Class III beta-tubulin in human development and cancer

Unraveling the interplay of kinesin-1, tau, and microtubules in neurodegeneration associated with Alzheimer's disease

Alzheimer's disease (AD) is marked by the gradual and age-related deterioration of nerve cells in the central nervous system. The histopathological features observed in the brain affected by AD are the aberrant buildup of extracellular and intracellular amyloid-β and the formation of neurofibrillary tangles consisting of hyperphosphorylated tau protein. Axonal transport is a fundamental process for cargo movement along axons and relies on molecular motors like kinesins and dyneins. Kinesin's responsibility for transporting crucial cargo within neurons implicates its dysfunction in the impaired axonal transport observed in AD. Impaired axonal transport and dysfunction of molecular motor proteins, along with dysregulated signaling pathways, contribute significantly to synaptic impairment and cognitive decline in AD. Dysregulation in tau, a microtubule-associated protein, emerges as a central player, destabilizing microtubules and disrupting the transport of kinesin-1. Kinesin-1 superfamily members, including kinesin family members 5A, 5B, and 5C, and the kinesin light chain, are intricately linked to AD pathology. However, inconsistencies in the abundance of kinesin family members in AD patients underline the necessity for further exploration into the mechanistic impact of these motor proteins on neurodegeneration and axonal transport disruptions across a spectrum of neurological conditions. This review underscores the significance of kinesin-1's anterograde transport in AD. It emphasizes the need for investigations into the underlying mechanisms of the impact of motor protein across various neurological conditions. Despite current limitations in scientific literature, our study advocates for targeting kinesin and autophagy dysfunctions as promising avenues for novel therapeutic interventions and diagnostics in AD.

NMNAT1 Is Essential for Human iPS Cell Differentiation to the Retinal Lineage

Purpose

The gene encoding nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1), a nicotinamide adenine dinucleotide synthetase localized in the cell nucleus, is a causative factor in Leber's congenital amaurosis, which is the earliest onset type of inherited retinal degeneration. We sought to investigate the roles of NMNAT1 in early retinal development.

Methods

We used human induced pluripotent stem cells (hiPSCs) and established NMNAT1-knockout (KO) hiPSCs using CRISPR/cas9 technology to reveal the roles of NMNAT1 in human retinal development.

Results

NMNAT1 was not essential for the survival and proliferation of immature hiPSCs; therefore, we subjected NMNAT1-KO hiPSCs to retinal organoid (RO) differentiation culture. The expression levels of immature hiPSC-specific genes decreased in a similar manner after organoid culture initiation up to 2 weeks in the control and NMNAT1-KO. Neuroectoderm-specific genes were induced in the control and NMNAT1-KO organoids within a few days after starting the organoid culture; PAX6 and TUBB3 were higher in NMNAT1-KO organoids up to 7 days than in the control organoids. However, the induction of genes involving retinal early development, such as RAX, which was induced at around day 10 in this culture, was considerably reduced in NMNAT1-KO organoids. Morphological examination also showed failure of retinal primordial structure formation, which became visible at around 2 weeks of the control culture, in the NMNAT1-KO organoids. Decreased intracellular NAD levels and poly(ADP-ribosyl)ation were observed in NMNAT1-KO organoids at 7 to 10 days of the culture. Mass spectrometry analysis of inhibited proteins in the poly(ADP-ribosyl)ation pathway identified poly(ADP-ribosyl)ation of poly(ADP-ribose) polymerase 1 (PARP1) as a major protein.

Conclusions

These results indicate that NMNAT1 was dispensable for neural lineage differentiation but essential for the commitment of retinal fate differentiation in hiPSCs. The NMNAT1-NAD-PARP1 axis may play a critical role in the appropriate development of human retinal lineage differentiation.

A novel model of autologous tooth transplantation for the study of nerve recruitment

BACKGROUND

Limited treatment options exist for damaged nerves and despite impressive advances in tissue engineering, scientists and clinicians have yet to fully replicate nerve development and recruitment. Innervation is a critical feature for normal organ function. While most organs are innervated prior to birth, a rare example of postnatal nerve recruitment occurs in the natural development of secondary teeth during adolescence. Many animals undergo postnatal shedding of deciduous teeth with development and eruption of secondary teeth, a process requiring recruitment of nerve and vasculature to each tooth pulp for viability. Here, the investigators created a novel model for the study of postnatal innervation by exploiting the natural phenomenon of tooth-driven nerve recruitment.

METHODS

The investigators theorized that developing teeth possess a special capacity to induce innervation which could be harnessed in a clinical setting for nerve regeneration, and hyptothesized that a transplant model could be created to capture this phenomenon. In this descriptive study, a rat model of autologous tooth transplantation and de novo nerve recruitment was developed by surgically transferring whole developing molars to the autologous tibia.

RESULTS

Downstream histological analysis performed 6 to 14 weeks after surgery demonstrated integration of molar into tibia in 81% of postoperative rats, with progressive pulpal expression of nerve marker ß-tubulin III suggestive of neuronal recruitment.

CONCLUSIONS

These findings provide a novel model for the study of organ transplantation and support the theory that developing dental tissues may retain nerve-inductive properties postnatally.

Modulation of the LIMK Pathway by Myricetin: A Protective Strategy Against Neurological Impairments in Spinal Cord Injury

OBJECTIVE

Spinal cord injury (SCI), one of the major disabilities concerning central nervous system injury, results in permanent tissue loss and neurological impairment. The existing therapeutic options for SCI are limited and predominantly consist of chemical compounds. In this study, we delved into the neuroprotective effects of myricetin, a natural flavonoid compound, and the underlying mechanisms, specifically in the context of SCI, utilizing an in vivo model. Previously, our investigations revealed an elevation in the phosphorylated form of Lin-11, Isl-1, and Mec-3 kinase1 (LIMK1) at chronic time points postinjury, coinciding with neuronal loss and scar formation. Our primary objective here was to assess the potential neuroprotective properties of myricetin in SCI and to ascertain if these effects were linked to LIMK inhibition, a hitherto unexamined pathway to date.

METHODS

Computational docking and molecular dynamics simulation studies were performed to assess myricetin's potential to bind with LIMK. Then, using a rat contusion model, SCI was induced and different molecular techniques (Western blot, Evans Blue assay, quantitative reverse transcription polymerase chain reaction and immunohistochemistry) were performed to determine the effects of myricetin.

RESULTS

Remarkably, computational docking models identified myricetin as having a better interaction profile with LIMK than standard. Subsequent to myricetin treatment, a significant downregulation in phosphorylated LIMK expression was observed at chronic time points. This reduction correlated with a notable decrease in glial and fibrotic scar formation, and enhanced neuroprotection indicating a positive outcome in vivo.

CONCLUSION

In summary, our findings underscore myricetin's potential as a bioactive compound capable of attenuating SCI-induced injury cascades by targeting the LIMK pathway.

Lipotype acquisition during neural development is not recapitulated in stem cell-derived neurons

During development, different tissues acquire distinct lipotypes that are coupled to tissue function and homeostasis. In the brain, where complex membrane trafficking systems are required for neural function, specific glycerophospholipids, sphingolipids, and cholesterol are highly abundant, and defective lipid metabolism is associated with abnormal neural development and neurodegenerative disease. Notably, the production of specific lipotypes requires appropriate programming of the underlying lipid metabolic machinery during development, but when and how this occurs is unclear. To address this, we used high-resolution MSALL lipidomics to generate an extensive time-resolved resource of mouse brain development covering early embryonic and postnatal stages. This revealed a distinct bifurcation in the establishment of the neural lipotype, whereby the canonical lipid biomarkers 22:6-glycerophospholipids and 18:0-sphingolipids begin to be produced in utero, whereas cholesterol attains its characteristic high levels after birth. Using the resource as a reference, we next examined to which extent this can be recapitulated by commonly used protocols for in vitro neuronal differentiation of stem cells. Here, we found that the programming of the lipid metabolic machinery is incomplete and that stem cell-derived cells can only partially acquire a neural lipotype when the cell culture media is supplemented with brain-specific lipid precursors. Altogether, our work provides an extensive lipidomic resource for early mouse brain development and highlights a potential caveat when using stem cell-derived neuronal progenitors for mechanistic studies of lipid biochemistry, membrane biology and biophysics, which nonetheless can be mitigated by further optimizing in vitro differentiation protocols.

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.

