scholarly journals Carbohydrates—Key Players in Tobacco Aroma Formation and Quality Determination

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1734
Author(s):  
Marija Banožić ◽  
Stela Jokić ◽  
Đurđica Ačkar ◽  
Marijana Blažić ◽  
Drago Šubarić
Keyword(s):  
Current Knowledge ◽  
Sugar Content ◽  
Special Focus ◽  
Pectin Degradation ◽  
Curing Conditions ◽  
Added Sugars ◽  
Tobacco Production ◽  
Key Players ◽  
Lower Temperature ◽  
Temperature Time

Carbohydrates are important compounds in natural products where they primarily serve as a source of energy, but they have important secondary roles as precursors of aroma or bioactive compounds. They are present in fresh and dried (cured) tobacco leaves as well. The sugar content of tobacco depends on the tobacco variety, harvesting, and primarily on the curing conditions (temperature, time and moisture). If the process of curing employs high temperatures (flue-curing and sun-curing), final sugar content is high. In contrast, when air curing has a lower temperature, at the end of the process, sugar level is low. Beside simple sugars, other carbohydrates reported in tobacco are oligosaccharides, cellulose, starch, and pectin. Degradation of polysaccharides results in a higher yield of simple sugars, but at the same time reduces sugars oxidization and transfer into carbon dioxide and water. Loss of sugar producers will compensate with added sugars, to cover undesirable aroma properties and achieve a better, pleasant taste during smoking. However, tobacco carbohydrates can be precursors for many harmful compounds, including formaldehyde and 5-hydroxymethylfurfural. Keeping in mind that added sugars in tobacco production are unavoidable, it is important to understand all changes in carbohydrates from harvesting to consuming in order to achieve better product properties and avoid the formation of harmful compounds. This review summarizes current knowledge about tobacco carbohydrates, including changes during processing with special focus on carbohydrates as precursors of harmful compounds during smoking.

scholarly journals Hypoxia, Acidification and Inflammation: Partners in Crime in Parkinson’s Disease Pathogenesis?

Immuno ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 78-90
Author(s):  
Johannes Burtscher ◽  
Grégoire P. Millet
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Neurodegenerative Diseases ◽  
Current Knowledge ◽  
Cell Types ◽  
Brain Cell ◽  
Special Focus ◽  
Molecular Alterations ◽  
Research Fields

Like in other neurodegenerative diseases, protein aggregation, mitochondrial dysfunction, oxidative stress and neuroinflammation are hallmarks of Parkinson’s disease (PD). Differentiating characteristics of PD include the central role of α-synuclein in the aggregation pathology, a distinct vulnerability of the striato-nigral system with the related motor symptoms, as well as specific mitochondrial deficits. Which molecular alterations cause neurodegeneration and drive PD pathogenesis is poorly understood. Here, we summarize evidence of the involvement of three interdependent factors in PD and suggest that their interplay is likely a trigger and/or aggravator of PD-related neurodegeneration: hypoxia, acidification and inflammation. We aim to integrate the existing knowledge on the well-established role of inflammation and immunity, the emerging interest in the contribution of hypoxic insults and the rather neglected effects of brain acidification in PD pathogenesis. Their tight association as an important aspect of the disease merits detailed investigation. Consequences of related injuries are discussed in the context of aging and the interaction of different brain cell types, in particular with regard to potential consequences on the vulnerability of dopaminergic neurons in the substantia nigra. A special focus is put on the identification of current knowledge gaps and we emphasize the importance of related insights from other research fields, such as cancer research and immunometabolism, for neurodegeneration research. The highlighted interplay of hypoxia, acidification and inflammation is likely also of relevance for other neurodegenerative diseases, despite disease-specific biochemical and metabolic alterations.

scholarly journals Thrombocytopathies: Not Just Aggregation Defects—The Clinical Relevance of Procoagulant Platelets

2021 ◽  
Vol 10 (5) ◽  
pp. 894
Author(s):  
Alessandro Aliotta ◽  
Debora Bertaggia Calderara ◽  
Maxime G. Zermatten ◽  
Matteo Marchetti ◽  
Lorenzo Alberio
Keyword(s):  
Platelet Activation ◽  
Clinical Relevance ◽  
Current Knowledge ◽  
Procoagulant Activity ◽  
Key Players ◽  
Platelet Defects

