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Proteolysis Targeting Chimeras (PROTACs) represent a significant advancement in therapeutic drug development by leveraging the ubiquitin‐proteasome system to enable targeted protein degradation, particularly impacting oncology. This review delves into the various types of PROTACs, such as peptide‐based, nucleic acid‐based, and small molecule PROTACs, each addressing distinct challenges in protein degradation. It also discusses innovative strategies like bridged PROTACs and conditional switch‐activated PROTACs, offering precise targeting of previously "undruggable" proteins. The potential of PROTACs extends beyond oncology, with ongoing research and technological advancements needed to maximize their therapeutic potential. Future progress in this field relies on interdisciplinary collaboration and the integration of advanced computational tools to open new treatment avenues across various diseases. [ABSTRACT FROM AUTHOR]

Genuine multipartite entanglement is crucial for quantum information and related technologies, but quantifying it has been a long-standing challenge. Most proposed measures do not meet the "genuine" requirement, making them unsuitable for many applications. In this work, we propose a journey toward addressing this issue by introducing an unexpected relation between multipartite entanglement and hypervolume of geometric simplices, leading to a tetrahedron measure of quadripartite entanglement. By comparing the entanglement ranking of two highly entangled four-qubit states, we show that the tetrahedron measure relies on the degree of permutation invariance among parties within the quantum system. We demonstrate potential future applications of our measure in the context of quantum information scrambling within many-body systems. [ABSTRACT FROM AUTHOR]

Intercalation of MoO2-supported nickel nanoparticles (NPs) with a mesoporous carbon layer has been achieved through thermal reduction of hierarchical nickel molybdate with Ni2+–polydopamine complex (PDA–Ni2+) coated on its surfaces. High coverage of nickel NPs was achieved from nickel molybdate and a carbonized PDA–Ni2+ layer under the protection of a nitrogen atmosphere. Doping of other transition metals such as cobalt ions has been achieved at the stage of nickel molybdate formation, with the added amount of cobalt ions playing a vital role in tailoring the composition and morphology of the cobalt-doped nickel molybdate. Cobalt-doped nickel molybdate was able to produce nickel-based bimetallic NiCo alloy NPs within the final configuration by the same strategy as for MoO2@C–Ni. The mesoporous 2D nanosheets combined with their constructed 1D hollow structures can expose more ultrafine Ni or NiCo sites while enhancing mass diffusion of small molecules or proteins. As a result, the hollow MoO2–Ni, NiCo/N-doped carbon microtubes exhibited high activity and robust cycling stability in both protein adsorption and the reduction of 4-nitrophenol. [ABSTRACT FROM AUTHOR]

Anchoring bimetallic alloys in a one-dimensional(1D) heteroatom-doped carbon matrix with excellent electro-conductibility is a powerful strategy for the reduction of 4-nitrophenol (4-NP). Herein, we report the design and fabrication of CoNi bimetallic nanoparticles (NPs) decorated on N, P, and S-doped carbon/MnO nanowires (NWs) as an active catalyst for the reduction of 4-NP. The CoNi bimetallic NPs enable the full utilization of accessible edge sites, and the unique 1D framework creates a large surface area, exposing abundant active sites and providing a fast charge/ionic diffusion pathway. Moreover, the synergistic electronic interaction between the CoNi NPs and N, P and S co-doped carbon layer leads to optimal electronic structures and good adhesion ability, thus facilitating the catalytic performance. As a result, the obtained CoNi decorated on N, P, and S-doped carbon/MnO NWs exhibited superior catalytic activities in the reduction of 4-NP as well as robust stability in catalyst recycling. This work highlights the effect of rationally constructing a 1D bimetallic catalyst. [ABSTRACT FROM AUTHOR]

We introduce the challenges of multi-party quantum entanglement and explain a recent success in learning to take its measure. Given the widely accepted reputation of entanglement as a counter-intuitive feature of quantum theory, we first describe pure-state entanglement itself. We restrict attention to multi-party qubit states. Then we introduce the features that have made it challenging for several decades to extend an entanglement measure beyond the 2-qubit case of Bell states. We finish with a description of the current understanding that solves the 3-qubit entanglement challenge. This necessarily takes into account the fundamental division of the 3-qubit state space into two completely independent sectors identified with the so-called GHZ and W states. [ABSTRACT FROM AUTHOR]

