Adenosine Triphosphate Research Articles

The molecular picture of the local environment in a stable model coacervate.

Complex coacervates play essential roles in various biological processes and applications. Although substantial progress has been made in understanding the molecular interactions driving complex coacervation, the mechanisms stabilizing coacervates against coalescence remain experimentally challenging and not fully elucidated. We recently showed that polydiallyldimethylammonium chloride (PDDA) and adenosine triphosphate (ATP) coacervates stabilize upon their transferto deionized (DI) water. Here, we perform molecular dynamics simulations of PDDA-ATP coacervates in supernatant and DI water, to understand the ion dynamics and structure within stable coacervates. We found that transferring the coacervates to DI water results in an immediate ejection of a significant fraction of small ions (Na+ and Cl-) from the surface of the coacervates to DI water. We also observed a notable reduction in the mobility of thesecounterions incoacervates whenin DI water, both in the cluster-forming and slab simulations, together with a lowered displacement of PDDA and ATP. These results suggest that the initial ejection of the ions from the coacervates in DI water may induce an interfacial skin layer formation, inhibiting further mobility of ionsin the skin layer.

TRIM27 revealing by tumor educated platelet RNA-sequencing, as a potential biomarker for malignant ground-glass opacities diagnosis mediates glycolysis of non-small cell lung cancer cells partially through HOXM1.

Efficient ground-glass opacities (GGOs) diagnosis is challenging. A diagnostic method distinguishing malignant from benign GGOs is warranted. In this study, we sought to construct a noninvasive method based on tumor educated platelet (TEP) RNA profiles for malignant GGOs diagnosis and explore the molecular mechanism of the potential biomarker for the first time. Based on TEP RNA-sequencing (TEP RNA-seq) in benign and malignant GGOs, a classification model was constructed using differentially expressed genes (DEGs) and was used to evaluate diagnostic performance. High-throughput quantitative polymerase chain reaction (HT-qPCR) verified 23 genes selected from the top 60 DEGs between benign and malignant GGOs. The correlation between 17 verified DEGs and 22 key glycolytic genes was analyzed. Tripartite motif-containing 27 (TRIM27) overexpressing and knockdown (KD) cell models were constructed using A549 and PC-9 cells, respectively in which cell growth, apoptosis, migration and invasion were evaluated. The protein levels of HK-1/2, PKM1/2, LDHA and GLUT1 were evaluated by western blot. Glycolysis was evaluated through adenosine triphosphate (ATP), reactive oxygen species (ROS), lactate acid (LD) production, glucose uptake, and lactate dehydrogenase (LDH) activity assays. RNA-seq was performed in loss-of TRIM27-KD PC-9 cells to clarify the downstream factors of TRIM27 which was verified using western blot and immunofluorescence double staining. In 81 samples, the 1,647-DEG-based classification model exhibited area under the curve (AUC), sensitivity, and specificity values of 0.99 [95% confidence interval (CI): 0.972-1.000], 100%, and 91%, respectively, while the top 60-DEG-based classification model exhibited AUC, sensitivity, and specificity values of 0.986 (95% CI: 0.962-1.000), 98%, and 91%, respectively. TRIM27 achieved AUC of 0.87 in the diagnosis of malignant GGOs, with 83.93% sensitivity, 78.79% specificity, 81.15% accuracy, 77.05% positive predictive value (PPV) and 85.25% negative predictive value (NPV). TRIM27 was highly expressed in non-small cell lung cancer (NSCLC) cells, and accelerated cell migration and invasion. In addition, TRIM27 was found to promote glycolysis in NSCLC cells partially through HMOX1 which was negatively correlated with TRIM27. We constructed a novel TEP RNA-seq based classifier for malignant GGOs diagnosis. TRIM27, an important target discovered, could accelerate migration, invasion and regulate glycolysis partially through HMOX1 in NSCLC cells, thus providing scientific support for TRIM27 as a diagnostic biomarker for malignant GGO diagnosis.

