The Neurokinin-1 Receptor Is Essential for the Viability of Human Glioma Cells: A Possible Target for Treating Glioblastoma.

Background: Glioblastoma or glioma is the most common malignant brain tumor. Patients have a prognosis of approximately 15 months, despite the current aggressive treatment. Neurokinin-1 receptor (NK-1R) occurs naturally in human glioma, and it is necessary for the tumor development. Objective: The purpose of the study was to increase the knowledge about the involvement of the substance P (SP)/NK-1R system in human glioma. Methods: Cellular localization of NK-1R and SP was studied in GAMG and U-87 MG glioma cell lines by immunofluorescence. The contribution of both SP and NK-1R to the viability of these cells was also assessed after applying the tachykinin 1 receptor (TAC1R) or the tachykinin 1 (TAC1) small interfering RNA gene silencing method, respectively. Results: Both SP and the NK-1R (full-length and truncated isoforms) were localized in the nucleus and cytoplasm of GAMG and U-87 MG glioma cells. The presence of full-length NK-1R isoform was mainly observed in the nucleus, while the level of truncated isoform was higher in the cytoplasm. Cell proliferation was decreased when glioma cells were transfected with TAC1R siRNA, but not with TAC1. U-87 MG cells were more sensitive to the effect of the TAC1R inhibition than GAMG cells. The decrease in the number of glioma cells after silencing of the TAC1R siRNA gene was due to apoptotic and necrotic mechanisms. In human primary fibroblast cultured cells, TAC1R silencing by siRNA did not produce any change in cell viability. Conclusions: Our results show for the first time that the expression of the TAC1R gene (NK-1R) is essential for the viability of GAMG and U-87 MG glioma cells. On the contrary, the TAC1R gene is not essential for the viability of normal cells, confirming that NK-1R could be a promising and specific therapeutic target for the treatment of glioma.

Map kinase signaling as therapeutic target for neurodegeneration.

Aging is known to be one of the major risk factors in many neurodegenerative diseases (ND) whose prevalence is estimated to rise in the coming years due to the increase in life expectancy. Examples of neurodegenerative diseases include Huntington's, Parkinson's, and Alzheimer's diseases, along with Amyotrophic Lateral Sclerosis, Spinocerebellar ataxias and Frontotemporal Dementia. Given that so far these ND do not have effective pharmacological therapies, a better understanding of the molecular and cellular mechanisms can contribute to development of effective treatments. During the previous decade, the data indicated that dysregulation of MAP kinases [which included c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1 and 2 (ERK1/2), and p38] are associated with several stages of the inflammatory process which in turn contributes to age-related neurodegenerative diseases. This evidence suggests that control of inflammation through regulation of MAP kinase could be a worthwhile approach against neurodegenerative diseases. In this review we summarize the pathways of MAP kinase signal transduction and different pharmacological inhibitors that can be used in its modulation against ND.

Effect of Age and Lipoperoxidation in Rat and Human Adipose Tissue-Derived Stem Cells.

A wide range of clinical applications in regenerative medicine were opened decades ago with the discovery of adult stem cells. Highly promising adult stem cells are mesenchymal stem/stromal cells derived from adipose tissue (ADSCs), primarily because of their abundance and accessibility. These cells have multipotent properties and have been used extensively to carry out autologous transplants. However, the biology of these cells is not entirely understood. Among other factors, the regeneration capacity of these cells will depend on both their capacity of proliferation/differentiation and the robustness of the biochemical pathways that allow them to survive under adverse conditions like those found in damaged tissues. The transcription factors, such as Nanog and Sox2, have been described as playing an important role in stem cell proliferation and differentiation. Also, the so-called longevity pathways, in which AMPK and SIRT1 proteins play a crucial role, are essential for cell homeostasis under stressful situations. These pathways act by inhibiting the translation through downregulation of elongation factor-2 (eEF2). In order to deepen knowledge of mesenchymal stem cell biology and which factors are determinant in the final therapeutic output, we evaluate in the present study the levels of all of these proteins in the ADSCs from humans and rats and how these levels are affected by aging and the oxidative environment. Due to the effect of aging and oxidative stress, our results suggest that before performing a cell therapy with ADSCs, several aspects reported in this study such as oxidative stress status and proliferation and differentiation capacity should be assessed on these cells. This would allow us to know the robustness of the transplanted cells and to predict the therapeutic result, especially in elder patients, where probably ADSCs do not carry out their biological functions in an optimal way.

