Background: Annulus fibrosus (AF) is an important part of the intervertebral disc (IVD) and its injury leads to back pain and impaired mobility. The stem/progenitor cells are essential for the maturation and repair of the AF, however, the identity of AF stem/progenitor cells remain elusive. Methods: In this study, we sorted cells from the murine IVDs and performed the single-cell RNA sequencing. Using single-cell transcriptomics, genetic lineage tracing, in vitro stem cell experiment, ablation models and cell transplantation, we elucidate the role of AF progenitor cells in maturation and injury. Results: On the basis of single-cell RNA-sequencing (scRNA-seq) analysis of the intervertebral disc, we found that the transcription factor Scleraxis (Scx) can specifically label a progenitor cell population of the outer AF. By lineage tracing assay, Scx-lineage AF cells proliferate mainly prior to sexual maturity, but barely proliferate after age of 8 weeks. The Scx-expressing AF cells are enriched for stem/progenitor cell markers and show a higher proliferative capacity and differentiation potential than the Scx− cells. The ablation of Scx-expressing AF cells impairs the maturation of AF. The Scx+ AF cells are enriched for TGFβ signaling. Transplantation of Scx-lineage cells to injured AF with Connective tissue growth factor (CTGF) improved the AF healing. Conclusions: Scleraxis-expressing progenitor cells are critical for the maturation of AF and demonstrate therapeutic potential for AF regeneration. The translational potential of this article: These findings expand the important role of stem cells in maturation and repair and provide new strategy for cellular therapy of AF repair.
McKinley D. Williams, Taylor R. Sweeney, Sabrina Trieu
et al.
ABSTRACT Biofilms are an important colonization mechanism employed by several microbial species to better establish themselves and monopolize the acquisition of resources across different environs. Some bacteria have evolved specialized metabolites that, when secreted, disrupt the formation and stability of biofilms generated by competing heterospecies, providing the producing organism with an ecological advantage. Soil-derived species are probable candidates for the identification of such compounds, given the intense level of competition that occurs within the terrestrial ecosystem. The MS14 strain of Burkholderia contaminans isolated from soil in Mississippi has previously been shown to produce antimicrobial compounds like occidiofungin and ornibactin. In this report, we demonstrate that this strain also produces 4-hydroxy-3-methyl-2-alkenylquinoline (HMAQ-7), an alkaloid-based metabolite structurally similar to others produced by Burkholderia. HMAQ-7 was isolated and purified in sufficient quantities to enable the elucidation of its covalent structure and the evaluation of its biological effects. The compound was found to possess a unique ability to inhibit biofilm biosynthesis in several species, including opportunistic pathogens like Staphylococcus haemolyticus and within saliva-derived multispecies biofilms. HMAQ-7 also demonstrated an ability to modulate additional cellular behaviors in Bacillus subtilis, including motility and sporulation, suggesting that this molecule is important to the interspecies dynamics present across many diverse microenvironments.IMPORTANCEThe present study furthers our understanding of the structural complexity and the biological functions of the 2-alkyl-4(1H)-quinolone metabolites produced by Burkholderia spp. Low micromolar concentrations of HMAQ-7′ induced observable bacterial growth morphology differences. The antibiofilm properties of the HMAQ-7′ characterized in this study will promote future investigations into possible biological and applied roles. The ability to alter biofilm formation using HMAQ-7′ may facilitate Burkholderia spp. colonization in a multitude of environments, that is, aquatic, soil, and possibly during infection. HMAQ may subvert competition by potential competitor species in natural environments of Burkholderia spp. and possibly lung infections of cystic fibrosis patients.
Edet Effiong Asanga, Ndifreke Daniel Ekpo, Affiong Asuquo Edeke
et al.