Platelets are active key players in haemostasis. Qualitative platelet dysfunctions result in thrombocytopathies variously characterized by defects of their adhesive and procoagulant activation endpoints. In this review, we summarize the traditional platelet defects in adhesion, secretion, and aggregation. In addition, we review the current knowledge about procoagulant platelets, focusing on their role in bleeding or thrombotic pathologies and their pharmaceutical modulation. Procoagulant activity is an important feature of platelet activation, which should be specifically evaluated during the investigation of a suspected thrombocytopathy.

scholarly journals Analytical Rheology of Honey: A State-of-the-Art Review

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1709
Author(s):  
Célia Faustino ◽  
Lídia Pinheiro
Keyword(s):  
Sugar Content ◽  
Rheological Behaviour ◽  
Principal Component ◽  
Rheological Parameters ◽  
Experimental Conditions ◽  
Thixotropic Behaviour ◽  
Ancient Times ◽  
Medicinal Properties ◽  
Complex Relationships ◽  
Temperature Time

Honey has been used as a nutraceutical product since ancient times due to its nutritional and medicinal properties. Honey rheology influences its organoleptic properties and is relevant for processing and quality control. This review summarizes the rheological behaviour of honeys of different botanical source(s) and geographical locations that has been described in the literature, focusing on the relation between rheological parameters, honey composition (moisture, water activity, sugar content, presence of colloidal matter) and experimental conditions (temperature, time, stress, shear rate). Both liquid and crystallized honeys have been addressed. Firstly, the main mathematical models used to describe honey rheological behaviour are presented highlighting moisture and temperature effects. Then, rheological data from the literature regarding distinct honey types from different countries is analysed and results are compared. Although most honeys are Newtonian fluids, interesting shear-thinning and thixotropic as well as anti-thixotropic behaviour have been described for some types of honey. Rheological parameters have also been successfully applied to identify honey adulteration and to discriminate between different honey types. Several chemometric techniques have also been employed to obtain the complex relationships between honey physicochemical and rheological properties, including partial least squares (PLS), principal component analysis (PCA) and artificial neural networks (ANN).

scholarly journals Stress-Related Dysfunction of Adult Hippocampal Neurogenesis—An Attempt for Understanding Resilience?

2021 ◽  
Vol 22 (14) ◽  
pp. 7339
Author(s):  
Julia Leschik ◽  
Beat Lutz ◽  
Antonietta Gentile
Keyword(s):  
Major Depression ◽  
Adult Neurogenesis ◽  
Current Knowledge ◽  
Functional Relation ◽  
Hippocampal Neurogenesis ◽  
Adult Hippocampal Neurogenesis ◽  
Special Focus ◽  
Extrinsic Cues ◽  
Health And Disease ◽  
Newborn Neurons

Newborn neurons in the adult hippocampus are regulated by many intrinsic and extrinsic cues. It is well accepted that elevated glucocorticoid levels lead to downregulation of adult neurogenesis, which this review discusses as one reason why psychiatric diseases, such as major depression, develop after long-term stress exposure. In reverse, adult neurogenesis has been suggested to protect against stress-induced major depression, and hence, could serve as a resilience mechanism. In this review, we will summarize current knowledge about the functional relation of adult neurogenesis and stress in health and disease. A special focus will lie on the mechanisms underlying the cascades of events from prolonged high glucocorticoid concentrations to reduced numbers of newborn neurons. In addition to neurotransmitter and neurotrophic factor dysregulation, these mechanisms include immunomodulatory pathways, as well as microbiota changes influencing the gut-brain axis. Finally, we discuss recent findings delineating the role of adult neurogenesis in stress resilience.

scholarly journals Rho GTPases as Key Molecular Players within Intestinal Mucosa and GI Diseases

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 66
Author(s):  
Rashmita Pradhan ◽  
Phuong A. Ngo ◽  
Luz d. C. Martínez-Sánchez ◽  
Markus F. Neurath ◽  
Rocío López-Posadas
Keyword(s):  
Intestinal Mucosa ◽  
Rho Gtpases ◽  
Current Knowledge ◽  
Cell Types ◽  
Effector Proteins ◽  
Special Focus ◽  
Specific Cell ◽  
Rho Proteins

