Hydrogen Ion Dynamics as the Fundamental Link between Neurodegenerative Diseases and Cancer: Its Application to the Therapeutics of Neurodegenerative Diseases with Special Emphasis on Multiple Sclerosis.

The pH-related metabolic paradigm has rapidly grown in cancer research and treatment. In this contribution, this recent oncological perspective has been laterally assessed for the first time in order to integrate neurodegeneration within the energetics of the cancer acid-base conceptual frame. At all levels of study (molecular, biochemical, metabolic, and clinical), the intimate nature of both processes appears to consist of opposite mechanisms occurring at the far ends of a physiopathological intracellular pH/extracellular pH (pHi/pHe) spectrum. This wide-ranging original approach now permits an increase in our understanding of these opposite processes, cancer and neurodegeneration, and, as a consequence, allows us to propose new avenues of treatment based upon the intracellular and microenvironmental hydrogen ion dynamics regulating and deregulating the biochemistry and metabolism of both cancer and neural cells. Under the same perspective, the etiopathogenesis and special characteristics of multiple sclerosis (MS) is an excellent model for the study of neurodegenerative diseases and, utilizing this pioneering approach, we find that MS appears to be a metabolic disease even before an autoimmune one. Furthermore, within this paradigm, several important aspects of MS, from mitochondrial failure to microbiota functional abnormalities, are analyzed in depth. Finally, and for the first time, a new and integrated model of treatment for MS can now be advanced.

From neural stem cells to glioblastoma: A natural history of GBM recapitulated in vitro.

Due to its aggressive and invasive nature glioblastoma (GBM), the most common and aggressive primary brain tumour in adults, remains almost invariably lethal. Significant advances in the last several years have elucidated much of the molecular and genetic complexities of GBM. However, GBM exhibits a vast genetic variation and a wide diversity of phenotypes that have complicated the development of effective therapeutic strategies. This complex pathogenesis makes necessary the development of experimental models that could be used to further understand the disease, and also to provide a more realistic testing ground for potential therapies. In this report, we describe the process of transformation of primary mouse embryo astrocytes into immortalized cultures with neural stem cell characteristics, that are able to generate GBM when injected into the brain of C57BL/6 mice, or heterotopic tumours when injected IV. Overall, our results show that oncogenic transformation is the fate of NSC if cultured for long periods in vitro. In addition, as no additional hit is necessary to induce the oncogenic transformation, our model may be used to investigate the pathogenesis of gliomagenesis and to test the effectiveness of different drugs throughout the natural history of GBM.

Usefulness of Melatonin and Other Compounds as Antioxidants and Epidrugs in the Treatment of Head and Neck Cancer.

Along with genetic mutations, aberrant epigenetic alterations are the initiators of head and neck cancer carcinogenesis. Currently, several drugs are being developed to correct these epigenetic alterations, known as epidrugs. Some compounds with an antioxidant effect have been shown to be effective in preventing these malignant lesions and in minimizing the complications derived from cytotoxic treatment. Furthermore, in vitro and in vivo studies show a promising role in the treatment of head and neck squamous cell carcinoma (HNSCC). This is the case of supplements with DNA methylation inhibitory function (DNMTi), such as epigallocatechin gallate, sulforaphane, and folic acid; histone deacetylase inhibitors (HDACi), such as sodium butyrate and melatonin or histone acetyltransferase inhibitors (HATi), such as curcumin. The objective of this review is to describe the role of some antioxidants and their epigenetic mechanism of action, with special emphasis on melatonin and butyric acid given their organic production, in the prevention and treatment of HNSCC.

Towards an Integral Therapeutic Protocol for Breast Cancer Based upon the New H+-Centered Anticancer Paradigm of the Late Post-Warburg Era.

A brand new approach to the understanding of breast cancer (BC) is urgently needed. In this contribution, the etiology, pathogenesis, and treatment of this disease is approached from the new pH-centric anticancer paradigm. Only this unitarian perspective, based upon the hydrogen ion (H+) dynamics of cancer, allows for the understanding and integration of the many dualisms, confusions, and paradoxes of the disease. The new H+-related, wide-ranging model can embrace, from a unique perspective, the many aspects of the disease and, at the same time, therapeutically interfere with most, if not all, of the hallmarks of cancer known to date. The pH-related armamentarium available for the treatment of BC reviewed here may be beneficial for all types and stages of the disease. In this vein, we have attempted a megasynthesis of traditional and new knowledge in the different areas of breast cancer research and treatment based upon the wide-ranging approach afforded by the hydrogen ion dynamics of cancer. The concerted utilization of the pH-related drugs that are available nowadays for the treatment of breast cancer is advanced.

