Search Results (898)

Crude glycerin (CG) is an energy-dense ingredient capable of partially or fully replacing corn in high-concentrate diets for ruminants. Its rapid ruminal absorption, favorable fermentative profile, and absence of lactic acid production may support safer adaptation to intensive feeding systems. The aim of this study was to evaluate the effects of replacing corn with CG (300 g/kg DM) on growth performance, feeding behavior, rumen morphometry, and proteomic responses of ruminal papillae in feedlot lambs. Sixty-five Santa Inês × Dorper lambs were assigned to either a control diet or a diet containing CG and were evaluated during pre-adaptation, adaptation, and finishing phases. Replacing corn with CG slightly reduced average daily gain (p = 0.02), without affecting final body weight, dry matter intake, or carcass yield (p > 0.05). Lambs fed CG exhibited lower subcutaneous fat thickness (p = 0.04) and reduced neutral detergent fiber intake during feeding behavior assessments (p < 0.05). Rumen papillae showed higher mitotic index and greater epithelial activity throughout the feedlot period, regardless of treatment. Proteomic analysis revealed upregulation of proteins involved in epithelial integrity (Claudin-1, Occludin) and mitochondrial energy metabolism (ATP synthase β, glycerol kinase) in CG-fed lambs, alongside downregulation of proteins related to oxidative stress and inflammation (HSP70, Annexin A1, SOD1, Peroxiredoxin-6). These findings demonstrate that CG promotes beneficial molecular adaptations in the ruminal epithelium without compromising carcass traits, supporting its use as a safe, functional, and sustainable alternative to corn in lamb finishing systems. Full article

The use of digitized slides for histopathological diagnosis has become common in veterinary pathology, and the validation of diagnostic techniques that are extrapolated from the evaluation of glass slides is needed. The goal of this study is to evaluate the efficiency of counting mitotic figures in physical glass slides and digitized slides of cutaneous tumors of dogs and cats. The mitotic count was performed by three pathologists on glass and digitized slides of ninety skin tumors, including 30 squamous cell carcinomas in dogs and cats, 30 mast cell tumors and 30 soft tissue tumors in dogs. An additional assessment of cellular proliferation was performed with immunohistochemistry for Ki67. Spearman’s correlation for the mean count of mitotic figures between the three observers on physical and digitized slides demonstrated a strong positive correlation for squamous cell carcinomas and mesenchymal tumors and a moderate correlation for mast cell tumors. Inter-observer agreement was moderate between the two methods. In conclusion, the results found suggest that digitized slides can be used reliably for mitotic figure counting in cutaneous neoplasms in small animals, without compromising their classification or prediction of prognosis. Full article

Mitotic catastrophe refers to a complicated mechanism of cell death characterized by failure to complete the processes of mitosis correctly due to aberrant chromosome segregation and abnormal tubulin polymerization. Post-translational modifications (PTMs) play a crucial role in the functional diversity of the proteome by mediating the covalent attachment of functional groups to proteins, which regulates the proteolytic cleavage of subunits, facilitating the degradation of entire proteins. Recent studies suggest that PTMs of key proteins are closely implicated in the occurrence, regulation and potential therapeutic targets of mitotic catastrophe. Here, we summarize how multiple PTMs, including phosphorylation, ubiquitination, acetylation, methylation and other types of PTMs, regulate mitotic catastrophe. In addition, potential therapeutic approaches targeting mitotic catastrophe were also discussed. It is anticipated that the inducement of mitotic catastrophe can serve as a promising new therapeutic approach for various diseases in the future. Full article

Osteosarcoma (OS) is an aggressive bone malignancy with poor prognosis, characterized by high metastasis rates. Kinesin family member 18B (KIF18B), a key protein in cell division and mitosis, has emerged as a potential diagnostic and therapeutic target in various cancers, including OS. This study investigates the role of KIF18B in OS progression and its underlying mechanisms. We found that KIF18B expression is significantly upregulated in OS tissues and correlates with lymph node metastasis (N-stage) and clinical stage. Knockdown of KIF18B inhibited OS cell migration, invasion, proliferation, and tumorigenesis. Mechanistically, KIF18B promotes OS survival through the ubiquitin–proteasome system (UPS) by regulating Skp2 protein degradation. KIF18B knockdown accelerated Skp2 ubiquitination, leading to reduced Skp2 levels and inhibited OS cell viability and glycolytic metabolism. Overexpression of KIF18B enhanced OS cell viability and glycolysis in an Skp2-dependent manner. These findings suggest that the KIF18B-Skp2 axis plays a critical role in the metabolic reprogramming of OS cells and serves as a novel prognostic biomarker and therapeutic target in OS. Full article

