βIII-Tubulin Gene Regulation in Health and Disease

Evaluation of the Neuroprotective Effect of Organic Selenium Compounds: An in Vitro Model of Alzheimer's Disease

Selenium (Se) is an essential trace element for human health and plays an important role in the development and maintenance of central nervous system functions. Se deficiency has been associated with cognitive decline and increased oxidative stress. The increase in oxidative stress is one of the hypotheses for the emergence and worsening of neurodegenerative diseases, such as Alzheimer's disease (AD). To investigate the neuroprotective effects of organic Se compounds in human neuroblastoma cells (SH-SY5Y) differentiated into cholinergic neurons-like. The SH-SY5Y cells were differentiated into cholinergic neuron-like with retinoic acid (RA) and brain-derived neurotrophic factor (BDNF). AD was mimicked exposing the cells to okadaic acid (OA) and beta-amyloid protein (Aβ). The neuroprotective effect of organic Se compounds, selenomethionine (SeMet) and Ebselen, was evaluated through cell viability tests, acetylcholinesterase and antioxidant enzyme activities, and detection of reactive oxygen species (ROS). None of the SeMet concentrations tested protected against the toxic effect of OA + Aβ. On the other hand, previous exposure to 0.1 and 1 µM Ebselen protected cells from the toxic effect of OA + Aβ. Cell differentiation induced by RA and BDNF exposure was effective, showing characteristics of neuronal cells, and pointing to a promising model of AD. Ebselen showed a protective effect, but more studies are needed to identify the mechanism of action.

Combination therapy using Cel-CSO/Taxol NPs for reversing drug resistance in breast cancer through inhibiting PI3K/AKT/NF-κB/HIF-1α pathway

The resistance of malignant tumors to multiple drugs is a significant obstacle in cancer treatment and prognosis. Accordingly, we synthesized a celastrol (Cel) prodrug (Cel-CSO) by conjugating chitosan oligosaccharides (CSO) to Cel for reversing Taxol resistance in chemotherapy, followed by self-assembly with Taxol into a novel nanoplatform of Cel-CSO/Taxol nanoparticles (termed NPs). NPs showed a suitable size (about 153 nm), excellent stability and prolonged release of Cel and Taxol in a manner that depended on both pH and time. NPs effectively inhibited the overexpression of multidrug resistance-related protein P-gp, hypoxia inducible factor-1α (HIF-1α), and triggered the MCF-7/Taxol cell apoptosis through inhibiting the PI3K/AKT/NF-κB/HIF-1α pathway. In tumor-bearing mice, NPs exhibited significant curative effects in inducing apoptosis of MCF-7/Taxol tumors which showed a low expression level of P-gp, microtubule-related proteins TUBB3 and Tau. The results indicated that NPs may be a promising strategy to overcome drug resistance caused by P-gp, which improve the antitumor effects in drug-resistant breast cancer.

Interaction Between Aging-Related Elastin-Derived Peptide (VGVAPG) and Sirtuin 2 and its Impact on Functions of Human Neuron Cells in an In Vitro Model

Elastin is a stable protein present in many tissues, including brain tissues, and is one of the most long-life proteins with a half-life of approximately 70 years. The peptide with a Val-Gly-Val-Ala-Pro-Gly (VGVAPG) amino acid sequence is released during elastin decay, which correlates with aging-related neurodegeneration. A recent study has shown enhanced protein expression of Sirtuin 2 (SIRT2 - one of the redox homeostatic factors) in aged rodent brains, while the correlation between VGVAPG and SIRT2 has never been evaluated so far. Therefore, the study aimed to determine the impact of the VGVAPG hexapeptide on SIRT2 and neuronal functions in differentiated SH-SY5Y cells at the gene and protein expression levels. The present results showed that VGVAPG caused a 52.69% decrease in the level of reactive oxygen species (ROS), as in the case of neurons treated with AGK2 (Sirtuin 2 inhibitor) after 24h and 48h. Furthermore, a decrease in superoxide dismutase (SOD) activity was observed. The SIRT2 gene expression was found to fluctuate after 6h and 24h as a result of the exposure to the VGVAPG peptide. In turn, a decrease in the PPARγ, P53, SOD2, and CAT mRNA expression was shown in VGVAPG-treated cells. Additionally, an increase in the Sirtuin 2 protein expression was recorded after 24h and 48h in the VGVAPG peptide-treated neurons. Last but not least, the decrease in the level of acetylation of α-tubulin after the hexapeptide treatment was correlated with shortening of neurites, which may indicate the destabilization of the microtubule and ROS-independent induction of neurodegeneration.

