Search Results (109)

Forest soil conservation is pivotal for controlling soil erosion and ensuring ecological security. Taking the Qilian Mountains Area in China as the research region, this study used ArcMap 10.8 software to process data for six prefecture-level cities in the area from 2008 to 2023. The Revised Universal Soil Loss Equation (RUSLE) model was applied to quantify the forest soil conservation amount and evaluate its ecosystem service value (ESV). Their spatiotemporal variations and dynamic evolution patterns were analyzed, alongside the influence of soil organic matter (OM) and nitrogen (N), phosphorus (P), and potassium (K) contents. The results showed that the average contents of OM, N, P and K in the forest soils of the Qilian Mountains Area were 24.22 g·kg⁻¹, 1.54 g·kg⁻¹, 0.70 g·kg⁻¹, and 19.96 g·kg⁻¹, respectively, with significant regional heterogeneity. Haibei Tibetan Autonomous Prefecture (HBTAP) had the highest while Jinchang City (JC) had the lowest. From 2008 to 2023, the average annual forest soil conservation amount and its ESV of the region were 1.749 × 10⁹ tons and 2.0444 × 10¹⁰ yuan, respectively, both showing a fluctuating trend of initial increase followed by a decrease. Spatially, HBTAP ranked first in average annual forest soil conservation amount per unit area and ESV. Jiuquan City (JQ) had the lowest forest soil conservation amount per unit area, and JC the lowest ESV. Forest soil conservation and its ESV in the region were affected by the contents of soil nutrients (OM and N, P, K elements), vegetation types and quality, topography, climate, and human activities (including ecological governance), which collectively intensified the spatiotemporal heterogeneity. These findings provide a theoretical basis for precise regional ecological protection and differentiated restoration strategies in arid regions. Full article

Background/Objectives: Parkinson’s disease (PD) is one of the most prevalent neurodegenerative disorders. Despite its multifactorial etiology, PD pathophysiology shared specific features such as cytoplasmic α-synuclein inclusions, oxidative stress, mitochondrial dysfunction, and impaired autophagy. Bromodomain and Extra-Terminal domain (BET) proteins, functioning as epigenetic readers, have recently emerged as promising therapeutic targets due to their regulatory role in redox homeostasis, neuroinflammation, and autophagy. However, their potential involvement in PD pathophysiology remains largely unexplored. Therefore, we aimed at evaluating whether BET modulation could ameliorate the parkinsonian phenotype in two cellular models. Methods: Differentiated SH-SY5Y and N1E-115 neuronal cells were exposed to rotenone toxin to mimic PD phenotype and co-treated with the small BET inhibitor JQ1. Results: BET inhibition significantly counteracted rotenone-induced cell death, neuromorphological alterations, and α-synuclein accumulation. These protective effects were accompanied by restoration of redox balance, as indicated by enhanced activation of the antioxidant system and suppression of the pro-oxidant NADPH oxidase complex. Moreover, JQ1 treatment alleviated mitochondrial dysfunction and corrected autophagy impairments triggered by rotenone. Conclusions: These data highlight a novel role for BET proteins in neurodegeneration, suggesting that their modulation may represent a promising approach to counteract PD neuropathology. Full article

The interplay between chromatin structure and phase-separating proteins is an emerging topic in cell biology with implications for understanding disease states. Here, we investigate the functional relationship between bromodomain protein 4 (BRD4) and chromatin architecture. By combining molecular dynamics simulations with live-cell imaging, we demonstrate that BRD4, when mutated at specific N-terminus sites, significantly impacts the organization and dynamics of chromatin nanodomains, known as nucleosome clutches. Our findings reveal that a constitutively phosphorylated mutant of BRD4 condenses nucleosome clutches, while treatment with (+)-JQ1 increases the diffusion dynamics of single nucleosomes and decondenses nucleosome clutches. Simultaneously, we demonstrate that BRD4 mutations can alter localization of BRD4 to chromatin as well as modify single nucleosome dynamics. These results suggest that both chromatin binding and phase separation of BRD4 could co-regulate the nanoscale chromatin architecture and the chromatin microenvironment. Our observations shed light on the nuanced regulation of chromatin structure by BRD4, offering insights into its role in maintaining the nuclear architecture and transcriptional activity. Full article

