p21-Activated kinase 4 (PAK4), a member of the PAK family, regulates a wide range of cellular functions, including cell adhesion, migration, proliferation, and survival. Dysregulation of its expression and activity thus contributes to the development of diverse pathological conditions. PAK4 plays a pivotal role in cancer progression by accelerating the epithelial-mesenchymal transition, invasion, and metastasis. Therefore, PAK4 is regarded as an attractive therapeutic target in diverse types of cancers, prompting the development of PAK4-specific inhibitors as anticancer drugs; however, these drugs have not yet been successful. PAK4 is essential for embryonic brain development and has a neuroprotective function. A long list of PAK4 effectors has been reported. Recently, the transcription factor CREB has emerged as a novel effector of PAK4. This finding has broad implications for the role of PAK4 in health and disease because CREB-mediated transcriptional reprogramming involves a wide range of genes. In this article, we review the PAK4 signaling pathways involved in prostate cancer, Parkinson's disease, and melanogenesis, focusing in particular on the PAK4-CREB axis.

Different diseases have been associated with PARK2/PACRG overlapping promoter polymorphisms (rs2276201 and rs9347683) in the recent past. However association of these polymorphisms with cancer remains elusive till date. Thus in this study we evaluated association between these polymorphisms and colorectal cancer (CRC) incidences among North Indians. Genomic DNA was isolated using venous blood of 400 unrelated subjects (200 CRC cases and 200 healthy controls) of North Indian origin. Both SNPs were genotyped using PCR-RFLP method. Promoter methylation status in tumor DNA was checked using MS-PCR. Statistical analysis was performed using SPSS-17 software. In-silico predictions for transcription factor binding were performed using "PROMO" a freely available online tool. SNP rs2276201 showed statistically significant difference (P = 0.047) among cases and controls while rs9347683 did not (P = 0.113). The TC genotype (OR: 1.855, 95% CI: 1.021-3.369, P = 0.043), CC genotype (OR: 1.617, 95% CI: 1.042-2.510, P = 0.032), TT vs CT+CC genetic model (OR: 1.60, P = 0.0158) and allelic model (OR: 1.3931, 95% CI: 1.0498-1.8485, P = 0.0214) of rs2276201 showed significant risk for CRC. For rs9347683 AC genotype (OR: 1.604, 95% CI: 1.019-2.523, P = 0.041) and AA vs AC+CC genetic model (OR: 1.57, P = 0.039) showed significant risk. Haplotype CC provided significant risk (OR: 1.618, 95% CI: 1.112-2.352, P = 0.011) whereas haplotype TA provided significant protection (OR: 0.732, 95% CI: 0.543-0.987, P = 0.040) against CRC. Promoter methylation was significantly higher in tumor grade III + IV (OR: 2.37, P = 0.019), while PARK2 expression was lower in cancer tissues compared to normal tissue. Here we provide the first report where PARK2 promoter SNP's rs2276201 and rs9347683 are shown to be significantly associated with the risk of CRC development.

