NF-κB p65 directs sex-specific neuroprotection in human neurons

The regulating effect of curcumin on NF-κB pathway in neurodegenerative diseases: a review of the underlying mechanisms

Neurodegenerative diseases are part of the central nervous system (CNS) disorders that indicate their presence with neuronal loss, neuroinflammation, and increased oxidative stress. Several pathophysiological factors and biomarkers are involved in this inflammatory process causing these neurological disorders. The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is an inflammation element, which induced transcription and appears to be one of the important players in physiological procedures, especially nervous disorders. NF-κB can impact upon series of intracellular actions and induce or inhibit many inflammation-related pathways. Multiple reports have focused on the modification of NF-κB activity, controlling its expression, translocation, and signaling pathway in neurodegenerative disorders and injuries like Alzheimer's disease (AD), spinal cord injuries (SCI), and Parkinson's disease (PD). Curcumin has been noted to be a popular anti-oxidant and anti-inflammatory substance and is the foremost natural compound produced by turmeric. According to various studies, when playing an anti-inflammatory role, it interacts with several modulating proteins of long-standing disease signaling pathways and has an unprovocative consequence on pro-inflammatory cytokines. This review article determined to figure out curcumin's role in limiting the promotion of neurodegenerative disease via influencing the NF-κB signaling route. Preclinical studies were gathered from plenty of scientific platforms including PubMed, Scopus, Cochrane, and Google Scholar to evaluate this hypothesis. Extracted findings from the literature review explained the repressing impact of Curcumin on the NF-κB signaling pathway and, occasionally down-regulating the cytokine expression. Yet, there is an essential need for further analysis and specific clinical experiments to fully understand this subject.

Long-term social isolation stress exacerbates sex-specific neurodegeneration markers in a natural model of Alzheimer's disease

Social interactions have a significant impact on health in humans and animal models. Social isolation initiates a cascade of stress-related physiological disorders and stands as a significant risk factor for a wide spectrum of morbidity and mortality. Indeed, social isolation stress (SIS) is indicative of cognitive decline and risk to neurodegenerative conditions, including Alzheimer's disease (AD). This study aimed to evaluate the impact of chronic, long-term SIS on the propensity to develop hallmarks of AD in young degus (Octodon degus), a long-lived animal model that mimics sporadic AD naturally. We examined inflammatory factors, bioenergetic status, reactive oxygen species (ROS), oxidative stress, antioxidants, abnormal proteins, tau protein, and amyloid-β (Aβ) levels in the hippocampus of female and male degus that were socially isolated from post-natal and post-weaning until adulthood. Additionally, we explored the effect of re-socialization following chronic isolation on these protein profiles. Our results showed that SIS promotes a pro-inflammatory scenario more severe in males, a response that was partially mitigated by a period of re-socialization. In addition, ATP levels, ROS, and markers of oxidative stress are severely affected in female degus, where a period of re-socialization fails to restore them as it does in males. In females, these effects might be linked to antioxidant enzymes like catalase, which experience a decline across all SIS treatments without recovery during re-socialization. Although in males, a previous enzyme in antioxidant pathway diminishes in all treatments, catalase rebounds during re-socialization. Notably, males have less mature neurons after chronic isolation, whereas phosphorylated tau and all detectable forms of Aβ increased in both sexes, persisting even post re-socialization. Collectively, these findings suggest that long-term SIS may render males more susceptible to inflammatory states, while females are predisposed to oxidative states. In both scenarios, the accumulation of tau and Aβ proteins increase the individual susceptibility to early-onset neurodegenerative conditions such as AD.

EPO regulates neuronal differentiation of adult human neural-crest derived stem cells in a sex-specific manner

BACKGROUND

Sexual differences in the biology of human stem cells are increasingly recognized to influence their proliferation, differentiation and maturation. Especially in neurodegenerative diseases such as Alzheimers disease (AD), Parkinson's disease (PD) or ischemic stroke, sex is a key player for disease progression and recovery of damaged tissue. Recently, the glycoprotein hormone erythropoietin (EPO) has been implicated as a regulator of neuronal differentiation and maturation in female rats.