Uterine Fibroids (UFs) are the most common benign tumors in women of reproductive age, affecting ~77% of women overall and are clinically manifest in ~25% by age 50. Bromodomain and extra-terminal domain (BET) proteins play key roles in epigenetic transcriptional regulation, influencing many biological processes, such as proliferation, differentiation, and DNA damage response. Although BET dysregulation contributes to various diseases, their specific role in the pathogenesis of UFs remains largely unexplored. The present study aimed to determine the expression pattern of BET proteins in UFs and matched myometrium and further assess the impact of BET inhibitors on UF phenotype and epigenetic changes. Our studies demonstrated that the levels of Bromodomain-containing protein (BRD)2 and detection rate of BRD4 were significantly altered in UFs compared to matched myometrium, suggesting that aberrant BET protein expression may contribute to the pathogenesis of UFs. To investigate the biological effects of BET proteins, two small-molecule inhibitors, JQ1 and I-BET762, were used to assess their impact on UF cell behavior and transcriptomic profiles. Targeted inhibition of BET proteins markedly reduced UF cell viability compared with myometrial cells and induced cell cycle arrest. Unbiased transcriptomic profiling coupled with bioinformatic analysis revealed that BET inhibition altered multiple biological pathways, including G2M checkpoint, E2F targets, mitotic spindle, mTORC1 signaling, TNF-α signaling via NF-κB, and inflammatory response, as well as reprogrammed the UF cell epigenome. Notably, BET inhibition decreased the expression of several genes encoding extracellular matrix (ECM) proteins, a hallmark of UFs. Collectively, these results support that BET proteins play a pivotal role in regulating key signaling pathways and cellular processes in UFs. Targeting BET proteins may therefore represent a promising non-hormonal therapeutic strategy for UF treatment. Full article

Background: In recent years, compounds known as Proteolysis Targeted Chimeras (PROTACs) have revitalized the field of bioactive molecule design. These compounds promote proteolysis of therapeutic targets by recruiting them to ubiquitin ligases. One of the most commonly used classes of compounds in the synthesis of PROTACs are immunomodulatory imides (IMiDs), such as thalidomide (TLD), which interact with the E3 ligase CRL4^CRBN via the CULT domain of the cereblon protein (CRBN). This domain has been identified in proteins across various phylogenetic groups, including trypanosomatids, leading to the hypothesis that IMiD-derived PROTACs should be active in these organisms. Methods: The trypanocidal activity of the PROTAC dBET1 and its separated components (JQ1 and TLD) were assayed using a T. cruzi strain expressing β-glalactosidase. Potential CRL4-E3L complexes from humans and trypanosomatids were assembled in silico with MultimerMapper. The IMiD-binding site of HsCRBN and its trypanosomatid homologs were analyzed using molecular dynamics and docking simulations. Results: We demonstrate that the compound dBET1 does not function as a PROTAC in Trypanosoma cruzi. In silico structural analysis of CRL4-E3L complex orthologs revealed that the trypanosomal CULT-containing protein is not part of such a complex. Molecular dynamics simulations showed that the pocket of this CULT domain is smaller than that of mammalian CRBN and cannot accommodate IMiDs within. Conclusions: We underscore the importance of functional and structural validation in drug discovery, particularly when extrapolating mechanisms between evolutionarily distant species. While PROTACs hold promise in human therapeutics, our work advocates for re-evaluating the rationale behind thalidomide-based PROTACs in trypanosomatid research. Full article

Background: Liver fibrosis is a progressive pathological condition characterized by excessive extracellular matrix deposition, driven by activated hepatic stellate cells (aHSCs). Effective therapeutic strategies require targeting aHSCs and agents capable of reversing their activated phenotype. Methods: In this study, we developed chitosan nanoparticles loaded with atorvastatin (AS) and JQ1 and functionalized them with varying densities of retinol (Rt) to exploit aHSC targeting. Results: In vitro, Rt-NPs demonstrated enhanced uptake in GRX cells, with optimal performance observed at high Rt density (HRt-NPs). In vivo biodistribution in CCl₄-induced fibrotic and healthy mice revealed that LRt-NPs achieved superior hepatic accumulation in fibrotic livers compared to unmodified and HRt-NPs, underscoring the importance of optimal ligand density for targeting. Western blot analysis showed that treatment of GRX cells with Rt-AS-NPs and Rt-JQ1-NPs either individually or combined significantly reduced the expression of fibronectin, vimentin, and PDGFR-β, key markers of HSC activation, with combination therapy providing more significant effects. Conclusions: This work highlights the potential of Rt-chitosan NPs loaded with AS and JQ1 as an effective dual-drug system for targeted antifibrotic therapy, offering enhanced hepatic selectivity, improved safety, and potent aHSC deactivation. Full article