The Pentose Phosphate Pathway Dynamics in Cancer and Its Dependency on Intracellular pH.

The Pentose Phosphate Pathway (PPP) is one of the key metabolic pathways occurring in living cells to produce energy and maintain cellular homeostasis. Cancer cells have higher cytoplasmic utilization of glucose (glycolysis), even in the presence of oxygen; this is known as the "Warburg Effect". However, cytoplasmic glucose utilization can also occur in cancer through the PPP. This pathway contributes to cancer cells by operating in many different ways: (i) as a defense mechanism via the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) to prevent apoptosis, (ii) as a provision for the maintenance of energy by intermediate glycolysis, (iii) by increasing genomic material to the cellular pool of nucleic acid bases, (iv) by promoting survival through increasing glycolysis, and so increasing acid production, and (v) by inducing cellular proliferation by the synthesis of nucleic acid, fatty acid, and amino acid. Each step of the PPP can be upregulated in some types of cancer but not in others. An interesting aspect of this metabolic pathway is the shared regulation of the glycolytic and PPP pathways by intracellular pH (pHi). Indeed, as with glycolysis, the optimum activity of the enzymes driving the PPP occurs at an alkaline pHi, which is compatible with the cytoplasmic pH of cancer cells. Here, we outline each step of the PPP and discuss its possible correlation with cancer.

A New and Integral Approach to the Etiopathogenesis and Treatment of Breast Cancer Based upon Its Hydrogen Ion Dynamics.

Despite all efforts, the treatment of breast cancer (BC) cannot be considered to be a success story. The advances in surgery, chemotherapy and radiotherapy have not been sufficient at all. Indeed, the accumulated experience clearly indicates that new perspectives and non-main stream approaches are needed to better characterize the etiopathogenesis and treatment of this disease. This contribution deals with how the new pH-centric anticancer paradigm plays a fundamental role in reaching a more integral understanding of the etiology, pathogenesis, and treatment of this multifactorial disease. For the first time, the armamentarium available for the treatment of the different types and phases of BC is approached here from a Unitarian perspective-based upon the hydrogen ion dynamics of cancer. The wide-ranged pH-related molecular, biochemical and metabolic model is able to embrace most of the fields and subfields of breast cancer etiopathogenesis and treatment. This single and integrated approach allows advancing towards a unidirectional, concerted and synergistic program of treatment. Further efforts in this line are likely to first improve the therapeutics of each subtype of this tumor and every individual patient in every phase of the disease.

Hydrogen Ion Dynamics of Cancer and a New Molecular, Biochemical and Metabolic Approach to the Etiopathogenesis and Treatment of Brain Malignancies.

The treatment of cancer has been slowly but steadily progressing during the last fifty years. Some tumors with a high mortality in the past are curable nowadays. However, there is one striking exception: glioblastoma multiforme. No real breakthrough has been hitherto achieved with this tumor with ominous prognosis and very short survival. Glioblastomas, being highly glycolytic malignancies are strongly pH-dependent and driven by the sodium hydrogen exchanger 1 (NHE1) and other proton (H+) transporters. Therefore, this is one of those pathologies where the lessons recently learnt from the new pH-centered anticancer paradigm may soon bring a promising change to treatment. This contribution will discuss how the pH-centric molecular, biochemical and metabolic perspective may introduce some urgently needed and integral novel treatments. Such a prospective therapeutic approach for malignant brain tumors is developed here, either to be used alone or in combination with more standard therapies.

Growth Hormone (GH) and Cardiovascular System.