METHODS

In this study, we used adult human neural crest-derived stem cells (NCSCs) as a model system for exploring potential sex specific effects of EPO on human neuronal differentiation. We started with expression validation of the specific EPO receptor (EPOR) by performing PCR analysis in the NCSCs. Next, EPO mediated activation of nuclear factor-κB (NF-κB) via Immunocytochemistry (ICC) was performed, followed by investigating the sex-specific effects of EPO on neuronal differentiation by determining morphological changes in axonal growth and neurite formation accompanied by ICC.

RESULTS

Undifferentiated male and female NCSCs showed a ubiquitous expression of the EPO receptor (EPOR). EPO treatment resulted in a statistically profound (male p = 0.0022, female p = 0.0012) nuclear translocation of NF-κB RELA in undifferentiated NCSCs of both sexes. But after one week of neuronal differentiation, we could show a highly significant (p = 0,0079) increase of nuclear NF-κB RELA in females only. In contrast, we observed a strong decrease (p = 0,0022) of RELA activation in male neuronal progenitors. Extending the view on the role of sex during human neuronal differentiation, here we demonstrate a significant increase of axon lengths in female NCSCs-derived neurons upon EPO-treatment (+ EPO: 167,73 (SD = 41,66) µm, w/o EPO: 77,68 (SD = 18,31) µm) compared to their male counterparts (+ EPO: 68,37 (SD = 11,97) µm, w/o EPO: 70,23 (SD = 12,89) µm).

CONCLUSION

Our present findings therefore show for the first time an EPO-driven sexual dimorphism in neuronal differentiation of human neural-crest derived stem cells and emphasize sex-specific variability as a crucial parameter in stem cell biology and for treating neurodegenerative diseases.

Systems level analysis of sex-dependent gene expression changes in Parkinson's disease

Parkinson's disease (PD) is a heterogeneous disorder, and among the factors which influence the symptom profile, biological sex has been reported to play a significant role. While males have a higher age-adjusted disease incidence and are more frequently affected by muscle rigidity, females present more often with disabling tremors. The molecular mechanisms involved in these differences are still largely unknown, and an improved understanding of the relevant factors may open new avenues for pharmacological disease modification. To help address this challenge, we conducted a meta-analysis of disease-associated molecular sex differences in brain transcriptomics data from case/control studies. Both sex-specific (alteration in only one sex) and sex-dimorphic changes (changes in both sexes, but with opposite direction) were identified. Using further systems level pathway and network analyses, coordinated sex-related alterations were studied. These analyses revealed significant disease-associated sex differences in mitochondrial pathways and highlight specific regulatory factors whose activity changes can explain downstream network alterations, propagated through gene regulatory cascades. Single-cell expression data analyses confirmed the main pathway-level changes observed in bulk transcriptomics data. Overall, our analyses revealed significant sex disparities in PD-associated transcriptomic changes, resulting in coordinated modulations of molecular processes. Among the regulatory factors involved, NR4A2 has already been reported to harbor rare mutations in familial PD and its pharmacological activation confers neuroprotective effects in toxin-induced models of Parkinsonism. Our observations suggest that NR4A2 may warrant further research as a potential adjuvant therapeutic target to address a subset of pathological molecular features of PD that display sex-associated profiles.

NF-κB in neurodegenerative diseases: Recent evidence from human genetics

The transcription factor NF-κB is commonly known to drive inflammation and cancer progression, but is also a crucial regulator of a broad range of cellular processes within the mammalian nervous system. In the present review, we provide an overview on the role of NF-κB in the nervous system particularly including its constitutive activity within cortical and hippocampal regions, neuroprotection as well as learning and memory. Our discussion further emphasizes the increasing role of human genetics in neurodegenerative disorders, namely, germline mutations leading to defects in NF-κB-signaling. In particular, we propose that loss of function mutations upstream of NF-κB such as ADAM17, SHARPIN, HOIL, or OTULIN affect NF-κB-activity in Alzheimer’s disease (AD) patients, in turn driving anatomical defects such as shrinkage of entorhinal cortex and the limbic system in early AD. Similarly, E3 type ubiquitin ligase PARKIN is positively involved in NF-κB signaling. PARKIN loss of function mutations are most frequently observed in Parkinson’s disease patients. In contrast to AD, relying on germline mutations of week alleles and a disease development over decades, somatic mutations affecting NF-κB activation are commonly observed in cells derived from glioblastoma multiforme (GBM), the most common malignant primary brain tumor. Here, our present review particularly sheds light on the mutual exclusion of either the deletion of NFKBIA or amplification of epidermal growth factor receptor (EGFR) in GBM, both resulting in constitutive NF-κB-activity driving tumorigenesis. We also discuss emerging roles of long non-coding RNAs such as HOTAIR in suppressing phosphorylation of IκBα in the context of GBM. In summary, the recent progress in the genetic analysis of patients, particularly those suffering from AD, harbors the potential to open up new vistas for research and therapy based on TNFα/NF-κB pathway and neuroprotection.