In this study, the J-integral method was used to evaluate the fracture toughness (J_Q) of the isolation layer at the top of SA508-III-309L/308L-316L dissimilar metal welded joints (DMWJs) of a pressure vessel. Tests were carried out at varying temperatures, from room temperature to 320 °C, to study the mechanism underlying temperature effects on unstable crack propagation. The results show that failure occurs in the middle position of the weld isolation layer of the welded joint at all test temperatures. The J_Q of the inner diameter of the joint decreases with increased temperature, with a maximum decrease of 31.8%. The analysis shows that the lath ferrite structure in the isolation layer provides a favorable path for crack propagation. The increase in temperature enlarges the difference in thermal expansion between SA508-III steel and the isolation layer, making it easier for second-phase particles in the isolation layer to induce crack initiation and propagation, thus reducing the J_Q of the steel. In addition, at high temperatures, the dislocation density of the isolation layer, the deformation resistance of the material, and the difference in the yield ratio of the joint weld all decrease, which is not conducive to the redistribution of the stress field at the tip of the fatigue crack, leading to further reduction in the J_Q. Full article

Bromodomain and extraterminal domain (BET) proteins act as epigenetic regulators of gene transcription. BET inhibitors have shown therapeutic potential in various models of heart failure; however, their efficacy in atrial fibrillation (AF) remains incompletely understood. This study investigated the effects of the BET inhibitor JQ1 in a mice model of AF. Wild-type male C57BL/6 mice were randomized into four groups: control, JQ1 alone (50 mg/kg, intraperitoneal), angiotensin II (AngII; 1 μg/kg/min), and AngII plus JQ1. After 2 weeks, electrophysiological studies revealed that JQ1 significantly reduced AngII-induced AF inducibility and duration. It also attenuated left atrial enlargement, diastolic dysfunction, and cardiac fibrosis. Molecular analyses indicated that JQ1 suppressed the AngII-induced upregulation of pro-fibrotic genes and restored Sirt1 expression. Moreover, JQ1 also inhibited AngII-enhanced oxidized CaMKII and phosphorylated RyR2 levels. In HL-1 atrial cardiomyocytes, JQ1 improved calcium handling abnormalities, shortened prolonged action potential duration (APD), and restored mitochondrial respiration and adenosine triphosphate (ATP) production, all of which had been impaired by AngII. These findings suggest that BET inhibition by JQ1 mitigates structural and electrical remodeling associated with AF by attenuating atrial fibrosis, and by restoring calcium homeostasis, mitochondrial function, and Sirt1 expression. JQ1 may represent a novel therapeutic strategy for the prevention and treatment of AF. Full article

Bromodomain and extraterminal domain (BET) family proteins are ubiquitous transcriptional co-activators that function broadly in cellular differentiation, proliferation, and stress responses. Pharmacological inhibition of BET proteins with small molecules that disrupt bromodomain engagement with acetyllysine residues (such as JQ1) or drive their degradation through the ubiquitin–proteasome system (such as dBET6) ameliorates pathological gene expression in a range of systems and shows promise as a potential therapeutic strategy. Understanding the cell-type and signaling pathway requirements that dictate BET dependence in a particular cellular context remains incomplete. We previously demonstrated that, in neonatal rat cardiomyocytes, GPCR-induced hypertrophy responses depended strongly on the BET protein Brd4 when signaling was coupled to Gαs, but not Gαq. Here, we tested whether Brd4 was differentially responsive to G protein isoforms in HEK 293 cells by expressing Gαs- or Gαq-coupled Designer Receptors Exclusively Activated by Designer Drugs (DREADDs). Gαq induced the expression of a group of early response genes and inflammatory genes in a manner largely insensitive to pharmacological BET inhibition, consistent with our previous data in cardiomyocytes. Gαs activated a small subset of the Gαq-induced genes, but this effect was largely reversed by dBET6. Our data further suggest that there may be general signaling requirements to activate Brd4 across cell types. Full article