Mammalian erythrocytes are highly specialized cells that have adapted to lose their nuclei and cellular components during maturation to ensure oxygen delivery. Nuclear extrusion, the most critical event during erythropoiesis, represents an extreme case of asymmetric partitioning that requires a dramatic reorganization of the cytoskeleton. However, the precise role of the microtubule cytoskeleton in the enucleation process remains controversial. In this study, we show that microtubule reorganization is critical for microtubule clearance and nuclear extrusion during erythropoiesis. Using a rodent anemia model, we found that microtubules were present in erythroblasts and reticulocytes but were undetectable in erythrocytes. Further analysis demonstrated that microtubules became disordered in reticulocytes and revealed that microtubule stabilization was critical for tubulin degradation. Disruption of microtubule dynamics using the microtubule‐stabilizing agent paclitaxel or the microtubule‐destabilizing agent nocodazole did not affect the efficiency of erythroblast enucleation. However, paclitaxel treatment resulted in the retention of tubulin in mature erythrocytes, and nocodazole treatment led to a defect in pyrenocyte morphology. Taken together, our data reveals a critical role for microtubules in erythrocyte development. Our findings also implicate the disruption of microtubule dynamics in the pathogenesis of anemia‐associated diseases, providing new insight into the pathogenesis of the microtubule‐targeted agent‐associated anemia frequently observed during cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Successful treatment of pancreatic cancer, which has the highest mortality rate among all types of malignancies, has challenged oncologists for decades, and early detection would undoubtedly increase favorable patient outcomes. The identification of proteins involved in pancreatic cancer progression could lead to biomarkers for early detection of this disease. This study identifies one potential candidate, cylindromatosis (CYLD), a deubiquitinase and microtubule‐binding protein that plays a suppressive role in pancreatic cancer development. In pancreatic cancer samples, downregulation of CYLD expression resulted from a loss in the copy number of the CYLD gene; additionally, reduced expression of CYLD negatively correlated with the clinicopathological parameters. Further study demonstrated that CYLD deficiency promoted colony formation in vitro and pancreatic cancer growth in vivo. Mechanistic studies revealed that CYLD is essential for spindle orientation and properly oriented cell division; CYLD deficiency resulted in a substantial increase in chromosome missegregation. Taken together, these data indicate a critical role for CYLD in suppressing pancreatic tumorigenesis, implicating its potential as a biomarker for early detection of pancreatic cancer and a prognostic indicator of patient outcomes. This study identifies one potential candidate, cylindromatosis (CYLD), a deubiquitinase and microtubule‐binding protein that plays a suppressive role in pancreatic cancer development, implicating its potential as a biomarker for early detection of pancreatic cancer and a prognostic indicator of patient outcomes. [ABSTRACT FROM AUTHOR]

Similar to bacteria, yeast, and other organisms that have evolved pathways to respond to environmental stresses, cancer cells develop mechanisms that increase genetic diversity to facilitate adaptation to a variety of stressful conditions, including hypoxia, nutrient deprivation, exposure to DNA‐damaging agents, and immune responses. To survive, cancer cells trigger mechanisms that drive genomic instability and mutation, alter gene expression programs, and reprogram the metabolic pathways to evade growth inhibition signaling and immune surveillance. A deeper understanding of the molecular mechanisms that underlie the pathways used by cancer cells to overcome stresses will allow us to develop more efficacious strategies for cancer therapy. Herein, we overview several key stresses imposed on cancer cells, including oxidative, metabolic, mechanical, and genotoxic, and discuss the mechanisms that drive cancer cell responses. The therapeutic implications of these responses are also considered, as these factors pave the way for the targeting of stress adaption pathways in order to slow cancer progression and block resistance to therapy. [ABSTRACT FROM AUTHOR]

Microtubule plus ends undergo highly dynamic modifications to regulate different aspects of cellular activities. Most microtubule plus-end tracking proteins (+TIPs) are recruited to the microtubule ends by the master loading factor, end-binding protein 1 (EB1). These proteins coordinately regulate microtubule dynamics and cellular plasticity. Acetylation is known to modulate EB1 function; however, the molecular details of EB1 acetylation remain largely unclear. We mapped the acetylation pattern of EB1 and identified several previously uncharacterized sites of EB1 acetylation. We examined the effects of lysine-212 (K212) acetylation and found that acetylation of this site accelerates autophagy-mediated EB1 degradation. By time-lapse microscopy, we found that the acetylation-deficient K212R mutant increased the percentage of fast-growing and long-lived microtubules. Although K212 acetylation did not affect microtubule stability in vitro and the association of EB1 with microtubules, the K212R mutant significantly promoted microtubule regrowth in cells. Coimmunoprecipitation assays further revealed that the K212 site was critical for the recruitment of different +TIP cargoes. These data thus uncover a critical role for a novel EB1 acetylation site in regulating the dynamic structure of microtubules. [ABSTRACT FROM AUTHOR]