History in Perspective: The Prime Pathological Players and Role of Phytochemicals in Alzheimer’s Disease

Alzheimer's disease is a steadily progressive, irreversible neurological disorder that is most frequently categorized under the umbrella term "neurodegeneration". Several attempts are underway to clarify the pathogenic mechanisms, identify the aetiologies, and determine a pathway by which the therapeutic steps can be implemented. Oxidative stress is one of the pathogenic processes, which is commonly believed to be associated with neurodegenerative diseases. Accumulation of extracellular amyloid-β protein (Aβ), hyperphosphorylation of tau, initiation of neurometabolic reactions characterized by the loss of neuronal function and synaptic failure, and decreased or lost learning capability and memory function are the most central neuropathological characteristics of AD. According to the amyloid cascade hypothesis, the enhanced deposition of Aβ deposits and neurofibrillary tangles due to hyperphosphorylation of Tau activates the cascade reactions in the brain. These reactions affect the synaptic activity and activation of microglia, which results in neuroinflammation due to enhanced immune function. Plant-based phytochemicals have also been used long ago against several diseases. Phytoconstituents play a significant neuroprotective property by preventing the pathophysiology of the disease. In this review, we have discussed the formation and crosstalk between amyloid and tau pathologies as well as the effect of neuroinflammation on the progression of AD. We have specifically focused on the formation of NFT, β-amyloids, inflammation, and pathophysiology of AD and the role of phytochemicals in the prevention of AD.

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AD is an insidious, slowly progressive, and neurodegenerative disorder.

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Common symptoms are memory loss, difficulty in recalling, and understanding.

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β-amyloids and Neurofibrillary tangles are the main factors in AD pathogenesis.

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Activated microglia and oxidative stress have different effects on AD progression.

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Phytochemicals show a key role against AD by inhibiting several pathways.

Inter- and Intrapopulational Heterogeneity of Characteristic Markers in Adult Human Neural Crest-derived Stem Cells

Adult human neural crest-derived stem cells (NCSCs) are found in a variety of adult tissues and show an extraordinary broad developmental potential. Despite their great differentiation capacity, increasing evidence suggest a remaining niche-dependent variability between different NCSC-populations regarding their differentiation behavior and expression signatures. In the present study, we extended the view on heterogeneity of NCSCs by identifying heterogeneous expression levels and protein amounts of characteristic markers even between NCSCs from the same niche of origin. In particular, populations of neural crest-derived inferior turbinate stem cells (ITSCs) isolated from different individuals showed significant variations in characteristic NCSC marker proteins Nestin, S100 and Slug in a donor-dependent manner. Notably, increased nuclear protein amounts of Slug were accompanied by a significantly elevated level of nuclear NF-κB-p65 protein, suggesting an NF-κB-dependent regulation of NCSC-makers. In addition to this interpopulational genetic heterogeneity of ITSC-populations from different donors, single ITSCs also revealed a strong heterogeneity regarding the protein amounts of Nestin, S100, Slug and NF-κB-p65 even within the same clonal culture. Our present findings therefor strongly suggest ITSC-heterogeneity to be at least partly based on an interpopulational genetic heterogeneity dependent on the donor accompanied by a stochastic intrapopulational heterogeneity between single cells. We propose this stochastic intrapopulational heterogeneity to occur in addition to the already described genetic variability between clonal NCSC-cultures and the niche-dependent plasticity of NCSCs. Our observations offer a novel perspective on NCSC-heterogeneity, which may build the basis to understand heterogeneous NCSC-behavior.