Tri-o-cresyl phosphate (TOCP) is widely used as a plasticizer, flame retardant, and lubricant additive, but has been reported to impair spermatogenesis. However, how TOCP affects spermatogenesis remains unclear. Therefore, the objective of this study is to investigate the underlying mechanism by which TOCP disrupts spermatogenesis. In order to achieve this, adult male mice were orally administered TOCP at doses of 0, 200, or 400 mg/kg for two weeks, and we found that TOCP exposure reduced the number of germ cells and decreased sperm density. Moreover, the numbers of PCNA-positive cells and phospho-histone H3 (Ser10)-positive cells in mouse testicular tissues were significantly decreased following TOCP treatment, indicating that germ cell proliferation may be impaired. In addition, TOCP did not affect the protein expression of neuropathy target esterase (NTE) in testicular tissues but markedly inhibited its enzymatic activity (by approximately 30% relative to the control level). In vitro experiments further demonstrate that TOCP suppressed cell proliferation and mitotic progression in mouse GC-1 spg cells and excessively activated endoplasmic reticulum (ER) stress. Treatment with 4-phenylbutyric acid (4-PBA), an ER stress inhibitor, partially reversed the TOCP-induced inhibition of cell proliferation and mitosis. Furthermore, TOCP inhibited NTE activity in GC-1 spg cells, and NTE knockdown produced a phenotype similar to that observed after TOCP exposure, characterized by suppressed cell proliferation and mitotic progression. Surprisingly, ER stress was not activated in GC-1 spg cells following NTE knockdown. Collectively, these findings suggest that TOCP may impair spermatogenesis by inhibiting the proliferation and mitotic progression of mouse germ cells, potentially through mechanisms involving excessive activation of ER stress or suppression of NTE activity. Full article

Neonicotinoids are widely used pesticides that have caused a catastrophic decrease in bee and bumblebee populations worldwide. In addition to insects, neonicotinoids induce toxic effects in other species, including lizards, birds, and mammals. Previous studies have shown that gestational exposure to thiacloprid promotes transgenerational effects in the testes and thyroid. In this project, we described the epigenetic effects of thiacloprid on prostate tissue in directly exposed F1 and non-directly exposed F3 outbred Swiss male mice. We used paraffin sections for morphological analysis and frozen tissue for immunofluorescence analysis, RT–qPCR, and protein analysis. We purified histones and analyzed them through Western blot. We used ChIP–qPCR for histone H3K4me3 occupancy analysis. A tendency to increase in epithelial hyperplasia in F1 but not in F3 prostate was detected. Elevated levels of phosphorylated histone H3 at serine 10, a marker of mitosis, in both the F1 and F3 prostates were noted. A significant increase in the level of the Ki-67 marker of proliferation was detected in the F1 but not in the F3 anterior prostate. Hox gene expression was upregulated in the F1 and downregulated in the F3 prostate. The changes in gene expression were positively associated with histone H3K4me3 alterations at the promoters of the Hoxa and Hoxb13 genes. We determined that regions of Hox genes that play important roles in prostate development had altered DNA methylation in the sperm of F1 and F3. These alterations in DNA methylation were negatively related to gene expression. This is an observational study, as it was part of our previous research on the effects of thiacloprid on the testis and thyroid. Our analysis revealed that gestational exposure to thiacloprid induced an increase in cell proliferation in the prostates of directly exposed F1. Some persistent epigenetic alterations in the prostate of F3 males were not associated with phenotypic changes. Full article