Establishing the Comprehensive Structure−Activity Relationship of the Natural Antibiotic Kibdelomycin/Amycolamicin

Abstract: Kibdelomycin (KBD) and amycolamicin (AMM) are potent natural antibiotics effective against antibiotic‐resistant Gram‐positive pathogens, including vancomycin‐intermediate Staphylococcus aureus (S. aureus, VISA), methicillin‐resistant S. aureus (MRSA), and quinolone‐resistant S. aureus (QRSA). Their antibacterial activity stems from an unprecedented dual mechanism: the lower binding sites occupy the adenosine triphosphate (ATP) binding pocket of bacterial type II topoisomerases, while the upper binding sites disrupt the enzyme dimer interface. This dual action, combined with their unique chemical structures, positions KBD and AMM as promising scaffolds for developing new antibiotics. However, the structure‐activity relationship (SAR) of KBD/AMM remains underexplored due to their highly complex chemical structures. In this study, we utilized total synthesis to produce KBD/AMM analogs with various site modifications and evaluated their antimicrobial activities. Our findings establish the first comprehensive SAR for KBD/AMM, paving the way for the development of novel KBD/AMM‐based antibiotics.

Real-Time Monitoring of Oxygen-Consumption Rate in Mouse Liver Slices Incubated in Organ-on-a-Chip Devices.

We developed an organ-on-a-chip (OOC) based on precision-cut liver slices to assess liver function in real-time, both in health and disease, in a controlled and noninvasive manner. We achieved this by integrating fiber-optic-based oxygen sensors before and after the microchamber in which a liver slice was incubated under flow, to measure oxygen concentrations in the medium in real time. We first demonstrated that the basal oxygen consumption rate (OCR) of liver slices is a reliable indicator of liver slice viability. By monitoring basal OCR (2.9-5.7 pmol O2/min/μg protein) in incubation medium, we found that it correlated well to cellular adenosine triphosphate (ATP) content (3.0-7.9 pmol/μg protein) (r = 0.82, p < 0.0001). Second, we induced a diseased state in liver slices by targeting the mitochondria, as they play a critical role in liver function and disease. We exposed the liver slices to succinate in abundance (40 mM) for short periods (1 h) to rapidly boost mitochondrial OCR. Two successive treatments of succinate increased the OCR of liver slices by 1.5 pmol/min/μg each time. However, between treatments, the liver slice OCR did not return to its basal OCR, instead decreasing drastically by 60-70%, suggesting succinate toxicity. We confirmed this with ATP analysis (1.0 pmol/μg protein) and hematoxylin and eosin staining, which showed tissue necrosis and apoptosis. Our system could be an advantageous model for future studies assessing liver (patho)physiology in response to potentially toxic drugs or lifestyle-related liver diseases.

Establishing the Comprehensive Structure-Activity Relationship of the Natural Antibiotic Kibdelomycin/Amycolamicin.

Kibdelomycin (KBD) and amycolamicin (AMM) are potent natural antibiotics effective against antibiotic-resistant Gram-positive pathogens, including vancomycin-intermediate Staphylococcus aureus (S. aureus, VISA), methicillin-resistant S. aureus (MRSA), and quinolone-resistant S. aureus (QRSA). Their antibacterial activity stems from an unprecedented dual mechanism: the lower binding sites occupy the adenosine triphosphate (ATP) binding pocket of bacterial type II topoisomerases, while the upper binding sites disrupt the enzyme dimer interface. This dual action, combined with their unique chemical structures, positions KBD and AMM as promising scaffolds for developing new antibiotics. However, the structure-activity relationship (SAR) of KBD/AMM remains underexplored due to their highly complex chemical structures. In this study, we utilized total synthesis to produce KBD/AMM analogs with various site modifications and evaluated their antimicrobial activities. Our findings establish the first comprehensive SAR for KBD/AMM, paving the way for the development of novel KBD/AMM-based antibiotics.

The role of lipoprotein‑associated phospholipase A2 in inflammatory response and macrophage infiltration in sepsis and the regulatory mechanisms.

