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Life Science Alliance Aug 2024In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 is...
In cells, mitochondria undergo constant fusion and fission. An essential factor for fission is the mammalian dynamin-related protein 1 (Drp1). Dysregulation of Drp1 is associated with neurodegenerative diseases including Parkinson's, cardiovascular diseases and cancer, making Drp1 a pivotal biomarker for monitoring mitochondrial status and potential pathophysiological conditions. Here, we developed nanobodies (Nbs) as versatile binding molecules for proteomics, advanced microscopy and live cell imaging of Drp1. To specifically enrich endogenous Drp1 with interacting proteins for proteomics, we functionalized high-affinity Nbs into advanced capture matrices. Furthermore, we detected Drp1 by bivalent Nbs combined with site-directed fluorophore labelling in super-resolution STORM microscopy. For real-time imaging of Drp1, we intracellularly expressed fluorescently labelled Nbs, so-called chromobodies (Cbs). To improve the signal-to-noise ratio, we further converted Cbs into a "turnover-accelerated" format. With these imaging probes, we visualized the dynamics of endogenous Drp1 upon compound-induced mitochondrial fission in living cells. Considering the wide range of research applications, the presented Nb toolset will open up new possibilities for advanced functional studies of Drp1 in disease-relevant models.
Topics: Dynamins; Mitochondrial Dynamics; Humans; Single-Domain Antibodies; Mitochondria; Proteomics; Animals; Protein Binding; HeLa Cells; Mitochondrial Proteins
PubMed: 38816213
DOI: 10.26508/lsa.202402608 -
Turkish Journal of Medical Sciences 2023Type 1 diabetes mellitus (T1DM) is caused by the autoimmune-mediated destruction of insulin-producing cells (IPCs) and still has no effective cure. Better understanding...
BACKGROUND/AIM
Type 1 diabetes mellitus (T1DM) is caused by the autoimmune-mediated destruction of insulin-producing cells (IPCs) and still has no effective cure. Better understanding of the molecular mechanisms involved in the differentiation of embryonic stem cells (ESCs) into IPCs may help us improve the therapeutic strategies for treating T1DM. 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatases (Pfkfb1-4) are key regulators of glucose metabolism. Although Pfkfb3 has been shown to be required for the growth of early differentiated mouse ESCs (mESCs), more studies are needed to further assess the roles of Pfkfb isoenzymes in embryonic development and differentiation, particularly into specific cell types. In this study, we aimed to elucidate the changes in the expression of Pfkfb isoenzymes on the differentiation of mESCs into IPCs.
MATERIALS AND METHODS
A 3-step protocol was used to differentiate R1 and J1 mESCs into IPCs. The changes in the gene expression of MafA, MafB, Ins2, and Nkx6.1 (IPC specific markers) and Pfkfb1-4 were analyzed using real-time quantitative polymerase chain reaction (qPCR). Insulin expression and secretion were determined by immunofluorescence (IF) staining and the enzyme linked immunosorbent assay (ELISA), respectively.
RESULTS
Upon differentiation, the IPC specific markers in differentiated cells were upregulated. Continued differentiation was confirmed by the development of insulin-positive islet-like clusters that secreted insulin in response to glucose uptake. Expressions of the Pfkfb2 and Pfkfb3 isoenzymes were markedly increased in various stages of differentiation.
CONCLUSION
These findings suggest that Pfkfb2 and Pfkfb3 may impact the differentiation of mESCs into IPCs and the regulation of the insulin response to glucose levels. This study also lays a foundation for researchers to further probe the roles of Pfkfb isoenzymes on the differentiation of mESCs into IPCs and may open new avenues for regenerative medicine.
Topics: Animals; Phosphofructokinase-2; Cell Differentiation; Mice; Mouse Embryonic Stem Cells; Isoenzymes; Insulin-Secreting Cells; Insulin
PubMed: 38813509
DOI: 10.55730/1300-0144.5725 -
Nature Communications May 2024G protein-coupled receptors (GPCRs) are sophisticated signaling machines able to simultaneously elicit multiple intracellular signaling pathways upon activation....