Alpha-Synuclein Gene Alterations Modulate Tyrosine Hydroxylase in Human iPSC-Derived Neurons in a Parkinson's Disease Animal Model

Parkinson's disease (PD) caused by SNCA gene triplication (3XSNCA) leads to early onset, rapid progression, and often dementia. Understanding the impact of 3XSNCA and its absence is crucial. This study investigates the differentiation of human induced pluripotent stem cell (hiPSC)-derived floor-plate progenitors into dopaminergic neurons. Three different genotypes were evaluated in this study: patient-derived hiPSCs with 3XSNCA, a gene-edited isogenic line with a frame-shift mutation on all SNCA alleles (SNCA 4KO), and a normal wild-type control. Our aim was to assess how the substantia nigra pars compacta (SNpc) microenvironment, damaged by 6-hydroxydopamine (6-OHDA), influences tyrosine hydroxylase-positive (Th+) neuron differentiation in these genetic variations. This study confirms successful in vitro differentiation into neuronal lineage in all cell lines. However, the SNCA 4KO line showed unusual LIM homeobox transcription factor 1 alpha (Lmx1a) extranuclear distribution. Crucially, both 3XSNCA and SNCA 4KO lines had reduced Th+ neuron expression, despite initial successful neuronal differentiation after two months post-transplantation. This indicates that while the SNpc environment supports early neuronal survival, SNCA gene alterations-either amplification or knock-out-negatively impact Th+ dopaminergic neuron maturation. These findings highlight SNCA's critical role in PD and underscore the value of hiPSC models in studying neurodegenerative diseases.

Neuronal differentiation requires BRAT1 complex to remove REST from chromatin

Repressor element-1 silencing transcription factor (REST) is required for the formation of mature neurons. REST dysregulation underlies a key mechanism of neurodegeneration associated with neurological disorders. However, the mechanisms leading to alterations of REST-mediated silencing of key neurogenesis genes are not known. Here, we show that BRCA1 Associated ATM Activator 1 (BRAT1), a gene linked to neurodegenerative diseases, is required for the activation of REST-responsive genes during neuronal differentiation. We find that INTS11 and INTS9 subunits of Integrator complex interact with BRAT1 as a distinct trimeric complex to activate critical neuronal genes during differentiation. BRAT1 depletion results in persistence of REST residence on critical neuronal genes disrupting the differentiation of NT2 cells into astrocytes and neuronal cells. We identified BRAT1 and INTS11 co-occupying the promoter region of these genes and pinpoint a role for BRAT1 in recruiting INTS11 to their promoters. Disease-causing mutations in BRAT1 diminish its association with INTS11/INTS9, linking the manifestation of disease phenotypes with a defect in transcriptional activation of key neuronal genes by BRAT1/INTS11/INTS9 complex. Finally, loss of Brat1 in mouse embryonic stem cells leads to a defect in neuronal differentiation assay. Importantly, while reconstitution with wild-type BRAT1 restores neuronal differentiation, the addition of a BRAT1 mutant is unable to associate with INTS11/INTS9 and fails to rescue the neuronal phenotype. Taken together, our study highlights the importance of BRAT1 association with INTS11 and INTS9 in the development of the nervous system.

dsRNAi-mediated silencing of PIAS2beta specifically kills anaplastic carcinomas by mitotic catastrophe

The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an undifferentiated cancer with high mortality. We show here that depletion of the PIAS2 beta isoform with a transcribed double-stranded RNA-directed RNA interference (PIAS2b-dsRNAi) specifically inhibits growth of ATC cell lines and patient primary cultures in vitro and of orthotopic patient-derived xenografts (oPDX) in vivo. Critically, PIAS2b-dsRNAi does not affect growth of normal or non-anaplastic thyroid tumor cultures (differentiated carcinoma, benign lesions) or cell lines. PIAS2b-dsRNAi also has an anti-cancer effect on other anaplastic human cancers (pancreas, lung, and gastric). Mechanistically, PIAS2b is required for proper mitotic spindle and centrosome assembly, and it is a dosage-sensitive protein in ATC. PIAS2b depletion promotes mitotic catastrophe at prophase. High-throughput proteomics reveals the proteasome (PSMC5) and spindle cytoskeleton (TUBB3) to be direct targets of PIAS2b SUMOylation at mitotic initiation. These results identify PIAS2b-dsRNAi as a promising therapy for ATC and other aggressive anaplastic carcinomas.

The nociceptive activity of peripheral sensory neurons is modulated by the neuronal membrane proteasome

Proteasomes are critical for peripheral nervous system (PNS) function. Here, we investigate mammalian PNS proteasomes and reveal the presence of the neuronal membrane proteasome (NMP). We show that specific inhibition of the NMP on distal nerve fibers innervating the mouse hind paw leads to reduction in mechanical and pain sensitivity. Through investigating PNS NMPs, we demonstrate their presence on the somata and proximal and distal axons of a subset of dorsal root ganglion (DRG) neurons. Single-cell RNA sequencing experiments reveal that the NMP-expressing DRGs are primarily MrgprA3+ and Cysltr2+. NMP inhibition in DRG cultures leads to cell-autonomous and non-cell-autonomous changes in Ca2+ signaling induced by KCl depolarization, αβ-meATP, or the pruritogen histamine. Taken together, these data support a model whereby NMPs are expressed on a subset of somatosensory DRGs to modulate signaling between neurons of distinct sensory modalities and indicate the NMP as a potential target for controlling pain.