This review describes the positive effects of growth hormone (GH) on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on vessels improving oxidative stress imbalance and endothelial dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease, inducing a neovascularization process that finally increases flow in ischemic tissues. We include some preliminary data from a trial in which GH or placebo is given to elderly people suffering from critical limb ischemia, showing some of the benefits of the hormone on plasma markers of inflammation, and the safety of GH administration during short periods of time, even in diabetic patients. We also analyze how Klotho is strongly related to GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH, most likely to repair the injury in the ischemic tissues. We also show how GH can help during wound healing by increasing the blood flow and some neurotrophic and growth factors. In summary, we postulate that short-term GH administration could be useful to treat cardiovascular diseases.

Chronic limb-threatening ischemia could benefit from growth hormone therapy for wound healing and limb salvage.

Revascularization for chronic limb-threatening ischemia (CLTI) is necessary to alleviate symptoms and wound healing. When it fails or is not possible, there are few alternatives to avoid limb amputation in these patients. Although experimental studies with stem cells and growth factors have shown promise, clinical trials have demonstrated inconsistent results because CLTI patients generally need arteriogenesis rather than angiogenesis. Moreover, in addition to the perfusion of the limb, there is the need to improve the neuropathic response for wound healing, especially in diabetic patients. Growth hormone (GH) is a pleiotropic hormone capable of boosting the aforementioned processes and adds special benefits for the redox balance. This hormone has the potential to mitigate symptoms in ischemic patients with no other options and improves the cardiovascular complications associated with the disease. Here, we discuss the pros and cons of using GH in such patients, focus on its effects on peripheral arteries, and analyze the possible benefits of treating CLTI with this hormone.

GPE Promotes the Proliferation and Migration of Mouse Embryonic Neural Stem Cells and Their Progeny In Vitro.

This study was designed to investigate a possible role of the N-terminal tripeptide of insulin-like growth factor-1 (IGF-I), Gly-Pro-Glu (GPE), physiologically generated in neurons following IGF-I-specific cleavage, in promoting neural regeneration after an injury. Primary cultures of mouse neural stem cells (NSCs), obtained from 13.5 Days post-conception (dpc) mouse embryos, were challenged with either GPE, growth hormone (GH), or GPE + GH and the effects on cell proliferation, migration, and survival were evaluated both under basal conditions and in response to a wound healing assay. The cellular pathways activated by GPE were also investigated by using specific chemical inhibitors. The results of the study indicate that GPE treatment promotes the proliferation and the migration of neural stem cells in vitro through a mechanism that involves the activation of extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase PI3K-Akt pathways. Intriguingly, both GPE effects and the signaling pathways activated were similar to those observed after GH treatment. Based upon the results obtained from this study, GPE, as well as GH, may be useful in promoting neural protection and/or regeneration after an injury.

Cellular acidification as a new approach to cancer treatment and to the understanding and therapeutics of neurodegenerative diseases.

During the last few years, the understanding of the dysregulated hydrogen ion dynamics and reversed proton gradient of cancer cells has resulted in a new and integral pH-centric paradigm in oncology, a translational model embracing from cancer etiopathogenesis to treatment. The abnormalities of intracellular alkalinization along with extracellular acidification of all types of solid tumors and leukemic cells have never been described in any other disease and now appear to be a specific hallmark of malignancy. As a consequence of this intracellular acid-base homeostatic failure, the attempt to induce cellular acidification using proton transport inhibitors and other intracellular acidifiers of different origins is becoming a new therapeutic concept and selective target of cancer treatment, both as a metabolic mediator of apoptosis and in the overcoming of multiple drug resistance (MDR). Importantly, there is increasing data showing that different ion channels contribute to mediate significant aspects of cancer pH regulation and etiopathogenesis. Finally, we discuss the extension of this new pH-centric oncological paradigm into the opposite metabolic and homeostatic acid-base situation found in human neurodegenerative diseases (HNDDs), which opens novel concepts in the prevention and treatment of HNDDs through the utilization of a cohort of neural and non-neural derived hormones and human growth factors.

Brain Recovery after a Plane Crash: Treatment with Growth Hormone (GH) and Neurorehabilitation: A Case Report.

