scholarly journals Structural basis for broad anti-phage immunity by DISARM

2021 ◽  
Author(s):  
Jack PK Bravo ◽  
Cristian A Maldonado ◽  
Franklin L Nobrega ◽  
Stan JJ Brouns ◽  
David W Taylor
Keyword(s):  
Molecular Mechanisms ◽  
Structural Rearrangement ◽  
In Vivo Studies ◽  
Structural Basis ◽  
Core Complex ◽  
Trigger Loop ◽  
Wide Range ◽  
Phage Dna ◽  
Island System

In the evolutionary arms race against phage, bacteria have assembled a diverse arsenal of antiviral immune strategies. While the recently discovered DISARM (Defense Island System Associated with Restriction-Modification) systems can provide protection against a wide range of phage, the molecular mechanisms that underpin broad antiviral targeting but avoiding autoimmunity remain enigmatic. Here, we report cryo-EM structures of the core DISARM complex, DrmAB, both alone and in complex with an unmethylated phage DNA mimetic. These structures reveal that DrmAB core complex is autoinhibited by a trigger loop (TL) within DrmA and binding to DNA substrates containing a 5' overhang dislodges the TL, initiating a long-range structural rearrangement for DrmAB activation. Together with structure-guided in vivo studies, our work provides insights into the mechanism of phage DNA recognition and specific activation of this widespread antiviral defense system.

scholarly journals Pleiotropic Biological Effects of Dietary Phenolic Compounds and their Metabolites on Energy Metabolism, Inflammation and Aging

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 596 ◽  
Author(s):  
María del Carmen Villegas-Aguilar ◽  
Álvaro Fernández-Ochoa ◽  
María de la Luz Cádiz-Gurrea ◽  
Sandra Pimentel-Moral ◽  
Jesús Lozano-Sánchez ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Phenolic Compounds ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Biological Properties ◽  
In Vivo Studies ◽  
Wide Range ◽  
High Prevalence

Dietary phenolic compounds are considered as bioactive compounds that have effects in different chronic disorders related to oxidative stress, inflammation process, or aging. These compounds, coming from a wide range of natural sources, have shown a pleiotropic behavior on key proteins that act as regulators. In this sense, this review aims to compile information on the effect exerted by the phenolic compounds and their metabolites on the main metabolic pathways involved in energy metabolism, inflammatory response, aging and their relationship with the biological properties reported in high prevalence chronic diseases. Numerous in vitro and in vivo studies have demonstrated their pleiotropic molecular mechanisms of action and these findings raise the possibility that phenolic compounds have a wide variety of roles in different targets.

Cnidium monnieri: A Review of Traditional Uses, Phytochemical and Ethnopharmacological Properties

2015 ◽  
Vol 43 (05) ◽  
pp. 835-877 ◽  
Author(s):  
Yi-Min Li ◽  
Min Jia ◽  
Hua-Qiang Li ◽  
Nai-Dan Zhang ◽  
Xian Wen ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Herbal Medicines ◽  
In Vivo Studies ◽  
Active Constituent ◽  
Active Constituents ◽  
Traditional Uses ◽  
Male Impotence ◽  
Wide Range

Cnidium monnieri (L.) Cuss., an annual plant of the Umbelliferae species is one of the most widely used traditional herbal medicines and its fruits have been used to treat a variety of diseases in China, Vietnam, and Japan. The aim of this review is to provide an up-to-date and comprehensive analysis of the botany, traditional uses, phytochemistry, pharmacology, toxicity and contraindication of Cnidium monnieri (L.) Cuss. and to provide future directions of research on this plant. To date, 350 compounds have been isolated and identified from Cnidium monnieri (L.) Cuss., including the main active constituent, coumarins. In vitro and in vivo studies suggest that osthole and other coumarin compounds possess wide range of pharmacological properties for the treatment of female genitals, male impotence, frigidity, skin-related diseases, and exhibit strong antipruritic, anti-allergic, antidermatophytic, antibacterial, antifungal, anti-osteoporotic effects. Although coumarins have been identified as the main active constituents responsible for the observed pharmacological effects, the molecular mechanisms of their actions are still unknown. Therefore, further studies are still required to reveal the structure–activity relationship of these active constituents. In addition, toxicological and clinical studies are also required to provide further data for pharmaceutical use.

scholarly journals Structural basis of PETISCO complex assembly during piRNA biogenesis in C. elegans