Poisoning from pesticides is a global public health problem and accounts for nearly 300,000 deaths worldwide every year. Exposure to pesticides is inevitable; there are different modes through which humans get exposed to pesticides. The mode of exposure is an important factor as it also signifies the concentration of pesticides exposure. Pesticides are used extensively in agricultural and domestic settings. These chemicals are believed to cause many disorders in humans and wildlife. Research from past few decades has tried to answer the associated mechanism of action of pesticides in conjunction with their harmful effects. This perspective considers the past and present research in the field of pesticides and associated disorders. We have reviewed the most common diseases including cancer which are associated with pesticides. Pesticides have shown to be involved in the pathogenesis of Parkinson's and Alzheimer's diseases as well as various disorders of the respiratory and reproductive tracts. Oxidative stress caused by pesticides is an important mechanism through which many of the pesticides exert their harmful effects. Oxidative stress is known to cause DNA damage which in turn may cause malignancies and other disorders. Many pesticides have shown to modulate the gene expression at the level of non-coding RNAs, histone deacetylases, DNA methylation patterns suggesting their role in epigenetics.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by dopaminergic neuron loss. At present, there are no drugs that stop the progression of PD. As with other multifactorial genetic disorders, genome-wide association studies (GWASs) found multiple risk loci for PD, although their clinical significance remains uncertain. Here, we report the identification of candidate drugs for PD by a method using GWAS data and in silico databases. We identified 57 Food and Drug Administration-approved drug families as candidate neuroprotective drugs for PD. Among them, dabrafenib, which is known as a B-Raf kinase inhibitor and is approved for the treatment of malignant melanoma, showed remarkable cytoprotective effects in neurotoxin-treated SH-SY5Y cells and mice. Dabrafenib was found to inhibit apoptosis, and to enhance the phosphorylation of extracellular signal-regulated kinase (ERK), and inhibit the phosphorylation of c-Jun NH2-terminal kinase. Dabrafenib targets B-Raf, and we confirmed a protein-protein interaction between B-Raf and Rit2, which is coded by RIT2, a PD risk gene in Asians and Caucasians. In RIT2-knockout cells, the phosphorylation of ERK was reduced, and dabrafenib treatment improved the ERK phosphorylation. These data indicated that dabrafenib exerts protective effects against neurotoxicity associated with PD. By using animal model, we confirmed the effectiveness of this in silico screening method. Furthermore, our results suggest that this in silico drug screening system is useful in not only neurodegenerative diseases but also other common diseases such as diabetes mellitus and hypertension.

The aim of the present study was to assess the neuroprotective effects of pinostrobin (PSB), a dietary bioflavonoid, and its underlying mechanisms in neurotoxin-induced Parkinson's disease (PD) models. First, PSB could attenuate 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced loss of dopaminergic neurons and improve behavior deficiency in zebrafish, supporting its potential neuroprotective actions in vivo. Next, PSB could decreased apoptosis and death in the 1-methyl-4-phenylpyridinium (MPP

The mutation of the Parkin gene is a cause of familial Parkinson's disease. A growing body of evidence suggests that Parkin also functions as a tumor suppressor. Parkin is an ubiquitin E3 ligase, and plays important roles in a variety of cellular processes implicated in tumorigenesis, including cell cycle, cell proliferation, apoptosis, metastasis, mitophagy and metabolic reprogramming. Here we review the role and mechanism of Parkin in cancer.

The concept that abnormal protein aggregates show prion-like propagation between cells has been considered to explain the onset and progression of many neurodegenerative diseases. Indeed, both synthetic amyloid-like fibrils and pathogenic proteins extracted from patients' brains induce self-templated amplification and cell-to-cell transmission in vitro and in vivo. However, it is unclear whether exposure to exogenous prion-like proteins can potentially cause these diseases in humans. Here, we investigated in detail the prion-like seeding activities of several kinds of pathogenic α-synuclein (α-syn), including synthetic fibrils and detergent-insoluble fractions extracted from brains of patients with α-synucleinopathies. Exposure to synthetic α-syn fibrils at concentrations above 100 pg/mL caused seeded aggregation of α-syn in SH-SY5Y cells, and seeded aggregation was also observed in C57BL/6 J mice after intracerebral inoculation of at least 0.1 μg/animal. α-Syn aggregates extracted from brains of multiple system atrophy (MSA) patients showed higher seeding activity than those extracted from patients with dementia with Lewy bodies (DLB), and their potency was similar to that of synthetic α-syn fibrils. We also examined the effects of various methods that have been reported to inactivate abnormal prion proteins (PrP

Cyclooxygenase-2 or COX-2 has been known to be crucial for Parkinson's disease (PD) pathogenesis; however, its exact role is still not known. We first time report that inhibition of COX-2 promotes 1-methyl-4-phenyl 1,2,3,6 tetrahydropyridine (MPTP)-induced neuronal cell death via induction of autophagic mechanisms. We found that treatment with MPTP induced cell death of neuroblastoma cells SH-SY5Y in a dose dependent manner. Treatment of MPTP has also upregulated the expressions of autophagic proteins such as LC3, beclin, ATG-5, and p62. Interestingly, nimesulide, a preferential COX-2 inhibitor, further potentiated the MPTP-induced cell death of human neuroblastoma cells. Treatment of nimesulide with MPTP further potentiated expressions of p62, ATG-5, beclin-1, LC3 autophagic proteins. Furthermore, nimesulide with MPTP increased apoptotic protein cleaved caspase-3 and also induced expression of p53 gene. Interestingly, it was observed that Akt inhibitor significantly increased MPTP-induced cell death of neuroblastoma cells. However, (-) deprenyl, a monoamine oxidase B (MAO B) inhibitor, attenuated MPTP-induced autophagic response and protected cell death. The prior treatment with prostaglandin E2 protected against nimesulide induced-death of neuronal cells. This study confirms that neuroinflammation is associated to the autophagy and may be one of the main pathological mechanisms in Parkinson's disease and other inflammation-associated disorders.