3-Amino-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carbonitrile: A fluorescent molecule that induces differentiation in PC12 cells

Neural differentiation is triggered by the activation of multiple signaling pathways initiated by various neurotrophic factors. An elucidation of these mechanisms is anticipated to facilitate the prevention of diseases and the development of novel therapeutic approaches. Alternative small-molecule inducers for neuroscience studies are required instead of protein-based reagents for more efficient and convenient experiments. We demonstrated that small molecules of thieno[2,3-b]pyridine derivatives that induce neural differentiation, compounds 3a and 9a in particular, exhibited significant neuritogenic activity in rat pheochromocytoma (PC12) cells. Moreover, 3a displayed pronounced fluorescence and a discernible Stokes shift. Furthermore, the outcome of the experiment conducted on the NGF-insensitive clones of rat PC12 cells, and the results of the intercellular uptake analyses suggested that the 3a-mediated activation of neural differentiation occurred independently of the TrkA receptor. Therefore, 3a portrays potential applicability both as a small molecule reagent to replace novel neurotrophic factors and as a potent fluorescent reagent for various techniques, including bioimaging.

Improved immunostaining of nanostructures and cells in human brain specimens through expansion-mediated protein decrowding

Proteins are densely packed in cells and tissues, where they form complex nanostructures. Expansion microscopy (ExM) variants have been used to separate proteins from each other in preserved biospecimens, improving antibody access to epitopes. Here, we present an ExM variant, decrowding expansion pathology (dExPath), that can expand proteins away from each other in human brain pathology specimens, including formalin-fixed paraffin-embedded (FFPE) clinical specimens. Immunostaining of dExPath-expanded specimens reveals, with nanoscale precision, previously unobserved cellular structures, as well as more continuous patterns of staining. This enhanced molecular staining results in observation of previously invisible disease marker-positive cell populations in human glioma specimens, with potential implications for tumor aggressiveness. dExPath results in improved fluorescence signals even as it eliminates lipofuscin-associated autofluorescence. Thus, this form of expansion-mediated protein decrowding may, through improved epitope access for antibodies, render immunohistochemistry more powerful in clinical science and, perhaps, diagnosis.

In Vitro Blood-Brain Barrier Models for Neuroinfectious Diseases: A Narrative Review

The blood-brain barrier (BBB) is a complex, dynamic, and adaptable barrier between the peripheral blood system and the central nervous system. While this barrier protects the brain and spinal cord from inflammation and infection, it prevents most drugs from reaching the brain tissue. With the expanding interest in the pathophysiology of BBB, the development of in vitro BBB models has dramatically evolved. However, due to the lack of a standard model, a range of experimental protocols, BBB-phenotype markers, and permeability flux markers was utilized to construct in vitro BBB models. Several neuroinfectious diseases are associated with BBB dysfunction. To conduct neuroinfectious disease research effectively, there stems a need to design representative in vitro human BBB models that mimic the BBB's functional and molecular properties. The highest necessity is for an in vitro standardised BBB model that accurately represents all the complexities of an intact brain barrier. Thus, this in-depth review aims to describe the optimization and validation parameters for building BBB models and to discuss previous research on neuroinfectious diseases that have utilized in vitro BBB models. The findings in this review may serve as a basis for more efficient optimisation, validation, and maintenance of a structurally- and functionally intact BBB model, particularly for future studies on neuroinfectious diseases.

Electroconductive Nanofibrous Scaffolds Enable Neuronal Differentiation in Response to Electrical Stimulation without Exogenous Inducing Factors

Among the various biochemical and biophysical inducers for neural regeneration, electrical stimulation (ES) has recently attracted considerable attention as an efficient means to induce neuronal differentiation in tissue engineering approaches. The aim of this in vitro study was to develop a nanofibrous scaffold that enables ES-mediated neuronal differentiation in the absence of exogenous soluble inducers. A nanofibrous scaffold composed of polycaprolactone (PCL), poly-L-lactic acid (PLLA), and single-walled nanotubes (SWNTs) was fabricated via electrospinning and its physicochemical properties were investigated. The cytocompatibility of the electrospun composite with the PC12 cell line and bone marrow-derived mesenchymal stem cells (BMSCs) was investigated. The results showed that the PCL/PLLA/SWNT nanofibrous scaffold did not exhibit cytotoxicity and supported cell attachment, spreading, and proliferation. ES was applied to cells cultured on the nanofibrous scaffolds at different intensities and the expression of the three neural markers (Nestin, Microtubule-associated protein 2, and β tubulin-3) was evaluated using RT-qPCR analysis. The results showed that the highest expression of neural markers could be achieved at an electric field intensity of 200 mV/cm, suggesting that the scaffold in combination with ES can be an efficient tool to accelerate neural differentiation in the absence of exogenous soluble inducers. This has important implications for the regeneration of nerve injuries and may provide insights for further investigations of the mechanisms underlying ES-mediated neuronal commitment.

A Library of Elastin-like Proteins with Tunable Matrix Ligands for In Vitro 3D Neural Cell Culture

Hydrogels with encapsulated cells have widespread biomedical applications, both as tissue-mimetic 3D cultures in vitro and as tissue-engineered therapies in vivo. Within these hydrogels, the presentation of cell-instructive extracellular matrix (ECM)-derived ligands and matrix stiffness are critical factors known to influence numerous cell behaviors. While individual ECM biopolymers can be blended together to alter the presentation of cell-instructive ligands, this typically results in hydrogels with a range of mechanical properties. Synthetic systems that allow for the facile incorporation and modulation of multiple ligands without modification of matrix mechanics are highly desirable. In the present work, we leverage protein engineering to design a family of xeno-free hydrogels (i.e., devoid of animal-derived components) consisting of recombinant hyaluronan and recombinant elastin-like proteins (ELPs), cross-linked together with dynamic covalent bonds. The ELP components incorporate cell-instructive peptide ligands derived from ECM proteins, including fibronectin (RGD), laminin (IKVAV and YIGSR), collagen (DGEA), and tenascin-C (PLAEIDGIELTY and VFDNFVL). By carefully designing the protein primary sequence, we form 3D hydrogels with defined and tunable concentrations of cell-instructive ligands that have similar matrix mechanics. Utilizing this system, we demonstrate that neurite outgrowth from encapsulated embryonic dorsal root ganglion (DRG) cultures is significantly modified by cell-instructive ligand content. Thus, this library of protein-engineered hydrogels is a cell-compatible system to systematically study cell responses to matrix-derived ligands.

Cytotoxicity of poly-guanidine in medulloblastoma cell lines

Medulloblastoma (MB) is the most common pediatric brain tumor. The therapy frequently causes serious side effects, and new selective therapies are needed. MB expresses hyper sialylation, a possible target for selective therapy. The cytotoxic efficacy of a poly guanidine conjugate (GuaDex) incubated with medulloblastoma cell cultures (DAOY and MB-LU-181) was investigated. The cells were incubated with 0.05-8 µM GuaDex from 15 min to 72 h. A fluorometric cytotoxicity assay (FMCA) measured the cytotoxicity. Labeled GuaDex was used to study tumor cell interaction. FITC-label Sambucus nigra confirmed high expression of sialic acid (Sia). Immunofluorescence microscopy was used to visualize the cell F-actin and microtubules. The cell interactions were studied by confocal and fluorescence microscopy. Annexin-V assay was used to detect apoptosis. Cell cycle analysis was done by DNA content determination. A wound-healing migration assay determined the effects on the migratory ability of DAOY cells after GuaDex treatment. IC50 for GuaDex was 223.4 -281.1 nM. FMCA showed potent growth inhibition on DAOY and MB-LU-181 cells at 5 uM GuaDex after 4 h of incubation. GuaDex treatment induced G2/M phase cell cycle arrest. S. nigra FITC-label lectin confirmed high expression of Sia on DAOY medulloblastoma cells. The GuaDex treatment polymerized the cytoskeleton (actin filaments and microtubules) and bound to DNA, inducing condensation. The Annexin V assay results were negative. Cell migration was inhibited at 0.5 µM GuaDex concentration after 24 h of incubation. GuaDex showed potent cytotoxicity and invasion-inhibitory effects on medulloblastoma cells at low micromolar concentrations. GuaDex efficacy was significant and warrants further studies.