Targeting BDNF signaling by natural products: Novel synaptic repair therapeutics for neurodegeneration and behavior disorders.

Neurodegenerative disorders like Alzheimer's disease, Huntington's disease, Parkinson's disease, spinocerebellar ataxias, amyotrophic lateral sclerosis, frontotemporal dementia to prion diseases, Friedreich's ataxia, hereditary spastic paraplegia and optic atrophy type 1, and behavior disorders like neuropsychiatric, hyperactivity and autism spectrum disorders are closely associated with neurobiological deficits. Brain derived neurotrophic factor (BDNF) is an extensively studied neurotrophin. BDNF is essential for neuronal genesis, differentiation, survival, growth, plasticity, synaptic viability and transmission. BDNF has emerged as a promising target for regulating synaptic activity and plasticity. An overview of effects and mechanisms of the natural products targeting BDNF is described. This review is an attempt to enumerate the effects of various natural products on BDNF as a novel therapeutic approach for neurodegenerative and neuropsychiatric disorders.

Phosphodiesterase inhibitors say NO to Alzheimer's disease.

Phosphodiesterases (PDEs) consisted of 11 subtypes (PDE1 to PDE11) and over 40 isoforms that regulate levels of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), the second messengers in cell functions. PDE inhibitors (PDEIs) have been attractive therapeutic targets due to their involvement in diverse medical conditions, e.g. cardiovascular diseases, autoimmune diseases, Alzheimer's disease (AD), etc. Among them; AD with a complex pathology is a progressive neurodegenerative disorder which affect mostly senile people in the world and only symptomatic treatment particularly using cholinesterase inhibitors in clinic is available at the moment for AD. Consequently, novel treatment strategies towards AD are still searched extensively. Since PDEs are broadly expressed in the brain, PDEIs are considered to modulate neurodegenerative conditions through regulating cAMP and cGMP in the brain. In this sense, several synthetic or natural molecules inhibiting various PDE subtypes such as rolipram and roflumilast (PDE4 inhibitors), vinpocetine (PDE1 inhibitor), cilostazol and milrinone (PDE3 inhibitors), sildenafil and tadalafil (PDE5 inhibitors), etc have been reported showing encouraging results for the treatment of AD. In this review, PDE superfamily will be scrutinized from the view point of structural features, isoforms, functions and pharmacology particularly attributed to PDEs as target for AD therapy.

Targeting pro-senescence mitogen activated protein kinase (Mapk) enzymes with bioactive natural compounds.

Aging is a multifactorial universal process characterized by a gradual decrease in physiological and biochemical functions. Given that life expectancy is on the rise, a better understanding of molecular mechanisms of the aging process is necessary in order to develop anti-aging interventions. Uncontrolled cellular senescence promotes persistent inflammation and accelerates the aging process by decreasing tissue renewal, repair and regeneration. Senescence of immune cells, immunesenescence, is another hallmark of aging. Targeting pro-senescent enzymes increases survival and therefore the lifespan. Although the upregulation of Mitogen Activated Protein Kinases (MAPK) enzymes in aging is still controversial, increasing evidence shows that dysregulation of those enzymes are associated with biological processes that contribute to aging such as irreversible senescence. In this manuscript components of the MAPK pathway will be summarized, including extracellular signal-regulated kinase 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38, as well as natural flavonoids, phenolic and diterpenoids with anti-senescence activity that shows positive effects on longevity and MAPK inhibition. Although more studies using additional aging models are needed, we suggest that these selected natural bioactive compounds that regulate MAPK enzymes and reduce senescent cells can be potentially used to improve longevity and prevent/treat age-related diseases.

Hydroxytyrosol protects from aging process via AMPK and autophagy; a review of its effects on cancer, metabolic syndrome, osteoporosis, immune-mediated and neurodegenerative diseases.