UNLABELLED: The aim of this study is to describe the results obtained after growth hormone (GH) treatment and neurorehabilitation in a young man that suffered a very grave traumatic brain injury (TBI) after a plane crash. METHODS: Fifteen months after the accident, the patient was treated with GH, 1 mg/day, at three-month intervals, followed by one-month resting, together with daily neurorehabilitation. Blood analysis at admission showed that no pituitary deficits existed. At admission, the patient presented: spastic tetraplegia, dysarthria, dysphagia, very severe cognitive deficits and joint deformities. Computerized tomography scanners (CT-Scans) revealed the practical loss of the right brain hemisphere and important injuries in the left one. Clinical and blood analysis assessments were performed every three months for three years. Feet surgery was needed because of irreducible equinovarus. RESULTS: Clinical and kinesitherapy assessments revealed a prompt improvement in cognitive functions, dysarthria and dysphagia disappeared and three years later the patient was able to live a practically normal life, walking alone and coming back to his studies. No adverse effects were observed during and after GH administration. CONCLUSIONS: These results, together with previous results from our group, indicate that GH treatment is safe and effective for helping neurorehabilitation in TBI patients, once the acute phase is resolved, regardless of whether or not they have GH-deficiency (GHD).

Growth hormone pathways signaling for cell proliferation and survival in hippocampal neural precursors from postnatal mice.

BACKGROUND: Accumulating evidence suggests that growth hormone (GH) may play a major role in the regulation of postnatal neurogenesis, thus supporting the possibility that it may be also involved in promoting brain repair after brain injury. In order to gain further insight on this possibility, in this study we have investigated the pathways signaling the effect of GH treatment on the proliferation and survival of hippocampal subgranular zone (SGZ)-derived neurospheres. RESULTS: Our results demonstrate that GH treatment promotes both proliferation and survival of SGZ neurospheres. By using specific chemical inhibitors we have been also able to demonstrate that GH treatment promotes the activation of both Akt-mTOR and JNK signaling pathways, while blockade of these pathways either reduces or abolishes the GH effects. In contrast, no effect of GH on the activation of the Ras-ERK pathway was observed after GH treatment, despite blockade of this signaling path also resulted in a significant reduction of GH effects. Interestingly, SGZ cells were also capable of producing GH, and blockade of endogenous GH also resulted in a decrease in the proliferation and survival of SGZ neurospheres. CONCLUSIONS: Altogether, our findings suggest that GH treatment may promote the proliferation and survival of neural progenitors. This effect may be elicited by cooperating with locally-produced GH in order to increase the response of neural progenitors to adequate stimuli. On this view, the possibility of using GH treatment to promote neurogenesis and cell survival in some acquired neural injuries may be envisaged.

Myostatin expression is regulated by underfeeding and neonatal programming in rats.

Confusing results have been reported regarding the influence of nutritional status on myostatin levels. Some studies indicate that short-term fasting results in increased myostatin mRNA levels in skeletal muscle, evident in several species. In contrast, other studies have demonstrated either a decrease or no change in myostatin levels during fasting. In the present study, we investigated the effect of different patterns of food deprivation on muscle myostatin expression in both newborn and adult rats. Adjustment of litter size in neonatal rats is a well-established model to study the effect of early overfeeding or underfeeding on body composition and in this study resulted in modifications in the pattern of muscle myostatin expression. Rat pups growing in large litters (22-24 newborns) showed a decrease in muscle myostatin mRNA and protein levels at 24 days of age. Interestingly, these effects were maintained at 60 days of age despite rats having free access to food since weaning, thus suggesting that changes in myostatin expression induced by neonatal reduction of food intake are long-lasting. In contrast, no changes in myostatin mRNA levels were observed in adult rats when food intake was decreased during 7 days by either food restriction or central leptin treatment. Similar results were obtained when food restriction was maintained in adult rats for a longer period (7 weeks), despite significant muscle loss. Overall, these data suggest that myostatin gene expression is programmed by nutritional status in neonatal life.

[Growth hormone revisited]. / Hormona de crecimiento: acciones y aplicaciones preventivas y terapéuticas.

