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Quantitative Proteomic Analysis of APP/PS1 Transgenic Mice.

BACKGROUND: Alzheimer's disease (AD) is a prevalent neurodegenerative disorder affecting the central nervous system (CNS), with its etiology still shrouded in uncertainty. The interplay of extracellular amyloid-β (Aβ) deposition, intracellular neurofibrillary tangles (NFTs) composed of tau protein, cholinergic neuronal impairment, and other pathogenic factors is implicated in the progression of AD. OBJECTIVE: The current study endeavors to delineate the proteomic landscape alterations in the hippocampus of an AD murine model, utilizing proteomic analysis to identify key physiological and pathological shifts induced by the disease. This endeavor aims to shed light on the underlying pathogenic mechanisms, which could facilitate early diagnosis and pave the way for novel therapeutic interventions for AD. METHODS: To dissect the proteomic perturbations induced by Aβ and Presenilin-1 (PS1) in the AD pathogenesis, we undertook a label-free quantitative (LFQ) proteomic analysis focusing on the hippocampal proteome of the APP/PS1 transgenic mouse model. Employing a multi-faceted approach that included differential protein functional enrichment, cluster analysis, and protein-protein interaction (PPI) network analysis, we conducted a comprehensive comparative proteomic study between APP/PS1 transgenic mice and their wild-type C57BL/6 counterparts. RESULTS: Mass spectrometry identified a total of 4817 proteins in the samples, with 2762 proteins being quantifiable. Comparative analysis revealed 396 proteins with differential expression between the APP/PS1 and control groups. Notably, 35 proteins exhibited consistent temporal regulation trends in the hippocampus, with concomitant alterations in biological pathways and PPI networks. CONCLUSIONS: This study presents a comparative proteomic profile of transgenic (APP/PS1) and wild-type mice, highlighting the proteomic divergences. Furthermore, it charts the trajectory of proteomic changes in the AD mouse model across the developmental stages from 2 to 12 months, providing insights into the physiological and pathological implications of the disease-associated genetic mutations.

Animals↗

Thymidylate synthase structure, function and implication in drug discovery.

Recent methodologies applied to the drug discovery process, such as genomics and proteomics, have greatly implemented our basic understanding of drug action and are giving more input to medicinal chemists, in finding genuinely new targets and opportunities for the development of drugs with original mechanisms of action. In this paper, an example of the successful application of some new techniques to the target enzymes with the Thymidylate Synthase (TS) function is given. The improved knowledge of the complex mechanism of the biological pathways in which thymidylate synthase is involved represents a unique chance to find new mechanism-based inhibitors, aimed to treat not only cancerous diseases, but also infectious pathologies. Thymidylate synthase (TS or ThyA) has long been considered as one of the best-known drug targets in the anti-cancer area, after which old and new drugs, such as 5-fluoro uracil and the anti-folate ZD1694, have been introduced into chemotherapy to treat solid tumours. Only a few attempts have been made to find non-classical anti-folate inhibitors that are dissimilar to the folate co-factor, with the aim of finding unshared protein target domains on the enzyme structure, in order to specifically inhibit TS enzymes from pathogens. Only recently from omic studies, a new Thymidylate Synthase Complementing Protein (TSCP or ThyX) has been identified in a number of pathogens, showing a different structure with respect to human TS, thus opening new avenues to specific inhibitions. A depiction of the most recent progress in the study of Thymidylate Synthase enzymes is presented in the following sections.

Antineoplastic Agents↗

Angiogenesis inhibitors: perspectives for medical, surgical and radiation oncology.