Signal transducer and activator of transcription 3 (STAT3) is an important oncogenic transcription factor residing in the cytoplasm in the resting cells. Upon stimulation, STAT3 is activated and translocated to the nucleus to regulate target genes. Although the canonical transcriptional function of STAT3 has been intensively studied, less is known about its cytoplasmic localization. In this study, by immunoprecipitation, microtubule cosedimentation, and immunofluorescence assays, we present the first evidence that cytoplasmic STAT3 interacts with both tubulin and microtubules. By using small-molecule inhibitor approaches, we further demonstrate that the localization of STAT3 on microtubules and its activation are independent of histone deacetylase 6 (HDAC6) activity. In addition, disruption of microtubule dynamics does not alter the activation and nuclear translocation of STAT3 in response to interleukin-6 treatment. These findings reveal that cytoplasmic STAT3 is physically associated with microtubules, whereas its activation and nuclear translocation are independent of microtubule dynamics, implicating that the association of STAT3 with microtubules might be involved in the regulation of noncanonical functions of STAT3 in the cytoplasm. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a common cardiovascular disease that involves the build-up of plaque on the inner walls of the arteries. Intraplaque neovacularization has been shown to be essential in the pathogenesis of atherosclerosis. Previous studies showed that small-molecule compounds targeting farnesyl transferase have the ability to prevent atherosclerosis in apolipoprotein E-deficient mice, but the underlying mechanism remains to be elucidated. In this study, we found that lonafarnib, a specific inhibitor of farnesyl transferase, elicits inhibitory effect on vascular endothelial capillary assembly in vitro in a dose-dependent manner. In addition, we showed that lonafarnib treatment led to a dose-dependent decrease in scratch wound closure in vitro, whereas it had little effect on endothelial cell proliferation. These data indicate that lonafarnib inhibits neovascularization via directly targeting endothelial cells and disturbing their motility. Moreover, we demonstrated that pharmacological inhibition of farnesyl transferase by lonafarnib significantly impaired centrosome reorientation toward the leading edge of endothelial cells. Mechanistically, we found that the catalytic β subunit of farnesyl transferase associated with a cytoskeletal protein important for the establishment and maintenance of cell polarity. Additionally, we showed that lonafarnib remarkably inhibited the expression of the cytoskeletal protein and interrupted its interaction with farnesyl transferase. Our findings thus offer novel mechanistic insight into the protective effect of farnesyl transferase inhibitors on atherosclerosis and provide encouraging evidence for the potential use of this group of agents in inhibiting plaque neovascularization. [ABSTRACT FROM AUTHOR]

PEG and PEG/PEI modified superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by the thermal decomposition of iron (III) acetylacetonate (Fe(acac) 3 ) in poly (ethylene glycol) (PEG) containing poly (ethylene imine) (PEI) (0 or 0.3 g). PEG/PEI-SPIONs were coated with Tween 80 (PEG/PEI/Tween 80-SPIONs). Fourier transform infrared spectroscopy (FTIR) analyses indicated that PEG, PEG/PEI and PEG/PEI/Tween 80 were attached to the surfaces of the SPIONs. The PEG-SPIONs, PEG/PEI-SPIONs and PEG/PEI/Tween 80-SPIONs performed excellent colloidal stability in the phosphate buffered saline (PBS), and in deionized water with the mean hydrodynamic sizes of 19.5, 21.0, 24.0 nm and the zeta potentials of -5.0, 35.0, 19.0 mV, respectively. All the SPIONs showed low cytotoxicity assessed by the MTT assay. In vivo magnetic resonance imaging (MRI) of the Kunming (KM) mouse brains were performed, the PEG-SPIONs, PEG/PEI-SPIONs and PEG/PEI/Tween 80-SPIONs exhibited vascular imaging effects in bulbus olfactorius, frontal cortex, temporal, thalamus and brain stem of the mouse brains after 24 h intravenous injection of the nanoparticles. The SPIONs have potentials as MRI contrast agents in the mouse brains. [ABSTRACT FROM AUTHOR]

Activated macrophages play an important role in both innate and adaptive immune responses, and aberrant activation of macrophages often leads to inflammatory and immune disorders. However, the molecular mechanisms of how macrophages are activated are not fully understood. In this study, we identify a novel role for histone deacetylse 6 (HDAC6) in lipopolysaccharide (LPS)-induced macrophage activation. Our data show that suppression of HDAC6 activity significantly restrains LPS-induced activation of macrophages and production of pro-inflammatory cytokines. Further study reveals that the regulation of macrophage activation by HDAC6 is independent of F-actin polymerization and filopodium formation; instead, it is mediated by the effects of HDAC6 on cell adhesion and microtubule acetylation. These data thus suggest that HDAC6 is an important regulator of LPS-induced macrophage activation and might be a potential target for the management of inflammatory disorders. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Atherosclerosis and other cardiovascular diseases are serious threats to human health and become the leading cause of death in the world. Emerging evidence reveals that inhibition of plaque neovascularization could be an effective approach for the treatment of atherosclerosis. This study was conducted to identify cytoplasmic linker protein 170 as a potential target for cardiovascular diseases through modulation of neovascularization. Methods and results: Immunofluorescence microscopy revealed that cytoplasmic linker protein 170 was ubiquitously expressed in mouse kidney, liver, lung, normal non-atherosclerotic aorta, and atherosclerotic aorta and was partly localized in the vascular endothelium. siRNAs were introduced to human umbilical vein endothelial cells (HUVECs) and the effect of knockdown was confirmed by Western blotting. Vascularization study was assessed with matrigel-based capillary assembly, branching, and in vivo matrigel plug assays. The data showed that siRNA-mediated knockdown of the cytoplasmic linker protein remarkably compromised the assembly and branching of capillary-like blood vessels and neovascularization in vivo. Cell motility and polarity properties were then analyzed using scratch wound repair, boyden chamber, and immunofluorescence assays, and the results revealed that the cytoplasmic linker protein was critical for the motility abilities of HUVECs through its actions on cell polarity. Conclusion: Both in vitro and in vivo studies demonstrate the significance of the cytoplasmic linker protein for blood vessel formation. Mechanistic investigation reveals that its effect on neovascularization is orchestrated through its regulation of vascular endothelial cell polarity and motility. These findings provide the basis for exploring effective approaches to regulate neovascularization in cardiovascular diseases. [Copyright &y& Elsevier]