Lipoproteinassociated phospholipase A2 (Lp-PLA2), encoded by the phospholipase A2 group VII (Pla2g7) gene, has been pertinent to inflammatory responses. This study investigates the correlation between Lp-PLA2 and inflammatory injury in septic mice and explores its regulatory mechanism. Lp-PLA2 was found to be upregulated in the serum of septic mice induced by cecal ligation and puncture and in the culture supernatant of RAW264.7 cells following lipopolysaccharide and adenosine triphosphate treatments. The contents of Lp-PLA2 were positively correlated with increased concentrations of proinflammatory cytokines in patients with sepsis. Both animal and cellular models showed increased concentrations of proinflammatory cytokines. Spi-1 proto-oncogene (Spi1), highly expressed in these models, was found to activate Pla2g7 transcription. Knockdown of Pla2g7 or Spi1 reduced the proinflammatory cytokine production, mitigated organ damage in mice, and suppressed macrophage migration in vitro. Retinoblastoma binding protein 6 (Rbbp6), poorly expressed in both models, was found to reduce Spi1 protein stability through ubiquitination modification. Rbbp6 overexpression similarly suppressed inflammatory activation of RAW264.7 cells, which was counteracted by Pla2g7 or Spi1 upregulation. In summary, this study demonstrates that the Pla2g7 loss and Spi1 upregulation participate in inflammatory responses in sepsis by elevating the Lp-PLA2 levels.

Isovalerylspiramycin I suppresses small cell lung cancer proliferation via ATR/CHK1 mediated DNA damage response and PERK/eIF2α/ATF4/CHOP mediated ER stress

Small cell lung cancer (SCLC) urgently needs new therapeutic approaches. We found that the antibiotic-derived compound Isovalerylspiramycin I (ISP-I) has potent anti-tumor activity against SCLC cell lines H1048 and DMS53 both in vitro and in vivo. ISP-I induced apoptosis, G2/M phase cell cycle arrest, and mitochondrial respiratory chain dysfunction in both cell lines. Comprehensive RNA sequencing revealed that the anti-SCLC effects of ISP-I were primarily attributed to ATR/CHK1-mediated DNA damage response and PERK/eIF2α/ATF4/CHOP-mediated ER stress. Importantly, the induction of DNA damage, ER stress, and apoptosis by ISP-I was mitigated by the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC), underscoring the critical role of ROS in the anti-SCLC mechanism of ISP-I. Moreover, ISP-I treatment induced immunogenic cell death (ICD) in SCLC cells, as evidenced by increased adenosine triphosphate (ATP) secretion, elevated release of high-mobility group box 1 (HMGB1), and enhanced exposure of calreticulin (CRT) on the cell surface. Additionally, network pharmacology analysis, combined with cellular thermal shift assay (CETSA) and cycloheximide (CHX) chase experiments, demonstrated that ISP-I acted as a ligand for apurinic/apyrimidinic endonuclease 1 (APEX1) and promoted its degradation, leading to the accumulation of ROS. In conclusion, our findings elucidate the multifaceted mechanisms underlying the anti-cancer effects of ISP-I, highlighting its potential as a promising therapeutic candidate for SCLC treatment.

Comparative assessment of acute neurotoxicity of real-world ultra-fine black carbon emitted from residential solid fuel combustion