Moderate Physical Activity Increases the Expression of ADNP in Rat Brain

Activity-dependent neuroprotective protein (ADNP) is a neuroprotective protein essential for embryonic development, proper brain development, and neuronal plasticity. Its mutation causes the autism-like ADNP syndrome (also called the Helsmoortel-Van der Aa syndrome), characterized by neural developmental disorders and motor dysfunctions. Similar to the ADNP syndrome, the ADNP haploinsufficient mouse shows low synapse density, leading to motor and cognitive ability delays. Moderate physical activity (PA) has several neuroprotective and cognitive benefits, promoting neuronal survival, differentiation, neurogenesis, and plasticity. Until now, no study has investigated the effect of moderate exercise on ADNP expression and distribution in the rat brain. The aim of the current investigation was to study the effects of moderate exercise on the ADNP expression and neuronal activation measured by the microtubule protein β-Tubulin III. In pursuit of this objective, twenty-four rats were selected and evenly distributed into two categories: sedentary control rats and rats exposed to moderate physical activity on a treadmill over a span of 12 weeks. Our results showed that moderate PA increases the expression of ADNP and β-Tubulin III in the dentate gyrus (DG) hippocampal region and cerebellum. Moreover, we found a co-localization of ADNP and β-Tubulin III in both DG and cerebellum, suggesting a direct association of ADNP with adult neuronal activation induced by moderate PA.

Pulsating Extremely Low-Frequency Electromagnetic Fields Influence Differentiation of Mouse Neural Stem Cells towards Astrocyte-like Phenotypes: In Vitro Pilot Study

Even though electromagnetic fields have been reported to assist endogenous neurogenesis, little is known about the exact mechanisms of their action. In this pilot study, we investigated the effects of pulsating extremely low-frequency electromagnetic fields on neural stem cell differentiation towards specific phenotypes, such as neurons and astrocytes. Neural stem cells isolated from the telencephalic wall of B6(Cg)-Tyrc-2J/J mouse embryos (E14.5) were randomly divided into three experimental groups and three controls. Electromagnetic field application setup included a solenoid placed within an incubator. Each of the experimental groups was exposed to 50Hz ELF-EMFs of varied strengths for 1 h. The expression of each marker (NES, GFAP, β-3 tubulin) was then assessed by immunocytochemistry. The application of high-strength ELF-EMF significantly increased and low-strength ELF-EMF decreased the expression of GFAP. A similar pattern was observed for β-3 tubulin, with high-strength ELF-EMFs significantly increasing the immunoreactivity of β-3 tubulin and medium- and low-strength ELF-EMFs decreasing it. Changes in NES expression were observed for medium-strength ELF-EMFs, with a demonstrated significant upregulation. This suggests that, even though ELF-EMFs appear to inhibit or promote the differentiation of neural stem cells into neurons or astrocytes, this effect highly depends on the strength and frequency of the fields as well as the duration of their application. While numerous studies have demonstrated the capacity of EMFs to guide the differentiation of NSCs into neuron-like cells or β-3 tubulin+ neurons, this is the first study to suggest that ELF-EMFs may also steer NSC differentiation towards astrocyte-like phenotypes.

Proteomic Assessment of SKBR3/HER2+ Breast Cancer Cellular Response to Lapatinib and Investigational Ipatasertib Kinase Inhibitors

Modern cancer treatment approaches aim at achieving cancer remission by using targeted and personalized therapies, as well as harnessing the power of the immune system to recognize and eliminate the cancer cells. To overcome a relatively short-lived response due to the development of resistance to the administered drugs, combination therapies have been pursued, as well. To expand the outlook of combination therapies, the objective of this study was to use high-throughput data generation technologies such as mass spectrometry and proteomics to investigate the response of HER2+ breast cancer cells to a mixture of two kinase inhibitors that has not been adopted yet as a standard treatment regime. The broader landscape of biological processes that are affected by inhibiting two major pathways that sustain the growth and survival of cancer cells, i.e., EGFR and PI3K/AKT, was investigated by treating SKBR3/HER2+ breast cancer cells with Lapatinib or a mixture of Lapatinib/Ipatasertib small molecule drugs. Changes in protein expression and/or activity in response to the drug treatments were assessed by using two complementary quantitative proteomic approaches based on peak area and peptide spectrum match measurements. Over 900 proteins matched by three unique peptide sequences (FDR<0.05) were affected by the exposure of cells to the drugs. The work corroborated the anti-proliferative activity of Lapatinib and Ipatasertib, and, in addition to cell cycle and growth arrest processes enabled the identification of several multi-functional proteins with roles in cancer-supportive hallmark processes. Among these, immune response, adhesion and migration emerged as particularly relevant to the ability to effectively suppress the proliferation and dissemination of cancer cells. The supplementation of Lapatinib with Ipatasertib further affected the expression or activity of additional transcription factors and proteins involved in gene expression, trafficking, DNA repair, and development of multidrug resistance. Furthermore, over fifty of the affected proteins represented approved or investigational targets in the DrugBank database, which through their protein-protein interaction networks can inform the selection of effective therapeutic partners. Altogether, our findings exposed a broad plethora of yet untapped opportunities that can be further explored for enhancing the anti-cancer effects of each drug as well as of many other multi-drug therapies that target the EGFR/ERBB2 and PI3K/AKT pathways. The data are available via ProteomeXchange with identifier PXD051094.