Parkin for more than a decade has been portrayed as a neuroprotector gene is now increasingly emerging as a multifaceted gene that can exert entirely opposite effects i.e., both cell proliferation and apoptosis. Parkinson's disease, a neurological disease, progresses due to excess in cell death, while, in case of cancer, cell death normally fails to occur. Parkin, an E3 ubiquitin ligase, was first identified as a gene implicated in autosomal recessive juvenile Parkinsonism, but several evidences indicate that Parkin is a tumor suppressor gene, involved in a variety of cancers. It is hard to imagine that two entirely different classes of disease, like cancer and Parkinson's disease, can converge at a critical point attributable to a single gene, Parkin. This mysterious and hidden connection may prove a boon in disguise and has raised hopes that studying the biology of one disease may help to identify novel targets of therapy for the other. In this Parkinson's disease-cancer story, if the detail of Parkin pathway is unraveled and gaps in the storyline are properly filled up, we may end getting an entirely new therapeutic option. This review mainly highlights the recent literature which suggests how Parkin gene regulates the various hallmarks of both the Parkinson's disease and cancer.

Isatin (indole-2,3-dione) is an oxidized indole. It is widely distributed in mammalian tissues and body fluids, where isatin concentrations vary significantly from <0.1 to > 10 µM. Isatin output is increased under conditions of stress. Exogenously administered isatin is characterized by low toxicity, mutagenicity, and genotoxicity in vivo. Cytotoxic effects of isatin on various cell cultures are usually observed at concentrations exceeding 100 µM. Binding of [

The ability of DJ-1 to modulate signal transduction has significant effects on how the cell regulates normal processes such as growth, senescence, apoptosis, and autophagy to adapt to changing environmental stimuli and stresses. Perturbations of DJ-1 levels or function can disrupt the equilibrium of homeostatic signaling networks and set off cascades that play a role in the pathogenesis of conditions such as cancer and Parkinson's disease.DJ-1 plays a major role in various pathways. It mediates cell survival and proliferation by activating the extracellular signal-regulated kinase (ERK1/2) pathway and the phosphatidylinositol-3-kinase (PI3K)/Akt pathway. It attenuates cell death signaling by inhibiting apoptosis signal-regulating kinase 1 (ASK1) activation as well as by inhibiting mitogen-activated protein kinase kinase kinase 1 (MEKK1/MAP3K1) activation of downstream apoptotic cascades. It also modulates autophagy through the ERK, Akt, or the JNK/Beclin1 pathways. In addition, DJ-1 regulates the transcription of genes essential for male reproductive function, such as spermatogenesis, by relaying nuclear receptor androgen receptor (AR) signaling. In this chapter, we summarize the ways that DJ-1 regulates these pathways, focusing on how its role in signal transduction contributes to cellular homeostasis and the pathologic states that result from dysregulation.