Incomplete combustion of residential solid fuel is one of the main anthropogenic sources for black carbon (BC). Fresh BC, mainly enriched in ultra-fine fraction of particles, can directly cross blood-brain barrier and are reported to be associated with neurodegenerative diseases. Because of the difficulties in collection and purification of BC from ambient particles, there are still significant knowledge gaps in understanding neurotoxicity caused by real-world BC. The purpose of this study is to compare the neurotoxic effects caused by BCs emitted from combustion of six residential solid fuels, and try to reveal associated biological mechanisms in SH-SY5Y cells. Two straw BC (Wheat-BC and Corn-BC) showed highest neurotoxic effects followed by wood BC (Pine-BC and Aspen-BC) and coal BC (Xvzhou and Longkou Coal), as indicated by viability, lactic dehydrogenase, malondialdehyde, adenosine triphosphate and acetylcholine levels. Coal BC caused nearly no toxicity in human neuroblastoma (SH-SY5Y) cells within highest dose of 200 μg/mL. RNA sequence and bioinformatics analysis were applied to effectively identify differential genes and signaling pathways. Based on Gene Ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, Protein Protein Interaction network (PPI network) construction, we found biomass BC affected mitochondrial function, interfered with cellular metabolic processes, disturbed redox homeostasis, and finally resulted in cellular damages. Coal-BC mainly caused cytokine/chemokine related inflammatory responses. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting methods were further applied to find out related signaling pathways. Biomass BC activated IL6R/JAK3/STAT3 and JAK3/STAT6 pathways leading to oxidative stress and inflammatory responses. Coal BC activated JAK3/STAT3 pathway leading to chemokine related responses. This study revealed the heterogeneity in neurotoxicity of BCs from different combustion sources and provided important data for health risk assessment. BC-related neurotoxicity should be considered when making air pollution emission control strategies, with residential biomass receiving more policy attention.

Biphasic effects of single-dose intravenous injection of uridine adenosine tetraphosphate on blood pressure in mice

PurposeTo explore the effects of a single dose of uridine adenosine tetraphosphate (Up4A) administered through the tail vein, on the blood pressure of mice.MethodsThe mice were separated into three groups: the Up4A group, the norepinephrine (NA) group, and the α, β-methylene adenosine triphosphate (α, β-meATP) group. Each group of mice were injected drugs through the tail vein at 1, 3, 10, and 30 nmol/kg doses in an ascending order. Additionally, six mice were injected Up4A through the tail vein at 20, 40, 60, and 80 nmol/kg doses in an ascending order. The administration intervals for each dose were 20 min.ResultsMice in these groups experienced a rapid increase in blood pressure, reaching its peak within 10 s after drug administration. It took approximately 120 s for the blood pressure to return to baseline levels after the administration of the drugs in both the NA and α, β-meATP groups. After higher doses of Up4A were administered to the mice, their blood pressure exhibited biphasic changes. Initially, blood pressure of the mice rapidly dropped to a minimum within 10 s, then rose rapidly to a peak within 30 s. Subsequently, it gradually declined, taking around 10 min to return to the levels before the drug administration.ConclusionCompared to NA and α, β-meATP, Up4A, which contains purine and pyrimidine components, displayed a weaker blood pressure-elevating potency. Through its corresponding structure, Up4A exerted vasodilatory and vasoconstrictive effects throughout the entire experiment resulting in biphasic changes in blood pressure.

The Different Responsiveness of C3- and C5-deficient Murine BM Cells to Oxidative Stress Explains Why C3 Deficiency, in Contrast to C5 Deficiency, Correlates with Better Pharmacological Mobilization and Engraftment of Hematopoietic Cells.

The liver-derived circulating in peripheral blood and intrinsic cell-expressed complement known as complosome orchestrate the trafficking of hematopoietic stem/progenitor cells (HSPCs) both during pharmacological mobilization and homing/engraftment after transplantation. Our previous research demonstrated that C3 deficient mice are easy mobilizers, and their HSPCs engraft properly in normal mice. In contrast, C5 deficiency correlates with poor mobilization and defects in HSPCs' homing and engraftment. The trafficking of HSPCs during mobilization and homing/engraftment follows the sterile inflammation cues in the BM microenvironment caused by stress induced by pro-mobilizing drugs or myeloablative conditioning for transplantation. Therefore, to explain deficiencies in HSPC trafficking between C3-KO and C5-KO mice, we evaluated the responsiveness of C3 and C5 deficient cells to low oxidative stress. As reported, oxidative stress in BM is mediated by the activation of purinergic signaling, which is triggered by the elevated level of extracellular adenosine triphosphate (eATP) and by the activation of the complement cascade (ComC). In the current work, we noticed that BM lineage negative cells (lin-) isolated from C3-KO mice display several mitochondrial defects reflected by an impaired ability to adapt to oxidative stress. In contrast, C5-KO-derived BM cells show a high level of adaptation to this challenge. To support this data, C3-KO BM lin- cells were highly responsive to eATP stimulation, which correlates with enhanced levels of reactive oxygen species (ROS) generation and more efficient activation of intracellular Nlrp3 inflammasome. We conclude that the enhanced sensitivity of C3-KO mice cells to oxidative stress and better activation of the Nox2-ROS-Nlrp3 inflammasome signaling axis explains the molecular level differences in trafficking between C3- and C5-deficient HSPCs.