The innate immune system is the first line of host defense against infection and involves several different cell types. Here we investigated the role of the phosphatidylinositol 3 kinase (PI3K) signaling pathway in innate immune cells. By blocking this pathway with pharmacological inhibitors, we found that the production of proinflammatory cytokines was drastically suppressed in monocytes and macrophages. Further study revealed that the suppression was mainly related to the mammalian target of rapamycin (mTOR)/p70S6K signaling. In addition, we found that the PI3K pathway was involved in macrophage motility and neovascularization. Our data provide a rationale that inhibition of the PI3K signaling pathway could be an attractive approach for the management of inflammatory disorders. [ABSTRACT FROM AUTHOR]

The photoreceptor cilium is vital for maintaining the structure and function of the retina. However, the molecular mechanisms underlying the photoreceptor cilium integrity and retinal homeostasis are largely unknown. Herein, it is shown that kinesin family member 11 (KIF11) localizes at the transition zone (connecting cilium) of the photoreceptor and plays a crucial role in orchestrating the cilium integrity. KIF11 depletion causes malformations of both the photoreceptor ciliary axoneme and membranous discs, resulting in photoreceptor degeneration and the accumulation of drusen‐like deposits throughout the retina. Mechanistic studies show that the stability of KIF11 is regulated by an interplay between its UFMylation and ubiquitination; UFMylation of KIF11 at lysine 953 inhibits its ubiquitination by synoviolin 1 and thereby prevents its proteasomal degradation. The lysine 953‐to‐arginine mutant of KIF11 is more stable than wild‐type KIF11 and also more effective in reversing the ciliary and retinal defects induced by KIF11 depletion. These findings identify a critical role for KIF11 UFMylation in the maintenance of photoreceptor cilium integrity and retinal homeostasis. [ABSTRACT FROM AUTHOR]

• Polythiourethane was modified by 2,3,5,6-tetrafluoro-1,4-benzenedimethanol. • "Ambiguous" surface was formed by C F and OH groups in the same side chains. • The coatings with 7.5 % modified agent show excellent antifouling properties. The development of environmentally friendly alternatives is a crucial issue, since the prohibition of tributyltin (TBT)-based antifouling coatings. In this work, a series of fluorinated diols modified polythiourethane (HO-FPTU-x) have been synthesized via a simple and convenient polymerization reaction with HDI, PETMP and various of 2,3,5,6-tetrafluoro-1,4-benzenedimethanol (HOCH 2 -FB-Al) at the room temperature, and their antifouling properties are explored as well. The laboratory assays and marine field tests (6 months) show that the HO-FPTU-7.5 (with 7.5 wt% HOCH 2 -FB-Al) coating has shown excellent antifouling/fouling release properties. The side chains of the HO-FPTU polymers simultaneously contain hydrophobic and hydrophilic groups, which construct an "ambiguous" surface after immersing into water. The marine organisms may be "confused" by the "ambiguous" surface and be removed easily during settlement and adhesion. This work provides a facile strategy for designing environment friendly marine antifouling coatings. [ABSTRACT FROM AUTHOR]

Cell junctions, which are typically associated with dynamic cytoskeletons, are essential for a wide range of cellular activities, including cell migration, cell communication, barrier function and signal transduction. Observing cell junctions in real-time can help us understand the mechanisms by which they regulate these cellular activities. This study examined the binding capacity of a modified tridecapeptide from Connexin 43 (Cx43) to the cell junction protein zonula occludens-1 (ZO-1). The goal was to create a fluorescent peptide that can label cell junctions. A cell-penetrating peptide was linked to the modified tridecapeptide. The heterotrimeric peptide molecule was then synthesized. The binding of the modified tridecapeptide was tested using pulldown and immunoprecipitation assays. The ability of the peptide to label cell junctions was assessed by adding it to fixed or live Caco-2 cells. The testing assays revealed that the Cx43-derived peptide can bind to ZO-1. Additionally, the peptide was able to label cell junctions of fixed cells, although no obvious cell junction labeling was observed clearly in live cells, probably due to the inadequate affinity. These findings suggest that labeling cell junctions using a peptide-based strategy is feasible. Further efforts to improve its affinity are warranted in the future. [ABSTRACT FROM AUTHOR]