INTRODUCTION: Although lung cancer is generally thought to be environmentally provoked, anecdotal familial clustering has been reported, suggesting that there may be genetic susceptibility factors. We systematically tested whether germline mutations in eight candidate genes may be risk factors for lung adenocarcinoma.
METHODS: We studied lung adenocarcinoma cases for which germline sequence data had been generated as part of The Cancer Genome Atlas project but had not been previously analyzed. We selected eight genes, ATM serine/threonine kinase gene (ATM), BRCA2, DNA repair associated gene (BRCA2), checkpoint kinase 2 gene (CHEK2), EGFR, parkin RBR E3 ubiquitin protein ligase gene (PARK2), telomerase reverse transcriptase gene (TERT), tumor protein p53 gene (TP53), and Yes associated protein 1 gene (YAP1), on the basis of prior anecdotal association with lung cancer or genome-wide association studies.
RESULTS: Among 555 lung adenocarcinoma cases, we detected 14 pathogenic mutations in five genes; they occurred at a frequency of 2.5% and represented an OR of 66 (95% confidence interval: 33-125, p < 0.0001 [chi-square test]). The mutations fell most commonly in ATM (50%), followed by TP53, BRCA2, EGFR, and PARK2. Most (86%) of these variants had been reported in other familial cancer syndromes. Another 12 cases (2%) carried ultrarare variants that were predicted to be deleterious by three protein prediction programs; these most frequently involved ATM and BRCA2.
CONCLUSIONS: A subset of patients with lung adenocarcinoma, at least 2.5% to 4.5%, carry germline variants that have been linked to cancer risk in Mendelian syndromes. The genes fall most frequently in DNA repair pathways. Our data indicate that patients with lung adenocarcinoma, similar to other solid tumors, include a subset of patients with inherited susceptibility.

BACKGROUND: PINK1 deficiency causes the autosomal recessive PARK6 variant of Parkinson's disease. PINK1 activates ubiquitin by phosphorylation and cooperates with the downstream ubiquitin ligase PARKIN, to exert quality control and control autophagic degradation of mitochondria and of misfolded proteins in all cell types.
METHODS: Global transcriptome profiling of mouse brain and neuron cultures were assessed in protein-protein interaction diagrams and by pathway enrichment algorithms. Validation by quantitative reverse transcriptase polymerase chain reaction and immunoblots was performed, including human neuroblastoma cells and patient primary skin fibroblasts.
RESULTS: In a first approach, we documented Pink1-deleted mice across the lifespan regarding brain mRNAs. The expression changes were always subtle, consistently affecting "intracellular membrane-bounded organelles". Significant anomalies involved about 250 factors at age 6 weeks, 1300 at 6 months, and more than 3500 at age 18 months in the cerebellar tissue, including Srsf10, Ube3a, Mapk8, Creb3, and Nfkbia. Initially, mildly significant pathway enrichment for the spliceosome was apparent. Later, highly significant networks of ubiquitin-mediated proteolysis and endoplasmic reticulum protein processing occurred. Finally, an enrichment of neuroinflammation factors appeared, together with profiles of bacterial invasion and MAPK signaling changes-while mitophagy had minor significance. Immunohistochemistry showed pronounced cellular response of Iba1-positive microglia and GFAP-positive astrocytes; brain lipidomics observed increases of ceramides as neuroinflammatory signs at old age. In a second approach, we assessed PINK1 deficiency in the presence of a stressor. Marked dysregulations of microbial defense factors Ifit3 and Rsad2 were consistently observed upon five analyses: (1) Pink1
CONCLUSIONS: Thus, an individual biomarker with expression correlating to progression was not identified. Instead, more advanced disease stages involved additional pathways. Hence, our results identify PINK1 deficiency as an early modulator of innate immunity in neurons, which precedes late stages of neuroinflammation during alpha-synuclein spreading.

Peptides and proteins have been found to possess an inherent tendency to convert from their native functional states into intractable amyloid aggregates. This phenomenon is associated with a range of increasingly common human disorders, including Alzheimer and Parkinson diseases, type II diabetes, and a number of systemic amyloidoses. In this review, we describe this field of science with particular reference to the advances that have been made over the last decade in our understanding of its fundamental nature and consequences. We list the proteins that are known to be deposited as amyloid or other types of aggregates in human tissues and the disorders with which they are associated, as well as the proteins that exploit the amyloid motif to play specific functional roles in humans. In addition, we summarize the genetic factors that have provided insight into the mechanisms of disease onset. We describe recent advances in our knowledge of the structures of amyloid fibrils and their oligomeric precursors and of the mechanisms by which they are formed and proliferate to generate cellular dysfunction. We show evidence that a complex proteostasis network actively combats protein aggregation and that such an efficient system can fail in some circumstances and give rise to disease. Finally, we anticipate the development of novel therapeutic strategies with which to prevent or treat these highly debilitating and currently incurable conditions.