In the past decade, many angiogenesis inhibitors have been developed for clinical use in oncology. Surgeons, radiotherapists as well as medical oncologists have been investigating with much effort and enthusiasm the translation of these agents from the preclinical setting into treatment strategies of patients. Recently, for the first time in history, the angiogenesis inhibitor bevacizumab (avastin), a humanized anti-vascular endothelial growth factor (VEGF) antibody, showed a survival benefit of 4.7 months in a phase III clinical trial in patients with advanced colorectal cancer when this agent was given in combination with chemotherapy. At the annual meeting of the American Association of Clinical Oncology 2005, similar results of bevacizumab in lung, breast and ovarian cancer clinical trials have been shown. These landmark studies proofed for the first time in the clinical setting that Dr. Folkman back in 1971 was right by proposing: "in order to stop tumor growth, one should attack its blood supply". Nowadays it seems trivial to propose such a hypothesis, at that time it was a very provocative hypothesis and it took more than 30 years to proof this hypothesis in the clinic. Although one may be excited about this major finding, there is no time to relax. The survival benefit of bevacizumab is only about 4 months. Therefore more potent antiangiogenic agents and more active treatment strategies are urgently warranted. Newer angiogenesis inhibitors that are currently in preclinical or early clinical development have shown in preclinical experiments improved antitumor activities. In addition, combinations of biological agents that interfere in multiple biological pathways in cancer growth including chemotherapy, are of major clinical interest as well. The multimodality approach in which surgeons, radiotherapists and medical oncologists collaborate needs to be explored as well. In a variety of cancer types, like breast colon and lung cancer, these specialists should design multimodality strategies based on current standard treatment in which they incorporate angiogenesis inhibitors in the right time frame of surgery and radiotherapy. In this review we will bring you up to date on the clinical development of angiogenesis inhibitors and we will summarize the multimodality strategies that are under development.

Angiogenesis Inhibitors↗

The making of a portrait--bringing it into focus.

The data generated by DNA arrays are often described as the molecular "portrait" of a particular physiological/pathological sample. Although the emotional reactions could range from revulsion to adoration when viewing those portraits, as it might be when viewing some contemporary art, array technology has fundamentally changed the way researchers approach many biomedical questions. With its ability to monitor the expression level of tens of thousands genes simultaneously, microarray technology has been able to identify "markers" for complex diseases such as cancer. While massive amounts of work lie ahead to validate those marker genes, many researchers are turning their attentions to the low-density, focused arrays. When incorporated with current knowledge on specific biological pathways, these specially tailored macroarrays may be better fitted for purposes such as diagnosis, drug discovery and validation, and prognostic assessment of clinical treatments.

Biotechnology↗

Role of nitric oxide and calpain activation in neuronal death and survival.

Dysregulation of intracellular calcium homeostasis is a common hallmark of degenerating neurons, at some point in the cell death cascade. It is also a feature of many neurological disorders, including stroke, epilepsy, trauma and several neurodegenerative diseases, commonly associated with the phenomenon of excitotoxicity. Nitric oxide (NO) is a signaling gaseous molecule formed in the brain as a part of the normal intracellular calcium signalling, playing highly diversified roles in cellular physiology. For the past 20 years, numerous studies have demonstrated that NO can acts as a neurotoxin in several disorders of the nervous system. More recent evidence shows that NO can also act as a neuroprotective agent. Calcium-dependent proteases, like calpains, were also shown to be activated in several conditions of the nervous system that involve excitotoxic neurodegeneration, and have been receiving increasing attention as therapeutical targets in recent years. In this review, we bring together the recent literature concerning the involvement of NO and calpains in neuronal survival and death. The biological pathways involved with NO and calpains may be good drug targets to alter neurodegenerative diseases.

Animals↗

The psoriasis genetics as a model of complex disease.

Psoriasis [OMIM*177900] is a common, chronic and papulosquamous inflammatory skin disease affecting approximately 2% of Caucasian. However, this disorder is rare among Japanese, Eskimos, West Africans and North American blacks and very uncommon in North American and South American natives. The causes for these variations are likely to be both genetic and environmental. Population-based studies and twin studies indicate that psoriasis is a heritable disease with a polygenic mode of inheritance with variable penetrance. Independent genome-wide scans have suggested the involvement of a large number of chromosomal regions (loci), and many candidate genes have been proposed. We discuss genetic approaches to the disease, results and interpretations of relevant studies, as well as future perspectives. Understanding the genetic basis of psoriasis will represent a major advance in our understanding of the disease and will reveal novel disease-specific biologic pathways.