Here we demonstrate the rational design and synthesis of hierarchical Fe 3 O 4 @PPy/Mgsilicate composites for applications in water treatments. Through a facile step-by-step strategy, ultrathin Mgsilicate nanosheets (NSs) are grown on polypyrrole (PPy) coated Fe 3 O 4 NPs to achieve the hollow structured Fe 3 O 4 @PPy/Mgsilicate composites. This smart design can effectively shorten the mass transfer of molecules, increase the specific surface area, and provide more active sites for adsorption of organic pollutants. Owing to its large specific surface area, hierarchical hollow structures, and the synergistic adsorption effect between the PPy interlayer and magnesium silicate outlayer, the resulting composites exhibited excellent adsorption on Congo Red (CR) with high adsorption capacity of 540.5 mg·g-1. The separation of the composites after sorption can be easily performed with an external magnet because of the multiple Fe 3 O 4 cores. These results indicate that the Fe 3 O 4 @PPy/Mgsilicate composites can be employed as a highly promising adsorbent in water treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Aptamers offer immense promise for targeted protein degradation. Aptamer–PROTAC (proteolysis-targeting chimera) conjugates present an advantageous strategy to improve delivery efficiency, solubility, and permeability while mitigating off-tissue distribution-induced on-target toxicity. Aptamer-based PROTACs provide a feasible and promising platform for the spatiotemporal degradation of undruggable proteins. Aptamer-based lysosome-targeting chimeras (LYTACs) constitute a cost-effective alternative for the degradation of membrane-bound and extracellular proteins. Targeted protein degradation (TPD) technologies, particularly proteolysis-targeting chimeras (PROTACs), have emerged as a significant advancement in drug discovery. However, several hurdles – such as the difficulty of identifying suitable ligands for traditionally undruggable proteins, poor solubility and impermeability, nonspecific biodistribution, and on-target off-tissue toxicity – present challenges to their clinical applications. Aptamers are promising ligands for broad-ranging molecular recognition. Utilizing aptamers in TPD has shown potential advantages in overcoming these challenges. Here, we provide an overview of recent developments in aptamer-based TPD, emphasizing their potential to achieve targeted delivery and their promise for the spatiotemporal degradation of undruggable proteins. We also discuss the challenges and future directions of aptamer-based TPD with the goal of facilitating their clinical applications. [ABSTRACT FROM AUTHOR]

Cell lysates were subjected to immunoblotting. gl We next examined the biological consequences of dp53m-RA-mediated p53-R175H degradation in cancer cells. dp53m-RA treatment dramatically inhibited the proliferation of p53-R175H-expressing H1299 cells and SKBR3 cells. Moreover, the proteasome inhibitor MG132 completely blocked dp53m-RA-induced p53-R175H degradation (Figure 2J), and dp53m-RA treatment increased polyubiquitination of p53-R175H over p53-WT (Figure 2K). To the Editor: I TP53 i encodes the tumour suppressor protein p53, a master regulator of genomic integrity and cell survival, and is the most frequently mutated gene.[1] p53 mutant proteins are stabilised and can acquire dominant-negative or oncogenic gain-of-function activities, thereby promoting malignant transformation, metastasis and chemoresistance.[[2]] Proteolysis targeting chimeras (PROTACs) that hijack cellular ubiquitin-proteasome machinery for targeted protein degradation have shown considerable promise in targeting previously undruggable proteins.[[4]] However, PROTACs targeting p53 mutants have not yet been reported, probably due to difficulty in identifying a suitable binder for these mutants. [Extracted from the article]

Primary cilia, microtubule‐based protrusions present on the surface of most mammalian cells, function as sensory organelles that monitor extracellular signals and transduce them into intracellular biochemical responses. There is renewed research interest in primary cilia due to their essential roles in development, tissue homeostasis, and human diseases. Primary cilia dysfunction causes a large spectrum of human diseases, collectively known as ciliopathies. Despite significant advances in our understanding of primary cilia, there are still no effective agents for treating ciliopathies. Primary ciliogenesis is a highly ordered process involving membrane trafficking, basal body maturation, vesicle docking and fusion, transition zone assembly, and axoneme extension, in which actin and microtubule networks play critical and multiple roles. Actin and microtubule network architecture, isotropy, and dynamics are tightly controlled by cytoskeleton‐associated proteins, a growing number of which are now recognized as responsible for cilium formation and maintenance. Here we summarize the roles of actin and microtubules and their associated proteins in primary ciliogenesis and maintenance. In doing so, we highlight that targeting cytoskeleton‐associated proteins may be a promising therapeutic strategy for the treatment of ciliopathies. [ABSTRACT FROM AUTHOR]

Retinopathy of prematurity (ROP) is one of the leading causes of childhood visual impairment and blindness. However, there are still very few effective pharmacological interventions for ROP. Histone deacetylase 6 (HDAC6)‐mediated disassembly of photoreceptor cilia has recently been implicated as an early event in the pathogenesis of ROP. Herein it is shown that enhanced expression of HDAC6 by intravitreal injection of adenoviruses encoding HDAC6 induces the typical pathological changes associated with ROP in mice, including disruption of the membranous disks of photoreceptor outer segments and a decrease in electroretinographic amplitudes. Hdac6 transgenic mice exhibit similar ROP‐related defects in retinal structures and functions and disassembly of photoreceptor cilia, whereas Hdac6 knockout mice are resistant to oxygen change‐induced retinal defects. It is further shown that blocking HDAC6‐mediated cilium disassembly by intravitreal injection of small‐molecule compounds protect mice from ROP‐associated retinal defects. The findings indicate that pharmacological targeting of the HDAC6‐cilium axis may represent a promising strategy for the prevention of ROP. [ABSTRACT FROM AUTHOR]