Cadmium (Cd) contamination, through induction of oxidative stress, severely impairs plant growth. Using primary roots of Vicia faba, we investigated how a 24 h incubation in CdCl₂ solution (175 µM) affects mitotic progression in meristems and assessed whether thyme essential oil (TO; 0.03%, v/v), as a natural antioxidant, can protect proliferating cells during simultaneous Cd exposure. Cd strongly inhibited root growth, reduced mitotic index tenfold (to 0.6%), induced chromatin condensation, decreased CDKA protein levels and CycB transcripts and proteins, caused pronounced microtubule bundling and alterations in their arrangement, disorganization of actin filaments, and disturbances in histone H3 phosphorylation (H3T3Ph, H3S10Ph). TO led to a partial recovery of mitotic index (to ~50% of the control), normalization of chromosome condensation, maintenance of cell-cycle regulators at near-control levels, preservation of proper cytoskeletal organization, and restoration of the correct H3 phosphorylation pattern. This enabled cells to progress from metaphase to anaphase and maintain phase proportions close to the control, resulting in normal root growth. These findings indicate that TO protects the mitotic cellular environment against Cd-induced disturbances. To the best of our knowledge, this is the first evidence that TO safeguards the plant mitotic apparatus under Cd stress, highlighting its potential as a natural bioprotective agent supporting plant growth. Full article

CRISPR screens are a powerful functional genomics approach for identifying genes that confer sensitivity and resistance to anti-cancer therapies. CFI-402257 (luvixasertib, 2257) is a small molecule inhibitor of threonine tyrosine kinase (TTK), a promising therapeutic target in genomically unstable cancers due to its critical role in establishing the spindle assembly checkpoint (SAC) during mitosis. To inform its ongoing development and evaluation in clinical trials, we sought to use CRISPR activation (i.e., gain of function) screens to identify cellular mechanisms of resistance to 2257 in models of triple-negative breast cancer (TNBC). In vitro screens conducted in two TNBC cell lines nominated ABCG2 as the top resistance-conferring gene in both models. Validation studies assessing clonogenic survival and apoptosis confirmed that ABCG2 overexpression enhanced TNBC resistance to 2257 in vitro, while knockdown enhanced sensitivity. These findings suggest that 2257 is a substrate of ABCG2’s drug efflux activity. However, overexpression of ABCG2 failed to confer resistance to 2257 in TNBC xenografts grown in mice and treated with a moderately active dose and schedule. Our results highlight the potential impact of drug transporters in in vitro CRISPR screens and the importance of confirming the relevance of drug response mechanisms identified in cultured cells using in vivo models that recapitulate drug pharmacokinetics and pharmacodynamics. Full article

Background/Objectives: SETD2 is a dual-function methyltransferase important for methylation of histone H3 at lysine 36 and α-tubulin in spindle microtubules. Genetic inactivation of SETD2 during oncogenesis drives loss of H3K36me3, genomic instability, and cancer progression. This study asked if disruption of genomic stability was a canonical feature of SETD2 inactivation via different pathways. Methods: We evaluated the impact of EPZ-719, a pharmacologic SETD2 inhibitor, and an H3.3K36M mutant histone (“oncohistone”) that binds and sequesters SETD2, on methylation activity and genomic stability in human cell lines. SETD2 activity was measured using in vitro methylation assays, H3K36me3 loss confirmed by Western analysis, and mitotic defects, specifically micronuclei and chromatin bridges, quantified with cytogenetic analysis. Results: EPZ-719 caused a dose- and time-dependent reduction in SETD2 activity on both histone and tubulin substrates, accompanied by significant increases in chromatin bridges and micronuclei in retinal pigmented epithelial (RPE-1) and 786-O ccRCC cells. Similarly, oncohistone expression markedly decreased SETD2 function, as determined by H3K36me3 levels, and induced comparable mitotic defects in 786-O cells, and aneuploidy in two chondrocyte cell lines expressing the H3.3K36M oncohistone. Combining EPZ-719 with H3.3K36M expression did not exacerbate mitotic defects beyond either oncohistone or pharmacologic inhibition alone, consistent with inhibition of SETD2 as their shared underlying mechanism of action. Conclusions: Pharmacologic inhibition and oncohistone-mediated sequestration of SETD2 converge on the induction of mitotic defects, underscoring SETD2’s essential role in maintaining genomic stability. Identification of loss of genomic stability as a canonical feature of SETD2 inactivation points to a potential therapeutic liability associated with targeting SETD2 in cancers where it is overexpressed and reveals a mechanism that could contribute to the progression of cancers expressing oncohistone mutations. Full article

