Search Results (121)

Reduced expression of MAPK organiser 1 (MORG1) exerts renoprotective effects in MORG1^+/− mice in models of type 1 and type 2 diabetes. To investigate the regulation of MORG1 expression, we generated endogenous hMORG1-luciferase-tagged HEK293 cells carrying a firefly luciferase reporter inserted downstream of the human MORG1 gene using the CRISPR/Cas9 method. This study analysed the time-dependent effects of 20 mM D-glucose on MORG1-luciferase activity and examined whether 20 µM metformin influences MORG1 expression. HEK293 cells were genomically modified using CRISPR/Cas9 to insert the firefly luciferase gene downstream of MORG1. Stable clones were selected with puromycin. The influence of D-glucose concentration on MORG1 expression was analysed in a dose- and time-dependent manner. Luciferase assays assessed MORG1 transcriptional activity, while Western blotting determined protein expression. qRT-PCR was used to assess MORG1 mRNA levels. The pharmacological effect of metformin was evaluated in parental and tagged HEK293 cells and TKPTS cells, simultaneously exposed to 5.5 mM or 20 mM D-glucose in the presence or absence of 20 µM metformin. High glucose significantly increased luciferase activity and MORG1 protein expression compared with 5.5 mM glucose controls. Time course experiments demonstrated significant induction of MORG1 transcription, confirmed by corresponding increases in protein levels. Metformin treatment significantly reduced glucose-induced luciferase activity, MORG1 mRNA levels, and MORG1 protein expression at 24 h. Analyses of TKPTS cells show that 20 mM D-glucose elevated Morg1 mRNA levels, while this induction was attenuated in the presence of 20 µM metformin. High glucose induces time-dependent upregulation of MORG1 transcription and protein expression in MORG1-luciferase-tagged HEK293 cells. Metformin application attenuates, but does not fully prevent, glucose-induced MORG1 mRNA and protein expression. Full article

A cell-based screening system for viral protease inhibitors was developed using firefly luciferase fragment complementation and validated on the SARS-CoV-2 3CLpro model. The optimal luciferase variant incorporating the VLQSGF proteolytic site (Luc III) retained 88% of its native activity. A critical requirement for system performance was the use of an extended nsp4–nsp6 fragment of the viral polyprotein rather than the mature protease, underscoring the importance of the native context for 3CLpro activity. The bicistronic construct pCAG-Luc-III-IRES-nsp4-6 enables coordinated expression of the reporter and protease, thereby increasing assay reproducibility. IC₅₀ values obtained in this system for nirmatrelvir and GC376 correlated with live-virus assay data but differed significantly from those of a cell-free FRET assay, reflecting the impact of cellular barriers. This approach combines simplicity, a standard substrate, and high reproducibility, making it promising for high-throughput screening in basic laboratory settings and adaptable to other viral proteases. Full article

Nitrate (NO₃⁻) serves as a pivotal molecule with dual functions in nutrient supply and signaling during plant growth and development. Precise monitoring of its spatiotemporal dynamics in planta is therefore essential for dissecting the regulatory mechanisms underlying plant nitrogen metabolism. However, conventional nitrate detection methods suffer from inherent limitations, including destructive sampling, insufficient spatiotemporal resolution, and an inability to achieve real-time whole-plant monitoring. Here, we report a genetically encoded nitrate biosensor, designated NitNRCL1, constructed using a split firefly luciferase complementation system. Functional validation in both prokaryotic and eukaryotic systems demonstrates that NitNRCL1 responds to changes in nitrate availability and generates stable chemiluminescent signals in bacteria and diverse plant species. Importantly, NitNRCL1 enables non-invasive, real-time, and whole-plant monitoring of nitrate levels in living plants. Using NitNRCL1, we successfully imaged the spatiotemporal dynamics of nitrate signaling in Arabidopsis thaliana. Collectively, our findings establish NitNRCL1 as a robust and novel tool for investigating nitrate transport, signaling, and metabolic pathways in plants. This biosensor advances our mechanistic understanding of plant nitrate biology and provides a technical foundation for breeding nitrogen-use-efficient crops and developing precision fertilization strategies. Full article