Inhibition of calpain reduces oxidative stress and attenuates pyroptosis and ferroptosis in Clostridium perfringens Beta-1 toxin-induced macrophages

Clostridium perfringens Beta-1 toxin (CPB1) is a lethal toxin, which can lead to necrotic enteritis, but the pathological mechanism has not been elucidated. We investigated whether reactive oxygen species (ROS) participated in CPB1-induced pyroptosis and ferroptosis, and investigated the effects of calpain on CPB1-induced oxidative stress and inflammation. Scavenging ROS by N-acetyl cysteine (NAC) led to the reduction of ROS, inhibited the death of macrophages, cytoplasmic swelling and membrane rupture, the expression of pyroptosis-related proteins and proinflammatory factor, while increased the expression of anti-inflammatory factors in cells treated with rCPB1. Adenosine triphosphate (ATP) synthase, H+ transporting, mitochondrial F1 complex, alpha subunit 1 (ATP5A1) was identified specifically interact with rCPB1. Silencing ATP5A1 inhibited accumulation of ATP and ROS, leaded to less cytoplasmic swelling and membrane rupture, attenuated pyroptosis and inflammation in rCPB1-treated cells. We also found that rCPB1 induces ferroptosis in macrophages, and the level of ferroptosis was similar with H2O2. Of note, H2O2 is a major ROS source, indicated that ROS production may play a major role in the regulation of ferroptosis in macrophages treated with rCPB1. This finding was further corroborated in rCPB1- induced human acute monocytic leukemia cells, which were treated with NAC. In addition, the inhibition of ferroptosis using liproxstatin-1 inhibited the shriveled mitochondrial morphology, increased the expression of glutathione peroxidase 4, nicotinamide adenine dinucleotide (phosphate) hydrogen: quinone oxidoreductase 1 and cysteine/glutamic acid reverse transport solute carrier family 7 members 11, decreased the expression of heme oxygenase 1, nuclear receptor coactivator 4 and transferrin receptor proteins, reduced malondialdehyde and lipid peroxidation levels, and increased intracellular L-glutathione levels in cells treated with rCPB1. Furthermore, calpain inhibitor PD151746 was used to investigate how pyroptosis and ferroptosis were involved simultaneously in rCPB1-treated macrophages. We showed that PD151746 inhibited ATP and ROS production, reversed the representative pyroptosis/ferroptosis indicators and subsequently reduced inflammation. The above findings indicate that rCPB1 might lead to macrophage pyroptosis and ferroptosis through the large and sustained increase in intracellular calpain and oxidative stress, further lead to inflammation.

Knockdown of Adenosine 5'-Triphosphate-Dependent Caseinolytic Protease Proteolytic Subunit 6 Enhances Aluminum Tolerance in Peanut Plants (Arachis hypogea L.).

Aluminum (Al3+) toxicity in acidic soils reduces root growth and can lead to a considerable reduction in peanut plants (Arachis hypogea L.). The caseinolytic protease (Clp) system plays the key role in abiotic stress response. However, it is still unknown whether it is involved in peanut response to Al3+ stress. The results from this study showed that Adenosine 5'-triphosphate (ATP)-dependent caseinolytic protease proteolytic subunit 6 (AhClpP6) in peanut plants was involved in the Al3 stress response through its effects on leaf photosynthesis. The AhClpP6 expression levels in the leaf and stem significantly increased with the Al3+ treatment times. Knockdown AhClpP6 peanut lines accumulated significantly more Al3+ when exposed to Al3+ stress, which reduced leaf photosynthesis. Furthermore, in response to Al3+ treatment, knockdown of AhClpP6 resulted in a flattened shape of chloroplasts, disordered and flattened thylakoid, and accumulating more starch grains than those of the wild-type (WT) peanut lines. Taken together, our results suggest that AhClpP6 regulates Al3+ tolerance by maintaining chloroplast integrity and enhancing photosynthesis.