Cell division is a highly regulated process that actively involves dynamic changes to the genetic material within the nucleus. DNA is faithfully replicated in the S-Phase of the cell cycle, being converted from loose, relaxed chromatin into tight, condensed chromosomes to be segregated in mitosis. In addition to scaffolding proteins that shape these mitotic chromosomes, post-translational modifications of histones within nucleosomes modulate chromosome dynamics throughout the cell cycle. In this review, we use a comparative approach to highlight some of the major epigenetic marks affected by the cell cycle during embryogenesis of Caenorhabditis elegans: H4K20me1, H3S10ph, H4S1ph, H2AS1ph, and H3T118ph. These five histone post-translational modifications will be specifically highlighted in the context of the mitotic cell cycle, as they are well documented in the C. elegans literature. Full article

Cardiovascular disease (CVD) persists as the leading cause of global mortality, with adult mammalian hearts exhibiting limited regenerative capacity. Although cardiomyocytes (CMs) can re-enter the cell cycle and undergo DNA synthesis in response to injury, they fail to complete mitosis and cytokinesis, resulting in a functional blockade of productive proliferation following ischemic or aging-related injury. Reactive oxygen species (ROS) exhibit a context-dependent duality in cardiac regeneration: while maintaining redox homeostasis and supporting developmental signaling at physiological concentrations, pathological ROS accumulation exacerbates myocardial decline by inducing DNA damage response (DDR)-mediated cell cycle arrest at G2/M phase, along with structural and functional impairments. This review examines the mechanisms of ROS generation—from its cellular origins to its molecular drivers—in ischemic heart disease, and explores the modulation of regenerative signaling by oxidative stress. We further critically assess emerging therapeutic interventions targeting ROS-mediated myocardial regeneration. By delineating the functional roles of ROS in cardiac injury and repair, this review provides a mechanistic and translational framework for developing redox-based therapies aimed at promoting cardiomyocyte proliferation and myocardial regeneration after ischemic injury. Full article

Lung adenocarcinoma (LUAD) remains a leading cause of cancer-related mortality worldwide, highlighting the urgent need to identify novel prognostic biomarkers and therapeutic targets. Kinesin Family Member 18B (KIF18B) is implicated in mitosis, yet its precise role in LUAD pathogenesis remains poorly defined. This study investigates the oncogenic and therapeutic role of KIF18B in LUAD. Integrated analysis of The Cancer Genome Atlas Program (TCGA) and Gene Expression Omnibus (GEO) datasets revealed that KIF18B is significantly upregulated in LUAD tissues, with its elevated expression strongly associated with an advanced pathological stage, high grade, and poor patient survival. Single-cell sequencing data analysis further indicated that KIF18B expression in LUAD is closely linked to key malignant processes, including cell cycle progression, proliferation, migration, and epithelial–mesenchymal transition (EMT). Functional experiments demonstrated that KIF18B knockdown markedly suppressed LUAD cell proliferation, migration, and invasion in vitro and inhibited tumor growth in vivo. Mechanistically, transcriptomic and pathway analyses revealed that KIF18B depletion downregulates Early 2 Factor (E2F) target genes. Luciferase reporter assays confirmed diminished E2F reporter activity as well as E2F2 promoter activity upon KIF18B silencing, while overexpression of E2F1, E2F2, or E2F3 rescued the inhibited proliferative phenotypes induced by KIF18B loss. Collectively, our findings establish KIF18B as an essential driver of LUAD progression that acts through the E2F transcriptional network, nominating it as a promising diagnostic and therapeutic target. Full article