Rho proteins operate as key regulators of the cytoskeleton, cell morphology and trafficking. Acting as molecular switches, the function of Rho GTPases is determined by guanosine triphosphate (GTP)/guanosine diphosphate (GDP) exchange and their lipidation via prenylation, allowing their binding to cellular membranes and the interaction with downstream effector proteins in close proximity to the membrane. A plethora of in vitro studies demonstrate the indispensable function of Rho proteins for cytoskeleton dynamics within different cell types. However, only in the last decades we have got access to genetically modified mouse models to decipher the intricate regulation between members of the Rho family within specific cell types in the complex in vivo situation. Translationally, alterations of the expression and/or function of Rho GTPases have been associated with several pathological conditions, such as inflammation and cancer. In the context of the GI tract, the continuous crosstalk between the host and the intestinal microbiota requires a tight regulation of the complex interaction between cellular components within the intestinal tissue. Recent studies demonstrate that Rho GTPases play important roles for the maintenance of tissue homeostasis in the gut. We will summarize the current knowledge on Rho protein function within individual cell types in the intestinal mucosa in vivo, with special focus on intestinal epithelial cells and T cells.

scholarly journals Hampering Stromal Cells in the Tumor Microenvironment as a Therapeutic Strategy to Destem Cancer Stem Cells

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3191
Author(s):  
Katherine Po Sin Chung ◽  
Rainbow Wing Hei Leung ◽  
Terence Kin Wah Lee
Keyword(s):  
Stem Cells ◽  
Tumor Microenvironment ◽  
Cancer Stem Cells ◽  
Cancer Cells ◽  
Stromal Cells ◽  
Current Knowledge ◽  
Special Focus ◽  
Intrinsic Regulation ◽  
Mechanistic Basis ◽  
Novel Therapeutic Strategies

Cancer stem cells (CSCs) within the tumor bulk play crucial roles in tumor initiation, recurrence and therapeutic resistance. In addition to intrinsic regulation, a growing body of evidence suggests that the phenotypes of CSCs are also regulated extrinsically by stromal cells in the tumor microenvironment (TME). Here, we discuss the current knowledge of the interplay between stromal cells and cancer cells with a special focus on how stromal cells drive the stemness of cancer cells and immune evasive mechanisms of CSCs. Knowledge gained from the interaction between CSCs and stromal cells will provide a mechanistic basis for the development of novel therapeutic strategies for the treatment of cancers.

scholarly journals Objective Biomarkers for Total Added Sugar Intake – Are We on a Wild Goose Chase?

2020 ◽  
Vol 11 (6) ◽  
pp. 1429-1436
Author(s):  
Jimmy Chun Yu Louie
Keyword(s):  
Human Physiology ◽  
Current Knowledge ◽  
Dietary Assessment ◽  
Added Sugar ◽  
Added Sugars ◽  
Sugar Intake ◽  
Adverse Health Outcomes ◽  
Dietary Assessment Methods ◽  
Nutritional Sciences ◽  
Wild Goose

ABSTRACT Misreporting of added sugar intake has been the major criticism of studies linking high added sugar consumption to adverse health outcomes. Despite the advancement in dietary assessment methodologies, the bias introduced by self-reporting can never be completely eliminated. The search for an objective biomarker for total added sugar intake has therefore been a topic of interest. In this article, the reasons this search may be a wild goose chase will be outlined and discussed. The limitations and inability of the 2 candidate biomarkers, namely urinary sucrose and fructose and δ¹³C isotope, which are based on the 2 only possible ways (i.e., difference in metabolism and plant sources) to identify added sugar based on current knowledge in human physiology and food and nutritional sciences, are discussed in detail. Validation studies have shown that these 2 candidate biomarkers are unlikely to be suitable for use as a predictive or calibration biomarker for total added sugar intake. Unless advancement in our understanding in human physiology and food and nutritional sciences leads to new potential ways to distinguish between naturally occurring and added sugars, it is extremely unlikely that any accurate objective added sugar biomarker could be found. It may be time to stop the futile effort in searching for such a biomarker, and resources may be better spent on further improving and innovating dietary assessment methods to minimize the bias introduced by self-reporting.

scholarly journals Electron Transport Disturbances and Neurodegeneration: From Albert Szent-Györgyi’s Concept (Szeged) till Novel Approaches to Boost Mitochondrial Bioenergetics

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Levente Szalárdy ◽  
Dénes Zádori ◽  
Péter Klivényi ◽  
József Toldi ◽  
László Vécsei
Keyword(s):  
Transcriptional Activation ◽  
Current Knowledge ◽  
Genetic Alterations ◽  
Cellular Respiration ◽  
Special Focus ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Disease Modifying Therapy ◽  
Mitochondrial Functions ◽  
Genes Encoding