Clinicopathological significance of TUBB3 in upper tract urothelial carcinoma and possible application in urine cytology

βIII-Tubulin, encoded by the TUBB3 gene, is a microtubule protein. We previously reported that TUBB3 is overexpressed in renal cell carcinoma. We investigated the clinicopathological significance of TUBB3 in upper tract urothelial carcinoma (UTUC) by immunohistochemistry. In normal tissue, TUBB3 expression was weak or absent. In contrast, TUBB3 overexpression was observed in urothelial carcinoma (UC) tissues in 51 (49%) of 103 UTUC cases. TUBB3 overexpression was associated with nodular/flat morphology, high-grade disease, high T stage, and a poor prognosis. Similar results were obtained in The Cancer Genome Atlas bladder cancer cohort. TUBB3 expression was also associated with high Ki-67 labeling index, CD44v9, HER2, EGFR, and p53 expression in UTUC. Among representative cancer-related molecules, TUBB3 was an independent predictor of progression-free survival and high-grade UC. Finally, using urine cytology samples, we analyzed TUBB3 expression by immunocytochemistry. TUBB3 expression was more frequently found in UC cells than in nonneoplastic cells. The diagnostic accuracy of urine cytology was improved when combined with TUBB3 immunostaining. The findings suggest the importance of TUBB3 in tumor progression and its potential application as a biomarker for high-grade disease and the prognosis of UC. Moreover, combination with TUBB3 immunostaining might improve the diagnostic accuracy of urine cytology.

Cellular Lipidome Changes during Retinoic Acid (RA)-Induced Differentiation in SH-SY5Y Cells: A Comprehensive In Vitro Model for Assessing Neurotoxicity of Contaminants

The SH-SY5Y, neuroblastoma cell line, is a common in vitro model used to study physiological neuronal function and the neuronal response to different stimuli, including exposure to toxic chemicals. These cells can be differentiated to neuron-like cells by administration of various reagents, including retinoic acid or phorbol-12-myristate-13-acetate. Despite their common use, there is an incomplete understanding of the molecular changes that occur during differentiation. Therefore, there is a critical need to fully understand the molecular changes that occur during differentiation to properly study neurotoxicity in response to various environmental exposures. Previous studies have investigated the proteome and transcriptome during differentiation; however, the regulation of the cellular lipidome in this process is unexplored. In this work, we conducted liquid chromatography-mass spectrometry (LC-MS)-based untargeted lipidomics in undifferentiated and differentiated SH-SY5Y cells, induced by retinoic acid. We show that there are global differences between the cellular lipidomes of undifferentiated and differentiated cells. Out of thousands of features detected in positive and negative electrospray ionization modes, 44 species were identified that showed significant differences (p-value ≤0.05, fold change ≥2) in differentiated cells. Identification of these features combined with targeted lipidomics highlighted the accumulation of phospholipids, sterols, and sphingolipids during differentiation while triacylglycerols were depleted. These results provide important insights into lipid-related changes that occur during cellular differentiation of SH-5YSY cells and emphasize the need for the detailed characterization of biochemical differences that occur during differentiation while using this in vitro model for assessing ecological impacts of environmental pollutants.

Gene expression and locomotor recovery in adult rats with spinal cord injury and plasma-synthesized polypyrrole/iodine application combined with a mixed rehabilitation scheme

Introduction

Spinal cord injury (SCI) can cause paralysis, for which effective therapeutic strategies have not been developed yet. The only accepted strategy for patients is rehabilitation (RB), although this does not allow complete recovery of lost functions, which makes it necessary to combine it with strategies such as plasma-synthesized polypyrrole/iodine (PPy/I), a biopolymer with different physicochemical properties than PPy synthesized by conventional methods. After SCI in rats, PPy/I promotes functional recovery. Therefore, the purpose of this study was to increase the beneficial effects of both strategies and identify which genes activate PPy/I when applied alone or in combination with a mixed scheme of RB by swimming and enriched environment (SW/EE) in rats with SCI.

Methods

Microarray analysis was performed to identify mechanisms of action underlying the effects of PPy/I and PPy/I+SW/EE on motor function recovery as evaluated by the BBB scale.

Results

Results showed robust upregulation by PPy/I in genes related to the developmental process, biogenesis, synapse, and synaptic vesicle trafficking. In addition, PPy/I+SW/EE increased the expression of genes related to proliferation, biogenesis, cell development, morphogenesis, cell differentiation, neurogenesis, neuron development, and synapse formation processes. Immunofluorescence analysis showed the expression of β-III tubulin in all groups, a decreased expression of caspase-3 in the PPy/I group and GFAP in the PPy/I+SW/EE group (p < 0.05). Better preservation of nerve tissue was observed in PPy/I and PPy/SW/EE groups (p < 0.05). In the BBB scale, the control group scored 1.72 ± 0.41, animals with PPy/I treatment scored 4.23 ± 0.33, and those with PPy/I+SW/EE scored 9.13 ± 0.43 1 month after follow-up.

Conclusion

Thus, PPy/I+SW/EE could represent a therapeutic alternative for motor function recovery after SCI.

Mesenchymal stromal cells derived from exfoliated deciduous teeth express neuronal markers before differentiation induction

OBJECTIVE

This study aimed to evaluate neuronal markers in stromal cells from human exfoliated deciduous teeth (SHED) and standardize the isolation and characterization of those cells.

METHODOLOGY

Healthy primary teeth were collected from children. The cells were isolated by enzymatic digestion with collagenase. By following the International Society for Cell and Gene Therapy (ISCT) guidelines, SHED were characterized by flow cytometry and differentiated into osteogenic, adipogenic, and chondrogenic lineages. Colony-forming unit-fibroblasts (CFU-F) were performed to assess these cells' potential and efficiency. To clarify the neuronal potential of SHED, the expression of nestin and βIII-tubulin were examined by immunofluorescence and SOX1, SOX2, GFAP, and doublecortin (DCX), nestin, CD56, and CD146 by flow cytometry.

RESULTS

SHED showed mesenchymal stromal cells characteristics, such as adhesion to plastic, positive immunophenotypic profile for CD29, CD44, CD73, CD90, CD105, and CD166 markers, reduced expression for CD14, CD19, CD34, CD45, HLA-DR, and differentiation in three lineages confirmed by staining and gene expression for adipogenic differentiation. The average efficiency of colony formation was 16.69%. SHED expressed the neuronal markers nestin and βIII-tubulin; the fluorescent signal intensity was significantly higher in βIII-tubulin (p<0.0001) compared to nestin. Moreover, SHED expressed DCX, GFAP, nestin, SOX1, SOX2, CD56, CD146, and CD271. Therefore, SHED had a potential for neuronal lineage even without induction with culture medium and specific factors.

CONCLUSION

SHEDs may be a new therapeutic strategy for regenerating and repairing neuronal cells and tissues.

Age-dependent increase of cytoskeletal components in sensory axons in human skin

Aging is a complex process characterized by several molecular and cellular imbalances. The composition and stability of the neuronal cytoskeleton is essential for the maintenance of homeostasis, especially in long neurites. Using human skin biopsies containing sensory axons from a cohort of healthy individuals, we investigate alterations in cytoskeletal content and sensory axon caliber during aging via quantitative immunostainings. Cytoskeletal components show an increase with aging in both sexes, while elevation in axon diameter is only evident in males. Transcriptomic data from aging males illustrate various patterns in gene expression during aging. Together, the data suggest gender-specific changes during aging in peripheral sensory axons, possibly influencing cytoskeletal functionality and axonal caliber. These changes may cumulatively increase susceptibility of aged individuals to neurodegenerative diseases.

Nerve Density and Neuronal Biomarkers in Cancer

Simple Summary

Researchers have shown that tumor biomarkers and increased nerve density are important clinical tools for determining cancer prognosis and developing effective treatments. The aims of our review were to synthesize these findings by detailing the histology of peripheral nerves, discuss the use of various neuronal biomarkers in cancer, and assess the impact of increased nerve density on tumorigenesis. This review demonstrates that specific neuronal markers may have an important role in tumorigenesis and may serve as diagnostic and prognostic factors for various cancers. Moreover, increased nerve density may be associated with worse prognosis in different cancers, and cancer therapies that decrease nerve density may offer benefit to patients.

Abstract

Certain histologic characteristics of neurons, novel neuronal biomarkers, and nerve density are emerging as important diagnostic and prognostic tools in several cancers. The tumor microenvironment has long been known to promote tumor development via promoting angiogenesis and cellular proliferation, but new evidence has shown that neural proliferation and invasion in the tumor microenvironment may also enable tumor growth. Specific neuronal components in peripheral nerves and their localization in certain tumor sites have been identified and associated with tumor aggressiveness. In addition, dense neural innervation has been shown to promote tumorigenesis. In this review, we will summarize the histological components of a nerve, explore the neuronal biomarkers found in tumor sites, and discuss clinical correlates between tumor neurobiology and patient prognosis.