Identification and validation of LINC01322 as a potential prognostic biomarker and oncogene promoting tumor progression in lung adenocarcinoma

Our study identified a novel long noncoding RNA, LINC01322, that acts as an oncogene in lung adenocarcinoma progression. Cytoplasmic and nuclear RNA purification assays indicated that LINC01322 was localized in the cytoplasm and nucleus. Gene set enrichment analysis revealed the involvement of LINC01322 in the regulation of cell proliferation, migration, and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway. LINC01322 may promote lung adenocarcinoma proliferation and migration through the Janus kinase/signal transducer and activator of transcription signaling pathway. In vitro experiments demonstrated that the knockdown of LINC01322 significantly suppressed lung adenocarcinoma cell proliferation, migration, and activation of the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway, whereas overexpression had the opposite effects. Inhibition of the Janus kinase 2/signal transducer and activator of transcription 3 pathway activity partially reversed the enhancement of cell proliferation and migration caused by LINC01322 overexpression. In vivo experiments further verified the oncogene role of LINC01322. Altogether, our findings suggest that LINC01322 promotes lung adenocarcinoma progression by activating the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway and that it could be a therapeutic target.

Role of MARK2 in the nervous system and cancer

Microtubule-Affinity Regulating Kinase 2 (MARK2), a member of the serine/threonine protein kinase family, phosphorylates microtubule-associated proteins, playing a crucial role in cancer and neurodegenerative diseases. This kinase regulates multiple signaling pathways, including the WNT, PI3K/AKT/mTOR (PAM), and NF-κB pathways, potentially linking it to cancer and the nervous system. As a crucial regulator of the PI3K/AKT/mTOR pathway, the loss of MARK2 inhibits the growth and metastasis of cancer cells. MARK2 is involved in the excessive phosphorylation of tau, thus influencing neurodegeneration. Therefore, MARK2 emerges as a promising drug target for the treatment of cancer and neurodegenerative diseases. Despite its significance, the development of inhibitors for MARK2 remains limited. In this review, we aim to present detailed information on the structural features of MARK2 and its role in various signaling pathways associated with cancer and neurodegenerative diseases. Additionally, we further characterize the therapeutic potential of MARK2 in neurodegenerative diseases and cancer, and hope to facilitate basic research on MARK2 and the development of inhibitors targeting MARK2.

Assessment of poly(hexamethylenebicyanoguanide-hexamethylenediamine) hydrochloride-induced developmental neurotoxicity via oxidative stress mechanism: Integrative approaches with neuronal cells and zebrafish

Poly(hexamethylenebicyanoguanide-hexamethylenediamine) hydrochloride (PHMB) is a biocide with a broad spectrum of antibacterial activity. Its use as a disinfectant and preservative in consumer products results in human exposure to PHMB. Toxicity studies on PHMB mainly focus on systemic toxicity or skin irritation; however, its effects on developmental neurotoxicity (DNT) and the underlying mechanisms are poorly understood. In this study, the DNT effects of PHMB were evaluated using IMR-32 and SH-SY5Y cell lines and zebrafish. In both cell lines, PHMB concentrations ≥ 10 µM reduced neurite outgrowth, and cytotoxicity was observed at concentrations up to 40 µM. PHMB regulated expression of neurodevelopmental genes and induced reactive oxygen species (ROS) production and mitochondrial dysfunction. Treatment with N-acetylcysteine reversed the toxic effects of PHMB. Toxicity tests on zebrafish embryos showed that PHMB reduced viability and heart rate and caused irregular hatching. PHMB concentrations of 1-4 µM reduced the width of the brain and spinal cord of transgenic zebrafish and attenuated myelination processes. Furthermore, PHMB modulated expression of neurodevelopmental genes in zebrafish and induced ROS accumulation. These results suggested that PHMB exerted DNT effects in vitro and in vivo through a ROS-dependent mechanism, highlighting the risk of PHMB exposure.