G protein-coupled receptors (GPCRs) are sophisticated signaling machines able to simultaneously elicit multiple intracellular signaling pathways upon activation. Complete (in)activation of all pathways can be counterproductive for specific therapeutic applications. This is the case for the serotonin 2 A receptor (5-HTR), a prominent target for the treatment of schizophrenia. In this study, we elucidate the complex 5-HTR coupling signature in response to different signaling probes, and its physiological consequences by combining computational modeling, in vitro and in vivo experiments with human postmortem brain studies. We show how chemical modification of the endogenous agonist serotonin dramatically impacts the G protein coupling profile of the 5-HTR and the associated behavioral responses. Importantly, among these responses, we demonstrate that memory deficits are regulated by G protein activation, whereas psychosis-related behavior is modulated through G stimulation. These findings emphasize the complexity of GPCR pharmacology and physiology and open the path to designing improved therapeutics for the treatment of stchizophrenia.
Topics: Humans; Receptor, Serotonin, 5-HT2A; Animals; Psychotic Disorders; Memory Disorders; Serotonin; Male; Signal Transduction; HEK293 Cells; Mice; Schizophrenia; Brain; Female; GTP-Binding Protein alpha Subunits, Gq-G11
PubMed: 38811567
DOI: 10.1038/s41467-024-48196-2 -
Nature Communications May 2024Two-dimensional layered organic-inorganic halide perovskites have successfully spread to diverse optoelectronic applications. Nevertheless, there remain gaps in our...
Two-dimensional layered organic-inorganic halide perovskites have successfully spread to diverse optoelectronic applications. Nevertheless, there remain gaps in our understanding of the interactions between organic and inorganic sublattices that form the foundation of their remarkable properties. Here, we examine these interactions using pump-probe spectroscopy and ab initio molecular dynamics simulations. Unlike off-resonant pumping, resonant excitation of the organic sublattice alters both the electronic and lattice degrees of freedom within the inorganic sublattice, indicating the existence of electronic coupling. Theoretical simulations verify that the reduced bandgap is likely due to the enhanced distortion index of the inorganic octahedra. Further evidence of the mechanical coupling between these two sublattices is revealed through the slow heat transfer process, where the resultant lattice tensile strain launches coherent longitudinal acoustic phonons. Our findings explicate the intimate electronic and mechanical couplings between the organic and inorganic sublattices, crucial for tailoring the optoelectronic properties of two-dimensional halide perovskites.
PubMed: 38811539
DOI: 10.1038/s41467-024-48707-1 -
Anais Da Academia Brasileira de Ciencias 2024This study investigated the association between the IFITM3 rs12252 polymorphism and the severity and mortality of COVID-19 in hospitalized Brazilian patients. A total of... (Meta-Analysis)
Meta-Analysis
This study investigated the association between the IFITM3 rs12252 polymorphism and the severity and mortality of COVID-19 in hospitalized Brazilian patients. A total of 102 COVID-19 patients were included, and the outcomes of interest were defined as death and the need for mechanical ventilation. Genotypes were assessed using Taqman probes. No significant associations were found between the rs12252 polymorphism and COVID-19 outcomes in the original sample, both for death and the need for mechanical ventilation. A meta-analysis, incorporating previous studies that used death as a severity indicator, revealed no association in the allelic and C-recessive models. However, due to the rarity of the T allele and its absence in the sample, further replication studies in larger and more diverse populations are needed to clarify the role of rs12252 in COVID-19 prognosis.
Topics: Humans; COVID-19; Brazil; Membrane Proteins; SARS-CoV-2; Severity of Illness Index; Male; Female; RNA-Binding Proteins; Polymorphism, Single Nucleotide; Middle Aged; Pandemics; Betacoronavirus; Pneumonia, Viral; Genotype; Aged; Genetic Predisposition to Disease; Respiration, Artificial; Adult
PubMed: 38808879
DOI: 10.1590/0001-3765202420231160 -
Infection and Drug Resistance 2024We compared the MeltPro assay to whole-genome sequencing (WGS) to investigate the molecular characterization of second-line injectable drug (SLID) resistance in...
OBJECTIVE
We compared the MeltPro assay to whole-genome sequencing (WGS) to investigate the molecular characterization of second-line injectable drug (SLID) resistance in multidrug-resistant tuberculosis (MDR-TB) isolates in Chongqing, China.
METHODS
A total of 122 MDR-TB patient isolates were collected between March 2019 and June 2020 from Chongqing Municipality, China. Conventional drug-susceptibility testing was performed using the proportion method, followed to generate minimum inhibitory concentrations (MICs) of SLIDs determined by microplate alamarblue assay. All strains were subjected to both MeltPro and WGS assays.