2021 ◽  
Author(s):  
Cecilia Perez-Borrajero ◽  
Nadezda Podvalnaya ◽  
Kay Holleis ◽  
Raffael Lichtenberger ◽  
Emil Karaulanov ◽  
...  
Keyword(s):  
Genome Stability ◽  
Effector Proteins ◽  
In Vivo Studies ◽  
Structural Basis ◽  
Subunit Interaction ◽  
Core Complex ◽  
C Elegans ◽  
Early Embryos

Piwi-interacting RNAs (piRNAs) constitute a class of small RNAs that bind PIWI proteins and are essential to repress transposable elements in the animal germline, thereby promoting genome stability and maintaining fertility. C. elegans piRNAs (21U RNAs) are transcribed individually from minigenes as precursors that require 5′ and 3′ processing. This process depends on the PETISCO complex, consisting of four proteins: IFE-3, TOFU-6, PID-3, and ERH-2. We used biochemical and structural biology approaches to characterize the PETISCO architecture and its interaction with RNA, together with its effector proteins TOST-1 and PID-1. These two proteins define different PETISCO functions: PID-1 governs 21U processing, whereas TOST-1 links PETISCO to an unknown process essential for early embryogenesis. Here, we show that PETISCO forms an octameric assembly with each subunit present in two copies. Determination of structures of the TOFU-6/PID-3 and PID-3/ERH-2 subcomplexes, supported by in vivo studies of subunit interaction mutants, allows us to propose a model for the formation of the TOFU-6/PID-3/ERH-2 core complex and its functionality in germ cells and early embryos. Using NMR spectroscopy, we demonstrate that TOST-1 and PID-1 bind to a common surface on ERH-2, located opposite its PID-3 binding site, explaining how PETISCO can mediate different cellular roles.

scholarly journals Bioactive Peptides as Potential Nutraceuticals for Diabetes Therapy: A Comprehensive Review

2021 ◽  
Vol 22 (16) ◽  
pp. 9059
Author(s):  
Priya Antony ◽  
Ranjit Vijayan
Keyword(s):  
Molecular Mechanisms ◽  
Bioactive Peptides ◽  
Nutritional Intervention ◽  
Food Sources ◽  
In Vivo Studies ◽  
Health Concern ◽  
Antidiabetic Activity ◽  
Wide Range

Diabetes mellitus is a major public health concern associated with high mortality and reduced life expectancy. The alarming rise in the prevalence of diabetes is linked to several factors including sedentary lifestyle and unhealthy diet. Nutritional intervention and increased physical activity could significantly contribute to bringing this under control. Food-derived bioactive peptides and protein hydrolysates have been associated with a number health benefits. Several peptides with antidiabetic potential have been identified that could decrease blood glucose level, improve insulin uptake and inhibit key enzymes involved in the development and progression of diabetes. Dietary proteins, from a wide range of food, are rich sources of antidiabetic peptides. Thus, there are a number of benefits in studying peptides obtained from food sources to develop nutraceuticals. A deeper understanding of the underlying molecular mechanisms of these peptides will assist in the development of new peptide-based therapeutics. Despite this, a comprehensive analysis of the antidiabetic properties of bioactive peptides derived from various food sources is still lacking. Here, we review the recent literature on food-derived bioactive peptides possessing antidiabetic activity. The focus is on the effectiveness of these peptides as evidenced by in vitro and in vivo studies. Finally, we discuss future prospects of peptide-based drugs for the treatment of diabetes.

scholarly journals Structural basis of PETISCO complex assembly during piRNA biogenesis in C. elegans

2021 ◽  
Author(s):  
Cecilia Perez-Borrajero ◽  
Nadezda Podvalnaya ◽  
Kay Holleis ◽  
Lichtenberger Raffael ◽  
Jerome Basquin ◽  
...  
Keyword(s):  
Genome Stability ◽  
Effector Proteins ◽  
In Vivo Studies ◽  
Structural Basis ◽  
Subunit Interaction ◽  
Core Complex ◽  
C Elegans ◽  
Early Embryos

