Biomolecules最新文献

Nitrite reductases play a crucial role in the nitrogen cycle, demonstrating significant potential for applications in the food industry and environmental remediation, particularly for nitrite degradation and detection. In this study, we identified a novel nitrite reductase (AhNiR) from a newly isolated denitrifying bacterium, Acinetobacter haemolyticus YD01. We constructed a heterologous expression system using E. coli BL21/pET28a-AhNir, which exhibited remarkable nitrite reductase enzyme activity of 29 U/mL in the culture broth, substantially higher than that reported for other strains. Structural analysis of AhNiR revealed the presence of [Fe-S] clusters, with molecular docking studies identifying Tyr-282 and Ala-289 as key catalytic sites. The enzymatic properties of AhNiR demonstrated an optimal pH of 7.5 and an optimal catalytic temperature of 30 °C. Its kinetic parameters, K_m and v_max, were 1.53 mmol/L and 10.18 mmol/min, respectively, fitting with the Michaelis-Menten equation. This study represents the first report of a nitrite reductase from a denitrifying bacterium, providing a new enzyme source for nitrite degradation applications in the food industry and environmental remediation, as well as for biosensing technologies aimed at nitrite detection.

In recent years, fungal infections have emerged as a significant health concern across veterinary species, especially in livestock such as cattle, where fungal diseases can result in considerable economic losses, as well as in humans. In particular, Aspergillus species, notably Aspergillus flavus and Aspergillus versicolor, are opportunistic pathogens that pose a threat to both animals and humans. This study focuses on the synthesis and antifungal evaluation of novel 9-fluorenylmethoxycarbonyl (Fmoc)-protected 1,2,4-triazolyl-α-amino acids and their dipeptides, designed to combat fungal pathogens. More in detail, we evaluated their antifungal activity against various species, including Aspergillus versicolor (ATCC 12134) and Aspergillus flavus (ATCC 10567). The results indicated that dipeptide 7a exhibited promising antifungal activity against Aspergillus versicolor with an IC₅₀ value of 169.94 µM, demonstrating greater potency than fluconazole, a standard treatment for fungal infections, which showed an IC₅₀ of 254.01 µM. Notably, dipeptide 7a showed slightly enhanced antifungal efficacy compared to fluconazole also in Aspergillus flavus (IC₅₀ 176.69 µM vs. 184.64 µM), suggesting that this dipeptide might be more potent even against this strain. Remarkably, 3a and 7a are also more potent than fluconazole against A. candidus 10711. On the other hand, the protected amino acid 3a demonstrated consistent inhibition across all tested Aspergillus strains, but with an IC₅₀ value of 267.86 µM for Aspergillus flavus, it was less potent than fluconazole (IC₅₀ 184.64 µM), still showing some potential as a good antifungal molecule. Overall, our findings indicate that the synthesized 1,2,4-triazolyl derivatives 3a and 7a hold significant promise as potential antifungal agents in treating Aspergillus-induced diseases in cattle, as well as for broader applications in human health. Our mechanistic studies based on molecular docking revealed that compounds 3a and 7a bind to the same region of the sterol 14-α demethylase as fluconazole. Given the rising concerns about antifungal resistance, these amino acid derivatives, with their unique bioactive structures, could serve as a novel class of therapeutic agents. Further research into their in vivo efficacy and safety profiles is warranted to fully realize their potential as antifungal drugs in clinical and agricultural settings.

About 296 million people worldwide are living with chronic hepatitis B viral (HBV) infection, and outcomes to end-stage liver diseases are potentiated by alcohol. HBV replicates in hepatocytes, but other liver non-parenchymal cells can sense the virus. In this study, we aimed to investigate the regulatory effects of macrophages on HBV marker and interferon-stimulated genes (ISGs) expressions in hepatocytes. This study was performed on HBV-replicating HepG2.2.15 cells and human monocyte-derived macrophages (MDMs). We found that exposure of HepG2.2.15 cells to an acetaldehyde-generating system (AGS) increased HBV RNA, HBV DNA, and cccDNA expressions and suppressed the activation of ISGs, APOBEC3G, ISG15, and OAS1. Supernatants collected from IFNα-activated MDMs decreased HBV marker levels and induced ISG activation in AGS-treated and untreated HepG2.215 cells. These effects were reversed by exposure of MDMs to ethanol and mimicked by treatment with exosome release inhibitor GW4869. We conclude that exosome-mediated crosstalk between IFN-activated macrophages and HBV-replicating hepatocytes plays a protective role via the up-regulation of ISGs and suppression of HBV replication. However, ethanol exposure to macrophages breaks this protection.