Abstract Background Chemotherapies target the PfEMP-1 and PfPKG proteins in Plasmodium falciparum, the parasite that causes malaria, in an effort to prevent the disease’s high fatality rate. This work identified the phytochemical components of Nauclea latifolia roots and docked the chemical compounds against target proteins, and examined the in vivo antiplasmodial effect of the roots on Plasmodium berghei-infected mice. Methods Standard protocols were followed for the collection of the plant’s roots, cleaning, and drying of the roots, extraction and fraction preparation, assessment of the in vivo antiplasmodial activity, retrieval of the PfEMP-1 and PfPKG proteins, GCMS, ADME, and docking studies, chromatographic techniques were employed to separate the residual fraction’s components, and the Swis-ADME program made it possible to estimate the drug’s likeness and pharmacokinetic properties. The Auto Dock Vina 4.2 tool was utilized for molecular docking analysis. Results The residual fraction showed the best therapeutic response when compared favorably to amodiaquine (80.5%) and artesunate (85.1%). It also considerably reduced the number of parasites, with the % growth inhibition of the parasite at 42.8% (D2) and 83.4% (D5). Following purification, 25 compounds were isolated and characterized with GCMS. Based on their low molecular weights, non-permeation of the blood–brain barrier, non-inhibition of metabolizing enzymes, and non-violation of Lipinski’s criteria, betulinic and ursolic acids were superior to chloroquine as the best phytochemicals. Hence, they are lead compounds. Conclusion In addition to identifying the bioactive compounds, ADME, and docking data of the lead compounds as candidates for rational drug design processes as observed against Plasmodium falciparum target proteins (PfEMP-1 and PfPKG), which are implicated in the pathogenesis of malaria, the study has validated that the residual fraction of N. latifolia roots has the best antiplasmodial therapeutic index.
Markus Orsi, Hippolyte Personne, Etienne Bonvin
et al.
Multidrug-resistant (MDR) bacteria represent a global public health threat, and antimicrobial peptides (AMPs), derived from naturally occurring linear or cyclic peptides, can provide the solution. However, most AMPs are sensitive to proteases and have poor pharmacokinetics. The EU-funded ERC Advanced Grant SPACE4AMPS aims to identify new AMPs by applying the concepts of chemical space and ligand-based virtual screening, which are well known for small molecule drug discovery, to the world of peptides. We create virtual libraries of peptides and related molecules and use these approaches to select a few tens of compounds for synthesis and detailed. evaluation of antibacterial, toxicity and stability effects. Recent results and prospects of this ongoing project are presented in this review.
John Reinhard, Leonhard Starke, Christian Klose
et al.
Abstract Biological membranes have a stunning ability to adapt their composition in response to physiological stress and metabolic challenges. Little is known how such perturbations affect individual organelles in eukaryotic cells. Pioneering work has provided insights into the subcellular distribution of lipids in the yeast Saccharomyces cerevisiae, but the composition of the endoplasmic reticulum (ER) membrane, which also crucially regulates lipid metabolism and the unfolded protein response, remains insufficiently characterized. Here, we describe a method for purifying organelle membranes from yeast, MemPrep. We demonstrate the purity of our ER membrane preparations by proteomics, and document the general utility of MemPrep by isolating vacuolar membranes. Quantitative lipidomics establishes the lipid composition of the ER and the vacuolar membrane. Our findings provide a baseline for studying membrane protein biogenesis and have important implications for understanding the role of lipids in regulating the unfolded protein response (UPR). The combined preparative and analytical MemPrep approach uncovers dynamic remodeling of ER membranes in stressed cells and establishes distinct molecular fingerprints of lipid bilayer stress.
Therapeutic tools in the biomedical field are increasingly utilizing nanoparticles (NPs) with a small size and large surface area. Chitosan (CS), a biotic polymeric carbohydrate found in shellfish, is a promising carrier for these diagnostic systems due to its biocompatibility, low toxic effects, and diverse shapes. CS-NPs are therapeutic transporters with properties such as bionomical, pH, and heat sensitivity, increased homogeneity, and potential to pass through the brain. These nanomaterials can detect and cure pathological conditions using curative instruments. CS-NPs slow down the movement and growth of anti-inflammatory colonies while encouraging the growth of cells causing inflammation. They could provide active substances for treating various medical conditions, such as auto-immune deformities, hyperglycemia, hypersensitivity, and cancer. Scientific resources are dedicated to improving the efficacy of CS-NP active agent compositions. Recent discoveries highlight the medicinal implications of CS-NPs preparations for drug delivery in managing severe inflammatory aberrations.