Plant growth-promoting rhizobacteria (PGPR) offer a sustainable strategy for enhancing crop productivity and suppressing phytopathogens. In this study, seven bacterial isolates obtained from the rhizosphere of healthy tomato plants were evaluated for their antagonistic activity against the fungal pathogen Passalora fulva, the leaf miner Tuta absoluta, and their effects on tomato growth. In vitro dual-culture assays revealed that isolates IQR1, IQR2, IQR3, and IQR5 significantly inhibited P. fulva mycelial growth, with inhibition rates exceeding 35%. Volatile organic compounds (VOCs) produced by the bacterial isolates exhibited considerable antifungal activity, with IQR5, IQR1, and IQR2 achieving over 84% inhibition. Molecular identification based on 16S rDNA sequencing indicated that these isolates belong to distinct taxa: Leucobacter aridicolis (ON799334.1) (genus Leucobacter), Paenochrobactrum sp. (JF804769.1) (genus Paenochrobactrum), an uncultured bacterium (JQ337400.1) (genus Psychrobacter), and marine bacterium AK6_052 (KF816539.1) (genus Brevundimonas). Under greenhouse conditions, isolates IQR3, IQR5, and IQR1 reduced disease incidence of P. fulva to 20–26%. The same isolates also promoted plant growth, enhancing stem height and collar diameter. In addition, IQR5 significantly reduced T. absoluta larval density and foliar damage, with the number of larvae per leaflet decreasing to 1.42, compared to 3.20 in the control. These findings highlight the potentials of these rhizobacterial strains—particularly IQR5—as effective biocontrol agents and biofertilizers for integrated pest and disease management in tomato cultivation. Full article

Smooth muscle cell (SMC) differentiation plays a crucial role in angiogenesis and vasculogenesis during embryonic development. The underlying mechanisms controlling SMC differentiation, especially progenitor-specific regulation, however, remain largely unclear. In this study, we identified bromodomain-containing protein 4 (BRD4) as a novel regulator for SMC differentiation. Transforming growth factor-β (TGF-β) induces BRD4 expression in the initial phase of SMC differentiation of pluripotent murine 10T1/2 cells. BRD4 was found critical in mediating TGF-β-induced SMC differentiation. Knockdown of BRD4 with siRNA suppressed TGF-β-induced expression of SMC markers including α-SMA and SM22α. In addition, the BRD4 inhibitor JQ1 and degraders ARV-825 and dBET1 suppressed TGF-β-induced SMC marker gene expression. BRD4 regulates SMC differentiation by activating SMC marker gene transcription. BRD4 mediated SMC differentiation is independent of the phosphorylation of Smad2/3. Instead, BRD4 mediated TAZ expression induced by TGF-β. Consistent with the function of TAZ, the inhibition of BRD4 reduced nuclear retention of Smad3, thereby impairing Smad3 mediated SMC gene transcription. Myocardin is an important transcriptional modulator for SMC markers. Interestingly, the knockdown of BRD4 also attenuated the induction of myocardin due to TGF-β in 10T1/2 cells. Taken together, this study demonstrates that BRD4 is a novel modulator for SMC differentiation from mesenchymal progenitor cells through the regulation of TAZ and myocardin. Full article