Highlights: [•] DIMEN displays higher anti-proliferative activity than enastron. [•] DIMEN induced mitotic arrest and apoptosis more significantly than enastron. [•] DIMEN blocked the conformational change of ADP-binding pocket more effectively. [•] DIMEN hindered ADP release more potently than enastron. [ABSTRACT FROM AUTHOR]

Ubiquitin‐specific protease 21 (USP21) has been implicated in several types of cancer. It promotes or suppresses tumor growth in a cell‐context dependent manner. Cholangiocarcinoma is a malignant tumor with a high mortality rate. However, the role of USP21 in cholangiocarcinoma remains unknown. Here, we identify that the level of USP21 is upregulated in cholangiocarcinoma using bioinformatics analysis and confirm this elevation in RBE cell lines. Cell counting and 5‐ethynyl‐2′‐deoxyuridine incorporation assays reveal that USP21 promotes the proliferation of cholangiocarcinoma. Wound healing and transwell assays demonstrate that USP21 accelerates RBE cell migration. In addition, rescue assays reveal that reintroduction of USP21 wildtype other than the deubiquitinase‐deficient C221A mutant restores USP21 depletion‐induced attenuation in cell proliferation and migration, indicative of the requirement of the deubiquitinase activity. Collectively, these data indicate that USP21 is critically involved in cholangiocarcinoma tumorigenesis and may be an effective target for the treatment of cholangiocarcinoma. [ABSTRACT FROM AUTHOR]

[Display omitted] Endothelial cilia are microtubule-based hair-like protrusions in the lumen of blood vessels that function as fluid mechanosensors to regulate vascular hemodynamics. However, the functions of endothelial cilia in vascular development remain controversial. In this study, depletion of several key proteins responsible for ciliogenesis allows us to identify a cilium-independent role for intraflagellar transport 88 (IFT88) in mammalian angiogenesis. Disruption of primary cilia by heat shock does not affect the angiogenic process. However, depletion of IFT88 significantly inhibits angiogenesis both in vitro and in vivo. IFT88 mediates angiogenesis by regulating the migration, polarization, proliferation, and oriented division of vascular endothelial cells. Further mechanistic studies demonstrate that IFT88 interacts with γ-tubulin and microtubule plus-end tracking proteins and promotes microtubule stability. Our findings indicate that IFT88 regulates angiogenesis through its actions in microtubule-based cellular processes, independent of its role in ciliogenesis. [ABSTRACT FROM AUTHOR]

Targeted protein degradation (TPD) has emerged as a promising therapeutic approach with potential advantages over traditional occupancy-based inhibitors in terms of dosing, side effects and targeting "undruggable" proteins. Targeted degraders can theoretically bind any nook or cranny of targeted proteins to drive degradation. This offers convenience versus the small-molecule inhibitors that must function in a well-defined pocket. The degradation process depends mainly on two cell self-destruction mechanisms, namely the ubiquitin-proteasome system and the lysosomal degradation pathway. Various TPD strategies (e.g., proteolytic-targeting chimeras, molecular glues, lysosome-targeting chimeras, and autophagy-targeting chimeras) have been developed. These approaches hold great potential for targeting dysregulated proteins, potentially offering therapeutic benefits. In this article, we systematically review the mechanisms of various TPD strategies, potential applications to drug discovery, and recent advances. We also discuss the benefits and challenges associated with these TPD strategies, aiming to provide insight into the targeting of dysregulated proteins and facilitate their clinical applications. Targeted protein degradation (TPD) is an emerging therapeutic modality whereby small-molecule ligands are used to target disease causing proteins. By using the two main eukaryotic intracellular proteolytic systems (the ubiquitin-proteasome system and the lysosomal degradation pathway) involved in maintaining proteostasis to remove dysregulated proteins, TPD strategy is highly attractive given the potential to overcome resistance to existing small-molecule inhibitors and the alluring promise to target proteins that have historically been considered "undruggable", such as transcription factors. By now various TPD strategies have been developed, but many opportunities and challenges for further improvements remain. [Display omitted] • Targeted protein degradation (TPD) offers immense promise for eliminating disease causing proteins. • TPD can target substrates that have historically been considered "undruggable". • The mechanisms and potential applications of various TPD strategies are summarized. • Recent advances and future challenges pertaining to TPD development are discussed. [ABSTRACT FROM AUTHOR]