Neuroprotection Mediated by Human Blood Plasma in Mouse Hippocampal Slice Cultures and in Oxidatively Stressed Human Neurons

Neuroprotection from oxidative stress is critical during neuronal development and maintenance but also plays a major role in the pathogenesis and potential treatment of various neurological disorders and neurodegenerative diseases. Emerging evidence in the murine system suggests neuroprotective effects of blood plasma on the aged or diseased brain. However, little is known about plasma-mediated effects on human neurons. In the present study, we demonstrate the neuroprotective effect mediated by human plasma and the most abundant plasma–protein human serum albumin against oxidative stress in glutamatergic neurons differentiated from human neural crest-derived inferior turbinate stem cells. We observed a strong neuroprotective effect of human plasma and human serum albumin against oxidative stress-induced neuronal death on the single cell level, similar to the one mediated by tumor necrosis factor alpha. Moreover, we detected neuroprotection of plasma and human serum albumin against kainic acid-induced excitatory stress in ex vivo cultured mouse hippocampal tissue slices. The present study provides deeper insights into plasma-mediated neuroprotection ultimately resulting in the development of novel therapies for a variety of neurological and, in particular, neurodegenerative diseases.

The Transcription Factor NF-κB in Stem Cells and Development

NF-κB (nuclear factor kappa B) belongs to a family of transcription factors known to regulate a broad range of processes such as immune cell function, proliferation and cancer, neuroprotection, and long-term memory. Upcoming fields of NF-κB research include its role in stem cells and developmental processes. In the present review, we discuss one role of NF-κB in development in Drosophila, Xenopus, mice, and humans in accordance with the concept of evo-devo (evolutionary developmental biology). REL domain-containing proteins of the NF-κB family are evolutionarily conserved among these species. In addition, we summarize cellular phenotypes such as defective B- and T-cell compartments related to genetic NF-κB defects detected among different species. While NF-κB proteins are present in nearly all differentiated cell types, mouse and human embryonic stem cells do not contain NF-κB proteins, potentially due to miRNA-dependent inhibition. However, the mesodermal and neuroectodermal differentiation of mouse and human embryonic stem cells is hampered upon the repression of NF-κB. We further discuss NF-κB as a crucial regulator of differentiation in adult stem cells such as neural crest-derived and mesenchymal stem cells. In particular, c-REL seems to be important for neuronal differentiation and the neuroprotection of human adult stem cells, while RELA plays a crucial role in osteogenic and mesodermal differentiation.

Between Fate Choice and Self-Renewal-Heterogeneity of Adult Neural Crest-Derived Stem Cells

Stem cells of the neural crest (NC) vitally participate to embryonic development, but also remain in distinct niches as quiescent neural crest-derived stem cell (NCSC) pools into adulthood. Although NCSC-populations share a high capacity for self-renewal and differentiation resulting in promising preclinical applications within the last two decades, inter- and intrapopulational differences exist in terms of their expression signatures and regenerative capability. Differentiation and self-renewal of stem cells in developmental and regenerative contexts are partially regulated by the niche or culture condition and further influenced by single cell decision processes, making cell-to-cell variation and heterogeneity critical for understanding adult stem cell populations. The present review summarizes current knowledge of the cellular heterogeneity within NCSC-populations located in distinct craniofacial and trunk niches including the nasal cavity, olfactory bulb, oral tissues or skin. We shed light on the impact of intrapopulational heterogeneity on fate specifications and plasticity of NCSCs in their niches in vivo as well as during in vitro culture. We further discuss underlying molecular regulators determining fate specifications of NCSCs, suggesting a regulatory network including NF-κB and NC-related transcription factors like SLUG and SOX9 accompanied by Wnt- and MAPK-signaling to orchestrate NCSC stemness and differentiation. In summary, adult NCSCs show a broad heterogeneity on the level of the donor and the donors' sex, the cell population and the single stem cell directly impacting their differentiation capability and fate choices in vivo and in vitro. The findings discussed here emphasize heterogeneity of NCSCs as a crucial parameter for understanding their role in tissue homeostasis and regeneration and for improving their applicability in regenerative medicine.