Background/Objectives: Pompe disease (PD) is a rare autosomal recessive disorder caused by a deficiency of the lysosomal acid α-1,4-glucosidase (GAA) encoded by the GAA gene, leading to muscular dysfunctions due to pathological accumulation of glycogen in skeletal and cardiac muscles. PD has been reported in several animals and Japanese quails (JQ; Coturnix japonica), but a causative mutation has yet to be found in JQs with PD. Here, we aimed to identify a pathogenic mutation in JQs associated with PD. Methods: Paraffin-embedded skeletal muscle blocks from four JQs stored since the 1970s were used in this study. After confirming the histopathological phenotypes of PD, Sanger sequencing was performed to identify a pathological mutation in the GAA I gene of JQs. A genotyping survey was conducted using a real-time polymerase chain reaction assay targeting a candidate mutation using DNA samples extracted from 70 new-hatched JQs and 10 eggs from commercial farms. Results: Microscopic analysis confirmed the presence of the PD phenotype in three affected JQs based on abnormal histopathological changes and accumulated glycogen in the affected muscles, while one JQ was unaffected and served as a control. Sanger sequencing revealed that the three affected JQs were homozygous for the deletion of guanine at position 1096 in the open reading frame (c.1096delG). A genotyping survey of 70 JQs and 10 eggs from commercial farms showed that none carried this deletion mutation. Conclusions: This study identified c.1096delG as the pathogenic mutation for PD in JQs. This mutation induces a frameshift and substitution of amino acids at position 366 (alanine to histidine), resulting in premature termination at the 23rd codon (p.A366Hfs*23). This suggests that this mutation causes the deficient activity of GAA in JQs with PD. The identification of the c.1096delG mutation enabled the systematic maintenance of the flock colony in the PD model. Furthermore, this PD model can be used to clarify unknown aspects of PD pathogenesis and develop therapeutic strategies. Full article

Fibrosis represents a pivotal pathological process in numerous diseases, characterized by excessive deposition of extracellular matrix (ECM) that disrupts normal tissue architecture and function. In the heart, cardiac fibrosis significantly impairs both structural integrity and functional capacity, contributing to the progression of heart failure. Central to this process are cardiac fibroblasts (CFs), which, upon activation, differentiate into contractile myofibroblasts, driving pathological ECM accumulation. Transforming growth factor-beta (TGFβ) is a well-established regulator of fibroblast activation; however, the precise molecular mechanisms, particularly the involvement of ion channels, remain poorly understood. Emerging evidence highlights the regulatory role of ion channels, including calcium-activated potassium (K_Ca) channels, in fibroblast activation. This study elucidates the role of ion channels and investigates the mechanism by which Yoda1, an agonist of the mechanosensitive ion channel Piezo1, modulates TGFβ-induced fibroblast activation. Using NIH/3T3 fibroblasts, we demonstrated that TGFβ-induced activation is regulated by tetraethylammonium (TEA)-sensitive potassium channels, but not by specific K⁺ channel subtypes such as BK, SK, or IK channels. Intriguingly, Yoda1 was found to inhibit TGFβ-induced fibroblast activation through a Piezo1-independent mechanism. Transcriptomic analysis revealed that Yoda1 modulates fibroblast activation by altering gene expression pathways associated with fibrotic processes. Bromodomain-containing protein 4 (BRD4) was identified as a critical mediator of Yoda1’s effects, as pharmacological inhibition of BRD4 with JQ1 or ZL0454 suppressed TGFβ-induced expression of the fibroblast activation marker Periostin (Postn). Conversely, BRD4 overexpression attenuated the inhibitory effects of Yoda1 in both mouse and rat CFs. These results provide novel insights into the pharmacological modulation of TGFβ-induced cardiac fibroblast activation and highlight promising therapeutic targets for the treatment of fibrosis-related cardiac pathologies. Full article

Defects in lysosomal cholesterol handling provoke fatal disorders presenting neurovisceral symptoms with variable onset and life spans. A prime example is Niemann–Pick type C disease (NPCD), where cholesterol export from the endosomal–lysosomal system is impaired due to variants of either NPC intracellular cholesterol transporter 1 (NPC1) or NPC intracellular cholesterol transporter 2 (NPC2). Therapeutic options for NPCD are limited to palliative care and disease-modifying drugs, and there is a need for new treatments. Here, we explored bromodomain and extra-terminal domain (BET) proteins as new drug targets for NPCD using patient-derived skin fibroblasts. Treatment with JQ1, a prototype BET protein inhibitor, raised the level of NPC1 protein, diminished lysosomal expansion and cholesterol accumulation, and induced extracellular release of lysosomal components in a dose-, time-, and patient-dependent manner. Lastly, JQ1 enhanced and reduced cholesterol accumulation induced by pharmacologic inhibition of NPC1 and of histone deacetylase (HDAC) activity, respectively. Taken together, bromodomain proteins should be further explored as therapeutic drug targets for lysosomal diseases like NPCD, and as new components regulating lysosomal function and cholesterol metabolism. Full article