Background: Resistance to HER2-targeted therapies remains a major limitation in the treatment of HER2-positive breast cancer, where disease progression inevitably occurs in advanced stages. Development of next-generation strategies that retain activity in resistant disease is therefore a critical priority. Disitamab vedotin (RC48) is a novel antibody–drug conjugate (ADC) targeting HER2 that couples a humanized anti-HER2 antibody to the potent microtubule-disrupting agent monomethyl auristatin E. Methods: We compared the activity and mechanism of action of RC48 with that of trastuzumab emtansine (T-DM1) across HER2-positive and HER2-low cellular models, including multiple sublines resistant to current HER2-targeted agents. Results: In HER2-overexpressing breast cancer cell lines, RC48 consistently demonstrated superior antiproliferative effect with respect to T-DM1. Treatment with RC48 induced G2/M arrest and apoptotic cell death, associated with increased pHistone-H3 and cyclin B1 and downregulation of Wee1, consistent with blockade of cell cycle progression in mitosis. Although RC48 and T-DM1 internalized similarly, RC48 displayed more efficient intracellular payload release, providing a mechanistic explanation for its enhanced efficacy. Notably, RC48 retained strong activity in BT474-derived sublines resistant to T-DM1, lapatinib, or neratinib, inducing cell cycle arrest, apoptosis, and caspase activation in all resistant models. In contrast, T-DM1 exhibited only partial effects in resistant cells and was completely ineffective in a T-DM1-refractory clone. Conclusions: Together, these findings identify disitamab vedotin as a potent next-generation HER2-targeting ADC with the unique capacity to overcome acquired resistance to HER2-directed therapies. RC48 represents a promising therapeutic strategy for patients with refractory HER2-positive breast cancer and warrants further clinical investigation. Full article

Background/Objectives: PDZ-binding kinase (PBK) regulates mitosis, but its clinical significance and cellular localization in colorectal cancer (CRC) remain unclear. We evaluated PBK expression in CRC tissues and examined its association with clinicopathological features, immune contexture, and outcomes. Methods: PBK expression was assessed by RNA in situ hybridization in tumors from 246 CRC patients. Associations with TNM stage, vascular invasion, MMR status (dMMR/pMMR), immune cell infiltration, and stromal programmed death-ligand 1 (PD-L1) were analyzed. Overall survival (OS) and recurrence-free survival (RFS) were evaluated using Kaplan–Meier and Cox models. Public single-cell RNA sequencing datasets were analyzed to identify PBK-expressing cell populations. Results: Among 246 cases, 75 (30.5%) showed high PBK expression. High PBK expression was associated with lower TNM stage, absence of vascular invasion, and dMMR status. High-PBK tumors showed an immune-activated microenvironment, including increased CD4⁺, CD8⁺, and FOXP3⁺ T-cell infiltration, higher stromal PD-L1 expression, and higher tumor-infiltrating lymphocyte scores. Single-cell analysis indicated that PBK expression was enriched mainly in proliferative tumor epithelial cell populations. High PBK expression was associated with longer OS and RFS and remained an independent favorable prognostic factor in multivariate analysis. Conclusions: PBK expression in CRC is linked to proliferative tumor epithelial states, an immune-activated microenvironment, and favorable outcomes, supporting its utility as a prognostic biomarker. Full article

During open mitosis, reassembly of the nuclear envelope requires the coordinated recruitment of the ESCRT machinery, initiated by the chromatin-associated factor BAF1 and the nuclear-envelope-associated factor LEM2. Because telomeres are enriched at the reforming envelope, we investigated whether ESCRT factors contribute to telomere integrity. Reduction in the pivotal nuclear ESCRT factor CHMP7 caused DNA damage, heterochromatin disorganization, and telomere defects, including sister telomere associations and telomere free ends. Extending this analysis, we found that additional ESCRT components, including TSG101, VPS28, CHMP4B, and the ESCRT-associated factor AKTIP/Ft1, also contribute to telomere integrity, although with different strengths. Genetic interaction analyses suggest that CHMP7 converges in a common pathway with CHMP4B and AKTIP/Ft1, while it functions in parallel routes to TNKS1, a telomere-specific regulator of the shelterin TRF1. More genetic analyses indicated that BAF1 and LEM2 contribute to safeguarding of telomeres during nuclear envelope reassembly. Because defects in nuclear envelope dynamics and chromatin–membrane coupling are hallmarks of disorders associated with nuclear deformation and fragility, including aging and cancer, our findings contribute a new angle into these conditions and suggest potential targets for selectively modulating telomere maintenance pathways. Full article