Increased Retinal Ganglion Cell Survival by Exogenous IL-2 Depends on IL-10, Dopamine D1 Receptors, and Classical IL-2/IL-2R Signaling Pathways

Interleukin-2 (IL-2) is a classical pro-inflammatory cytokine known to display neuroprotective roles in the central nervous system including the retina. In the present study, we investigate the molecular targets involved in the neurotrophic effect of IL-2 on retinal ganglion cells (RGC) after optic nerve axotomy. Analysis of retrograde labeling of RGC showed that common cell survival mediators, as Trk receptors, Src, PI3K, PKC, and intracellular calcium do not mediate the neurotrophic effect of IL-2 on RGC. No involvement of MAPK p38 was also observed. However, other MAPKs as MEK and JNK appear to be mediating this IL-2 effect. Our data also indicate that JAK2/3 are important intracellular proteins for the IL-2 effect. Interestingly, we demonstrate that the IL-2 effect depends on dopamine D1 receptors (D1R), the cAMP/PKA pathway, interleukin-10 (IL-10), and NF-κB, suggesting that RGC survival induced by IL-2 encompasses a molecular network of major complexity. In addition, treatment of retinal cells with recombinant IL-10 or 6-Cl-pb (D1R full agonist) was able to increase RGC survival similar to IL-2. Taken together, our results suggest that after optic nerve axotomy, the increase in RGC survival triggered by IL-2 is mediated by IL-10 and D1R along with the intracellular pathways of MAPKs, JAK/STAT, and cAMP/PKA.

Candidate Alzheimer's Disease Biomarker miR-483-5p Lowers TAU Phosphorylation by Direct ERK1/2 Repression

MicroRNAs have been demonstrated as key regulators of gene expression in the etiology of a range of diseases including Alzheimer's disease (AD). Recently, we identified miR-483-5p as the most upregulated miRNA amongst a panel of miRNAs in blood plasma specific to prodromal, early-stage Alzheimer's disease patients. Here, we investigated the functional role of miR-483-5p in AD pathology. Using TargetScan and miRTarBase, we identified the microtubule-associated protein MAPT, often referred to as TAU, and the extracellular signal-regulated kinases 1 and 2 (ERK1 and ERK2), known to phosphorylate TAU, as predicted direct targets of miR-483-5p. Employing several functional assays, we found that miR-483-5p regulates ERK1 and ERK2 at both mRNA and protein levels, resulting in lower levels of phosphorylated forms of both kinases. Moreover, miR-483-5p-mediated repression of ERK1/2 resulted in reduced phosphorylation of TAU protein at epitopes associated with TAU neurofibrillary pathology in AD. These results indicate that upregulation of miR-483-5p can decrease phosphorylation of TAU via ERK pathway, representing a compensatory neuroprotective mechanism in AD pathology. This miR-483-5p/ERK1/TAU axis thus represents a novel target for intervention in AD.

Interaction of NF-κB and Wnt/β-catenin Signaling Pathways in Alzheimer's Disease and Potential Active Drug Treatments

The most important neuropathological features of Alzheimer's disease (AD) are extracellular amyloid-β protein (Aβ) deposition, tau protein hyperphosphorylation and activation of neurometabolic reaction in the brain accompanied by neuronal and synaptic damage, and impaired learning and memory function. According to the amyloid cascade hypothesis, increased Aβ deposits in the brain to form the core of the senile plaques that initiate cascade reactions, affecting the synapses and stimulating activation of microglia, resulting in neuroinflammation. A growing number of studies has shown that NF-κB and Wnt/β-catenin pathways play important roles in neurodegenerative diseases, especially AD. In this review, we briefly introduce the connection between neuroinflammation-mediated synaptic dysfunction in AD and elaborated on the mechanism of these two signaling pathways in AD-related pathological changes, as well as their interaction. Based on our interest in natural compounds, we also briefly introduce and conduct preliminary screening of potential therapeutics for AD.

Transcriptome Analysis Reveals High Similarities between Adult Human Cardiac Stem Cells and Neural Crest-Derived Stem Cells

For the identification of a stem cell population, the comparison of transcriptome data enables the simultaneous analysis of tens of thousands of molecular markers and thus enables the precise distinction of even closely related populations. Here, we utilized global gene expression profiling to compare two adult human stem cell populations, namely neural crest-derived inferior turbinate stem cells (ITSCs) of the nasal cavity and human cardiac stem cells (hCSCs) from the heart auricle. We detected high similarities between the transcriptomes of both stem cell populations, particularly including a range of neural crest-associated genes. However, global gene expression likewise reflected differences between the stem cell populations with regard to their niches of origin. In a broader analysis, we further identified clear similarities between ITSCs, hCSCs and other adherent stem cell populations compared to non-adherent hematopoietic progenitor cells. In summary, our observations reveal high similarities between adult human cardiac stem cells and neural crest-derived stem cells from the nasal cavity, which include a shared relation to the neural crest. The analyses provided here may help to understand underlying molecular regulators determining differences between adult human stem cell populations.