Long noncoding RNAs (lncRNAs) have emerged recently as a new class of genes that regulate cellular processes. HOTAIR (Hox transcript antisense intergenic RNA), an approximately 2.2 kb long noncoding RNA transcribed from the HOXC locus, is upregulated in various diseases. However, the role of HOTAIR in Parkinson's disease (PD) remains unclear. A mouse model of PD was developed by intraperitoneal injection of MPTP. The expression of HOTAIR and LRRK2 were detected in the PD mice and in human neuroblastoma cell lines SH-SY5Y pretreated with MPP+. The effect of HOTAIR on the expression of LRRK2 was examined in SH-SY5Y cells through overexpressing or knockdown of HOTAIR. MTT and flow cytometry assay were performed to measure the cell viability and apoptosis of SH-SY5Y cells. We found that HOTAIR was up-regulated in midbrain tissue of MTPT induced PD mice and in SH-SY5Y cells exposed to MPP+. With the presence of HOTAIR overexpression in SH-SY5Y cells, the expression of LRRK2 was increased compared with that in the control. HOTAIR knockdown showed a protective effect on the cell viability of SH-SY5Y cells pretreated with MPP+. HOTAIR knockdown provided protection against MPP+-induced DA neuronal apoptosis by repressing caspase 3 activity. The finding that HOTAIR promoted PD induced by MPTP could add our understanding of the molecular mechanisms in PD. These findings suggested that inhibition of HOTAIR levels is an effective disease-modifying strategy in PD.

BACKGROUND: Parkin (PARK2) is an E3 ubiquitin ligase that is commonly mutated in Familial Parkinson's Disease (PD). In cell culture models, Parkin is recruited to acutely depolarised mitochondria by PINK1. PINK1 activates Parkin activity leading to ubiquitination of multiple proteins, which in turn promotes clearance of mitochondria by mitophagy. Many substrates have been identified using cell culture models in combination with depolarising drugs or proteasome inhibitors, but not in more physiological settings.
METHODS: Here we utilized the recently introduced BioUb strategy to isolate ubiquitinated proteins in flies. Following Parkin Wild-Type (WT) and Parkin Ligase dead (LD) expression we analysed by mass spectrometry and stringent bioinformatics analysis those proteins differentially ubiquitinated to provide the first survey of steady state Parkin substrates using an in vivo model. We further used an in vivo ubiquitination assay to validate one of those substrates in SH-SY5Y cells.
RESULTS: We identified 35 proteins that are more prominently ubiquitinated following Parkin over-expression. These include several mitochondrial proteins and a number of endosomal trafficking regulators such as v-ATPase sub-units, Syx5/STX5, ALiX/PDCD6IP and Vps4. We also identified the retromer component, Vps35, another PD-associated gene that has recently been shown to interact genetically with parkin. Importantly, we validated Parkin-dependent ubiquitination of VPS35 in human neuroblastoma cells.
CONCLUSIONS: Collectively our results provide new leads to the possible physiological functions of Parkin activity that are not overtly biased by acute mitochondrial depolarisation.

Peripheral blood mononuclear cells (PBMCs) were collected from a clinically diagnosed 64-year old male Parkinson's disease (PD) patient with S1647T variant in the LRRK2 gene. The PMBCs were reprogrammed with the human OSKM transcription factors using the Sendai-virus reprogramming system. The transgene-free iPSC showed pluripotency confirmed by immunofluorescent staining for pluripotency markers and differentiated into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This cellular model will be useful for further function studies and therapeutic screening.

Peripheral blood mononuclear cells (PBMCs) were collected from a clinically diagnosed 64-year old male Parkinson's disease (PD) patient with N551K variant in the LRRK2 gene. The PMBCs were reprogrammed with the human OSKM transcription factors using the Sendai-virus reprogramming system. The transgene-free iPSC showed pluripotency confirmed by immunofluorescent staining for pluripotency markers and differentiated into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This cellular model can complement in vivo PD models for pathophysiological studies and drug screening.