Piwi-interacting RNAs (piRNAs) constitute a class of small RNAs that bind PIWI proteins and are essential to repress transposable elements in the animal germline, thereby promoting genome stability and maintaining fertility. C. elegans piRNAs (21U RNAs) are transcribed individually from minigenes as precursors that require 5′ and 3′ processing. This process depends on the PETISCO complex, consisting of four proteins: IFE-3, TOFU-6, PID-3, and ERH-2. We employ biochemical and structural biology approaches to characterize the PETISCO architecture and its interaction with RNA, together with its effector proteins TOST-1 and PID-1. These two proteins define different PETISCO functions: PID-1 governs 21U processing whereas TOST-1 links PETISCO to an unknown process essential for early embryogenesis. Here, we show that PETISCO forms an octameric assembly with each subunit present in two copies. Determination of structures of the TOFU-6/PID-3 and PID-3/ERH-2 subcomplexes, supported by in vivo studies of subunit interaction mutants, allows us to propose a model for the formation of the TOFU-6/PID-3/ERH-2 core complex, and its functionality in germ cells and early embryos. Using NMR spectroscopy, we demonstrate that TOST-1 and PID-1 bind to a common surface on ERH-2, located opposite its PID-3 binding site, explaining how PETISCO can mediate different cellular roles.

scholarly journals Autophagy Deficiency by Atg4B Loss Leads to Metabolomic Alterations in Mice

Metabolites ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 481
Author(s):  
Gemma G. Martínez-García ◽  
Raúl F. Pérez ◽  
Álvaro F. Fernández ◽  
Sylvere Durand ◽  
Guido Kroemer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Mammalian Cells ◽  
Tissue Homeostasis ◽  
In Vivo Studies ◽  
Protective Mechanism ◽  
Cardiac Damage ◽  
Wide Range ◽  
First Time

Autophagy is an essential protective mechanism that allows mammalian cells to cope with a variety of stressors and contributes to maintaining cellular and tissue homeostasis. Due to these crucial roles and also to the fact that autophagy malfunction has been described in a wide range of pathologies, an increasing number of in vivo studies involving animal models targeting autophagy genes have been developed. In mammals, total autophagy inactivation is lethal, and constitutive knockout models lacking effectors of this route are not viable, which has hindered so far the analysis of the consequences of a systemic autophagy decline. Here, we take advantage of atg4b−/− mice, an autophagy-deficient model with only partial disruption of the process, to assess the effects of systemic reduction of autophagy on the metabolome. We describe for the first time the metabolic footprint of systemic autophagy decline, showing that impaired autophagy results in highly tissue-dependent alterations that are more accentuated in the skeletal muscle and plasma. These changes, which include changes in the levels of amino-acids, lipids, or nucleosides, sometimes resemble those that are frequently described in conditions like aging, obesity, or cardiac damage. We also discuss different hypotheses on how impaired autophagy may affect the metabolism of several tissues in mammals.

scholarly journals The Antitumor Activity of Sodium Selenite Alone and in Combination with Gemcitabine in Pancreatic Cancer: An In Vitro and In Vivo Study

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3169
Author(s):  
Kevin Doello ◽  
Cristina Mesas ◽  
Francisco Quiñonero ◽  
Gloria Perazzoli ◽  
Laura Cabeza ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Sodium Selenite ◽  
Molecular Mechanisms ◽  
Combined Therapy ◽  
Significant Inhibition ◽  
In Vivo Studies ◽  
C57bl Mice ◽  
Migration Capacity

Sodium selenite acts by depleting enzymes that protect against cellular oxidative stress. To determine its effect alone or in combination with gemcitabine (GMZ) in pancreatic cancer, we used PANC-1 and Pan02 cell lines and C57BL mice bearing a Pan02-generated tumor. Our results demonstrated a significant inhibition of pancreatic cancer cell viability with the use of sodium selenite alone and a synergistic effect when associated with GMZ. The molecular mechanisms of the antitumor effect of sodium selenite alone involved apoptosis-inducing factor (AIF) and the expression of phospho-p38 in the combined therapy. In addition, sodium selenite alone and in association with GMZ significantly decreased the migration capacity and colony-forming ability, reduced tumor activity in multicellular tumor spheroids (MTS) and decreased sphere formation of cancer stem cells. In vivo studies demonstrated that combined therapy not only inhibited tumor growth (65%) compared to the untreated group but also relative to sodium selenite or GMZ used as monotherapy (up to 40%), increasing mice survival. These results were supported by the analysis of C57BL/6 albino mice bearing a Pan02-generated tumor, using the IVIS system. In conclusion, our results showed that sodium selenite is a potential agent for the improvement in the treatment of pancreatic cancer and should be considered for future human clinical trials.

scholarly journals Unraveling the neurotoxicity of titanium dioxide nanoparticles: focusing on molecular mechanisms