Direct Potential Modulation of Neurogenic Differentiation Markers by Granulocyte-Colony Stimulating Factor (G-CSF) in the Rodent Brain

The hematopoietic granulocyte-colony stimulating growth factor (G-CSF, filgrastim) is an approved drug in hematology and oncology. Filgrastim's potential in neurodegenerative disorders is gaining increasingly more attention, as preclinical and early clinical studies suggest it could be a promising treatment option. G-CSF has had a tremendous record as a safe drug for more than three decades; however, its effects upon the central nervous system (CNS) are still not fully understood. In contrast to conceptual long-term clinical application with lower dosing, our present pilot study intends to give a first insight into the molecular effects of a single subcutaneous (s.c.) high-dose G-CSF application upon different regions of the rodent brain. We analyzed mRNA-and in some instances-protein data of neurogenic and non-neurogenic differentiation markers in different regions of rat brains five days after G-CSF (1.3 mg/kg) or physiological saline. We found a continuous downregulation of several markers in most brain regions. Remarkably, cerebellum and hypothalamus showed an upregulation of different markers. In conclusion, our study reveals minor suppressive or stimulatory effects of a single exceptional high G-CSF dose upon neurogenic and non-neurogenic differentiation markers in relevant brain regions, excluding unregulated responses or unexpected patterns of marker expression.

In vitro neurotoxicity evaluation of biocidal disinfectants in a human neuron-astrocyte co-culture model

Biocidal disinfectants (BDs) that kill microorganisms or pathogens are widely used in hospitals and other healthcare fields. Recently, the use of BDs has rapidly increased as personal hygiene has become more apparent owing to the pandemic, namely the coronavirus outbreak. Despite frequent exposure to BDs, toxicity data of their potential neurotoxicity (NT) are lacking. In this study, a human-derived SH-SY5Y/astrocyte was used as a co-culture model to evaluate the chemical effects of BDs. Automated high-content screening was used to evaluate the potential NT of BDs through neurite growth analysis. A set of 12 BD substances classified from previous reports were tested. Our study confirms the potential NT of benzalkonium chloride (BKC) and provides the first evidence of the potential NT of poly(hexamethylenebicyanoguanide-hexamethylenediamine) hydrochloride (PHMB). BKC and PHMB showed significant NT at concentrations without cytotoxicity. This test system for analyzing the potential NT of BDs may be useful in early screening studies for NT prior to starting in vivo studies.

Patterns of tubb2b Promoter-Driven Fluorescence in the Forebrain of Larval Xenopus laevis

Microtubules are essential components of the cytoskeleton of all eukaryotic cells and consist of α- and β-tubulin heterodimers. Several tissue-specific isotypes of α- and β-tubulins, encoded by distinct genes, have been described in vertebrates. In the African clawed frog (Xenopus laevis), class II β-tubulin (tubb2b) is expressed exclusively in neurons, and its promoter is used to establish different transgenic frog lines. However, a thorough investigation of the expression pattern of tubb2b has not been carried out yet. In this study, we describe the expression of tubb2b-dependent Katushka fluorescence in the forebrain of premetamorphic Xenopus laevis at cellular resolution. To determine the exact location of Katushka-positive neurons in the forebrain nuclei and to verify the extent of neuronal Katushka expression, we used a transgenic frog line and performed several additional antibody stainings. We found tubb2b-dependent fluorescence throughout the Xenopus forebrain, but not in all neurons. In the olfactory bulb, tubb2b-dependent fluorescence is present in axonal projections from the olfactory epithelium, cells in the mitral cell layer, and fibers of the extrabulbar system, but not in interneurons. We also detected tubb2b-dependent fluorescence in parts of the basal ganglia, the amygdaloid complex, the pallium, the optic nerve, the preoptic area, and the hypothalamus. In the diencephalon, tubb2b-dependent fluorescence occurred mainly in the prethalamus and thalamus. As in the olfactory system, not all neurons of these forebrain regions exhibited tubb2b-dependent fluorescence. Together, our results present a detailed overview of the distribution of tubb2b-dependent fluorescence in neurons of the forebrain of larval Xenopus laevis and clearly show that tubb2b-dependent fluorescence cannot be used as a pan-neuronal marker.

Glioblastoma: Current Status, Emerging Targets, and Recent Advances

Glioblastoma (GBM) is a highly malignant brain tumor characterized by a heterogeneous population of genetically unstable and highly infiltrative cells that are resistant to chemotherapy. Although substantial efforts have been invested in the field of anti-GBM drug discovery in the past decade, success has primarily been confined to the preclinical level, and clinical studies have often been hampered due to efficacy-, selectivity-, or physicochemical property-related issues. Thus, expansion of the list of molecular targets coupled with a pragmatic design of new small-molecule inhibitors with central nervous system (CNS)-penetrating ability is required to steer the wheels of anti-GBM drug discovery endeavors. This Perspective presents various aspects of drug discovery (challenges in GBM drug discovery and delivery, therapeutic targets, and agents under clinical investigation). The comprehensively covered sections include the recent medicinal chemistry campaigns embarked upon to validate the potential of numerous enzymes/proteins/receptors as therapeutic targets in GBM.

Nuclear βII-Tubulin and its Possible Utility in Cancer Diagnosis, Prognosis and Treatment

Microtubules are organelles that usually occur only in the cytosol. Walss et al. (1999) discovered the βII isotype of tubulin, complexed with α, in the nuclei of certain cultured cells, in non-microtubule form. When fluorescently labeled tubulins were microinjected into the cells, only αβII appeared in the nucleus, and only after one cycle of nuclear disassembly and reassembly. It appeared as if αβII does not cross the nuclear envelope but is trapped in the nucleus by the re-forming nuclear envelope in whose reassembly βII may be involved. βII is present in the cytoplasm and nuclei of many tumor cells. With some exceptions, normal tissues that expressed βII rarely had βII in their nuclei. It is possible that βII is involved in nuclear reassembly and then disappears from the nucleus. Ruksha et al. (2019) observed that patients whose colon cancer cells in the invasive front showed no βII had a median survival of about 5.5 years, which was more than halved if they had cytosolic βII and further lessened if they had nuclear βII, suggesting that the presence and location of βII in biopsies could be a useful prognostic indicator and also that βII may be involved in cancer progression. Yeh and Ludueña. (2004) observed that many tumors were surrounded by non-cancerous cells exhibiting cytosolic and nuclear βII, suggesting a signaling pathway that causes βII to be synthesized in nearby cells and localized to their nuclei. βII could be useful in cancer diagnosis, since the presence of βII in non-cancerous cells could indicate a nearby tumor. Investigation of this pathway might reveal novel targets for chemotherapy. Another possibility would be to combine αβII with CRISPR-Cas9. This complex would likely enter the nucleus of a cancer cell and, if guided to the appropriate gene, might destroy the cancer cell or make it less aggressive; possible targets will be discussed here. The possibilities raised here about the utility of βII in cancer diagnosis, prognosis, biology and therapy may repay further investigation.

Quantitative proteomics and in-cell cross-linking reveal cellular reorganisation during early neuronal differentiation of SH-SY5Y cells

The neuroblastoma cell line SH-SY5Y is commonly employed to study neuronal function and disease. This includes cells grown under standard conditions or differentiated to neuron-like cells by administration of chemical reagents such as retinoic acid (RA) or phorbol-12-myristate-13-acetate (PMA). Even though SH-SY5Y cells are widely explored, a complete description of the resulting proteomes and cellular reorganisation during differentiation is still missing. Here, we relatively quantify the proteomes of cells grown under standard conditions and obtained from two differentiation protocols employing RA or a combination of RA and PMA. Relative quantification and KEGG pathway analysis of the proteins reveals the presence of early differentiating cells and provides a list of marker proteins for undifferentiated and differentiated cells. For characterisation of neuronal sub-types, we analyse expression of marker genes and find that RA-differentiated cells are acetylcholinergic and cholinergic, while RA/PMA-differentiated cells show high expression of acetylcholinergic and dopaminergic marker genes. In-cell cross-linking further allows capturing protein interactions in different cellular organelles. Specifically, we observe structural reorganisation upon differentiation involving regulating protein factors of the actin cytoskeleton.

Quantitative proteomic analyses are employed to explore the changes in the proteome that occur upon neuronal differentiation in the SH-SY5Y cell line.

Anti-proliferative activity of labdane diterpenes isolated from Polyalthia cerasoides and their molecular interaction studies

BACKGROUND

Polyalthia cerasoides is well known for its therapeutic effects and is extensively used by the tribal people of South India and Africa to treat infertility, toothache, inflammation, rheumatism, fever, and to combat stress.

OBJECTIVE

In the present research, the anti-proliferative potential of two bioactive compounds isolated from the stem bark of P. cerasoides (Roxb.) Bedd. of the Annonaceae family were investigated.