Peripheral blood mononuclear cells (PBMCs) were collected from a clinically diagnosed 72-year old female Parkinson's disease (PD) patient with R1398H variant in the LRRK2 gene. The PMBCs were reprogrammed with the human OSKM transcription factors using the Sendai-virus reprogramming system. The transgene-free iPSC showed pluripotency confirmed by immunofluorescent staining for pluripotency markers and differentiated into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This cellular model provides a good platform for studying the mechanism of PD, and also for drug testing and gene therapy studies.

Peripheral blood mononuclear cells (PBMCs) were collected from a clinically diagnosed 59-year old male Parkinson's disease (PD) patient with R1628P variant in the LRRK2 gene. The PMBCs were reprogrammed with the human OSKM transcription factors using the Sendai-virus reprogramming system. The transgene-free iPSC showed pluripotency confirmed by immunofluorescent staining for pluripotency markers and differentiated into the 3 germ layers in vivo. The iPSC line also showed normal karyotype. This cellular model will provide a good resource for further pathophysiological studies of PD.

BACKGROUND AND OBJECTIVE: A high percentage of medical errors, committed because of physician's lack of experience, huge volume of data to be analyzed, and inaccessibility to medical records of previous patients, can be reduced using computer-aided techniques. Therefore, designing more efficient medical decision-support systems (MDSSs) to assist physicians in decision-making is crucially important. Through combining the properties of fuzzy logic and neural networks, fuzzy cognitive maps (FCMs) are among the latest, most efficient, and strongest artificial intelligence techniques for modeling complex systems. This review study is conducted to identify different FCM structures used in MDSS designs. The best structure for each medical application can be introduced by studying the properties of FCM structures.
METHODS: This paper surveys the most important decision- making methods and applications of FCMs in the medical field in recent years. To investigate the efficiency and capability of different FCM models in designing MDSSs, medical applications are categorized into four key areas: decision-making, diagnosis, prediction, and classification. Also, various diagnosis and decision support problems addressed by FCMs in recent years are reviewed with the goal of introducing different types of FCMs and determining their contribution to the improvements made in the fields of medical diagnosis and treatment.
RESULTS: In this survey, a general trend for future studies in this field is provided by analyzing various FCM structures used for medical purposes, and the results from each category.
CONCLUSIONS: Due to the unique specifications of FCMs in integrating human knowledge and experience with computer-aided techniques, they are among practical instruments for MDSS design. In the not too distant future, they will have a significant role in medical sciences.

PARK2 is a gene implicated in disease states with opposing responses in cell fate determination, yet its contribution in pro-survival signaling is largely unknown. Here we show that PARK2 is altered in over a third of all human cancers, and its depletion results in enhanced phosphatidylinositol 3-kinase/Akt (PI3K/Akt) activation and increased vulnerability to PI3K/Akt/mTOR inhibitors. PARK2 depletion contributes to AMPK-mediated activation of endothelial nitric oxide synthase (eNOS), enhanced levels of reactive oxygen species, and a concomitant increase in oxidized nitric oxide levels, thereby promoting the inhibition of PTEN by S-nitrosylation and ubiquitination. Notably, AMPK activation alone is sufficient to induce PTEN S-nitrosylation in the absence of PARK2 depletion. Park2 loss and Pten loss also display striking cooperativity to promote tumorigenesis in vivo. Together, our findings reveal an important missing mechanism that might account for PTEN suppression in PARK2-deficient tumors, and they highlight the importance of PTEN S-nitrosylation in supporting cell survival and proliferation under conditions of energy deprivation.

The PARK2 gene encodes an ubiquitin E3 ligase that is involved in mitochondrial homeostasis and linked to Parkinson's disease. In this issue, Gupta et al. (2017) demonstrate that PARK2 expression is frequently reduced in human cancers and that this alteration leads to dysregulated PI3K signaling.