Background: Microtubules are the major cytoskeletal component in eukaryotes which are essential for a large spectrum of cellular activities. Monitoring the behavior of microtubules is helpful for a better understanding of the regulatory mechanism governing microtubule architecture and microtubule‐based activities. Here, we characterized the binding capability of a modified heptapeptide from tau to both tubulin and microtubules and sought to develop it as a fluorescent peptide for monitoring microtubules. Methods: To deliver the fluorescent peptide into the cells, a cell‐penetrating peptide was conjugated to the modified heptapeptide from tau and synthesized. The affinity of the modified heptapeptide was determined by microscale thermophoresis. The microtubule labeling ability was determined by adding the peptide into the polymerized microtubule solutions or cultured HeLa cells.; Results: Affinity determination revealed that the tau‐derived peptide specifically bound to tubulin. In addition, the peptide was able to label polymerized microtubules in solution, although no obvious microtubule filaments were observed clearly in living cells, probably due to the inadequate affinity. Conclusions: These results suggest that using a peptide‐based strategy for imaging microtubules might be plausible and attempts to improve its affinity is warranted in the future. [ABSTRACT FROM AUTHOR]

Mucociliary epithelium lining the upper and lower respiratory tract constitutes the first line of defense of the airway and lungs against inhaled pollutants and pathogens. The concerted beating of multiciliated cells drives mucociliary clearance. Abnormalities in both the structure and function of airway cilia have been implicated in obstructive lung diseases. Emerging evidence reveals a close correlation between lung diseases and environmental stimuli such as sulfur dioxide and tobacco particles. However, the underlying mechanism remains to be described. In this review, we emphasize the importance of airway cilia in mucociliary clearance and discuss how environmental pollutants affect the structure and function of airway cilia, thus shedding light on the function of airway cilia in preventing obstructive lung diseases and revealing the negative effects of environmental pollutants on human health. [ABSTRACT FROM AUTHOR]

Background: Exopolysaccharides with structural diversity have shown wide applications in biomaterial, food, and pharmaceutical industries. Herein, we isolated an endophytic strain, 14‐DS‐1, from the traditional medicinal plant Codonopsis pilosula to elucidate the characteristics and anti‐cancer activities of purified exopolysaccharides. Methods: HPLC and GC‐MS were conducted to purify and characterize the exopolysaccharides isolated from 14‐DS‐1. Quantitative RT‐PCR, cell migration assays, immunofluorescence staining, and flow cytometry analysis were conducted to investighate the biological activity of DSPS. Results: We demonstrated that exopolysaccharides isolated from 14‐DS‐1 (DSPS), which were predominately composed of six monosaccharides, showed anti‐cancer activities. Biological activity analysis revealed that exposure to DSPS induced macrophage activation and polarization by promoting the production of TNF‐α and nitric oxide. Further analysis revealed that DSPS treatment promoted macrophage infiltration, whereas cancer cell migration was suppressed. In addition, DSPS exposure led to S‐phase arrest and apoptosis in cancer cells. Immunofluorescence staining revealed that treatment with DSPS resulted in defects in spindle orientation and positioning. Conclusion: These findings thus suggest that DSPS may have promising potential in cancer therapy. [ABSTRACT FROM AUTHOR]

Background Treatments that prevent the motility of breast cancer cells and inhibit formation of new capillary vessels are urgently needed. FSTL1 is a secreted protein that has been implicated in maintaining the normal physiological function of the cardiovascular system, in addition to a variety of other biological functions. We investigated the role of FSTL1 in the proliferation and migration of breast cancer and vascular endothelial cells. Methods Human umbilical vein endothelial cells and human breast cancer BT-549 cells were used to test the effects of FSTL1 and the N-terminal domain of FSTL1. Immunofluorescence microscopy and 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide, transwell invasion, and wound healing assays were conducted. Results Different doses of the N-terminal fragment of FSTL1 ( FSTL- N) have variable effects on the migration of these cells. However, FSTL1 does not significantly affect tube formation in vitro from vascular endothelial cells. FSTL1- FL and FSTL1- N have modest effects on the invasion of breast cancer and vascular endothelial cells. Interestingly, FSTL1- FL, but not FSTL- N, modulates vascular endothelial cell polarization. Conclusion FSTL1 modestly affects the proliferation of breast cancer cells and vascular endothelial cells. Our findings improve our understanding of the functions of FSTL1 in breast cancer development and angiogenesis. [ABSTRACT FROM AUTHOR]

The tumor suppressor, cylindromatosis (CYLD), is a negative regulator of NF-κB signaling by removing lysine 63-linked ubiquitin chains from multiple NF-κB signaling components, including TRAF2, TRAF6, and NEMO. How CYLD itself is regulated, however, remains yet to be characterized. In this study, we present the first evidence that UV irradiation is able to induce CYLD translocation from the cytoplasm to microtubules and that the cytoskeleton-associated CYLD is subject to posttranslational modification and degradation in a proteasome-independent manner. By immunostaining, we found that CYLD displayed microtubule-like filament localization under ultraviolet (UV) irradiation. Further studies revealed that the cytoskeleton-associated CYLD underwent posttranslational modification, which in turn contributed to CYLD degradation in an unknown manner, distinct from proteasome-mediated degradation under normal conditions. Collectively, our data suggest that UV-induced CYLD degradation might serve as an underlying mechanism for UV-induced NF-κB pathway activation. [ABSTRACT FROM AUTHOR]