METHOD

The dried stem bark was powdered and subjected to extraction using methanol and further partitioned using petroleum ether. Yellow viscous oil was isolated from the petroleum ether fraction using column and preparative thin-layer chromatography. The chromatographic fractions were characterized using GC-MS. The anti-proliferative effect of the isolated compounds was assessed against HepG2 Cells using MTT- Cytotoxicity test. Furthermore, comparative in-silico docking studies were performed to predict the binding pattern of isolated molecules individually, as well as simultaneously with α, β -tubulin, a critical protein involved in the molecular mechanism of microtubule formation.

RESULTS

GC-MS analysis of yellow viscous oil from petroleum fraction confirmed the presence of two labdane diterpenes and were identified as 12E-3,4-Seco-labda-4(18),8(17),12,14-tetraen-3-oic acid , and methyl harvadate C by mass fragmentation analysis. The MTT-Cytotoxicity assay showed the dose-dependent cytotoxic effect on HepG2 Cells. The comparative docking studies of the isolated compounds exhibited strong interactions with the α, β -tubulin protein.

CONCLUSION

The prominent anti-proliferative effect exhibited by the isolated compounds along with effective binding to α, β -tubulin protein encourages their future utilization as prominent anti-cancer molecules.

Neuronal differentiation potential of primary and immortalized adipose stem cells by photobiomodulation

Adipose Stem Cells (ASCs) are capable of neuronal differentiation, which makes them an ideal choice for therapies in nerve injuries. Principally, the differentiation of autologous ASCs to neurons offers solutions for the replacement therapies of nervous system with patient's own genetic background. On the contrary, the use of genetically modified (immortalized) ASCs has the benefit of accessibility by surpassing ethical concerns and ease for propagation as a continuous cell culture. Photobiomodulation (PBM) is a therapeutic modality with laser or light, which is widely been used for modulating stem cell bioprocesses viz. proliferation and differentiation. A comparative analysis was performed to evaluate the neuronal differentiation potential of primary ASCs isolated from a healthy human subject with commercially obtained immortalized ASCs with PBM. The outcome of this analysis will help us to know either primary or immortalized ASCs are most suitable for biomedical applications. Both primary and immortalized ASCs were characterized using their surface protein markers CD44/90/133/166 and induced to differentiate into neuronal cells using Fibroblast Growth Factor, basic (bFGF) and forskolin following PBM using Near Infra-Red (NIR) lasers. Based on the expression of nestin, an early neuronal marker an exposure to 5, 10 and 15 J/cm² of NIR and growth inducers for 14 days the primary ASCs demonstrated a higher neuronal differentiation potential compared to the immortalized ASCs. However, newly differentiated cells from either of these ASCs did not reveal βIII-tubulin, an intermediate neuronal marker even by 21 days of differentiation. This study gives an indication that immortalized ASCs have a phenotype and differentiation potential slightly less but comparable to the freshly isolated ASCs. We suggest that PBM along with growth inducers offer a better solution of differentiating ASCs to neurons.

βIII-Tubulin Gene Regulation in Health and Disease

Microtubule proteins form a dynamic component of the cytoskeleton, and play key roles in cellular processes, such as vesicular transport, cell motility and mitosis. Expression of microtubule proteins are often dysregulated in cancer. In particular, the microtubule protein βIII-tubulin, encoded by the TUBB3 gene, is aberrantly expressed in a range of epithelial tumours and is associated with drug resistance and aggressive disease. In normal cells, TUBB3 expression is tightly restricted, and is found almost exclusively in neuronal and testicular tissues. Understanding the mechanisms that control TUBB3 expression, both in cancer, mature and developing tissues will help to unravel the basic biology of the protein, its role in cancer, and may ultimately lead to the development of new therapeutic approaches to target this protein. This review is devoted to the transcriptional and posttranscriptional regulation of TUBB3 in normal and cancerous tissue.

Pumpkin extract and fermented whey individually and in combination alleviated AFB1- and OTA-induced alterations on neuronal differentiation invitro

Food and feed are daily exposed to mycotoxin contamination which effects may be counteracted by functional compounds like carotenoids and fermented whey. Among mycotoxins, the most toxic and studied are aflatoxin B1 (AFB1) and ochratoxin A (OTA), which neurotoxicity is not well reported. Therefore, SH-SY5Y human neuroblastoma cells ongoing differentiation were exposed during 7 days to digested bread extracts contained pumpkin and fermented whey, individually and in combination, along with AFB1 and OTA and their combination, in order to evaluate their presumed effects on neuronal differentiation. The immunofluorescence analysis of βIII-tubulin and dopamine markers pointed to OTA as the most damaging treatment for cell differentiation. Cell cycle analysis reported the highest significant differences for OTA-contained bread compared to the control in phase G₀/G₁. Lastly, RNA extraction was performed and gene expression was analyzed by qPCR. The selected genes were related to neuronal differentiation and cell cycle. The addition of functional ingredients in breads not only enhancing the expression of neuronal markers, but also induced an overall improvement of gene expression compromised by mycotoxins activity. These data confirm that in vitro neuronal differentiation may be impaired by AFB1 and OTA-exposure, which could be modulated by bioactive compounds naturally found in diet.

Research Progress on Natural Diterpenoids in Reversing Multidrug Resistance

Multidrug resistance (MDR) is one of the main impediments in successful chemotherapy in cancer treatment. Overexpression of ATP-binding cassette (ABC) transporter proteins is one of the most important mechanisms of MDR. Natural products have their unique advantages in reversing MDR, among which diterpenoids have attracted great attention of the researchers around the world. This review article summarizes and discusses the research progress on diterpenoids in reversing MDR.

Possible Roles of Specific Amino Acids in β-Tubulin Isotypes in the Growth and Maintenance of Neurons: Novel Insights From Cephalopod Mollusks

Microtubules, are formed of the protein tubulin, which is a heterodimer of α- and β-tubulin subunits. Both α- and β-tubulin exist as numerous isotypes, differing in amino acid sequence and tissue distribution. Among the vertebrate β isotypes, βIII has a very narrow distribution, being found primarily in neurons and in advanced cancers. The places in the amino acid sequence where βIII differs from the other β isotypes are highly conserved in evolution. βIII appears to be highly resistant to reactive oxygen species and it forms highly dynamic microtubules. The first property would be very useful in neurons, which have high concentrations of free radicals, and the high dynamicity would aid neurite outgrowth. The same properties make βIII useful in cancers. Examination of the amino acid sequences indicates a cysteine cluster at positions 124-129 in βIII (CXXCXC). This occurs in all βIII isotypes but not in βI, βII, or βIV. βIII also lacks the easily oxidized C239. Both features could play roles in free radical resistance. Many aggressive tumors over-express βIII. However, a recent study of breast cancer patients showed that many of them mutated their βI, βII, and βIV at particular places to change the residues to those found at the corresponding sites in βIII; these are all sites that are highly conserved in vertebrate βIII. It is possible that these residues are important, not only in the resistance to free radicals, but also in the high dynamicity of βIII. The cephalopod mollusks are well known to be highly intelligent and can remodel their own brains. Interestingly, several cephalopods contain the cysteine cluster as well as up to 7 of the 17 residues that are highly conserved in vertebrate βIII, but are not found in βI, βII, or βIV. In short, it is possible that we are looking at a case of convergent evolution, that a βIII-like isotype may be required for neuronal growth and function and that a structure-function study of the particular residues conserved between vertebrate βIII and cephalopod tubulin isotypes could greatly increase our understanding of the role of the various tubulin isotypes in neuronal growth and function and could aid in the development of novel anti-tumor drugs.

Cooperative Metal Ion Coordination to the Short Self-Assembling Peptide Promotes Hydrogelation and Cellular Proliferation

Non-covalent interactions among short peptides and proteins led to their molecular self-assembly into supramolecular packaging, which provides the fundamental basis of life. These biomolecular assemblies are highly susceptible to the environmental conditions, including temperature, light, pH, and ionic concentration, thus inspiring the fabrication of a new class of stimuli-responsive biomaterials. Here, we report for the first time the cooperative effect of the divalent metal ions to promote hydrogelation in the short collagen inspired self-assembling peptide for developing advanced biomaterials. Introduction of the biologically relevant metal ions (Ca²⁺ /Mg²⁺ ) to the peptide surpasses its limitation to self-assemble into a multi-scale structure at physiological pH. In particular, in presence of metal ions, the negatively charged peptide showed a distinct shift in its equilibrium point of gelation and demonstrated conversion from sol to gel and thus enabling the scope of fabricating an advanced biomaterial for controlling cellular behaviour. Interestingly, tunable mechanical strength and improved cellular response were observed within ion-coordinated peptide hydrogels compared to the peptide gelator. Microscopic analyses, rheological assessment, and biological studies established the importance of utilizing a novel strategy by simply using metal ions to modulate the physical and biological attributes of CIPs to construct next-generation biomaterials. This article is protected by copyright. All rights reserved.