GWAS of Post-Orthodontic Aggressive External Apical Root Resorption Identified Multiple Putative Loci at X-Y Chromosomes

Personalized dental medicine requires from precise and customized genomic diagnostic. To conduct an association analysis over multiple putative loci and genes located at chromosomes 2, 4, 8, 12, 18, X, and Y, potentially implicated in an extreme type of external apical root resorption secondary to orthodontic forces (aEARR). A genome-wide association study of aEARR was conducted with 480 patients [ratio~1:3 case/control]. Genomic DNA was extracted and analyzed using the high-throughput Axiom platform with the GeneTitan^® MC Instrument. Up to 14,377 single nucleotide polymorphisms (SNPs) were selected at candidate regions and clinical/diagnostic data were recorded. A descriptive analysis of the data along with a backward conditional binary logistic regression was used to calculate odds ratios, with 95% confidence intervals [p < 0.05]. To select the best SNP candidates, a logistic regression model was fitted assuming a log-additive genetic model using R software [p < 0.0001]. In this sample the top lead genetic variants associated with aEARR were two novel putative genes located in the X chromosome, specifically, STAG 2 gene, rs151184635 and RP1-30E17.2 gene, rs55839915. These variants were found to be associated with an increased risk of aEARR, particularly restricted to men [OR: 6.09; 95%CI: 2.6–14.23 and OR: 6.86; 95%CI: 2.65–17.81, respectively]. Marginal associations were found at previously studied variants such as SSP1: rs11730582 [OR: 0.54; 95%CI: 0.34–0.86; p = 0.008], P2RX7: rs1718119 [OR: 0.6; 95%CI: 0.36–1.01; p = 0.047], and TNFRSF11A: rs8086340 [OR: 0.6; 95%CI: 0.38–0.95; p = 0.024]), found solely in females. Multiple putative genetic variants located at chromosomes X and Y are potentially implicated in an extreme phenotype of aEARR. A gender-linked association was noted.

Effect of α2‑macroglobulin in the early stage of jaw osteoradionecrosis

Advanced osteoradionecrosis (ORN) is one of the most serious complications in patients with head and neck cancer, resulting in poor prognosis. Numerous studies have therefore focused on the pathogenesis and interventions of ORN early stage. The present study aimed to investigate whether α2-macroglobulin (α2M) could prevent early-stage jaw osteoradionecrosis caused by radiotherapy (RT). Following local injection of α2M, a single dose of 30 Gy was delivered to rats for pathological exploration. For 28 days, the irradiated mandible and soft tissues were examined for potential changes. Furthermore, primary human bone marrow mesenchymal stem cells pretreated with α2M followed by 8 Gy irradiation (IR) were also used. Tartrate-resistant acid phosphatase assay, terminal uridine deoxynucleotidyl nick end labeling assay and immunohistochemical staining were performed on irradiated mandibular bone, tongue or buccal mucosa tissues from rats. Cell proliferation was assessed by evaluating the cell morphology by microscopy and by using the cell counting kit-8. Fluorescence staining, flow cytometry and western blotting were conducted to detect the reactive oxygen species level, cell apoptosis and protein expression of superoxide dismutase 2 (SOD2), heme oxygenase-1 (HO-1) and phosphorylated Akt following irradiation. The results demonstrated that α2M attenuated physical inflammation, osteoclasts number and fat vacuole accumulation in mandibular bone marrow and bone marrow cell apoptosis following IR in vivo. Furthermore, α2M pretreatment suppressed the expression of 8-hydroxy-2′-deoxyguanosine in mandibular bone and tongue paraffin embedded sections, which is a marker of oxidative damage, and increased SOD2 expression in mucosa and tongue paraffin embedded sections. The present study demonstrated the efficient regulation of antioxidative enzymes, including SOD2 and heme oxygenase-1, and reduction in oxidative damage by α2M. In addition, in vitro results confirmed that α2M may protect cells from apoptosis and suppress reactive oxygen species accumulation. Overall, the present study demonstrated that α2M treatment may exert some radioprotective effects in early-stage ORN via antioxidant mechanisms, and may therefore be considered as a potential alternative molecule in clinical prophylactic treatments.