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with limited treatment options and high resistance to chemotherapy. Doxorubicin is commonly used, but its efficacy is limited by variable sensitivity and resistance. Bacopaside II, a saponin compound, has shown anti-cancer potential. This study evaluates the effects of doxorubicin and bacopaside II, both individually and in combination, across TNBC subtypes to explore mechanisms of resistance and enhanced drug efficacy.

Methods: The growth-inhibitory effects of doxorubicin and bacopaside II were assessed in four TNBC cell lines. IC50 values were determined using dose-response assays, and doxorubicin accumulation was measured via spectral flow cytometry. ATP-binding cassette (ABC) transporter expression (ABCB1, ABCC1, ABCC3, and ABCG2) was analyzed for correlations with drug sensitivity. In silico docking assessed the binding affinity of bacopaside II to ABC transporters. A 3D culture model simulated drug-resistant TNBC, and combination effects were evaluated with live-cell imaging.

Results: Doxorubicin sensitivity varied across TNBC molecular subtypes, correlating to intracellular accumulation. Bacopaside II inhibited growth across subtypes, inducing apoptosis in sensitive cells and necrosis in resistant cells. Bacopaside II increased doxorubicin accumulation, independent of P-glycoprotein (ABCB1), possibly through interactions with other ABC transporters. In drug-resistant 3D cultures, bacopaside II maintained efficacy and enhanced doxorubicin accumulation, counteracting ABC transporter-mediated resistance. The doxorubicin and bacopaside II combination showed synergistic growth inhibition.

Conclusions: Bacopaside II enhances doxorubicin efficacy in TNBC by increasing drug accumulation and overcoming ABC transporter-mediated resistance, suggesting its potential as an adjuvant in TNBC treatment. These findings support further investigation of bacopaside II, particularly for resistant TNBC subtypes.

This study aims to develop a protocol for respiratory disease-associated biomarker discovery by combining urine proteome studies with urinary exosome components analysis (i.e., miRNAs). To achieve this, urine was DTT treated to decrease uromodulin, then concentrated and ultracentrifuged. Proteomic analyses of exosome-free urine were performed using LC-MS/MS. Simultaneously, miRNA expression from urine exosomes was measured using either RTqPCR (pre-amplification) or nCounter Nanostring (non-amplication) analyses. We detected 548 different proteins in exosome-free urine samples (N = 5) with high confidence (FDR < 1%), many of them being expressed in different non-renal tissues. Specifically, lung-related proteins were overrepresented (Fold enrichment = 1.31; FDR = 0.0335) compared to whole human proteome, and 10-15% were already described as protein biomarkers for several pulmonary diseases. Urine proteins identified belong to several functional categories important in respiratory pathology. We could confirm the expression of miRNAs previously connected to respiratory diseases (i.e., miR-16-5p, miR-21-5p, miR-146a-5p, and miR-215-5p) in urine exosomes by RTqPCR. Finally, we detected 333 miRNAs using Nanostring, 15 of them up-regulated in T2^high asthma (N = 4) compared to T2^low asthma (N = 4) and healthy subjects (N = 4). Therefore, this protocol combining the urinary proteome (exosome free) with the study of urinary exosome components (i.e., miRNAs) holds great potential for molecular biomarker discovery of non-renal and particularly respiratory pathologies.

Immuno-fibrotic networks and their protein mediators, such as cytokines and chemokines, have increasingly been appreciated for their critical role in cardiac healing and fibrosis during cardiomyopathy. Immune activation, trafficking, and extravasation are tightly regulated to ensure a targeted and effective response against non-self antigens/pathogens while preserving tolerance towards self-antigens and coordinate fibrotic responses for efficient scar formation, a distinction that is severely compromised during chronic diseases. It is clear that immune cells are not only the critical regulators of post-infarct healing and scarring but are also the key players in regulating fibroblast activation during left-ventricular (LV) remodeling. Incomplete resolution coupled with sustained low-grade inflammation during dilated cardiomyopathy precipitates a "frustrated" immune cell response resulting in unconstrained pro-fibrotic and pro-hypertrophic signaling to induce maladaptive structural and functional changes in the myocardium. The aims of this review are to (i) briefly summarize the role of key immune cells that regulate wound healing during MI and fibrosis during LV remodeling; (ii) underscore phenotypic diversities in immune cells and their subsets to underscore their role in regulating fibrotic responses, and, last but not the least, (iii) highlight gaps in our understanding that restrict the translation of immuno-modulatory therapies from the preclinical models to heart failure patients.

