ignited combustion process that enables stable engine operation using 100% liquid NH₃ as a single fuel. A modified single cylinder research engine, equipped with NH₃ port fuel injection and a high-energy capacitive ignition system was used to investigate combustion behavior under various load conditions. The results show that stable, knock-free combustion with pure NH₃ is feasible at every operating point without any ignition aids like diesel fuel or hydrogen (H₂). The full load conditions of a diesel engine can be represented with an indicated efficiency of 50% using this combustion process. The emission measurements show nitrogen oxides (NO_x) and NH₃ emissions in a 1:1 ratio, which is advantageous for a passive SCR system. Increased nitrous oxides (N₂O) formation occurs at low loads and cold combustion chamber temperatures. This work demonstrates the technical viability of carbon-free NH₃ combustion in spark-ignited (SI) engines and represents a promising step towards net-zero combustion. Full article

N⁶-methyladenosine (m⁶A) has recently emerged as a post-transcriptional modulator governing cell-specific gene expression in innate immune cells, particularly in monocytes. Disruptions in m⁶A homeostasis, manifested as the altered expression of m⁶A-related proteins and m⁶A levels, have been implicated in autoimmune disorders. Perturbations in m⁶A dynamics within total Peripheral blood mononuclear cells (PBMCs) have shown strong correlations with disease severity in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). It remains unclear in which specific cell type(s) m⁶A homeostasis is disturbed, and also whether other rheumatic diseases such as juvenile idiopathic arthritis (JIA) show similar features. Here, we assess the involvement of m⁶A and m⁶A-regulatory proteins in JIA monocytes. Notably, the diminished expression of m⁶A-eraser proteins FTO and ALKBH5 was observed in JIA monocytes extracted from the inflamed joint. This resulted in increased m⁶A-methylated transcripts in monocytes from these patients. Correspondingly, we observed that culturing monocytes in the presence of synovial fluid from JIA inflamed joints reduced the expression of both FTO and ALKBH5. The knock-out of FTO in human monocytes of healthy controls increased monocyte activation, indicating the relevance of FTO and m⁶A in the context of JIA. These findings underscore the potential of ALKBH5 and FTO expression as a biomarker in JIA and identify the m⁶A machinery as a potential therapeutic target for the treatment of JIA and possibly other autoimmune diseases in the future. Full article

Exploring the metabolic regulatory mechanisms of bacteria for ramie degumming and constructing more efficient engineered strains are preferred strategies to solve the technical bottleneck of high residual gum content in fibers. Bacillus subtilis strain 168, an advantageous bacterium for microbial degumming, was previously found to significantly up-regulate the expression of bast two-component system (TCS) response regulators CitT, YvcP, and YycI when using ramie as the sole carbon source. In this study, the genes encoding CitT, YvcP, and YycI proteins were knocked out and compared the effects between these gene knockouts and the original strain on the degumming efficiency. The aim was to identify the key TCS response regulators that significantly affect degumming efficiency and to explore the functions of these different response regulators. The results demonstrated that knockout of citT, yvcP, or yycI genes significantly reduced degumming efficiency. Specifically, CitT protein primarily regulated the degradation of pectin, YvcP protein mainly regulated the degradation of hemicellulose, and YycI protein was involved in the regulation of both pectin and hemicellulose degradation. Notably, the absence of CitT protein caused the most significant reduction in degumming efficiency. These findings provide valuable insights into the construction of engineered strains with high degumming efficiency for ramie fibers. Full article

FOXL2 (forkhead box protein L2) is a transcription factor, its function and regulatory mechanism have been mainly studied in mammals; related research on marine invertebrates is still insufficient. It was found that oogenesis was affected, and even a small number of cells resembling spermatogonial morphology appeared in C. farreri ovaries after the FOXL2 was knocked down through RNA interference (RNAi) technology in our laboratory previously. Based on previous research, this paper conducted transcriptome sequencing and differential expression analysis on the ovarian tissues between the experimental group (post-RNAi) and the control group (pre-RNAi) of C. farreri, and used recombinant C. farreri FOXL2 protein for antibody production in Chromatin Immunoprecipitation Sequencing (ChIP seq) experiments to comprehensively analyze the pathways and key genes regulated by FOXL2 during oogenesis. The results showed that in the RNAi experimental group, 389 genes were upregulated, and 1615 genes were downregulated. Among the differentially expressed genes (DEGs), the differential genes related to gender or gonadal development are relatively concentrated in physiological processes such as steroid hormone synthesis, spermatogenesis, gonadal development, and ovarian function maintenance, as well as the FoxO and estrogen signaling pathways. Combining transcriptome and ChIP-seq data, it was found that there were some genes related to sex gonadal development among genes which were directly regulated by FOXL2, such as Wnt4, SIRT1, HSD17B8, GABABR1, KRAS, NOTCH1, HSD11B1, cPLA2, ADCY9, IP3R1, PLCB4, and Wnt1. This study lays the foundation for a deeper understanding of the FOXL2′s specific regulatory mechanism during oogenesis in scallops as a transcription factor. Full article

Hyperthyroidism is known to increase basal metabolism and glucose uptake in the skeletal muscles while promoting gluconeogenesis in the liver. However, the specific mechanism underlying thyroid hormone-induced postprandial hyperglycemia remains unclear. This study explored the influence of thyroid hormones on sodium/glucose cotransporter 1 (SGLT1) expression in the small intestine and their impact on postprandial glucose metabolism. Specifically, we examined the distribution of thyroid hormone receptors in the small intestine and the subsequent effect of thyroid hormones on SGLT1 expression using rat and genetically modified mouse models. Our results demonstrated a significant upregulation of SGLT1 in the distal small intestine following T4 treatment, which corresponded with the enhanced postprandial glucose levels after oral glucose administration but not intraperitoneal administration. Furthermore, in TRβΔ337T knock-in mice that exhibited resistance to thyroid hormones, we observed increased SGLT1 expression and postprandial hyperglycemia, reinforcing our findings in rats. These findings suggest that thyroid hormones enhance glucose absorption in the small intestine via SGLT1, contributing to postprandial hyperglycemia. This study elucidates a previously unexplored aspect of thyroid hormone physiology and highlights the regulatory role of thyroid hormones in SGLT1 expression, offering potential therapeutic avenues for managing postprandial hyperglycemia in patients with diabetes. Full article

Silicon-based MEMS devices are essential in extreme radiation environments but suffer progressive reliability degradation from irradiation-induced defects. Here, the generation, aggregation, and clustering of defects in single-crystal silicon were systematically investigated through molecular dynamics (MD) simulations via employing a hybrid Tersoff–ZBL potential that was validated by nanoindentation and transmission electron microscopy. The influences of the primary knock-on atom energy, temperature, and pre-strain state on defect evolution were quantified in detail. Frenkel defects were found to cause a linear reduction in the Young’s modulus and a nonlinear decline in thermal conductivity via enhanced phonon scattering. To link atomic-scale damage with device-level performance, MD-predicted modulus degradation was incorporated into finite element (FE) models of a sensing diaphragm. The FE analysis revealed that modulus reductions result in nonlinear increases in deflection and stress concentration, potentially impairing sensing accuracy. This integrated MD–FE framework establishes a robust, physics-based approach for predicting and mitigating irradiation damage in silicon-based MEMS operating in extreme environments. Full article