RESULTS
Among 122 MDR-TB isolates, 30 (24.6%), 22 (18.0%), and 14 (11.5%) were resistant to kanamycin (KM), amikacin (AM), and capreomycin (CM), respectively. Of the 31 SLID-resistant isolates, 24 (77.4%, 24/31) isolates harbored mutations in the gene, with the most prevalent mutations in A1401G (22/24, 91.7%). Mutation in A1401G was associated with high levels of resistance to KM (MIC, ≥40 μg/mL) and AM (MIC, ≥64 μg/mL), but disparities in CM-resistance levels. Using phenotypic drug-susceptibility testing as gold standard, we found that the overall sensitivity of MeltPro and WGS was 87.1% and 90.32% and specificity 100% and 97.8%, respectively. Seven isolates had discordant results between phenotypic and genotypic resistance of SLIDs.
CONCLUSION
MeltPro is a promising diagnostic tool for accurate identification of SLID-resistant MTB isolates with mutations in the and genes. There was a disparity between MeltPro with WGS results in the proportion of heterogeneous drug-resistant bacteria with mutation and limited probes. Resistance mechanisms other than genetic mutations will affect the consistency of MeltPro and WGS with phenotypic drug-susceptibility results.
PubMed: 38807773
DOI: 10.2147/IDR.S459142 -
Scientific Reports May 2024The fabrication of the first label-free electrochemical DNA probe biosensor for highly sensitive detection of Candidatus Liberibacter asiaticus (CLas), as the causal...
The fabrication of the first label-free electrochemical DNA probe biosensor for highly sensitive detection of Candidatus Liberibacter asiaticus (CLas), as the causal agent of citrus huanglongbing disease, is conducted here. An OMP probe was designed based on the hybridization with its target-specific sequence in the outer membrane protein (OMP) gene of CLas. The characterization of the steps of biosensor fabrication and hybridization process between the immobilized OMP-DNA probe and the target ssDNA oligonucleotides (OMP-complementary and three mismatches OMP or OMP-mutation) was monitored using cyclic voltammetry and electrochemical impedance spectroscopy based on increasing or decreasing in the electron transfer in [Fe (CN)] on the modified gold electrode surface. The biosensor sensitivity indicated that the peak currents were linear over ranges from 20 to 100 nM for OMP-complementary with the detection limit of 0.026 nM (S/N = 3). The absence of any cross-interference with other biological DNA sequences confirmed a high selectivity of fabricated biosensor. Likewise, it showed good specificity in discriminating the mutation oligonucleotides from complementary target DNAs. The functional performance of optimized biosensor was achieved via the hybridization of OMP-DNA probe with extracted DNA from citrus plant infected with CLas. Therefore, fabricated biosensor indicates promise for sensitivity and early detection of citrus huanglongbing disease.
Topics: Biosensing Techniques; Citrus; Plant Diseases; DNA Probes; Bacterial Outer Membrane Proteins; Electrochemical Techniques; Electrodes; Nucleic Acid Hybridization; Dielectric Spectroscopy; Limit of Detection; Rhizobiaceae; Liberibacter
PubMed: 38806617
DOI: 10.1038/s41598-024-63112-w -
Scientific Reports May 2024Emergence of Coronavirus disease 2019 (COVID-19) pandemic has posed a huge threat to public health. Rapid and reliable test to diagnose infected subjects is crucial for...
Emergence of Coronavirus disease 2019 (COVID-19) pandemic has posed a huge threat to public health. Rapid and reliable test to diagnose infected subjects is crucial for disease spread control. We developed a colorimetric test for COVID-19 detection using a Colorimetric Assay based on thiol-linked RNA modified gold nanoparticles (AuNPs) and oligonucleotide probes. This method was conducted on RNA from 200 pharyngeal swab samples initially tested by Real-Time polymerase chain reaction (RT-PCR) as gold standard. A specific oligonucleotide probe designed based on ORF1ab of COVID-19 was functionalized with AuNPs-probe conjugate. The exposure of AuNP-probe to isolated RNA samples was tested using hybridization. In this comparative study, the colorimetric functionalized AuNPs assay exhibited a detection limit of 25 copies/µL. It was higher in comparison to the RT-PCR method, which could only detect 15 copies/µL. The results demonstrated 100% specificity and 96% sensitivity for the developed method. Herein, we developed an incredibly rapid, simple and cost-effective Colorimetric Assay lasting approximately 30 min which could process considerably higher number of COVID-19 samples compared to the RT-PCR. This AuNP-probe conjugate colorimetric method could be considered the optimum alternatives for conventional diagnostic tools especially in over-populated and/or low-income countries.