Comparative evaluation of divergent concoction of NGF, BDNF, EGF, and FGF growth factor's role in enhancing neuronal differentiation of adipose-derived mesenchymal stem cells

MSCs (Mesenchymal Stem Cells) can differentiate into various lineages, including neurons and glial cells. In the past few decades, MSCs have been well explored in the context of neuronal differentiation and have been reported to have the immense potential to form distinct kinds of neurons. The distinguishing features of MSCs make them among the most desired cell sources for stem cell therapy. This study involved the trans-differentiation of Adipose-derived human Mesenchymal Stem Cells (ADMSCs) into neurons. The protocol employs a cocktail of chemical inducers in different combinations, including Brain-derived neurotrophic factor (BDNF), epidermal growth factor (EGF), and Nerve growth factor (NGF) Fibroblastic growth factor (FGF), in induction media. Both types have been successfully differentiated into neurons, confirmed by morphological aspects and the presence of neural-specific markers through RT-PCR (Reverse transcription polymerase chain reaction) studies and immunocytochemistry assay. They have shown excellent morphology with long neurites, synaptic connections, and essential neural markers to validate their identity. The results may significantly contribute to cell replacement therapy for neurological disorders.

Novel Brain-Penetrant, Small-Molecule Tubulin Destabilizers for the Treatment of Glioblastoma

Glioblastoma (GB) is the most lethal brain cancer in adults, with a 5-year survival rate of 5%. The standard of care for GB includes maximally safe surgical resection, radiation, and temozolomide (TMZ) therapy, but tumor recurrence is inevitable in most GB patients. Here, we describe the development of a blood-brain barrier (BBB)-penetrant tubulin destabilizer, RGN3067, for the treatment of GB. RGN3067 shows good oral bioavailability and achieves high concentrations in rodent brains after oral dosing (Cmax of 7807 ng/mL (20 μM), Tmax at 2 h). RGN3067 binds the colchicine binding site of tubulin and inhibits tubulin polymerization. The compound also suppresses the proliferation of the GB cell lines U87 and LN-18, with IC50s of 117 and 560 nM, respectively. In four patient-derived GB cell lines, the IC50 values for RGN3067 range from 148 to 616 nM. Finally, in a patient-derived xenograft (PDX) mouse model, RGN3067 reduces the rate of tumor growth compared to the control. Collectively, we show that RGN3067 is a BBB-penetrant small molecule that shows in vitro and in vivo efficacy and that its design addresses many of the physicochemical properties that prevent the use of microtubule destabilizers as treatments for GB and other brain cancers.

Engineering Neurotoxin-Functionalized Exosomes for Targeted Delivery to the Peripheral Nervous System

The administration of therapeutics to peripheral nerve tissue is challenging due to the complexities of peripheral neuroanatomy and the limitations imposed by the blood-nerve barrier (BNB). Therefore, there is a pressing need to enhance delivery effectiveness and implement targeted delivery methods. Recently, erythrocyte-derived exosomes (Exos) have gained widespread attention as biocompatible vehicles for therapeutics in clinical applications. However, engineering targeted Exos for the peripheral nervous system (PNS) is still challenging. This study aims to develop a targeted Exo delivery system specifically designed for presynaptic terminals of peripheral nerve tissue. The clostridium neurotoxin, tetanus toxin-C fragment (TTC), was tethered to the surface of red blood cell (RBC)-derived Exos via a facile and efficient bio-orthogonal click chemistry method without a catalyst. Additionally, Cyanine5 (Cy5), a reactive fluorescent tag, was also conjugated to track Exo movement in both in vitro and in vivo models. Subsequently, Neuro-2a, a mouse neuronal cell line, was treated with dye-labeled Exos with/without TTC in vitro, and the results indicated that TTC-Exos exhibited more efficient accumulation along the soma and axonal circumference, compared to their unmodified counterparts. Further investigation, using a mouse model, revealed that within 72 h of intramuscular administration, engineered TTC-Exos were successfully transported into the neuromuscular junction and sciatic nerve tissues. These results indicated that TTC played a crucial role in the Exo delivery system, improving the affinity to peripheral nerves. These promising results underscore the potential of using targeted Exo carriers to deliver therapeutics for treating peripheral neuropathies.

Neural Marker Expression in Adipose-Derived Stem Cells Grown in PEG-Based 3D Matrix Is Enhanced in the Presence of B27 and CultureOne Supplements

Adipose-derived stem cells (ADSCs) have incredible potential as an avenue to better understand and treat neurological disorders. While they have been successfully differentiated into neural stem cells and neurons, most such protocols involve 2D environments, which are not representative of in vivo physiology. In this study, human ADSCs were cultured in 1.1 kPa polyethylene-glycol 3D hydrogels for 10 days with B27, CultureOne (C1), and N2 neural supplements to examine the neural differentiation potential of ADSCs using both chemical and mechanical cues. Following treatment, cell viability, proliferation, morphology, and proteome changes were assessed. Results showed that cell viability was maintained during treatments, and while cells continued to proliferate over time, proliferation slowed down. Morphological changes between 3D untreated cells and treated cells were not observed. However, they were observed among 2D treatments, which exhibited cellular elongation and co-alignment. Proteome analysis showed changes consistent with early neural differentiation for B27 and C1 but not N2. No significant changes were detected using immunocytochemistry, potentially indicating a greater differentiation period was required. In conclusion, treatment of 3D-cultured ADSCs in PEG-based hydrogels with B27 and C1 further enhances neural marker expression, however, this was not observed using supplementation with N2.