Aging is a complex process. It is considered a risk factor for several diseases such as cancer, neurodegenerative diseases, cardiovascular diseases, and diabetes, most of which have an oxidative and inflammatory base. Given that life expectancy is increasing, there is a present interest in the search for anti-aging strategies that allow a healthy aging. Interestingly, in Spain, where the Mediterranean Diet (MD) is the reference food pattern, life expectancy will have the highest average by 2040. This diet is characterized, among other items, by virgin olive oil intake, which contains between 50-200 mg/kg of hydroxytyrosol, a major polyphenolic component of olive oil. Hydroxytyrosol is formed by the hydrolysis of oleuropein during the maturing of olives, storage of olive oil, and preparation of table olives. It is a yield of oleuropein by microbiota action in the organism after virgin olive oil consumption. The daily intake in context of the MD is estimated to be around 0.15 and 30 mg/day. In the last few years, hydroxytyrosol has received increasing attention due to its multiple pharmacological activities, such as antioxidant, anti-inflammatory and pro-apoptotic activities. It has also been the focus of extensive research regarding its bioactivity. In this sense, hydroxytyrosol is under consideration for the development of new anti-aging strategies. In this review we will summarize the potential anti-aging effects of hydroxytyrosol and its protective role in several age-related diseases.

Advantages and disadvantages of apoptosis in the aging process.

Researchers cannot predict as yet how long a human being can live. Life expectancy has been steadily increasing in the last century, but perhaps not always the quality of life in parallel with it. Future generations will be faced with the problems of an increased life expectancy along with the emergence of new age-related diseases. A deeper understanding of the aging process is crucial to ameliorate, if not to prevent, these projected new old-age diseases. One of the mechanisms responsible for healthy aging is through the effective maintenance of physiological, biochemical, and immunological functions. To carry this out, the organism needs to create new cells to replace old ones and to induce the disappearance of old and damaged cells. Apoptosis is involved in all these processes. However, if apoptosis is dysregulated, premature senescence-associated diseases are likely to appear. In our review, the focus will be on a better understanding of the role of apoptosis in the aging process. These signaling pathways will most assuredly be pharmacologically targeted in antiaging medicine therapies.

Dysregulation of the Hippo pathway signaling in aging and cancer.

Human beings are facing emerging degenerative and cancer diseases, in large part, as a consequence of increased life expectancy. In the near future, researchers will have to put even more effort into fighting these new challenges, one of which will be prevention of cancer while continuing to improve the aging process through this increased life expectancy. In the last few decades, relevance of the Hippo pathway on cancer has become an important study since it is a major regulator of organ size control and proliferation. However, its deregulation can induce tumors throughout the body by regulating cell proliferation, disrupting cell polarity, releasing YAP and TAZ from the Scribble complexes and facilitating survival gene expression via activation of TEAD transcription factors. This pathway is also involved in some of the most important mechanisms that control the aging processes, such as the AMP-activated protein kinase and sirtuin pathways, along with autophagy and oxidative stress response/antioxidant defense. This could be the link between two tightly connected processes that could open a broader range of targeted molecular therapies to fight aging and cancer. Therefore, available knowledge of the processes involved in the Hippo pathway during aging and cancer must necessarily be well understood.

Adipose-derived stem cells decreased microglia activation and protected dopaminergic loss in rat lipopolysaccharide model.

Adult stem cell therapy is being used extensively to rejuvenate damaged tissue. One important tissue source to obtain these cells is adipose, which contains cells called adipose-derived stem cells (ADSCs). These cells have a great therapeutic potential not only for their multipotent properties as well as for immunomodulatory effects on the immune system. Parkinson's disease is characterized as neurodegenerative disorder which etiology is undoubtedly related to neuroinflammation process. The properties of ADSCs can be used as a new tool in stem cells therapy to treat neurodegenerative disorders. However, their efficacies are still controversial. Some authors have reported neuroprotection effects, while others did not find differences or stem cells increased the damage. Our previous study showed that ADSCs can survive long time after transplantation, suggesting us some biological effects could need more time to be repaired. In this study, we assessed the neuroprotection 6 months after transplantation. Our results suggest ADSCs can protect the dopaminergic loss after lipopolysaccharide (LPS) injection both reducing the microglia activation and differentiating into dopaminergic cells.

Uric acid enhances longevity and endurance and protects the brain against ischemia.