Phage-Modified Clear Hydrogel for Simultaneous Detection of Multiple Bacteria.

The proliferation speed of live foodborne pathogens is fast. A small number of pathogens will have a great impact on food and the environment if positive samples are not detected timely. In this study, transparent porous hydrogel stir bars, modified by two different phages (corresponding to two different bacteria (Escherichia coli and Hafnia sp)), have been developed for rapid detection of foodborne bacteria. A large number of samples can be analyzed simultaneously with a small animal live imager device to screen out the positive samples, while an adenosine triphosphate (ATP) bioluminescence sensor can be used to quantify the number of bacteria in the positive samples. The phage has good specificity and capture ability to bacteria, which makes the method highly sensitive. In addition, the use of multiple phages also enables the method to detect multiple bacteria simultaneously. The three-dimensional structure of the hydrogel allows it to modify more phages, and its transparent nature also allows the inside bioluminescence to be detected. Both can enhance the sensitivity of the detection. Finally, the reagents needed for bioluminescence, such as d-luciferin, can also be preencapsulated in the hydrogel, thus simplifying the detection step. Under the best conditions, the detection range of the method is 102-108 CFU·mL-1, and the limit of detection is 30 CFU·mL-1 within 11 min. The test results of actual samples show that there is no difference between using the method developed through this study and the traditional plate counting method, but the detection time is greatly shortened.

Oxidized Carbon Nanoparticles Enhance Cellular Energetics With Application to Injured Brain.

Pro-energetic effects of functionalized, oxidized carbon nanozymes (OCNs) are reported. OCNs, derived from harsh acid oxidation of single-wall carbon nanotubes or activated charcoal are previously shown to possess multiple nanozymatic activities including mimicking superoxide dismutase and catalyzing the oxidation of reduced nicotinamide adenine dinucleotide (NADH) to NAD+. These actions are predicted to generate a glycolytic shift and enhance mitochondrial energetics under impaired conditions. Impaired mitochondrial energy metabolism is increasingly recognized as an important facet of traumatic brain injury (TBI) pathophysiology and decreases the efficiency of electron transport chain (ETC)-coupled adenosine triphosphate (ATP) and NAD+ regeneration. In vitro, OCNs promote a pro-aerobic shift in energy metabolism that persists through ETC inhibition and enhances glycolytic flux, glycolytic ATP production, and cellular generation of lactate, a crucial auxiliary substrate for energy metabolism. To address specific mechanisms of iron injury from hemorrhage, OCNs with the iron chelator, deferoxamine (DEF), covalently-linked were synthesized. DEF-linked OCNs induce a glycolytic shiftin-vitroandin-vivoin tissue sections from a rat model of TBI complicated by hemorrhagic contusion. OCNs further reduced hemorrhage volumes 3 days following TBI. These results suggest OCNs are promising as pleiotropic mediators of cell and tissue resilience to injury.

Multi-omics analysis reveals the mechanisms by which C6-HSL enhances the resistance of typical functional bacteria in activated sludge to low-temperature stress