Polylysine (PLL) coated iron oxide nanoparticles (SPIONs) have potential in biomedical application. In the present work PEG coated SPIONs (PEG-SPIONs) with the particle size of 9.4±1.4 nm were synthesized by thermal decomposition of Fe(acac) 3 in PEG, and then coated with PLL (PLL/PEG-SPIONs). The PEG-SPIONs and PLL/PEG-SPIONs were superparamagnetic with the saturation magnetization of 53 and 44 emu/g, respectively. The hydrodynamic diameter of PEG-SPIONs in deionized water was 18.8 nm, which increased to 21.3−28.2 nm after mixing with different amount of PLL. The zeta potentials of PLL/PEG-SPIONs were −8.9 − −3.4 mV which were changing with time. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated that PLL was attached to the PEG-SPIONs. [ABSTRACT FROM AUTHOR]

Retinopathy of prematurity (ROP) is a leading cause of childhood blindness. However, the pathogenesis and molecular mechanisms underlying ROP remain elusive. Herein, using the oxygen-induced retinopathy (OIR) mouse model of ROP, we demonstrate that disassembly of photoreceptor connecting cilia is an early event in response to oxygen changes. Histone deacetylase 6 (HDAC6) is upregulated in the retina of OIR mice and accumulates in the transition zone of connecting cilia. We also show that in response to oxygen changes, apoptosis signal-regulating kinase 1 (ASK1) is activated and phosphorylates HDAC6, blocking its ubiquitination by von Hippel-Lindau and subsequent degradation by the proteasome. Moreover, depletion of HDAC6 or inhibition of the ASK1/HDAC6 axis protects mice from oxygen-change-induced pathological changes of photoreceptors. These findings reveal a critical role for ASK1/HDAC6-mediated connecting cilium disassembly in the OIR mouse model of ROP and suggest a potential value of ASK1/HDAC6-targeted agents for prevention of this disease. • HDAC6 upregulation drives connecting cilium disassembly in OIR mouse model of ROP • Oxygen changes activate ASK1 to phosphorylate HDAC6 in the OIR mouse retina • HDAC6 phosphorylation blocks its ubiquitination by VHL and proteasomal degradation • Inhibition of ASK1 or HDAC6 protects mice from oxygen-change-induced pathologies Using the oxygen-induced retinopathy (OIR) mouse model for retinopathy of prematurity (ROP), Ran et al. show that oxygen changes trigger ASK1 activation to phosphorylate HDAC6, blocking HDAC6 ubiquitination by VHL and proteasomal degradation. HDAC6 then drives photoreceptor connecting cilium disassembly, which they demonstrate is an early event in OIR pathogenesis. [ABSTRACT FROM AUTHOR]

Microtubule-binding proteins provide an alternative and vital pathway to the functional diversity of microtubules. Considerable work is still required to understand the complexities of microtubule-associated cellular processes and to identify novel microtubule-binding proteins. In this study, we identify Bcl2-associated athanogene cochaperone 6 (BAG6) as a novel microtubule-binding protein and reveal that it is crucial for primary ciliogenesis. By immunofluorescence we show that BAG6 largely colocalizes with intracellular microtubules and by co-immunoprecipitation we demonstated that it can interact with α-tubulin. Additionally, both the UBL and BAG domains of BAG6 are indispensable for its interaction with α-tubulin. Moreover, the assembly of primary cilia in RPE-1 cells is significantly inhibited upon the depletion of BAG6. Notably, BAG6 inhibition leads to an abnormal G0/G1 transition during the cell cycle. In addition, BAG6 colocalizes and interactes with the centrosomal protein γ-tubulin, suggesting that BAG6 might regulate primary ciliogenesis through its action in centrosomal function. Collectively, our findings suggest that BAG6 is a novel microtubule-bindng protein crucial for primary ciliogenesis. [ABSTRACT FROM AUTHOR]

End binding protein 1 (EB1) is a key regulator of microtubule dynamics that orchestrates hierarchical interaction networks at microtubule plus ends to control proper cell division. EB1 activity is known to be regulated by serine/threonine phosphorylation; however, how tyrosine phosphorylation affects EB1 activity remains poorly understood. In this study, we mapped the tyrosine phosphorylation pattern of EB1 in synchronized cells and identified two tyrosine phosphorylation sites (Y217 and Y247) in mitotic cells. Using phospho-deficient (Y/F) and phospho-mimic (Y/D) mutants, we revealed that Y247, but not Y217, is critical for astral microtubule stability. The Y247D mutant contributed to increased spindle angle, indicative of defects in spindle orientation. Time-lapse microscopy revealed that the Y247D mutant significantly delayed mitotic progression by increasing the duration times of prometaphase and metaphase. Structural analysis suggests that Y247 mutants lead to instability of the hydrophobic cavity in the EB homology (EBH) domain, thereby affecting its interactions with p150glued, a protein essential for Gαi/LGN/NuMA complex capture. These findings uncover a crucial role for EB1 phosphorylation in the regulation of mitotic spindle orientation and cell division. [ABSTRACT FROM AUTHOR]