Genetic Linkage↗

Gene expression correlates of unexplained fatigue.

Quantitative trait analysis (QTA) can be used to test whether the expression of a particular gene significantly correlates with some ordinal variable. To limit the number of false discoveries in the gene list, a multivariate permutation test can also be performed. The purpose of this study is to identify peripheral blood gene expression correlates of fatigue using quantitative trait analysis on gene expression data from 20,000 genes and fatigue traits measured using the multidimensional fatigue inventory (MFI). A total of 839 genes were statistically associated with fatigue measures. These mapped to biological pathways such as oxidative phosphorylation, gluconeogenesis, lipid metabolism, and several signal transduction pathways. However, more than 50% are not functionally annotated or associated with identified pathways. There is some overlap with genes implicated in other studies using differential gene expression. However, QTA allows detection of alterations that may not reach statistical significance in class comparison analyses, but which could contribute to disease pathophysiology. This study supports the use of phenotypic measures of chronic fatigue syndrome (CFS) and QTA as important for additional studies of this complex illness. Gene expression correlates of other phenotypic measures in the CFS Computational Challenge (C3) data set could be useful. Future studies of CFS should include as many precise measures of disease phenotype as is practical.

Adult↗

Translational regulation of p53 as a potential tumor therapy target.

The tumor suppressor p53 is a central player in apoptosis induction in response to oncogenic stimuli and DNA damage. As activation of p53 has been suggested as a prime strategy for future tumor therapy, inhibition of negative regulators of p53 activity would be a similarly desirable strategy. The small worm Caenorhabditis elegans is a model organism in which many conserved biological pathways, including the core apoptotic machinery, were elucidated. The discovery of a worm p53 homolog cep-1/p53 (which stands for C. elegans p53) that specifically induces apoptosis upon DNA damage through a pathway that is conserved from worm to man opened the way for the use of C. elegans genetics to uncover regulatory mechanisms - and hence novel therapeutic targets - of p53-mediated apoptosis. The authors have recently reported a novel mechanism of C. elegans cep-1/p53 regulation through germ line defective-1-mediated translational repression. This review discusses the potential of the worm system to screen for apoptosis-inducing cancer drugs and to identify novel p53 regulators whose human counterparts might become potential tumor therapy targets.

Animals↗

Monoclonal antibody therapy.

The concept of targeted therapy was conceived through increased understanding of the biological pathways involved in the pathogenesis of cancer and subsequently identification of the most appropriate antigens to target. Monoclonal antibody therapy harnesses host defense mechanisms through activation of the antibody dependent cytotoxic pathway and complement mediated cytotoxicity. However, these two processes alone do not explain the therapeutic efficacy of antibody therapy; they also act by apoptotic signaling and growth inhibitory pathways. Conjugation of monoclonal antibody therapy, with radionuclides or toxins, offers more therapeutic approaches. Initial data demonstrates efficacy of single agent use, although combination therapy appears potentially more beneficial. Monoclonal antibody therapy is having a significant impact on many disease processes, particularly malignancies of solid and hematological origin. In this article, we shall review and discuss the monoclonal antibodies approved by the US Food and Drug Administration (FDA). in the management of cancer.

Alemtuzumab↗

Polyps as biomarkers for colorectal neoplasia.