Signaling molecules, particularly acyl-homoserine lactones (AHLs), can enhance microbial activity under low-temperature stress. However, the specific mechanisms underlying this effect remain unclear. This study identified a typical activated sludge functional bacterium that is sensitive to low temperatures and regulated by hexanoyl-L-homoserine lactone (C6-HSL), a representative of AHLs. It elucidates how C6-HSL modulates the bacterium's resistance to low-temperature stress. Experimental results indicated that C6-HSL significantly increased the levels of adenosine triphosphate (ATP), superoxide dismutase (SOD), peroxidase (POD) and glutathione peroxidase (GSH-Px) in strain LB-001 under low-temperature stress, while also decreasing the levels of reactive oxygen species (ROS). Additionally, C6-HSL markedly repaired the damage to cell membrane structure caused by low-temperature stress. At the genetic level, C6-HSL upregulated the expression of 20 key genes related to energy metabolism, antioxidation, and fatty acid synthesis. At the metabolic level, C6-HSL increased the levels of metabolites related to energy metabolism and antioxidation, boosted the content of unsaturated fatty acids, and reduced the content of saturated fatty acids. This study utilized C6-HSL and low-temperature induction in conjunction with 16S microbial diversity sequencing, genomics, transcriptomics, and metabolomics. These methods were employed to elucidate the molecular mechanisms by which exogenous C6-HSL regulates the resistance of activated sludge microbial communities to low-temperature stress. This research lays the foundation for the application of AHLs and cell communication in wastewater biological treatment, fostering deeper exploration and further innovation in related academic research.

Development of a CRISPR/Cas12a-facilitated fluorescent aptasensor for sensitive detection of small molecules

The integration of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated proteins (Cas) exhibits superior performance in biosensor construction. And the distinctive role of aptamers in target recognition has long been a focal point of research. Through the combination of Cas12a with cis-cleavage activity and aptamer with specific recognition, a simple and rapid fluorescent biosensor has been constructed. Interestingly, with modified fluorescent and quenching groups at two ends, aptamers play a dual role: primarily as the elements for target recognition and additionally functioning act as the fluorescent probe for signal output. Coupling with cis-cleavage of Cas12a, the demand of additional signal probes is eliminated, thus simplifying the reaction system and enhancing result accuracy. Taking okadaic acid (OA) as a representative small molecule model to evaluate the sensor's performance, a simple and straightforward detection method was established. Following this, the universality of the constructed fluorescent aptasensor was validated by incorporating an adenosine triphosphate (ATP) aptamer. Consequently, the CRISPR/Cas12a-assisted aptasensor was demonstrated to serve as a versatile detection platform for small molecules in food safety and clinical diagnostics. In the forthcoming research endeavors, it can be further extended for applications in environmental analysis and various other fields.

The interactome of cystic fibrosis transmembrane conductance regulator and its role in male fertility: A critical review.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a cyclic adenosine monophosphate (cAMP)-regulated chloride and bicarbonate ion channel found in many human cells. Its unique biochemical characteristics and role as a member of the adenosine triphosphate (ATP)-binding cassette transporters superfamily are pivotal for the transport of several substrates across cellular membranes. CFTR is known to interact, physically and functionally, with several other cellular proteins. Hence, its properties are essential for moving various substances across cell membranes and ensuring correct cell functioning. Genetic mutations or environmental factors may disrupt CFTR's function resulting in different possible phenotypes due to gene variations that affect not only CFTR's function, localization, and processing within cells, but also those of its interactors. This has been reported as an underlying cause of various diseases, including cystic fibrosis. The severe clinical implications of cystic fibrosis have driven intense research into the role of CFTR in lung function but its significance to fertility, particularly in men, has been comparatively understudied. However, ongoing and more recent research into CFTR and its interacting proteins in the testis or specific testicular cells is beginning to shed light on this field. Herein, we provide a comprehensive and up-to-date overview of the CFTR, its interactome, and its crucial role in male reproduction, highlighting recent discoveries and advancements in understanding the molecular mechanisms involved. The comprehension of these complex interactions may pave the way for potential therapeutic approaches to improve fertility of men suffering from alterations in the function of CFTR.