ABSTRACT: Metabolic aberrations, notably deviations in glutamine metabolism, are crucial in the oncogenic process, offering vital resources for the unlimited proliferation and enhanced survival capabilities of cancer cells. The dependency of malignant cells on glutamine metabolism has led to the proposition of targeted therapeutic strategies. However, the capability of cancer cells to initiate adaptive responses undermines the efficacy of these therapeutic interventions. This review meticulously examines the multifaceted adaptive mechanisms that cancer cells deploy to sustain survival and growth following the disruption of glutamine metabolism. Emphasis is placed on the roles of transcription factors, alterations in metabolic pathways, the mechanistic target of rapamycin complex 1 signaling axis, autophagy, macropinocytosis, nucleotide biosynthesis, and the scavenging of ROS. Thus, the delineation and subsequent targeting of these adaptive responses in the context of therapies aimed at glutamine metabolism offer a promising avenue for circumventing drug resistance in cancer treatment.
Methyltransferases are a wide-ranging, yet well-conserved, class of molecules that have been found to modify a wide variety of substrates. Interest in RNA methylation has surged in recent years with the identification of the major eukaryotic mRNA m6A methyltransferase METTL3. METTL16 has also been identified as an RNA m6A methyltransferase; however, much less is known about its targets and actions. Interestingly, in addition to their catalytic activities, both METTL3 and METTL16 also have “methylation-independent” functions, including translational regulation, which have been discovered. However, evidence suggests that METTL16’s role as an RNA-binding protein may be more significant than is currently recognized. In this review, we will introduce RNA methylation, specifically m6A, and the enzymes responsible for its deposition. We will discuss the varying roles that these enzymes perform and delve deeper into their RNA targets and possible roles as methylation-independent RNA binding proteins. Finally, we will touch upon the many open questions still remaining.
Bone regeneration and repair are complex processes with the potential of added complications, like delayed repair, fracture non-union, and post-surgical infections. These conditions remain a challenge globally, pressurizing the economy and patients suffering from these conditions. Applications of nanotechnology (NBT) in the field of medicine have provided a medium for several approaches to support these global challenges. Tissue engineering is one such field that has been on the rise in the last three decades through the utilization of NBT for addressing the challenges related to bone regeneration. First, NBT enables the formation of scaffolds at the nanoscale needed for bone tissue engineering (BTE) using natural and synthetic polymers, as well as with minerals and metals. Then, it aids the development of the nano-formulation strategized to deliver antimicrobial drugs and/or growth factors through various ways to enhance bone repair through the scaffold. Third, NBT facilitates the use of specialized nanoparticles to image and track cellular events in vitro as well as in vivo. This review is an effort to bring together the current knowledge in the field of BTE and present the scope of ever-evolving NBT, a contribution towards precision medicine.
Yael Shostak, Mordechai R. Kramer, Omer Edni
et al.
Two doses of mRNA SARS-CoV-2 vaccines elicit an attenuated humoral immune response among immunocompromised patients. Our study aimed to assess the immunogenicity of a third dose of the BNT162b2 vaccine among lung transplant recipients (LTRs). We prospectively evaluated the humoral response by measuring anti-spike SARS-CoV-2 and neutralizing antibodies in 139 vaccinated LTRs ~4–6 weeks following the third vaccine dose. The t-cell response was evaluated by IFNγ assay. The primary outcome was the seropositivity rate following the third vaccine dose. Secondary outcomes included: positive neutralizing antibody and cellular immune response rate, adverse events, and COVID-19 infections. Results were compared to a control group of 41 healthcare workers. Among LTRs, 42.4% had a seropositive antibody titer, and 17.2% had a positive t-cell response. Seropositivity was associated with younger age (t = 3.736, <i>p</i> < 0.001), higher GFR (t = 2.355, <i>p</i> = 0.011), and longer duration from transplantation (t = −1.992, <i>p</i> = 0.024). Antibody titer positively correlated with neutralizing antibodies (r = 0.955, <i>p</i> < 0.001). The current study may suggest the enhancement of immunogenicity by using booster doses. Since monoclonal antibodies have limited effectiveness against prevalent sub-variants and LTRs are prone to severe COVID-19 morbidity, vaccination remains crucial for this vulnerable population.