Among mammals, there is a positive correlation between serum uric acid (UA) levels and life span. Humans have high levels of UA because they lack a functional urate oxidase (UOX) enzyme that is present in shorter lived mammals. Here, we show that male and female mice with UOX haploinsufficiency exhibit an age-related elevation of UA levels, and that the life span of female but not male UOX+/- mice is significantly increased compared to wild-type mice. Serum UA levels are elevated in response to treadmill exercise in UOX+/- mice, but not wild-type mice, and the endurance of the UOX+/- mice is significantly greater than wild-type mice. UOX+/- mice exhibit elevated levels of brain-derived neurotrophic factor, reduced brain damage and improved functional outcome in a model of focal ischemic stroke. Levels of oxidative protein nitration and lipid peroxidation are reduced in muscle and brain tissues of UOX+/- mice under conditions of metabolic and oxidative stress (running in the case of muscle and ischemia in the case of the brain), consistent with prior evidence that UA can scavenge peroxynitrite and hydroxyl radical. Our findings reveal roles for UA in life span determination, endurance and adaptive responses to brain injury, and suggest novel approaches for protecting cells against injury and for optimizing physical performance.

Targeting ERK signaling pathway by polyphenols as novel therapeutic strategy for neurodegeneration.

Numerous chemicals, such as phenolic compounds are strong radical scavengers, capable of alleviating oxidative stress induced neurodegeneration. Dietary antioxidants, especially flavonoids, are being considered as a promising approach to prevent or slow the pathological development of neurological illness and aging. One of the major advantage of natural products is that of their anti-amyloid effects over synthetic counterpart, however a healthy diet provides these beneficial natural substances as nutraceuticals. The extracellular-signal-regulated kinase (ERK) is one of the main pharmacological target of natural phenolic compounds, participating in several therapeutic effects. Mounting evidence revealed that numerous bioflavonoids, obtained from a variety of dietary fruits or plants as well as medicinal herbal sources, exhibit protective or therapeutic functions versus development of neurodegenerative diseases mainly through modulation of different compartments of ERK signaling pathway. Currently, there is remarkable interest in the beneficial effects of natural flavonoids to improve neural performance and prevent the onset and development of major neurodegenerative diseases. Natural products originated from medicinal plants, in particular antioxidants, have gained a great deal of attention due to their safe and non-toxic natures. Here, we summarized the effect of natural bioflavonoids on ERK signaling pathway and their molecular mechanism.

Targeting mTORs by omega-3 fatty acids: A possible novel therapeutic strategy for neurodegeneration?

Neurodegenerative diseases (NDs) such as Parkinson's (PD), Alzheimer's (AD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) cause significant world-wide morbidity and mortality. To date, there is no drug of cure for these, mostly age-related diseases, although approaches in delaying the pathology and/or giving patients some symptomatic relief have been adopted for the last few decades. Various studies in recent years have shown the beneficial effects of omega-3 poly unsaturated fatty acids (PUFAs) through diverse mechanisms including anti-inflammatory effects. This review now assesses the potential of this class of compounds in NDs therapy through specific action against the mammalian target of rapamycin (mTOR) signaling pathway. The role of mTOR in neurodegenerative diseases and targeted therapies by PUFAs are discussed.

Signaling Pathways in Inflammation and Anti-inflammatory Therapies.

During the past decade, an abundance of new evidence highlighted the importance of inflammation in the development of chronic pathologies such as neurodegeneration, cancer, diabetes, cardiovascular disease and inflammatory bowel disease. However, most of the current therapies do not address the underlying problem and better therapies are urgently needed. A growing number of researchers have discovered various signaling pathways that are associated with the initiation and progression of inflammation. Among different pathways, we will focus on three classical inflammatory pathways: p38 MAPK, IL-6/JAK/STAT3 and PI3K; and a non-classical inflammatory pathway, the Hippo. Recently, the Hippo pathway has been linked to various inflammatory modulators such as FoxO1/3, TNFα, IL-6, COX2, HIF-1α, AP-1, JAK and STAT. In this review, the molecular mechanisms, associated pathologies and selected drugs (both preclinical and clinical) of these signaling pathways will be summarized. Finally, limitations and potential risks of anti-inflammatory drugs will also be discussed.

Cell tracking, survival, and differentiation capacity of adipose-derived stem cells after engraftment in rat tissue.