Methylmercury chloride inhibits meiotic maturation of mouse oocytes in vitro by disrupting the cytoskeleton

Methylmercury chloride (MMC) is a persistent heavy metal contaminant that can bioaccumulate in humans via the food chain, exerting detrimental effects on health. Nevertheless, the specific influence of MMC on oocyte meiotic maturation has yet to be elucidated. This research demonstrated that MMC exposure during the in vitro cultivation of mouse oocytes did not influence germinal vesicle breakdown but markedly decreased oocyte maturation rates. Subsequent analysis indicated that MMC exposure resulted in aberrant spindle morphology and disorganized chromosome alignment, alongside continuous activation of the spindle assembly checkpoint (SAC). However, MMC exposure didn't alter the localization pattern of microtubule-organizing center-associated proteins. MMC exposure considerably diminished the acetylation level of α-tubulin, signifying reduced microtubule stability. Additionally, MMC exposure disrupted the dynamic alterations of F-actin. MMC exposure didn't affect mitochondrial localization, mitochondrial membrane potential, adenosine triphosphate content or the concentrations of reactive oxygen species. Nonetheless, MMC exposure triggered DNA damage and modified histone modification levels. Consequently, the defects in oocyte maturation induced by MMC exposure can be attributed to impaired cytoskeleton dynamics and DNA damage. This study offers the first comprehensive elucidation of the negative impacts of MMC on oocyte maturation, highlighting the potential reproductive health risks associated with MMC exposure.

A Well-Coupled Supramolecular System Accelerates Photophosphorylation.

Supramolecular assembly allows multiple chemical/bio-components integrated as one system for cascade biochemical reactions. Herein the graphitic carbon nitrides (g-C3N4) as photocatalyst trapped in a dipeptide hydrogel covering adenosine triphosphate (ATP) synthase accelerates the photophosphorylation through ATP synthesis. Self-assembled N-fluorenylmethoxycarbonyl diphenylalanine (Fmoc-FF) as nanofibrils to allow g-C3N4 nanosheets are embedded as a complex Fmoc-FF/g-C3N4 hydrogel. Fmoc-FF gel exhibits good electronic coupling with g-C3N4, which enables a photo-induced proton generation. The transmembrane proton gradient can be established by ATP synthase-lipid reconstituted on the surface of the Fmoc-FF/g-C3N4 hydrogel to enhance the ATP synthesis. It indicates that the Fmoc-FF/g-C3N4/ATP synthase-lipid film can possess a longer-term ATP production capability and allow repeated immersion for sustained ATP production. Such a hydrogel-supported ATP synthesis platform is achieved by a procedure at a larger scale.

Kinetic and Mechanistic Studies of Human Oligoadenylate Synthetase 1.

Oligoadenylate synthetase 1 (OAS1) catalyzes the dsRNA-dependent polymerization of ATP to form oligoadenylate, a second messenger of the innate immunity system. This paper reports kinetic and mechanistic studies of OAS1-catalyzed dimerization of ATP to form 2'-5'-diadenylate and pyrophosphate (PPi), the first step in ATP polymerization. Major findings include the following: (1) Reaction progress curves for the production of PPi are biphasic, characterized by a presteady-state lag followed by the linear, steady-state production of PPi. (2) The dependence of steady-state velocity on ATP concentration is sigmoidal and can be described by a rate law derived for a mechanism involving enzyme-catalyzed substrate dimerization. (3) Steady-state velocities were determined as a function of ATP concentration at fixed concentrations of poly(I:C), a synthetic dsRNA activator of OAS1. The data suggest a random mechanism in which either ATP or poly(I:C) can add first to the enzyme. (4) The dependence of klag on poly(I:C) and ATP concentration requires expansion of this mechanism to include slow conformational isomerization of various poly(I:C)- and ATP-bound complexes of inactive OAS1 to form complexes comprising an active enzyme, to ultimately form the reactive Michaelis complex of active OAS1, poly(I:C), and two molecules of ATP. Finally, within this complex, the two molecules of ATP dimerize to form 2'-5'-diadenylate and pyrophosphate. (5) The pH dependence and solvent deuterium isotope effect for kcat suggests that proton transfer occurs in the rate-limiting transition state, which likely involves proton abstraction from the 2'-hydroxyl of the adenylate acceptor ATP as the oxygen of this hydroxyl attacks the a-phosphate of the adenylate donor ATP in an SN2 fashion.