Ioanna Aggeletopoulou, Efthymios P. Tsounis, Athanasia Mouzaki
et al.
The microbiome has a major impact on human physiology and plays a critical role in enhancing or impairing various physiological functions such as regulation of the immune system, metabolic activities, and biosynthesis of vitamins and hormones. Variations in the gut microbial community play a critical role in both health and disease. Regulation of calcium and bone metabolism, as well as cellular functions such as proliferation, apoptosis, differentiation, and immune modulation, are among the known effects of vitamin D. These biological functions are primarily carried out through the binding of vitamin D to the vitamin D receptor (VDR), a member of the nuclear receptor superfamily. The immunomodulatory properties of vitamin D suggest that this molecule plays an important role in various diseases. Maintenance of immune homeostasis appears to occur in part through the interaction of the gut microbiota with vitamin D. Increasing evidence points to the central role of vitamin D in maintaining mucosal barrier function, as vitamin D deficiency has been associated with disruption of gut barrier integrity, translocation of bacteria into the bloodstream, and systemic inflammation. In parallel, a bidirectional interaction between vitamin D and the gut microbiota has been demonstrated as data show upregulation of intestinal VDR expression and downregulation of inflammatory markers in response to fermentation products. The aim of this review is to provide an overview of the evidence of a link between the gut microbiome and vitamin D, with a focus on data from experimental models and translational data from human studies related to vitamin D-induced changes in gut microbiota composition.
Abstract Background Loss of the transcription factor GLI-Similar 3 (GLIS3) function causes congenital hypothyroidism (CH) in both humans and mice due to decreased expression of several thyroid hormone (TH) biosynthetic genes in thyroid follicular cells. Whether and to what extent, GLIS3 regulates thyroid gene transcription in coordination with other thyroid transcriptional factors (TFs), such as PAX8, NKX2.1 and FOXE1, is poorly understood. Methods PAX8, NKX2.1, and FOXE1 ChIP-Seq analysis with mouse thyroid glands and rat thyrocyte PCCl3 cells was performed and compared to that of GLIS3 to analyze the co-regulation of gene transcription in thyroid follicular cells by these TFs. Results Analysis of the PAX8, NKX2.1, and FOXE1 cistromes identified extensive overlaps between these TF binding loci and those of GLIS3 indicating that GLIS3 shares many of the same regulatory regions with PAX8, NKX2.1, and FOXE1, particularly in genes associated with TH biosynthesis, induced by thyroid stimulating hormone (TSH), and suppressed in Glis3KO thyroid glands, including Slc5a5 (Nis), Slc26a4, Cdh16, and Adm2. ChIP-QPCR analysis showed that loss of GLIS3 did not significantly affect PAX8 or NKX2.1 binding and did not cause major alterations in H3K4me3 and H3K27me3 epigenetic signals. Conclusions Our study indicates that GLIS3 regulates transcription of TH biosynthetic and TSH-inducible genes in thyroid follicular cells in coordination with PAX8, NKX2.1, and FOXE1 by binding within the same regulatory hub. GLIS3 does not cause major changes in chromatin structure at these common regulatory regions. GLIS3 may induce transcriptional activation by enhancing the interaction of these regulatory regions with other enhancers and/or RNA Polymerase II (Pol II) complexes.
Zhong-Yuan Lyu, Zhong-Yuan Lyu, Qing-Ting Bu
et al.