A Matter of Choice: Inhibition of c-Rel Shifts Neuronal to Oligodendroglial Fate in Human Stem Cells

The molecular mechanisms underlying fate decisions of human neural stem cells (hNSCs) between neurogenesis and gliogenesis are critical during neuronal development and neurodegenerative diseases. Despite its crucial role in the murine nervous system, the potential role of the transcription factor NF-κB in the neuronal development of hNSCs is poorly understood. Here, we analyzed NF-κB subunit distribution during glutamatergic differentiation of hNSCs originating from neural crest-derived stem cells. We observed several peaks of specific NF-κB subunits. The most prominent nuclear peak was shown by c-REL subunit during a period of 2–5 days after differentiation onset. Furthermore, c-REL inhibition with pentoxifylline (PTXF) resulted in a complete shift towards oligodendroglial fate, as demonstrated by the presence of OLIG2⁺/O4⁺-oligodendrocytes, which showed PDGFRα, NG2 and MBP at the transcript level. In addition c-REL impairment further produced a significant decrease in neuronal survival. Transplantation of PTXF-treated predifferentiated hNSCs into an ex vivo oxidative-stress-mediated demyelination model of mouse organotypic cerebellar slices further led to integration in the white matter and differentiation into MBP⁺ oligodendrocytes, validating their functionality and therapeutic potential. In summary, we present a human cellular model of neuronal differentiation exhibiting a novel essential function of NF-κB-c-REL in fate choice between neurogenesis and oligodendrogenesis which will potentially be relevant for multiple sclerosis and schizophrenia.

Effects of genistein on lipopolysaccharide-induced injury of mouse alveolar epithelial cells and its mechanism

Alveolar and bronchial epithelial cells have critical functions in acute respiratory distress syndrome progress. Genistein could protect the lungs from acute lung injury, however, whether genistein protects the alveolar epithelial cells from LPS-induced injury was less studied. Spectrophotometric method 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and enzyme-linked immunosorbent assay (ELISA) were performed to detect cell viability and levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6. Flow cytometry and western blot assay were performed to detect cells apoptosis and protein levels. In LPS-induced model of mouse lung epithelial (MLE)-12 cells, PBEF (proinflammatory cytokine) expression, and cell apoptosis were increased and cell viability was decreased, whereas NF-κB was activated and expression levels of TNF-α, IL-1β, and IL-6 were increased. However, genistein partly reversed the effect of LPS, and it plays a protective role in lung injury by reducing expression of PBEF, inhibiting the activation of NF-κB and alleviating inflammatory response of cells.

Sexual dimorphisms in adult human neural, mesoderm-derived, and neural crest-derived stem cells

Sexual dimorphisms contribute, at least in part, to the severity and occurrence of a broad range of neurodegenerative, cardiovascular, and bone disorders. In addition to hormonal factors, increasing evidence suggests that stem cell-intrinsic mechanisms account for sex-specific differences in human physiology and pathology. Here, we discuss sex-related intrinsic mechanisms in adult stem cell populations, namely mesoderm-derived stem cells, neural stem cells (NSCs), and neural crest-derived stem cells (NCSCs), and their implications for stem cell differentiation and regeneration. We particularly focus on sex-specific differences in stem cell-mediated bone regeneration, in neuronal development, and in NSC-mediated neuroprotection. Moreover, we review our own recently published observations regarding the sex-dependent role of NF-κB-p65 in neuroprotection of human NCSC-derived neurons and sex differences in NCSC-related disorders, so-called neurocristopathies. These observations are in accordance with the increasing evidence pointing toward sex-specific differences in neurocristopathies and degenerative diseases like Parkinson's disease or osteoporosis. All findings discussed here indicate that sex-specific variability in stem cell biology may become a crucial parameter for the design of future treatment strategies.