Highly-multiplexed volumetric mapping with Raman dye imaging and tissue clearing

Mapping the localization of multiple proteins in their native three-dimensional (3D) context would be useful across many areas of biomedicine, but multiplexed fluorescence imaging has limited intrinsic multiplexing capability, and most methods for increasing multiplexity can only be applied to thin samples (<100 µm). Here, we harness the narrow spectrum of Raman spectroscopy and introduce Raman dye imaging and tissue clearing (RADIANT), an optical method that is capable of imaging multiple targets in thick samples in one shot. We expanded the range of suitable bioorthogonal Raman dyes and developed a tissue-clearing strategy for them (Raman 3D imaging of solvent-cleared organs (rDISCO)). We applied RADIANT to image up to 11 targets in millimeter-thick brain slices, extending the imaging depth 10- to 100-fold compared to prior multiplexed protein imaging methods. We showcased the utility of RADIANT in extracting systems information, including region-specific correlation networks and their topology in cerebellum development. RADIANT will facilitate the exploration of the intricate 3D protein interactions in complex systems.

Predictive and Prognostic Significance of mRNA Expression and DNA Copies Aberrations of ERCC1, RRM1, TOP1, TOP2A, TUBB3, TYMS, and GSTP1 Genes in Patients with Breast Cancer

Increasingly, many researchers are focusing on the sensitivity in breast tumors (BC) to certain chemotherapy drugs and have personalized their research based on the assessment of this sensitivity. One such personalized approach is to assess the chemotherapy’s gene expression, as well as aberrations in the number of DNA copies—deletions and amplifications with the ability to have a significant effect on the gene’s activity. Thus, the aim of this work was to study the predictive and prognostic significance of the expression and chromosomal aberrations of eight chemosensitivity genes in breast cancer patients. Material and methods. The study involved 97 patients with luminal B breast cancer IIB–IIIB stages. DNA and RNA were isolated from samples of tumor tissue before and after treatment. Microarray analysis was performed for all samples on high-density microarrays (DNA chips) of Affymetrix (USA) CytoScanTM HD Array and Clariom™ S Assay, human. Detection of expression level of seven chemosensitivity genes—RRM1, ERCC1, TOP1, TOP2a, TUBB3, TYMS, and GSTP1—was performed using PCR real-time (RT-qPCR). Results. The expression of the RRM1 (AC scheme), TOP2α, TYMS, and TUBB3 genes in patients with an objective response to treatment (complete and partial regression) is higher than in patients with stabilization and progression (p < 0.05). According to our results, the presence of a high level of GSTP1 in a tumor biopsy is associated with the low efficiency of the NAC CP scheme (p = 0.05). The presence of RRM1 deletion is associated with complete and partial regression, as for the TOP1 and TUBB3 genes (p < 0.05). Higher rates of metastatic survival are associated with a high level of expression and amplification of the GSTP1 gene (log-rank test p = 0.02 and p = 0.05). Conclusion. Thus, a complex assessment of the chemotherapy’s gene expression is important not only for understanding the heterogeneity and molecular biology of breast cancer but also to obtain a more accurate disease prognosis.

The phosphatase of regenerating liver-3 protein(PRL-3)promotes glioma cell invasiveness by interacting with β3 -tubulin

PRL-3 is a tyrosine phosphatase linked with tumor metastasis. It is detected high expression in different kinds of cancers, including colorectal, gastric, ovarian, and liver cancer. Its high expression is positively correlated with the progression of tumors and negatively with survivals of patients. However, the detailed mechanism underlying PRL-3 in tumor metastasis still remains unclear. In the present study, we found that PRL-3 is able to bind to β3-tubulin in pull-down and co-immunoprecipitation assays. Furthermore, overexpression of PRL-3 dephosphorylated β3-tubulin, a component of cytoskeleton, which plays critical role in cell shape formation and migration. Using cell wound healing and matrigel invasion assays, we found that PRL-3 could promote the migration and invasion of glioma cells. Taken together, our study revealed that PRL-3 may be involved in migration and invasion of glioma by dephosphorylating β3-tubulin. It is tempting to speculate that dephosphorylation of β3-tubulin by PRL-3 results in assembly of the cytoskeleton and facilitates cell migration and/or tumor metastasis.

Diagnostic, Predictive, and Prognostic Biomarkers in Non-Small Cell Lung Cancer (NSCLC) Management

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite growing efforts for its early detection by screening populations at risk, the majority of lung cancer patients are still diagnosed in an advanced stage. The management of lung cancer has dramatically improved in the last decade and is no longer based on the "one-fits-all" paradigm or the general histological classification of non-small cell versus small cell lung cancer. Emerging options of targeted therapies and immunotherapies have shifted the management of lung cancer to a more personalized treatment approach, significantly influencing the clinical course and outcome of the disease. Molecular biomarkers have emerged as valuable tools in the prognosis and prediction of therapy response. In this review, we discuss the relevant biomarkers used in the clinical management of lung tumors, from diagnosis to prognosis. We also discuss promising new biomarkers, focusing on non-small cell lung cancer as the most abundant type of lung cancer.

Lactoferrin Protects against Methamphetamine Toxicity by Modulating Autophagy and Mitochondrial Status

Lactoferrin (LF) was used at first as a vehicle to deliver non-soluble active compounds to the body, including the central nervous system (CNS). Nonetheless, it soon became evident that, apart from acting as a vehicle, LF itself owns active effects in the CNS. In the present study, the effects of LF are assessed both in baseline conditions, as well as to counteract methamphetamine (METH)-induced neurodegeneration by assessing cell viability, cell phenotype, mitochondrial status, and specific autophagy steps. In detail, cell integrity in baseline conditions and following METH administration was carried out by using H&E staining, Trypan blue, Fluoro Jade B, and WST-1. Western blot and immuno-fluorescence were used to assess the expression of the neurofilament marker βIII-tubulin. Mitochondria were stained using Mito Tracker Red and Green and were further detailed and quantified by using transmission electron microscopy. Autophagy markers were analyzed through immuno-fluorescence and electron microscopy. LF counteracts METH-induced degeneration. In detail, LF significantly attenuates the amount of cell loss and mitochondrial alterations produced by METH; and mitigates the dissipation of autophagy-related proteins from the autophagy compartment, which is massively induced by METH. These findings indicate a protective role of LF in the molecular mechanisms of neurodegeneration.

βIII-tubulin overexpression in cancer: Causes, consequences, and potential therapies

Class III β-tubulin (βIII-tubulin) is frequently overexpressed in human tumors and is associated with resistance to microtubule-targeting agents, tumor aggressiveness, and poor patient outcome. Understanding the mechanisms regulating βIII-tubulin expression and the varied functions βIII-tubulin may have in different cancers is vital to assess the prognostic value of this protein and to develop strategies to enhance therapeutic benefits in βIII-tubulin overexpressing tumors. Here we gather all the available evidence regarding the clinical implications of βIII-tubulin overexpression in cancer, describe factors that regulate βIII-tubulin expression, and discuss current understanding of the mechanisms underlying βIII-tubulin-mediated resistance to microtubule-targeting agents and tumor aggressiveness. Finally, we provide an overview of emerging therapeutic strategies to target tumors that overexpress βIII-tubulin.

Exosomal TUBB3 mRNA expression of metastatic castration-resistant prostate cancer patients: Association with patient outcome under abiraterone

Background

To use ddPCR to quantify plasma exosomal class III β‐tubulin (βIII‐tubulin, TUBB3, encoded by the TUBB3 gene) mRNA expression in metastatic castration‐resistant prostate cancer (mCRPC) patients, and study the association of this expression with abiraterone efficacy.

Methods

Blood samples were prospectively collected from 52 mCRPC patients using abiraterone as first‐line therapy to measure plasma exosomal TUBB3 mRNA expression value before the initiation of abiraterone. Study endpoints were PSA response rate, PSA‐progression‐free survival (PSA‐PFS), and overall survival (OS, from CRPC to death).

Results

Patients with positive exosomal TUBB3 expression showed shorter PSA‐PFS (negative TUBB3 vs. positive TUBB3: 11.0 vs. 7.9 months; p = 0.014). Further analysis demonstrated that patients with strongly positive exosomal TUBB3 (>20 copies/20 µl) was associated with even shorter PSA‐PFS (negative TUBB3 vs. positive TUBB3 [<20 copies/20 µl] vs. strongly positive TUBB3 [>20 copies/20 µl]: 11.0 vs. 8.3 vs. 3.6 months, p = 0.005). In multivariate analyzes, TUBB3 (+) (HR: 2.114, p = 0.033) and ECOG score >2 (HR: 3.039, p = 0.006) were independent prognosticators of poor PSA‐PFS. PSA response and OS did not present significant differences.