INTRODUCTION: The discovery and development of therapeutic strategies for the treatments of Parkinson's disease (PD) and other synucleinopathies are limited by a lack of understanding of the pathomechanisms and their connection with different diseases such as cancers. Areas covered: The hallmarks of these diseases are frequently multifunctional disordered proteins displaying moonlighting and/or chameleon features, which are challenging drug targets. A representative of these proteins is the disordered Tubulin Polymerization Promoting Protein (TPPP/p25) expressed specifically in oligodendrocytes (OLGs) in normal brain. Its non-physiological level is tightly related to the etiology of PD and Multiple System Atrophy (TPPP/p25 enrichment in inclusions of neurons and OLGs, respectively), multiple sclerosis (TPPP/p25-positive OLG destruction), as well as glioma (loss of TPPP/p25 expression). The established anti-proliferative potency of TPPP/p25 may raise its influence in cancer development. The recognition that whereas too much TPPP/p25 could kill neurons in PD, but its loss keeps cells alive in cancer could contribute to our understanding of the interrelationship of 'TPPP/p25 diseases'. Expert commentary: The knowledge accumulated so far underlines the key roles of the multifunctional TPPP/p25 in both physiological and diverse pathological processes, consequently its validation as drug target sorely needs a new innovative strategy that is briefly reviewed here.

Human mtDNA genetic variants have traditionally been considered markers for ancient population migrations. However, during the past three decades, these variants have been associated with altered susceptibility to various phenotypes, thus supporting their importance for human health. Nevertheless, mtDNA disease association has frequently been supported only in certain populations, due either to population stratification or differential epistatic compensations among populations. To partially overcome these obstacles, we performed meta-analysis of the multiple mtDNA association studies conducted until 2016, encompassing 53,975 patients and 63,323 controls. Our findings support the association of mtDNA haplogroups and recurrent variants with specific phenotypes such as Parkinson's disease, type 2 diabetes, longevity, and breast cancer. Strikingly, our assessment of mtDNA variants' involvement with multiple phenotypes revealed significant impact for Caucasian haplogroups H, J, and K. Therefore, ancient mtDNA variants could be divided into those that affect specific phenotypes, versus others with a general impact on phenotype combinations. We suggest that the mtDNA could serve as a model for phenotype specificity versus allele heterogeneity.

Intrastriatal injection of mesencephalic astrocyte-derived neurotrophic factor (MANF) protein has been shown to provide neuroprotective and neurorestorative effects in a 6-hydroxydopamine (6-OHDA) - lesioned rat model of Parkinson's disease. Here, we used an adeno-associated virus serotype 9 (AAV9) vector to deliver the human MANF (hMANF) gene into the rat striatum 10days after a 6-OHDA lesion to examine long-term effects of hMANF on nigral dopaminergic neurons and mechanisms underlying MANF neuroprotection. Intrastriatal injection of AAV9-hMANF vectors led to a robust and widespread expression of the hMANF gene in the injected striatum up to 24weeks. Increased levels of hMANF protein were also detected in the ipsilateral substantia nigra. The hMANF gene transfer promoted the survival of nigral dopaminergic neurons, regeneration of striatal dopaminergic fibers and an upregulation of striatal dopamine levels, resulting in a long-term improvement of rotational behavior up to 16weeks after viral injections. By using SH-SY5Y cells, we found that intra- and extracellular application of MANF protected cells against 6-OHDA-induced toxicity via inhibiting the endoplasmic reticulum stress and activating the PI3K/Akt/mTOR pathway. Our results suggest that AAV9-mediated hMANF gene delivery into the striatum exerts long-term neuroprotective and neuroregenerative effects on the nigrostriatal dopaminergic system in parkinsonian rats, and provide insights into mechanisms responsible for MANF neuroprotection.

The enzyme DOPA decarboxylase (aromatic-L-amino-acid decarboxylase, DDC) plays an important role in the dopaminergic system and participates in the uptake and decarboxylation of amine precursors in the peripheral tissues. Apart from catecholamines, DDC catalyses the biosynthesis of serotonin and trace amines. It has been shown that the DDC amino acid sequence is highly evolutionarily conserved across many species. The activity of holoenzyme is regulated by stimulation/blockade of membrane receptors, phosphorylation of serine residues, and DDC interaction with regulatory proteins. A single gene codes for DDC both in neuronal and non-neuronal tissue, but synthesized isoforms of mRNA differ in the 5' UTR and in the presence of alternative exons. Tissue-specific expression of the DDC gene is controlled by two spatially distinct promoters - neuronal and non-neuronal. Several consensus sequences recognized by the HNF and POU family proteins have been mapped in the neuronal DDC promoter. Since DDC is located close to the imprinted gene cluster, its expression can be subjected to tightly controlled epigenetic regulation. Perturbations in DDC expression result in a range of neurodegenerative and psychiatric disorders and correlate with neoplasia. Apart from the above issues, the role of DDC in prostate cancer, bipolar affective disorder, Parkinson's disease and DDC deficiency is discussed in our review. Moreover, novel and prospective clinical treatments based on gene therapy and stem cells for the diseases mentioned above are described.