Topics: Colorimetry; Humans; COVID-19; Metal Nanoparticles; Gold; Nasopharynx; SARS-CoV-2; RNA, Viral; Sensitivity and Specificity; Limit of Detection; Oligonucleotide Probes; COVID-19 Nucleic Acid Testing; Real-Time Polymerase Chain Reaction; COVID-19 Testing
PubMed: 38802360
DOI: 10.1038/s41598-024-53747-0 -
Cureus Apr 2024Rotavirus-induced viral gastroenteritis outbreaks result in over two million hospitalizations globally yearly. Wastewater-based epidemiology (WBE) has emerged as a...
INTRODUCTION
Rotavirus-induced viral gastroenteritis outbreaks result in over two million hospitalizations globally yearly. Wastewater-based epidemiology (WBE) has emerged as a crucial tool for detecting and monitoring viral outbreaks. The adoption of WBE has been instrumental in the early detection and surveillance of such viral outbreaks, providing a non-invasive method to assess public health.
OBJECTIVE
This study aims to utilize droplet digital polymerase chain reaction (ddPCR) technology to detect and quantify Rotavirus in wastewater samples collected from the Bhopal region of India, thereby contributing to the understanding and management of viral gastroenteritis outbreaks through environmental surveillance.
METHODS
In this study, we used ddPCR to detect and quantify Rotavirus in wastewater samples collected from the Bhopal region of India. We monitored its viral presence in municipal sewage treatment plants bi-weekly using an advanced ddPCR assay. Targeting the rotavirus non-structural protein 3 (NSP-3) region with custom primers and TaqMan probes, we detected virus concentration employing polyethylene glycol (PEG). Following RNA isolation, complementary DNA (cDNA) synthesis, and ddPCR analysis, our novel method eliminated standard curve dependence, propelling virus research and treatment forward.
RESULTS
Out of the 42 samples collected, a 16.60% positivity rate was observed, indicating a moderate presence of Rotavirus in Bhopal. The wastewater treatment plants (WWTP) attached to a hospital exhibited a 42.85% positivity rate, indicating the need for targeted monitoring. Leveraging ddPCR, precise quantification of rotavirus concentrations (ranging from 0.75 to 28.9 copies/µL) facilitated understanding and supported effective remediation.
CONCLUSIONS
This study emphasizes the importance of vigilant wastewater surveillance, especially in WWTPs with higher rotavirus prevalence. The significance of ddPCR in comparison to conventional and real-time PCR lies in its superior sensitivity and specificity in detecting and quantifying positive samples. Furthermore, it can identify positive samples even in the smallest quantities without the need for a standard curve to evaluate. This makes ddPCR a valuable tool for accurate and precise detection and quantification of samples.
PubMed: 38800300
DOI: 10.7759/cureus.58882 -
ACS Central Science May 2024We report a blueprint for the rational design of G protein coupled receptor (GPCR) ligands with a tailored functional response. The present study discloses the...
We report a blueprint for the rational design of G protein coupled receptor (GPCR) ligands with a tailored functional response. The present study discloses the structure-based design of cannabinoid receptor type 2 (CBR) selective inverse agonists ()- and ()-, which were derived from privileged agonist HU-308 by introduction of a phenyl group at the -dimethylheptyl side chain. Epimer ()- exhibits high affinity for CBR with = 39.1 nM and serves as a platform for the synthesis of a wide variety of probes. Notably, for the first time these fluorescent probes retain their inverse agonist functionality, high affinity, and selectivity for CBR independent of linker and fluorophore substitution. Ligands ()-, ()-, and their derivatives act as inverse agonists in CBR-mediated cAMP as well as G protein recruitment assays and do not trigger β-arrestin-receptor association. Furthermore, no receptor activation was detected in live cell ERK phosphorylation and Ca-release assays. Confocal fluorescence imaging experiments with ()- (Alexa488) and ()- (Alexa647) probes employing BV-2 microglial cells visualized CBR expressed at endogenous levels. Finally, molecular dynamics simulations corroborate the initial docking data in which inverse agonists restrict movement of toggle switch Trp258 and thereby stabilize CBR in its inactive state.
PubMed: 38799662
DOI: 10.1021/acscentsci.3c01461