Conclusion

The exosomal TUBB3 mRNA expression level is associated with poor PSA‐PFS of abiraterone in mCRPC patients. The detection of exosomal TUBB3 can be valuable in their management.

A screened PirB antagonist peptide antagonizes Aβ42-mediated inhibition of neurite outgrowth in vitro

Alzheimer's disease (AD) is a type of progressive neurodegenerative disease, and amyloid β-protein 42 (Aβ₄₂) serves an important role in the pathological process of development of AD. Paired immunoglobulin-like receptor B (PirB) is a functional receptor for myelin inhibitors of neuron regeneration in the CNS, and it has also been identified to function as a high-affinity receptor for Aβ. Here, we used a phage display to identify a specific PirB antagonist peptide 11(PAP11, PFRLQLS), which could reverse Aβ₄₂-induced neurotoxicity and promote neurite outgrowth in vitro. Immunofluorescence analysis showed that PAP11 colocalized with PirB on the membrane of cortical neurons. Horseradish peroxidase-streptavidin-biotin assay further proved that PAP11 directly binds to PirB and the dissociation constant (K_d) was 0.128μM. PAP11 functionally antagonized the neurite outgrowth inhibitory effect induced by Aβ₄₂ in cortical neurons, and the underlying mechanism was associated with a PirB-ROCK2/CRMP2 signaling pathway. The novel PirB antagonist peptide PAP11 may be a promising candidate therapeutic agent for the treatment of AD and other neurodegenerative diseases. KEY POINTS: • PAP11 was the first PirB antagonist peptide screened by phage display technology. • PAP11 could protect neurons by blocking the binding of Aβ₄₂ and PirB. • PAP11 reverse inhibitory effect of neurite outgrowth through ROCK2/CRMP2 pathway.

Extensive analysis of the molecular biomarkers excision repair cross complementing 1, ribonucleotide reductase M1, β-tubulin III, thymidylate synthetase, and topoisomerase IIα in breast cancer: Association with clinicopathological characteristics

Excision repair cross complementing 1 (ERCC1), ribonucleotide reductase M1 (RRM1), β-tubulin III (TUBB3), thymidylate synthetase (TYMS), and topoisomerase IIα (TOP2A) genes have been shown to be associated with the pathogenesis and prognosis of various types of carcinomas; however, their roles in breast cancer have not been fully validated. In this study, we evaluated the correlations among these biomarkers and the associations between their expression intensity and the clinicopathological characteristics to investigate whether the above genes are underlying biomarkers for patients with breast cancer.Ninety-seven tissue specimens collected from breast cancer patients. The expression levels of these biomarkers were measured by the multiplex branched DNA liquidchip (MBL) technology and clinicopathological characteristics were collected simultaneously.The expression levels of ERCC1, TUBB3, TYMS, and TOP2A were significantly associated with the characteristics of menopausal status, tumor size, lymph node metastasis, hormone receptor status, triple-negative status, Ki-67 index, and epidermal growth factor receptor. The expression intensity of ERCC1 negatively associated with that of TUBB3 and TYMS, and positively associated with that of RRM1. The expression intensity of TOP2A positively associated with that of TYMS. Hierarchical clustering analysis and difference test indicated that breast cancer with higher levels of TUBB3, TYMS, and TOP2A, as well as lower levels of ERCC1 and RRM1 tended to have higher histological grade and Ki-67 index.Our studies showed that ERCC1, TYMS, TUBB3, and TOP2A may be potential biomarkers for prognosis and individualized chemotherapy guidance, while there may be interactions between ERCC1 and RRM1, or TUBB3, or TYMS, as well as between TOP2A and TYMS in pathogenesis and development of breast cancer.

TUBB3 is associated with PTEN, neuroendocrine differentiation, and castration resistance in prostate cancer

BACKGROUND

Tubulin-β3 encoded by the Tubulin-β3 (TUBB3) gene is a microtubule protein. Previous studies have shown that TUBB3 expression is upregulated in castration-resistant prostate cancer (CaP) and is involved in taxane resistance. However, the biological mechanism of TUBB3 involvement in the progression to castration-resistant CaP is not fully elucidated. This study aimed to analyze the expression and function of TUBB3 in localized and metastatic CaP.

METHODS

TUBB3 expression was determined using immunohistochemistry in localized and metastatic CaP. We also investigated the association between TUBB3, phosphatase and tensin homolog (PTEN), and neuroendocrine differentiation and examined the involvement of TUBB3 in new antiandrogen drugs (enzalutamide and apalutamide) resistance in metastatic CaP.

RESULTS

In 155 cases of localized CaP, immunohistochemistry showed that 5 (3.2%) of the CaP cases were positive for tubulin-β3. Kaplan-Meier analysis showed that high expression of tubulin-β3 was associated with poor prostate-specific antigen recurrence-free survival after radical prostatectomy. In 57 cases of metastatic CaP, immunohistochemistry showed that 14 (25%) cases were positive for tubulin-β3. Tubulin-β3 expression was higher in metastatic CaP than in localized CaP. High tubulin-β3 expression was correlated with negative PTEN expression. TUBB3 expression was increased in neuroendocrine CaP based on several public databases. PTEN knockout decreased the sensitivity to enzalutamide and apalutamide in 22Rv-1 cells. TUBB3 knockdown reversed the sensitivity to enzalutamide and apalutamide in PTEN-CRISPR 22Rv-1 cells. High expression of tubulin-β3 and negative expression of PTEN were significantly associated with poor overall survival in metastatic CaP treated with androgen deprivation therapy.

CONCLUSIONS

These results suggest that TUBB3 may be a useful predictive biomarker for survival and play an essential role in antiandrogen resistance in CaP.

Enhanced Neural Differentiation Using Simultaneous Application of 3D Scaffold Culture, Fluid Flow, and Electrical Stimulation in Bioreactors

Neural differentiation is studied using a simultaneous application of 3D scaffold culture and hydrodynamic and electrical stimuli in purpose-designed recirculation bioreactors operated with continuous fluid flow. Pheochromocytoma (PC12) cells are seeded into nonwoven microfibrous viscose-rayon scaffolds functionalized with poly-l-lysine and laminin. Compared with the results from static control cultures with and without electrical stimulation and bioreactor cultures with the fluid flow without electrical stimulation, expression levels of the differentiation markers β3-tubulin, shootin1, and ephrin type-A receptor 2 are greatest when cells are cultured in bioreactors with fluid flow combined with in-situ electrical stimulus. Immunocytochemical assessment of neurite development and morphology within the scaffolds confirm the beneficial effects of exposing the cells to concurrent hydrodynamic and electrical treatments. Under the conditions tested, electrical stimulation by itself produces more pronounced levels of cell differentiation than fluid flow alone; however, significant additional improvements in differentiation are achieved by combining these treatments. Fluid flow and electrical stimuli exert independent and noninteractive effects on cellular differentiation, suggesting that interference between the mechanisms of differentiation enhancement by these two treatments is minimal during their simultaneous application. This work demonstrates the beneficial effects of combining several different potent physical environmental stimuli in cell culture systems to promote neurogenesis.

The sequence [EKRKI(E/R)(K/L/R/S/T)] is a nuclear localization signal for importin 7 binding (NLS7)

BACKGROUND

Nuclear translocation of large proteins is mediated through specific protein carriers, collectively named karyopherins (importins, exportins and adaptor proteins). Cargo proteins are recognized by importins through specific motifs, known as nuclear localization signals (NLS). However, only the NLS recognized by importin α and transportin (M9 NLS) have been identified so far METHODS: An unsupervised in silico approach was used, followed by experimental validation.

RESULTS

We identified the sequence EKRKI(E/R)(K/L/R/S/T) as an NLS signal for importin 7 recognition. This sequence was validated in the breast cancer cell line T47D, which expresses importin 7. Finally, we verified that importin 7-mediated nuclear protein transport is affected by cargo protein phosphorylation.

CONCLUSIONS

The NLS sequence for importin 7 was identified and we propose this approach as an identification method of novel specific NLS sequences for β-karyopherin family members.

GENERAL SIGNIFICANCE

Elucidating the complex relationships of the nuclear transporters and their cargo proteins may help in laying the foundation for the development of novel therapeutics, targeting specific importins, with an immediate translational impact.