The molecular mechanisms underlying the anti-breast cancer effects of polyphyllin I, a natural compound extracted from Paris polyphylla rhizomes, are not fully understood. In the present study, we found that polyphyllin I induces mitochondrial translocation of DRP1 by dephosphorylating DRP1 at Ser637, leading to mitochondrial fission, cytochrome c release from mitochondria into the cytosol and, ultimately apoptosis. Polyphyllin I also increased the stabilization of full-length PINK1 at the mitochondrial surface, leading to the recruitment of PARK2, P62, ubiquitin, and LC3B-II to mitochondria and culminating in mitophagy. PINK1 knockdown markedly suppressed polyphyllin I-induced mitophagy and enhanced polyphyllin I-induced, DRP1-dependent mitochondrial fission and apoptosis. Furthermore, suppression of DRP1 by mdivi-1 or shRNA inhibited PINK1 knockdown/polyphyllin I-induced mitochondrial fragmentation and apoptosis, suggesting that PINK1 depletion leads to excessive fission and, subsequently, mitochondrial fragmentation. An in vivo study confirmed that polyphyllin I greatly inhibited tumor growth and induced apoptosis in MDA-MB-231 xenografts, and these effects were enhanced by PINK1 knockdown. These data describe the mechanism by which PINK1 contributes to polyphyllin I-induced mitophagy and apoptosis and suggest that polyphyllin I may be an effective drug for breast cancer treatment.

Mutation of the PARK2 gene can promote both Parkinson's Disease and cancer, yet the underlying mechanisms of how PARK2 controls cellular physiology is incompletely understood. Here, we show that the PARK2 tumor suppressor controls the apoptotic regulator BCL-XL and modulates programmed cell death. Analysis of approximately 10,000 tumor genomes uncovers a striking pattern of mutual exclusivity between PARK2 genetic loss and amplification of BCL2L1, implicating these genes in a common pathway. PARK2 directly binds to and ubiquitinates BCL-XL. Inactivation of PARK2 leads to aberrant accumulation of BCL-XL both in vitro and in vivo, and cancer-specific mutations in PARK2 abrogate the ability of the ubiquitin E3 ligase to target BCL-XL for degradation. Furthermore, PARK2 modulates mitochondrial depolarization and apoptosis in a BCL-XL-dependent manner. Thus, like genes at the nodal points of growth arrest pathways such as p53, the PARK2 tumor suppressor is able to exert its antiproliferative effects by regulating both cell cycle progression and programmed cell death.

OBJECTIVE: Individuals with Parkinson disease are more likely to develop melanoma, and melanoma patients are reciprocally at higher risk of developing Parkinson disease. Melanoma is strongly tied to red hair/fair skin, a phenotype of loss-of-function polymorphisms in the MC1R (melanocortin 1 receptor) gene. Loss-of-function variants of MC1R have also been linked to increased risk of Parkinson disease. The present study is to investigate the role of MC1R in dopaminergic neurons in vivo.
METHODS: Genetic and pharmacological approaches were employed to manipulate MC1R, and nigrostriatal dopaminergic integrity was determined by comprehensive behavioral, neurochemical, and neuropathological measures.
RESULTS: MC1R
INTERPRETATION: Our findings reveal a protective role of MC1R in the nigrostriatal dopaminergic system, and they provide a rationale for MC1R as a potential therapeutic target for Parkinson disease. Together with its established role in melanoma, MC1R may represent a common pathogenic pathway for melanoma and Parkinson disease. Ann Neurol 2017;81:395-406.