2016 ◽  
Vol 7 ◽  
pp. 645-654 ◽  
Author(s):  
Bin Song ◽  
Yanli Zhang ◽  
Jia Liu ◽  
Xiaoli Feng ◽  
Ting Zhou ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Titanium Dioxide ◽  
Molecular Mechanisms ◽  
Titanium Dioxide Nanoparticles ◽  
Brain Dysfunction ◽  
In Vivo Studies ◽  
Cell Components ◽  
New Perspective ◽  
The Brain

Titanium dioxide nanoparticles (TiO2 NPs) possess unique characteristics and are widely used in many fields. Numerous in vivo studies, exposing experimental animals to these NPs through systematic administration, have suggested that TiO2 NPs can accumulate in the brain and induce brain dysfunction. Nevertheless, the exact mechanisms underlying the neurotoxicity of TiO2 NPs remain unclear. However, we have concluded from previous studies that these mechanisms mainly consist of oxidative stress (OS), apoptosis, inflammatory response, genotoxicity, and direct impairment of cell components. Meanwhile, other factors such as disturbed distributions of trace elements, disrupted signaling pathways, dysregulated neurotransmitters and synaptic plasticity have also been shown to contribute to neurotoxicity of TiO2 NPs. Recently, studies on autophagy and DNA methylation have shed some light on possible mechanisms of nanotoxicity. Therefore, we offer a new perspective that autophagy and DNA methylation could contribute to neurotoxicity of TiO2 NPs. Undoubtedly, more studies are needed to test this idea in the future. In short, to fully understand the health threats posed by TiO2 NPs and to improve the bio-safety of TiO2 NPs-based products, the neurotoxicity of TiO2 NPs must be investigated comprehensively through studying every possible molecular mechanism.

Phytochemistry and Pharmacology of the Genus Pedicularis Used in Traditional Chinese Medicine

2014 ◽  
Vol 42 (05) ◽  
pp. 1071-1098 ◽  
Author(s):  
Mao-Xing Li ◽  
Xi-Rui He ◽  
Rui Tao ◽  
Xinyuan Cao
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Chemical Constituents ◽  
Iridoid Glycosides ◽  
In Vivo Studies ◽  
Chemical Components ◽  
Wide Range ◽  
Phenylpropanoid Glycosides

In the present review, the literature data on the chemical constituents and biological investigations of the genus Pedicularis are summarized. Some species of Pedicularis have been widely applied in traditional Chinese medicine. A wide range of chemical components including iridoid glycosides, phenylpropanoid glycosides (PhGs), lignans glycosides, flavonoids, alkaloids and other compounds have been isolated and identified from the genus Pedicularis. In vitro and in vivo studies indicated some monomer compounds and extracts from the genus Pedicularis have been found to possess antitumor, hepatoprotective, anti-oxidative, antihaemolysis, antibacterial activity, fatigue relief of skeletal muscle, nootropic effect and other activities.

scholarly journals Development of an LDL Receptor-Targeted Peptide Susceptible to Facilitate the Brain Access of Diagnostic or Therapeutic Agents

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 161
Author(s):  
Séverine André ◽  
Lionel Larbanoix ◽  
Sébastien Verteneuil ◽  
Dimitri Stanicki ◽  
Denis Nonclercq ◽  
...  
Keyword(s):  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Therapeutic Agents ◽  
In Vivo Studies ◽  
Phage Display Technology ◽  
Brain Penetration ◽  
Wide Range ◽  
The Brain

Blood-brain barrier (BBB) crossing and brain penetration are really challenging for the delivery of therapeutic agents and imaging probes. The development of new crossing strategies is needed, and a wide range of approaches (invasive or not) have been proposed so far. The receptor-mediated transcytosis is an attractive mechanism, allowing the non-invasive penetration of the BBB. Among available targets, the low-density lipoprotein (LDL) receptor (LDLR) shows favorable characteristics mainly because of the lysosome-bypassed pathway of LDL delivery to the brain, allowing an intact discharge of the carried ligand to the brain targets. The phage display technology was employed to identify a dodecapeptide targeted to the extracellular domain of LDLR (ED-LDLR). This peptide was able to bind the ED-LDLR in the presence of natural ligands and dissociated at acidic pH and in the absence of calcium, in a similar manner as the LDL. In vitro, our peptide was endocytosed by endothelial cells through the caveolae-dependent pathway, proper to the LDLR route in BBB, suggesting the prevention of its lysosomal degradation. The in vivo studies performed by magnetic resonance imaging and fluorescent lifetime imaging suggested the brain penetration of this ED-LDLR-targeted peptide.

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