Individualized chemotherapy guided by the expression of ERCC1, RRM1, TUBB3, TYMS and TOP2A genes versus classic chemotherapy in the treatment of breast cancer: A comparative effectiveness study

ERCC1, RRM1, TUBB3, TYMS and TOP2A genes have been shown to be associated with drug resistance in various types of tumors; however, their roles in breast cancer chemotherapy have not been fully validated. In the present study, 140 well-matched patients with breast cancer, comprising 70 patients receiving individualized chemotherapy and 70 receiving classic chemotherapy, were analyzed. In the individualized chemotherapy group, the mRNA expression levels of ERCC1, RRM1, TUBB3, TYMS and TOP2A in breast cancer tissues were measured using multiplex branched DNA liquidchip technology prior to chemotherapy; an individualized chemotherapy regimen was developed for each patient according to the results. As a control, patients in the classic chemotherapy group received a docetaxel + epirubicin + cyclophosphamide regimen. Survival analyses were performed using the Kaplan-Meier method. The prognostic factors for disease-free survival (DFS) and overall survival (OS) in the patients were identified via Cox's proportional hazards regression model. Adverse reactions were evaluated according to the National Cancer Institute Common Toxicity Criteria 4. Compared with the classic chemotherapy group, the DFS and OS of the individualized chemotherapy group were significantly longer (DFS, 77.4 vs. 67.1 months, P=0.039; OS, 81.4 vs. 75.4 months, P=0.031), and the incidence of grade 2 or 3 palpitations and chest tightness was lower (12.9 vs. 27.1%, P=0.035). The chemotherapy strategy guided by genetic detection was an independent protection factor for DFS [hazard ratio (HR)=0.389, 95% confidence interval (CI): 0.153, 0.989, P=0.047], but not an independent protection factor for OS (HR=0.340, 95% CI: 0.107, 1.078, P=0.067). The results indicate that the combined detection of ERCC1, RRM1, TUBB3, TYMS and TOP2A gene expression and use of the results to guide individualized chemotherapy can improve treatment efficacy and reduce unnecessary toxicity.

mRNA expression in low grade serous ovarian cancer: Results of a nanoString assay in a diverse population

OBJECTIVE

Mutations in the MAP kinase pathway (KRAS, NRAS, BRAF) are common in low grade serous ovarian carcinoma (LGSOC). The effect of these and other mutations on RNA transcription in this disease is poorly understood. Our objective was to describe patterns of somatic mutations and gene transcription in a racially diverse population with LGSOC.

METHODS

Utilizing an institutional tumor registry, patients with LGSOC were identified and charts were reviewed. RNA was extracted from available tumor tissue. Commercial tumor profiling results were analyzed with PanCancer pathway nanoString mRNA expression data. Along with nanoString n-Solver software, Chi-squared, Fishers Exact, and Cox proportional hazards models were used for statistical analysis, with significance set at p < 0.05.

RESULTS

39 patients were identified-20% Black, 43% Hispanic, and 36% non-Hispanic White. 18 patients had commercial somatic DNA test results, and 23 had available tumor tissue for RNA extraction and nanoString analysis. The most common somatic alterations identified was KRAS (11 patients, 61%), followed by ERCC1 and TUBB3 (9 each, 50%). KRAS mutations were less common in smokers (14.3% vs 90.9%, p = 0.002). RNA expression analysis demonstrated a greater than two-fold decrease in expression of HRAS in tumors from older patients (p = 0.04), and a greater than two-fold decrease in the expression of HRAS in recurrent tumors (p = 0.007). No significant differences were seen in somatic testing results, RNA expression analysis, or progression free survival between different racial and ethnic cohorts.

CONCLUSIONS

Somatic deficiencies in ERCC1, TUBB3, and KRAS are common in LGSOC in a population of minority patients. HRAS demonstrates decreased expression in tumors from older patients and recurrent tumors.

Stearoyl-CoA desaturase 5 (SCD5), a Δ-9 fatty acyl desaturase in search of a function

A large body of research has demonstrated that human stearoyl-CoA desaturase 1 (SCD1), a universally expressed fatty acid Δ9-desaturase that converts saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA), is a central regulator of metabolic and signaling pathways involved in cell proliferation, differentiation, and survival. Unlike SCD1, stearoyl-CoA desaturase 5 (SCD5), a second SCD isoform found in a variety of vertebrates, including humans, has received considerably less attention but new information on the catalytic properties, regulation and biological functions of this enzyme has begun to emerge. This review will examine the new evidence that supports key metabolic and biological roles for SCD5, as well as the potential implication of this desaturase in the mechanisms of human diseases.

Elevated intraocular pressure induces neuron-specific β-III-tubulin expression in non-neuronal vascular cells

PURPOSE

Pathological alterations within optic nerve axons and progressive loss of the parental retinal ganglion cell (RGC) bodies are characteristics of glaucomatous neuropathy. Abnormally elevated intraocular pressure (IOP) is thought to be the major risk factor for most forms of glaucomatous changes, while lowering of the IOP is the mainstream of treatment. However, the pathophysiological mechanisms involved in neurodegenerative changes are poorly understood. It remains still a matter of debate whether elevated IOP harms the neurons directly or indirectly through alterations in the retinal vascularization.

METHODS

We analysed morphological and molecular changes within the retina exposed to elevated IOP in an animal model of glaucoma in vivo, in retinal explants and in cultured dissociated retinal cells each incubated under elevated air pressure in vitro, imitating elevated IOP.

RESULTS

Although ß-III-tubulin expressing RGCs decreased within the course of the disease, total amount of ß-III-tubulin protein within the retina increased, leading to the assumption that other cells than RGCs abnormally express ß-III-tubulin due to elevated IOP. Surprisingly, we found that β-III-tubulin, a marker developmentally regulated and specifically expressed in neurons under normal conditions, was strongly up-regulated in desmin-, PDGFR-β- and α-SMA-positive pericytes as well as in endothelin-1-positive endothelial cells both in vivo under elevated IOP and in vitro under elevated culture atmosphere pressure that simulated IOP elevation. Beta-III-tubulin-driven signalling pathways (ERK 1/2, pERK1/2 and cdc42/Rac) were also regulated.

CONCLUSION

The unprecedented regulation of neuron-specific β-III-tubulin in pericytes and endothelial cells is likely associated with a role of the retinal vasculature in the IOP-induced development and manifestation of glaucomatous degenerative optic nerve response.

TUBB3 Is Associated with High-Grade Histology, Poor Prognosis, p53 Expression, and Cancer Stem Cell Markers in Clear Cell Renal Cell Carcinoma

BACKGROUND

βIII-Tubulin, encoded by the TUBB3 gene, is a microtubule protein. Several studies have shown that overexpression of TUBB3 is linked to poor prognosis and is involved in taxane resistance in some cancers.

OBJECTIVE

The aim of this study was to analyze the expression and function of TUBB3 in clear cell renal cell carcinoma (ccRCC).

METHODS

The expression of TUBB3 was determined using immuno-histochemistry in ccRCC specimens. The effects of TUBB3 knockdown on cell growth and invasion were evaluated in RCC cell lines. We analyzed the interaction between TUBB3, p53, cancer stem cell markers, and PD-L1.

RESULTS

In 137 cases of ccRCC, immunohistochemistry showed that 28 (20%) of the ccRCC cases were positive for TUBB3. High TUBB3 expression was significantly correlated with high nuclear grade, high T stage, and N stage. A Kaplan-Meier analysis showed that high expression of TUBB3 was associated with poor overall survival after nephrectomy. In silico analysis also showed that high TUBB3 expression was correlated with overall survival. Knockdown of TUBB3 suppressed cell growth and invasion in 786-O and Caki-1 cells. High TUBB3 expression was associated with CD44, CD133, PD-L1, and p53 in ccRCC. We generated p53 knockout cells using the CRISPR-Cas9 system. Western blotting revealed that p53 knockout upregulated the expression of TUBB3.

CONCLUSION

These results suggest that TUBB3 may play an oncogenic role and could be a potential therapeutic target in ccRCC.

Autoantibodies and Malaria: Where We Stand? Insights Into Pathogenesis and Protection

Autoantibodies are frequently reported in patients with malaria, but whether they contribute to protection or to pathology is an issue of debate. A large body of evidence indicates that antibodies against host-self components are associated to malaria clinical outcomes such as cerebral malaria, renal dysfunction and anemia. Nonetheless, self-reactive immunoglobulins induced during an infection can also mediate protection. In light of these controversies, we summarize here the latest findings in our understanding of autoimmune responses in malaria, focusing on Plasmodium falciparum and Plasmodium vivax. We review the main targets of self-antibody responses in malaria as well as the current, but still limited, knowledge of their role in disease pathogenesis or protection.