The effect of immunomodulatory drugs on aortic stenosis: a Mendelian randomisation analysis

There are currently no approved pharmacological treatment options for aortic stenosis (AS), and there are limited identified drug targets for this chronic condition. It remains unclear whether inflammation plays a role in AS pathogenesis and whether immunomodulation could become a therapeutic target. We evaluated the potentially causal association between inflammation and AS by investigating the genetically proxied effects of tocilizumab (IL6 receptor, IL6R, inhibitor), canakinumab (IL1β inhibitor) and colchicine (β-tubulin inhibitor) through a Mendelian randomisation (MR) approach. Genetic proxies for these drugs were identified as single nucleotide polymorphisms (SNPs) in the gene, enhancer or promoter regions of IL6R, IL1β or β-tubulin gene isoforms, respectively, that were significantly associated with serum C-reactive protein (CRP) in a large European genome-wide association study (GWAS; 575,531 participants). These were paired with summary statistics from a large GWAS of AS in European patients (653,867 participants) to then perform primary inverse-variance weighted random effect and sensitivity MR analyses for each exposure. This analysis showed that genetically proxied tocilizumab was associated with reduced risk of AS (OR 0.56, 95% CI 0.45-0.70 per unit decrease in genetically predicted log-transformed CRP). Genetically proxied canakinumab was not associated with risk of AS (OR 0.80, 95% CI 0.51-1.26), and only one suitable SNP was identified to proxy the effect of colchicine (OR 34.37, 95% CI 1.99-592.89). The finding that genetically proxied tocilizumab was associated with reduced risk of AS is concordant with an inflammatory hypothesis of AS pathogenesis. Inhibition of IL6R may be a promising therapeutic target for AS management.

Tunable hydrogel viscoelasticity modulates human neural maturation

Human-induced pluripotent stem cells (hiPSCs) have emerged as a promising in vitro model system for studying neurodevelopment. However, current models remain limited in their ability to incorporate tunable biomechanical signaling cues imparted by the extracellular matrix (ECM). The native brain ECM is viscoelastic and stress-relaxing, exhibiting a time-dependent response to an applied force. To recapitulate the remodelability of the neural ECM, we developed a family of protein-engineered hydrogels that exhibit tunable stress relaxation rates. hiPSC-derived neural progenitor cells (NPCs) encapsulated within these gels underwent relaxation rate-dependent maturation. Specifically, NPCs within hydrogels with faster stress relaxation rates extended longer, more complex neuritic projections, exhibited decreased metabolic activity, and expressed higher levels of genes associated with neural maturation. By inhibiting actin polymerization, we observed decreased neuritic projections and a concomitant decrease in neural maturation gene expression. Together, these results suggest that microenvironmental viscoelasticity is sufficient to bias human NPC maturation.

Taxol acts differently on different tubulin isotypes

Taxol is a small molecule effector that allosterically locks tubulin into the microtubule lattice. We show here that taxol has different effects on different single-isotype microtubule lattices. Using in vitro reconstitution, we demonstrate that single-isotype α1β4 GDP-tubulin lattices are stabilised and expanded by 10 µM taxol, as reported by accelerated microtubule gliding in kinesin motility assays, whereas single-isotype α1β3 GDP-tubulin lattices are stabilised but not expanded. This isotype-specific action of taxol drives gliding of segmented-isotype GDP-taxol microtubules along convoluted, sinusoidal paths, because their expanded α1β4 segments try to glide faster than their compacted α1β3 segments. In GMPCPP, single-isotype α1β3 and α1β4 lattices both show accelerated gliding, indicating that both can in principle be driven to expand. We therefore propose that taxol-induced lattice expansion requires a higher taxol occupancy than taxol-induced stabilisation, and that higher taxol occupancies are accessible to α1β4 but not α1β3 single-isotype lattices.

OSGIN1 is a novel TUBB3 regulator that promotes tumor progression and gefitinib resistance in non-small cell lung cancer

BACKGROUND

Oxidative stress induced growth inhibitor 1 (OSGIN1) regulates cell death. The role and underlying molecular mechanism of OSGIN1 in non-small cell lung cancer (NSCLC) are uncharacterized.