Growth hormone (GH) is a pleiotropic hormone, expressed at pituitary and peripheral level, which plays a number of different roles far beyond of those classically described. Among these effects it is remarkable the neurotropic role of GH: the hormone increases the proliferation and survival of neural precursors in response to neurological injuries. At the cardiovascular level, GH improves the lipidic profile and decreases the factors of cardiac risk; the hormone recovers the endothelial function, improves the cardiac function and potentiates revascularisation in ischemic territories. Differently to that occurring with autocrine GH, exogenous GH administration does not seem to be related to oncogenesis. According to its effects, there are multiple potential clinical applications of GH: acute treatment of brain injury, due to its antiapoptotic effect; central or peripheral neural regeneration; acute treatment of perinatal anoxia, prevention cerebral palsy; revascularisation of ischemic areas; decrease of the time of bone consolidation after a bone fracture; and torpid ulcer healing.

Recovery from neurological sequelae secondary to oncological brain surgery in an adult growth hormone-deficient patient after growth hormone treatment.

OBJECTIVE: To report an unusual case of significant neurological recovery in a 26-year-old growth hormone-deficient female patient with significant neurological sequelae resulting from brain surgery at 11 years of age. DESIGN: Case report. RESULTS: Most of the neurological sequelae present at admission recovered after 8 months of combined growth hormone administration and kinesitherapy/speech therapy. These include an increase in tongue size and mobility and in the amount and quality of saliva, improvement in vocal cords function, recovery of oesophageal peristalsis and disappearance of sleep apnoea. CONCLUSION: Since the patient had undergone intensive physical rehabilitation for a 15-year period with no significant improvement, it is tempting to speculate that the correction of growth hormone deficiency improved her rehabilitation. Therefore, we propose that growth hormone treatment, combined with the adequate kinesitherapy, may be a useful therapy for effective recovery from some neurological deficits in patients with growth hormone deficiency.

Differential response to exogenous and endogenous myostatin in myoblasts suggests that myostatin acts as an autocrine factor in vivo.

Myostatin is a member of the TGF-beta superfamily that is essential for proper regulation of skeletal muscle growth. As do other TGF-beta superfamily members, myostatin signals into the cell via a receptor complex that consists of two distinct transmembrane proteins, known as the type I and type II receptors. Vertebrates have seven distinct type I receptors, each of which can mix and match with one of five type I receptors to mediate signals for all the TGF-beta family ligands. Accumulating evidence indicates that myostatin shares its pair of receptors with activin, and therefore, the question arises about how specificity in signaling is achieved. Our hypothesis is that a mechanism has to exist to restrict myostatin actions to the muscle cells. To investigate this possibility, we compared the effect of endogenous myostatin (myostatin overexpressed by myoblasts) and exogenous myostatin (recombinant myostatin added to the culture medium) in cultured myoblasts. As opposed to exogenous myostatin, endogenous myostatin induced the transcription of a reporter vector in cultured myoblasts. Notably, the myostatin concentrations that failed to induce a response in myoblasts were effective in MCF-7 cells (human mammary carcinoma) and in HepG2 cells (human hepatic carcinoma). Based on our observations, we propose that a mechanism exists that differentially regulates the bioavailability of endogenous and exogenous myostatin to muscle cells. This is consistent with a model in which myostatin actions are exerted in vivo in an autocrine fashion.

Activation of human somatostatin receptor 2 promotes apoptosis through a mechanism that is independent from induction of p53.

The ability of both somatostatin (SS) and its stable analogues to inhibit cell growth depends on the stimulation of specific membrane receptors (SSTR1-5), which belong to the G protein-coupled receptor family. Accumulating evidence suggests that the SSTR2 plays a major role in mediating cell cycle arrest, and it is also clear that SHP-1, a cytoplasmic phosphotyrosine phosphatase (PTP), is an essential component of the SSTR2-mediated cytostatic effect. In contrast, the possibility that SSTR2 activation may also lead to increased apoptosis is still beyond debate, despite SHP-1 activation is also able to promote cell death in several cell types. In the present work we have investigated the ability of SSTR2 to induce apoptosis in HL-60 cells. We have found that HL-60 cells uniquely express the SSTR2 subtype, and that stimulation of SSTR2 with the SS analogue SMS 201-995 results in an increased cell death. In all, these findings demonstrate that activation of SSTR2 promotes apoptosis in HL-60 cells. Moreover, in contrast with the proapoptotic mechanism previously reported for SSTR3, cell death induced by activation of SSTR2 is independent from accumulation of p53.