Current understanding of colorectal carcinogenesis suggests a series of genetic changes occurring pari passu with morphological changes ultimately resulting in a cancerous lesion. The adenomatous polyp was originally the prototype of the preneoplastic lesion but recently, other colonic polyps, primarily the hamartomas, have been clinically characterized as colorectal cancer biomarkers with genetic changes found mainly in the mesenchymal component as opposed to the ectodermal, or epithelial element. This, with the current interest in angiogenesis playing a role in the propagation of neoplastic lesions, has now encompassed every tissue element and opened the way for an understanding of the oncogenic process. This has suggested that considerable interaction occurs between all tissue elements, including what was previously described as epithelial-matrix interactions. While hyperplastic polyps are thought not to confer risk for cancer, they may offer clues as to the first steps of the overall process. Microadenomas have introduced new clinical as well as biological considerations, as unique risk factors. Investigation of these lesions has moved from purely morphological correlations to mechanistic dissections of important biological pathways using both genetic and protein chemistry tools. This review explores the microcosm of the colonic polyp and its relation to cancer as the quintessential premalignant biomarker.

Adenoma↗

Contralateral adrenal metastasis in renal cell cancer.

A 60-year-old female patient presenting with anemia was found to have a left-sided renal tumor and a contralateral adrenal mass of 2 cm in diameter. Imaging studies for metastases were negative. Nephrectomy along with contralateral adrenalectomy was performed and histology disclosed renal cell carcinoma stage pT3a pNO G2 with solitary contralateral adrenal metastasis. In a survey of the literature, 24 previous cases of renal cancer with solitary contralateral adrenal metastasis were identified. The most probable biological pathway to explain this peculiar metastatic pattern is transpulmonal passage of circulating cancer cells and seeding in the adrenal gland on the basis of a particular susceptibility of adrenal tissue to circulating renal cancer cells. The case illustrates that surgery of solitary metastases from renal cell carcinoma may be beneficial to the patient. The case further highlights the caution that is required diagnostically in the interpretation of incidentally found adrenal masses when other malignancies are present.

Adrenal Gland Neoplasms↗

Epigenetic events in medulloblastoma development.

Over the last decade, the analysis of genetic defects in primary tumors has been central to the identification of molecular events and biological pathways involved in the pathogenesis of medulloblastoma, the most common malignant brain tumor of childhood. Despite this, understanding of the molecular basis of the majority of cases remains poor. In recent years, the emerging field of epigenetics, which describes heritable alterations in gene expression that occur in the absence of DNA sequence changes, has forced a revision of the understanding of the mechanisms of gene disruption in cancer. Accumulating evidence indicates a significant involvement for epigenetic events in medulloblastoma development. Recent studies have identified a series of candidate tumor suppressor genes (for example, RASSF1A, CASP8, and HIC1) that are each specifically epigenetically inactivated in a large proportion (> 30%) of medulloblastomas by promoter hypermethylation, leading to the silencing of their gene expression. These findings shed new light on medulloblastoma and offer great potential for an improved understanding of its molecular pathology. The authors review the current understanding of epigenetic events in cancer and their contribution to medulloblastoma development. Their nature, origins, and functional role(s) in tumorigenesis are considered, and the authors assess the potential utility of these events as a basis for novel diagnostic and therapeutic approaches.

Animals↗

Elevated plasma homocysteine levels: risk factor or risk marker for the development of dementia and Alzheimer's disease?

Elevated plasma homocysteine (tHcy) concentrations have been associated with an increased risk of developing dementia and Alzheimer's disease (AD). It is not clear, however, if an elevation in tHcy concentration is a "risk factor" with a direct pathophysiological role in the development of the disease or merely a "risk marker" reflecting an underlying process such as oxidative stress responsible for both the high tHcy concentrations and the development of AD. Epidemiological studies have confirmed that elevations in plasma tHcy temporally precede the development of dementia and that there is a continuous, inverse linear relation between plasma tHcy concentrations and cognitive performance in older persons. Several potential biological pathways that could mediate the observed association are briefly reviewed. In light of these data and the growing parallel interest in plasma tHcy as an emerging vascular risk factor there was considerable hope that vitamin therapy with folate, B12 and B6, shown to lower plasma tHcy levels, could significantly reduce the risk of stroke and dementia permitting healthy brain aging. The results from recent trials addressing the secondary prevention of stroke and myocardial infarction trials have been disappointing. However, the role of vitamins and other homocysteine lowering treatments in the primary prevention of stroke and dementia, as well as their role in preserving cognition among persons with mild cognitive impairment and early dementia deserves to be fully pursued.