Daptomycin is a cyclic lipopeptide antibiotic with a significant antibacterial action against antibiotic-resistant Gram-positive bacteria. Despite numerous attempts to enhance daptomycin yield throughout the years, the production remains unsatisfactory. This study reports the application of multilevel metabolic engineering strategies in Streptomyces roseosporus to reconstruct high-quality daptomycin overproducing strain L2797-VHb, including precursor engineering (i.e., refactoring kynurenine pathway), regulatory pathway reconstruction (i.e., knocking out negative regulatory genes arpA and phaR), byproduct engineering (i.e., removing pigment), multicopy biosynthetic gene cluster (BGC), and fermentation process engineering (i.e., enhancing O2 supply). The daptomycin titer of L2797-VHb arrived at 113 mg/l with 565% higher comparing the starting strain L2790 (17 mg/l) in shake flasks and was further increased to 786 mg/l in 15 L fermenter. This multilevel metabolic engineering method not only effectively increases daptomycin production, but can also be applied to enhance antibiotic production in other industrial strains.
Reseña del libro Domínguez, E., Giorgi, A., Gómez N. (Compiladores). (2019). La bioindicación en el monitoreo y evaluación de los sistemas fluviales de la Argentina: bases para el análisis de la integridad ecológica. Eudeba, 98 pp.
Este es un libro fruto de la reflexión sobre el tema de los bioindicadores en cursos fluviales originado en un congreso de la Asociación Argentina de Limnología. En el prólogo los compiladores destacan que se trata de “dejar de hablar entre nosotros y comunicar con la comunidad” y hablan de “analfabetismo ecológico”. La reflexión ha sido amplia pues ha involucrado a 40 autores, 17 revisores y dos colaboradores, muchos de ellos con gran experiencia en el tema y numerosas publicaciones.
Ali Osman, May Bin-Jumah, Mohamed E. Abd El-Hack
et al.
ABSTRACT: The current research aimed to estimate the effect of dietary supplementation with glycinin isolated from soybeans on the growth performance, carcass traits, and selected blood metabolites of broiler chicks. A total of 200 1-wk-old broiler chicks were administered diets without glycinin (control treatment) or diets supplemented with 3 concentrations of soy glycinin (0.5, 1.0, or 1.5 g/kg of feed) for 6 wk. At the end of the feeding period, body weight was significantly higher in broiler chicks with glycinin supplementation (P < 0.05 or 0.01). The best values for body weight and body weight gain were recorded in the groups fed diets supplemented with 0.5 and 1.0 g glycinin/kg feed. Feed conversion was significantly (P < 0.05) improved in broilers in the glycinin-supplemented groups during the 1 to 6 and 3 to 6 wk growth periods. The highest value of breast yield was observed in broiler chicks supplemented with glycinin at a concentration of 1.0 g/kg of feed. Water-holding capacity increased with increasing concentrations of glycinin in the feed, up to 1.0%. Serum creatinine and urea concentrations decreased gradually (P < 0.01) as the concentration of glycinin in the feed increased. Broiler chicks receiving increasing concentrations of glycinin exhibited significantly (P < 0.01) lower levels of serum triglycerides, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. All meat samples from broiler chicks supplemented with glycinin had significantly higher catalase activities. These data suggest that feeding broiler chicks diets supplemented with soy glycinin (0.5 to 1.5 g/kg of feed) can improve feed conversion, enhance body weight gain, and lower abdominal fat.
Simona-Rebeca Ignat, Sorina Dinescu, Anca Hermenean
et al.
Inflammation has been known to be an important driver of fibrogenesis in the liver and onset of hepatic fibrosis. It starts off as a process meant to protect the liver from further damage, but it can become the main promoter of liver fibrosis. There are many inflammation-related pathways activated during liver fibrosis that lead to hepatic stellate cells (HSCs) activation and collagen-deposition in the liver. Such events are mostly modulated upstream of HSCs and involve signals from hepatocytes and innate immune cells. One particular event is represented by cell death during liver injury that generates multiple inflammatory signals that further trigger sterile inflammation and enhancement of inflammatory response. The assembly of inflammasome that responds to danger-associated molecular patterns (DAMPs) stimulates the release of pro-inflammatory cytokines and at the same time, initiates programmed cell death called pyroptosis. This review focuses on cellular and molecular mechanisms responsible for initiation and progress of inflammation in the liver.