METHODS

OSGIN1 expression in NSCLC samples was detected using immunohistochemistry and Western blotting. Growth of NSCLC cells and gefitinib-resistant cells expressing OSGIN1 or TUBB3 knockdown was determined by MTT, soft agar, and foci formation assays. The effect of OSGIN1 knockdown on in vivo tumor growth was assessed using NSCLC patient-derived xenograft models and gefitinib-resistant patient-derived xenograft models. Potentially interacting protein partners of OSGIN1 were identified using IP-MS/MS, immunoprecipitation, PLA, and Western blotting assays. Microtubule dynamics were explored by tubulin polymerization assay and immunofluorescence. Differential expression of signaling molecules in OSGIN1 knockdown cells was investigated using phospho-proteomics, KEGG analysis, and Western blotting.

RESULTS

We found that OSGIN1 is highly expressed in NSCLC tissues and is positively correlated with low survival rates and tumor size in lung cancer patients. OSGIN1 knockdown inhibited NSCLC cell growth and patient-derived NSCLC tumor growth in vivo. Knockdown of OSGIN1 strongly increased tubulin polymerization and re-established gefitinib sensitivity in vitro and in vivo. Additionally, knockdown of TUBB3 strongly inhibited NSCLC cell proliferation. Mechanistically, we found that OSGIN1 enhances DYRK1A-mediated TUBB3 phosphorylation, which is critical for inducing tubulin depolymerization. The results of phospho-proteomics and ontology analysis indicated that knockdown of OSGIN1 led to reduced propagation of the MKK3/6-p38 signaling axis.

CONCLUSIONS

We propose that OSGIN1 modulates microtubule dynamics by enhancing DYRK1A-mediated phosphorylation of TUBB3 at serine 172. Moreover, elevated OSGIN1 expression promotes NSCLC tumor growth and gefitinib resistance through the MKK3/6-p38 signaling pathway. Our findings unveil a new mechanism of OSGIN1 and provide a promising therapeutic target for NSCLC treatment in the clinic.

Cytoprotective, Cytotoxic and Cytostatic Roles of Autophagy in Response to BET Inhibitors

The bromodomain and extra-terminal domain (BET) family inhibitors are small molecules that target the dysregulated epigenetic readers, BRD2, BRD3, BRD4 and BRDT, at various transcription-related sites, including super-enhancers. BET inhibitors are currently under investigation both in pre-clinical cell culture and tumor-bearing animal models, as well as in clinical trials. However, as is the case with other chemotherapeutic modalities, the development of resistance is likely to constrain the therapeutic benefits of this strategy. One tumor cell survival mechanism that has been studied for decades is autophagy. Although four different functions of autophagy have been identified in the literature (cytoprotective, cytotoxic, cytostatic and non-protective), primarily the cytoprotective and cytotoxic forms appear to function in different experimental models exposed to BET inhibitors (with some evidence for the cytostatic form). This review provides an overview of the cytoprotective, cytotoxic and cytostatic functions of autophagy in response to BET inhibitors in various tumor models. Our aim is to determine whether autophagy targeting or modulation could represent an effective therapeutic strategy to enhance the response to these modalities and also potentially overcome resistance to BET inhibition.

BRAT1 associates with INTS11/INTS9 heterodimer to regulate key neurodevelopmental genes

Integrator is a multi-subunits protein complex involved in regulation of gene expression. Several Integrator subunits have been found to be mutated in human neurodevelopmental disorders, suggesting a key role for the complex in the development of nervous system. BRAT1 is similarly linked with neurodegenerative diseases and neurodevelopmental disorders such as rigidity and multifocal-seizure syndrome. Here, we show that INTS11 and INTS9 subunits of Integrator complex interact with BRAT1 and form a trimeric complex in human HEK293T cells as well as in pluripotent human embryonal carcinoma cell line (NT2). We find that BRAT1 depletion disrupts the differentiation of NT2 cells into astrocytes and neural cells. Loss of BRAT1 results in inability to activate many neuronal genes that are targets of REST, a neuronal silencer. We identified BRAT1 and INTS11 co-occupying the promoter region of these genes and pinpoint a role for BRAT1 in recruiting INTS11 to their promoters. Disease-causing mutations in BRAT1 diminish its association with INTS11/INTS9, linking the manifestation of disease phenotypes with a defect in transcriptional activation of key neuronal genes by BRAT1/INTS11/INTS9 complex.

Highlights

Integrator subunits INTS9 and INTS11 tightly interact with BRAT1 Depletion of BRAT1 causes a dramatic delay in human neural differentiation BRAT1 and INTS11 module targets the promoters of neural marker genes and co-regulates their expression. The recruitment of INTS11 to these sites is BRAT1-dependent. Pathogenic E522K mutation in BRAT1 disrupts its interaction with INTS11/INTS9 heterodimer.