Alzheimer Disease↗

The Role of Homologous Recombination Deficiency (HRD) in Renal Cell Carcinoma (RCC): Biology, Biomarkers, and Therapeutic Opportunities.

Renal Cell Carcinoma (RCC) is a common malignancy, often diagnosed incidentally. In recent years, the prognosis of metastatic disease has been improved due to the development of immune checkpoint inhibitors (ICI) and tyrosine kinase inhibitors (TKI) as first-line treatments. However, when progression occurs, the therapeutic options are limited. Understanding crucial biological pathways could lead to a greater understanding of the natural history of the disease, which could help to overcome the mechanism of resistance and to develop new treatments. The clinical significance of homologous recombination deficiency (HRD) in RCC remains to be investigated. To improve the knowledge about this topic, we conducted a narrative review to summarize the current evidence on HRD-related variations and signatures in RCC, together with their prognostic and predictive implications. Preliminary evidence indicates that canonical HRD variants (BRCA1/2) are infrequent in RCC, while broader DNA damage response (DDR) alterations like BAP1, PBRM1, ATM, and SETD2 are more prevalent. Elevated HRD genomic scores in clear-cell RCC correlate with a worse prognosis and an immunologically exhausted microenvironment. From a therapeutic point of view, PARP inhibitor monotherapy has exhibited initial efficacy in small cohorts with high levels of DDR mutation, yet remains investigational for RCC.

Humans↗

Personalised Nutraceutical Treatment Guided by MTHFR Genotype in Mental Health: A Retrospective Cohort Study.

BACKGROUND & AIMS: One-carbon metabolism plays a central role in neurotransmitter synthesis, methylation capacity, and neurobiological resilience. Variants in the methylenetetrahydrofolate reductase (MTHFR) gene can reduce enzymatic activity, affecting folate- and methionine-cycle functions and potentially influencing biological pathways relevant to mood and anxiety disorders. Personalised nutraceutical treatment strategies, particularly those addressing methylation capacity through targeted B-vitamin, folate, and adjunctive metabolic interventions are increasingly implemented in integrative clinical practice, yet evidence regarding their clinical outcomes remains limited. METHODS: We conducted a retrospective cohort study of 50 adults attending an integrative general practice clinic for anxiety and/or depression. All received personalised nutraceutical treatment informed by clinical assessment, laboratory testing and, for 37/50 patients, MTHFR genotyping. Psychological distress was measured using the Kessler-10 (K10) scale at baseline and approximately three months later. Secondary analyses evaluated whether outcomes differed by MTHFR genotype, whether specific supplements (e.g., L-methylfolate and SAMe) were associated with greater improvement, whether biomarker changes correlated with symptom change, and the safety/tolerability profile. RESULTS: Across the full cohort, mean K10 scores significantly decreased by four points over the treatment period, with 72% of patients showing clinical improvement. Reductions in psychological distress were seen across all MTHFR genotypes, including individuals with homozygous variant genotypes. Supplement-specific analyses showed improvement among those receiving methylfolate or SAMe, although the differences were not statistically significant. Following nutraceutical treatment, biomarker analyses demonstrated significant increases in serum vitamin B12 and modest reductions in homocysteine, but biomarker shifts did not correlate strongly with K10 change. No serious adverse events or clinically significant abnormalities in liver or renal function were identified. CONCLUSIONS: In this real-world primary care cohort, personalised nutraceutical treatment, grounded in one-carbon metabolism support and applied alongside usual care, was associated with clinically meaningful reductions in psychological distress. Outcomes were comparable across MTHFR genotypes when treatments were appropriately tailored, suggesting that genotype and biomarker-informed nutraceutical strategies may mitigate potential metabolic disadvantages. These findings support further controlled research into precision nutraceutical psychiatry for anxiety and depression. Secondary analyses of genotype subgroup, specific supplements, and biomarker-outcome associations are reported alongside Benjamini-Hochberg FDR-adjusted p-values and should be interpreted as hypothesis-generating.