Impaired function of certain mitochondrial respiratory complexes has long been linked to the pathogenesis of chronic neurodegenerative disorders such as Parkinson’s and Huntington’s diseases. Furthermore, genetic alterations of mitochondrial genome or nuclear genes encoding proteins playing essential roles in maintaining proper mitochondrial function can lead to the development of severe systemic diseases associated with neurodegeneration and vacuolar myelinopathy. At present, all of these diseases lack effective disease modifying therapy. Following a brief commemoration of Professor Albert Szent-Györgyi, a Nobel Prize laureate who pioneered in the field of cellular respiration, antioxidant processes, and the roles of free radicals in health and disease, the present paper overviews the current knowledge on the involvement of mitochondrial dysfunction in central nervous system diseases associated with neurodegeneration including Parkinson’s and Huntington’s disease as well as mitochondrial encephalopathies. The review puts special focus on the involvement and the potential therapeutic relevance of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α), a nuclear-encoded master regulator of mitochondrial biogenesis and antioxidant responses in these disorders, the transcriptional activation of which may hold novel therapeutic value as a more system-based approach aiming to restore mitochondrial functions in neurodegenerative processes.

scholarly journals Echinocandins: structural diversity, biosynthesis, and development of antimycotics

2020 ◽  
Vol 105 (1) ◽  
pp. 55-66
Author(s):  
Wolfgang Hüttel
Keyword(s):  
Isotope Labeling ◽  
Current Knowledge ◽  
Complex Structure ◽  
Hydrolytic Stability ◽  
Structural Diversity ◽  
Gene Clusters ◽  
Special Focus ◽  
Key Points ◽  
Invasive Mycosis ◽  
History Of

Abstract Echinocandins are a clinically important class of non-ribosomal antifungal lipopeptides produced by filamentous fungi. Due to their complex structure, which is characterized by numerous hydroxylated non-proteinogenic amino acids, echinocandin antifungal agents are manufactured semisynthetically. The development of optimized echinocandin structures is therefore closely connected to their biosynthesis. Enormous efforts in industrial research and development including fermentation, classical mutagenesis, isotope labeling, and chemical synthesis eventually led to the development of the active ingredients caspofungin, micafungin, and anidulafungin, which are now used as first-line treatments against invasive mycosis. In the last years, echinocandin biosynthetic gene clusters have been identified, which allowed for the elucidation but also engineering of echinocandin biosynthesis on the molecular level. After a short description of the history of echinocandin research, this review provides an overview of the current knowledge of echinocandin biosynthesis with a special focus of the diverse structural elements, their biosynthetic background, and structure−activity relationships. Key points • Complex and highly oxidized lipopeptides produced by fungi. • Crucial in the design of drugs: side chain, solubility, and hydrolytic stability. • Genetic methods for engineering biosynthesis have recently become available.

An Emerging Role for Chloroplasts in Disease and Defense

2021 ◽  
Vol 59 (1) ◽  
pp. 423-445
Author(s):  
Pradeep Kachroo ◽  
Tessa M. Burch-Smith ◽  
Murray Grant
Keyword(s):  
Immune Responses ◽  
De Novo ◽  
Current Knowledge ◽  
Reactive Oxygen ◽  
Host Immunity ◽  
Retrograde Signaling ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
De Novo Synthesis ◽  
Key Players

Chloroplasts are key players in plant immune signaling, contributing to not only de novo synthesis of defensive phytohormones but also the generation of reactive oxygen and nitrogen species following activation of pattern recognition receptors or resistance (R) proteins. The local hypersensitive response (HR) elicited by R proteins is underpinned by chloroplast-generated reactive oxygen species. HR-induced lipid peroxidation generates important chloroplast-derived signaling lipids essential to the establishment of systemic immunity. As a consequence of this pivotal role in immunity, pathogens deploy effector complements that directly or indirectly target chloroplasts to attenuate chloroplast immunity (CI). Our review summarizes the current knowledge of CI signaling and highlights common pathogen chloroplast targets and virulence strategies. We address emerging insights into chloroplast retrograde signaling in immune responses and gaps in our knowledge, including the importance of understanding chloroplast heterogeneity and chloroplast involvement in intraorganellular interactions in host immunity.

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