Adipose tissue is an important source of adipose derived stem cells (ADSCs). These cells have the potential of being used for certain therapies, in which the main objective is to recover the function of a tissue/organ affected by a disease. In order to contribute to repair of the tissue, these cells should be able to survive and carry out their functions in unfavorable conditions after being transplanted. This process requires a better understanding of the biology involved: such as the time cells remain in the implant site, how long they stay there, and whether or not they differentiate into host tissue cells. This report focuses on these questions. ADSC were injected into three different tissues (substantia nigra, ventricle, liver) and they were tracked in vivo with a dual GFP-Luc reporter system. The results show that ADSCs were able to survive up to 4 months after the engraftment and some of them started showing resident cell tissue phenotype. These results demonstrate their long-term capacity of survival and differentiation when injected in vivo.

Apigenin as neuroprotective agent: Of mice and men.

Neurodegenerative disorders (NDDs) such as Alzheimer's and Parkinson's diseases are the most common age-related pathologies that affect millions of people all over the world. To date, effective therapy for NDDs is not available and current approaches to disease management include neuroprotection strategy with a hope of maintaining and enhancing the function of survising neurons. Of course, such an approach by its own will not offer a cure but is likely to delay the disease progression by ameliorating the increase of neurotoxic agents such reactive oxygen species (ROS) as well as the associated inflammatory cascades. In this regard, natural products including flavonods that offer neuroprotection through multiple mechanisms have gained a lot of interest in recent years. In this communication, evidences from the various experimental models and clinical trials on the therapeutic potential of one promising flavonod, apigenin, is presented. Its chemistry, mechanism of action and potential benefits in the various examples of NDDs are discussed in the light of drug discovery aspects.

Application of Kinase Inhibitors for Anti-aging Intervention.

Protein phosphorylation, mediated by protein kinases, has important physiological and pathological implications in our lives. Targeting kinase is one of the most interesting of the emerging topics in the pharmaceutical industry, especially since there is a focus on cancer therapy. Given that kinases may be involved in the aging process the focus will be on using the kinase inhibitor for anti-aging intervention to enhance healthspan and increase longevity. In this review, we will summarize: (i) the impact of the phosphoproteomic approach to elucidate molecular mechanisms of diseases; (ii) importance of the drug discovery approach for targeting kinases; (iii) the dysregulation of Janus kinase (JAK) / signal-transducing adapter molecules (STAT) and p70 ribosomal protein S6 kinase (S6Ks) pathway in aging and the age-related process; (iv) the epidemiological studies available in order to see whether a correlation between JAK/STAT and S6Ks mRNA expression levels exist in cancer and in patient outcome; (v) finally, we will show selected inhibitors of these kinases approved by the US Food and Drug Administration (FDA).

Aging and Oxidative Stress Decrease Pineal Elongation Factor 2: In Vivo Protective Effect of Melatonin in Young Rats Treated With Cumene Hydroperoxide.

We studied the alterations of Elongation Factor 2 (eEF2) in the pineal gland of aged rats as well as the possible protective role of exogenous melatonin on these changes in young rats treated with cumene hydroperoxide (CH), a compound that promotes lipid peroxidation and inhibits protein synthesis. The study was performed using male Wistar rats of 3 (control), 12, and 24 months and 3-month-old rats treated with CH, melatonin, and CH plus melatonin. We found that pineal eEF-2 is affected by aging and CH, these changes being prevented by exogenous melatonin in the case of CH-treated rats. The proteomic studies show that many other proteins are affected by aging and oxidative stress in the pineal gland. The results suggest that one of the possible mechanisms underlying pineal gland dysfunction during aging is the effect of lipid peroxidation on eEF-2, which is a key component of protein synthesis machinery. J. Cell. Biochem. 118: 182-190, 2017. © 2016 Wiley Periodicals, Inc.

Synergistic deleterious effect of chronic stress and sodium azide in the mouse hippocampus.

Alzheimer's disease is the most common cause of dementia in the elderly. Although the primary cause of the disease is presently unknown, to date several risk factors have been described. Evidence suggests that one of these risk factors could be chronic stress. The aim of this work is to demonstrate that chronic stress is able to induce Alzheimer's disease features after the administration of nontoxic doses of sodium azide. We found that chronic stress increases the levels of several proteins involved in Alzheimer's disease pathogenesis, such as presenilin 1, presenilin 2, and S100ß, besides inducing the aggregation of Tau, ubiquitin, and ß-amyloid proteins in the hippocampus. More important, our work shows a synergistic effect of stress and sodium azide treatment leading to significant neuronal death in the mouse hippocampus. Our results point out that chronic stress is a risk factor contributing to amplify and accelerate Alzheimer's disease features in the hippocampus.