Humans↗

Using yeast two-hybrid system to identify ECRG2 associated proteins and their possible interactions with ECRG2 gene.

AIM: To identify esophageal cancer related gene2 (ECRG2) associated proteins and their possible interactions with ECRG2 gene. METHODS: In the yeast forward two-hybrid system, ECRG2 was fused with the DNA-binding domain (DBD) of Gal4 and human fetal liver cDNA library was fused with the transcriptional activation domain (AD) of Gal4. We performed a high-stringency scale procedure to screen ECRG2 against human fetal liver cDNA library and characterized positives by sequence analysis. RESULTS: We found the following 9 putatively associated proteins. They were metallothionein2A, metallothionein1H, metallothionein1G, ferritin, erythrocyte membrane protein band4.2, mitochondrial ribosomal protein S12, hypothetical protein FLJ10101, and a novel gene whose cDNA was found to have no strong homology to any other previously characterized gene whose DDBJ/EMBL/GenBank accession number is AF422192 mapped to human chromosome 14q31. CONCLUSION: MT, a potential interaction partner for ECRG2, might be involved in the regulation of cell proliferation and apoptosis, and in various physiological processes. Determination of a reliability score for each single protein-protein interaction, especially interaction of ECRG2 and MT, permits the assignment of ECRG2 and unannotated proteins to biological pathways. A further understanding of the association between ECRG2 and MT should facilitate the functions of ECRG2 gene.

Fetus↗

Neuroimaging studies of serotonin gene polymorphisms: exploring the interplay of genes, brain, and behavior.

Because of the unique ability it provides to investigate information processing at the level of neural systems, functional neuroimaging is a powerful tool to explore the relationship between genes, brain, and behavior. Recently, functional neuroimaging has provided dramatic illustrations of how a promoter polymorphism in the human serotonin transporter gene, which has been weakly related to several dimensions of emotional behaviors (such as neuroticism and anxiety traits), is strongly related to the engagement of neural systems--namely, the amygdala and subgenual prefrontal cortex, subserving emotional information processing. This review will outline the experimental strategy by which these genetic effects on brain function have been explored and highlight the effectiveness of this strategy to delineate biological pathways and mechanisms contributing to the emergence of individual differences in brain function that potentially bias behavior and risk for psychiatric illness.

Animals↗

Integration of targeted therapies in gemcitabine chemotherapy regimens.

Lung cancer is one of the most common malignancies in the United States and the most lethal. Non-small-cell lung cancer (NSCLC), which accounts for over 80% of all lung cancer cases, results in a particularly poor prognosis and a high mortality rate. The 5-year survival rate is still only 15%, and most patients ultimately die from this disease. Unfortunately, the therapeutic improvements resulting from the new generation of cytotoxic agents seems to have reached a plateau. Targeted therapeutics, or agents aimed at specific biologic pathways, represent a potential for great improvements in survival from this disease. Because of their greater specificity, targeted therapeutics have the potential for decreased toxicity and increased efficacy. The main categories of targeted therapies applicable for NSCLC include receptor-targeted therapy, signal transduction or cell-cycle inhibition, angiogenesis inhibition, gene therapy, and vaccines. These new agents are, in theory, more target-specific, less toxic, easier to administer, and may lead to enhanced safety and survival for patients with advanced NSCLC. Targeted therapies are in different phases of clinical testing and have shown encouraging activity as single agents or in combination with chemotherapy as well as radiation therapy. Herein we explore targeted therapy in combination with gemcitabine.

Journal Article↗