Adipose-Derived Stem Cells Spontaneously Express Neural Markers When Grown in a PEG-Based 3D Matrix

Neurological diseases are among the leading causes of disability and death worldwide and remain difficult to treat. Tissue engineering offers avenues to test potential treatments; however, the development of biologically accurate models of brain tissues remains challenging. Given their neurogenic potential and availability, adipose-derived stem cells (ADSCs) are of interest for creating neural models. While progress has been made in differentiating ADSCs into neural cells, their differentiation in 3D environments, which are more representative of the in vivo physiological conditions of the nervous system, is crucial. This can be achieved by modulating the 3D matrix composition and stiffness. Human ADSCs were cultured for 14 days in a 1.1 kPa polyethylene glycol-based 3D hydrogel matrix to assess effects on cell morphology, cell viability, proteome changes and spontaneous neural differentiation. Results showed that cells continued to proliferate over the 14-day period and presented a different morphology to 2D cultures, with the cells elongating and aligning with one another. The proteome analysis revealed 439 proteins changed in abundance by >1.5 fold. Cyclic nucleotide 3'-phosphodiesterase (CNPase) markers were identified using immunocytochemistry and confirmed with proteomics. Findings indicate that ADSCs spontaneously increase neural marker expression when grown in an environment with similar mechanical properties to the central nervous system.

Targeting hormone-resistant breast cancer cells with docetaxel: a look inside the resistance

Aim: The study aims to analyze the effect of long-term incubation of ERα-positive MCF7 breast cancer cells with 4-hydroxytamoxifen (HT) on their sensitivity to tubulin polymerization inhibitor docetaxel. Methods: The analysis of cell viability was performed by the MTT method. The expression of signaling proteins was analyzed by immunoblotting and flow cytometry. ERα activity was evaluated by gene reporter assay. To establish hormone-resistant subline MCF7, breast cancer cells were treated with 4-hydroxytamoxifen for 12 months. Results: The developed MCF7/HT subline has lost sensitivity to 4-hydroxytamoxifen, and the resistance index was 2. Increased Akt activity (2.2-fold) and decreased ERα expression (1.5-fold) were revealed in MCF7/HT cells. The activity of the estrogen receptor α was reduced (1.5-fold) in MCF7/HT. Evaluation of class III β-tubulin expression (TUBB3), a marker associated with metastasis, revealed the following trends: higher expression of TUBB3 was detected in triple-negative breast cancer MDA-MB-231 cells compared to hormone-responsive MCF7 cells (P < 0.05). The lowest expression of TUBB3 was found in hormone-resistant MCF7/HT cells (MCF7/HT < MCF7 < MDA-MB-231, approximately 1:2:4). High TUBB3 expression strongly correlated with docetaxel resistance: IC₅₀ value of docetaxel for MDA-MB-231 cells was greater than that for MCF7 cells, whereas resistant MCF7/HT cells were the most sensitive to the drug. The accumulation of cleaved PARP (a 1.6-fold increase) and Bcl-2 downregulation (1.8-fold) were more pronounced in docetaxel-treated resistant cells (P < 0.05). The expression of cyclin D1 decreased (2.8-fold) only in resistant cells after 4 nM docetaxel treatment, while this marker was unchanged in parental MCF7 breast cancer cells. Conclusion: Further development of taxane-based chemotherapy for hormone-resistant cancer looks highly promising, especially for cancers with low TUBB3 expression.

A novel liver zonation phenotype-associated molecular classification of hepatocellular carcinoma

Background

Liver zonation is a unique phenomenon in which the liver exhibits distinct functions among hepatocytes along the radial axis of the lobule. This phenomenon can cause the sectionalized initiation of several liver diseases, including hepatocellular carcinoma (HCC). However, few studies have explored the zonation features of HCC.

Methods

Four single-cell RNA sequencing datasets were used to identify hepatocyte-specific zonation markers. Integrative analysis was then performed with a training RNA-seq cohort (616 HCC samples) and an external validating microarray cohort (285 HCC samples) from the International Cancer Genome Consortium, The Cancer Genome Atlas, Gene Expression Omnibus, and EMBL's European Bioinformatics Institute for clustering using non-negative matrix factorization consensus clustering based on zonation genes. Afterward, we evaluated the prognostic value, clinical characteristics, transcriptome and mutation features, immune infiltration, and immunotherapy response of the HCC subclasses.

Results

A total of 94 human hepatocyte-specific zonation markers (39 central markers and 55 portal markers) were identified for the first time. Subsequently, three subgroups of HCC, namely Cluster1, Cluster2, and Cluster3 were identified. Cluster1 exhibited a non-zonational-like signature with the worst prognosis. Cluster2 was intensively associated with a central-like signature and exhibited low immune infiltration and sensitivity toward immune blockade therapy. Cluster3 was intensively correlated with a portal-like signature with the best prognosis. Finally, we identified candidate therapeutic targets and agents for Cluster1 HCC samples.

Conclusion

The current study established a novel HCC classification based on liver zonation signature. By classifying HCC into three clusters with non-zonational-like (Cluster1), central-like (Cluster2), and portal-like (Cluster3) features, this study provided new perspectives on the heterogeneity of HCC and shed new light on delivering precision medicine for HCC patients.