Epilepsy is a prevalent chronic neurological disorder that can significantly impact patients' lives. The incidence and risk of psychosis in individuals with epilepsy are notably higher than in the general population, adversely affecting both the management and rehabilitation of epilepsy and further diminishing patients' quality of life. This review provides an overview of the classification and clinical features of psychosis of epilepsy, with the aim of offering insights and references for the clinical diagnosis and treatment of various types of psychosis of epilepsy. Additionally, we examine the potential pathophysiological mechanisms underlying the psychosis of epilepsy from three perspectives: neuroimaging, neurobiology, and genetics. The alterations in brain structure and function, neurotransmitters, neuroinflammatory mediators, and genetic factors discussed in this review may offer insights into the onset and progression of psychotic symptoms in epilepsy patients and are anticipated to inform the identification of novel therapeutic targets in the future.

Pantothenate (Pan), or vitamin B5, is essential for the synthesis of co-enzyme A (CoA), acetyl-CoA, and numerous downstream physiological processes. We previously demonstrated that Pan is not only essential for mosquito survival, but also for the development of malaria parasites within the mosquito, suggesting that targeting Pan and CoA biosynthesis may be a novel approach for malaria control. However, little is known about how Pan is acquired and mobilized within the mosquito. In this work, we examined Pan levels in the important human malaria vector Anopheles stephensi, including the abundance of Pan during immature development and adulthood. We also assessed the distribution of Pan in various adult tissues and examined the impact of provisioning Pan to the mosquito via a sugar or blood meal on mosquito survival and reproduction. Furthermore, we examined how Pan was mobilized in the mosquito via a putative Pan transporter, the A. stephensi sodium multi-vitamin transporter. We demonstrated that this transporter is capable of mobilizing both Pan and biotin (vitamin B7) in a dose dependent manner. We also assessed the distribution of A. stephensi sodium multi-vitamin transporter in the mosquito and its capacity to transport vitamins. This work establishes the basic physiology of Pan uptake and mobilization in the mosquito, providing essential information for Pan based malaria control strategies.

Background: The mammalian NAD-dependent deacetylase sirtuin-1 family (named also silent information regulator or SIRT family, where NAD stands for "nicotinamide adenine dinucleotide" (NAD)) appears to have a dual role in several human cancers by modulating cell proliferation and death. This study examines how SIRT1 protein levels correlate with clinicopathological characteristics and survival outcomes in patients with breast cancer.

Methods: A total of 407 BC formalin-fixed paraffin-embedded (FFPE) samples were collected from King Abdulaziz University Hospital, Saudi Arabia. SIRT1 was stained on tissue microarray slides using automated immunohistochemistry.

Results: All BC subtypes expressed more nuclear SIRT1 proteins than their cytoplasm counterparts. In luminal A, luminal B, and TNBC, nuclear and cytoplasmic SIRT1 were highly associated (p < 0.001). Kaplan-Meier analysis showed reduced disease-specific survival (DSS) in H2BC with high SIRT1 nuclear expression (p = 0.001, log-rank). Moreover, the cytoplasmic expression of SIRT1 in HER2-positive BC was associated with a larger tumor size (p = 0.036) and lymph node metastasis (p = 0.045). Nuclear SIRT1 expression was also positively associated with lymph node metastasis (LNM) (p = 0.048). As low-grade tumors had a higher frequency of SIRT1 protein expression than other groups, SIRT1 expression was associated with a favorable prognosis in patients with luminal A BC (p < 0.001).

Conclusions: SIRT1 expression seems to be involved in different molecular pathways either suppressing or promoting tumor growth depending on the subtype of BC. These molecular functions require further investigations and validation on larger BC cohorts.

The species Niphon spinosus (Cuvier, 1829) is the only representative of the family Niphonidae and the genus Niphon, and its taxonomic history is complicated; it is still unclear in a phylogenetic sense. In this study, we report the complete mitochondrial genome of N. spinosus (OP391482), which was determined to be 16,503 bp long with biased A + T contents (53.8%) using next-generation technology. The typical set of 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and one control region (D-loop) are included in the mitochondrial genome. The H-strand encoded 28 genes (14 tRNA, 2 rRNA, and 12 PCGs), and D-loop, whereas the L-strand encoded the remaining 9 genes (8 tRNA and ND6). Its nucleotide composition, gene arrangement, codon usage patterns, and tRNA secondary structures are identical with other members of the Percoidei suborder. Furthermore, we reconstructed phylogenetic trees based on the 13 PCGs. The resulting phylogenetic trees showed N. spinosus placing as a separate lineage within the family Niphonidae, its close relationship to Trachinus draco (Trachinidae), and the clustering of major subfamilies like Luciopercinae and Percinae of the Percoidei suborder. These findings will contribute to future studies on the evolutionary history, population genetics, molecular taxonomy, and phylogeny of N. spinosus and related species.