Transient DNA transfection is routinely used to study gene function and elucidate the regulation of biological pathways, and it is also widely applied in biotechnology for large-scale recombinant protein production. The results of recent studies involving mammalian cells have highlighted that competition for cellular resources during gene expression can bias data interpretation, directly affecting co-transfection experiments. In this study, our results showed that co-transfected plasmids markedly enhance transient—but not stable—expression of various reporter genes across different cell types. The enhancement of transient reporter gene expression by additional plasmid DNA occurs when these DNAs are co-delivered simultaneously and is unlikely to be mediated by cytokine induction. Furthermore, co-transfected plasmids were shown to upregulate transcription, but not translation, of the reporter gene during transient expression. Thus, the observed enhancement may result from competition between co-transfected plasmids and reporter constructs for cellular proteins that interact with transfected DNA, such as histones. Indeed, Pracinostat (SB939), an inhibitor of histone deacetylase, was able to enhance the transient expression of the reporter gene dose-dependently. Overall, this study provides insights that may facilitate improved transient expression of recombinant genes in biotechnological applications. Full article

Extracellular vesicles, which carry bioactive cargos such as proteins, RNAs, and lipids, represent promising drug delivery vehicles owing to their biocompatibility, low immunogenicity, and inherent tissue-targeting capabilities. To address the current limitations in controlled cargo loading, we developed an abscisic acid (ABA)-inducible proximity system that directs proteins into exosomes during biogenesis. We engineered exosomal scaffolds by fusing the ABA receptor PYL1 to EV-enriched proteins—including BASP1, CD9, PTGFRN, and a truncated form PTGFRNΔ687—thereby creating docking sites within the exosomal lumen, while the target cargo (e.g., EGFP, firefly luciferase, or Cas9) was tagged with the ABI1 phosphatase domain. We demonstrate that ABA administration in producer cells induces PYL1–ABI1 complex formation, which recruits ABI1-fused cargo for selective encapsulation into EVs. Among the scaffolds tested, BASP1–PYL1 proved the most effective, enabling robust, ABA-dependent enrichment of cargo proteins. Purified EVs maintained canonical morphology, size, and marker expression (CD63, syntenin-1, CD9), confirming preserved biogenesis. Critically, these loaded exosomes efficiently delivered functional cargo to recipient cells, enabling Cas9/sgRNA-mediated genome editing. Together, our findings establish an ABA-triggered molecular switch for controllable EV protein loading, providing a versatile platform for next-generation therapeutic delivery. Full article

Background/Objectives: Antigen presenting cells (APCs) and immune cells have unique properties to drive or suppress immune responses. They are therefore key targets for the expression of vaccine antigens or transgene proteins. To better determine the utility of different molecular therapies to modify these cells, mRNA and DNA-based molecular therapy vectors were compared for their ability to genetically modify immune cells after intradermal injections in mice. DNA-based vectors included naked plasmid DNA, plasmid packaged in lipid nanoparticles (LNPs), and replication-defective adenovirus (Ad) vectors. mRNA delivery was mediated by packaging into LNPs like those used in COVID-19 vaccines. Methods: Each vector was used to deliver Cre recombinase into Cre reporter mice whose cells were activated to express green fluorescent protein (GFP) and firefly luciferase after Cre recombination. The mice were injected intradermally (ID) near the base of their tail at a site that drains into the inguinal lymph node. Luciferase activity was imaged in the living mice 1 or 4 days after vector injection. The animals were then euthanized, and luciferase activity was imaged in the draining inguinal lymph node. Cells were prepared from the intradermal injection site and from the draining lymph node to determine which immune cells were genetically modified by phenotyping CD45, CD3, and CD11b GFP-positive cells by flow cytometry. Given that the skin uniquely contains Langerhans dendritic cells, these CD207⁺ cells were also phenotyped in skin samples and in the draining lymph node. Results: In both the skin and in the draining lymph node, the rank order of luciferase and GFP activation by the vectors were: (1) Ad; (2) mRNA-LNP; (3) DNA-LNP; and (4) naked DNA. Only mRNA-LNP and Ad vectors mediated obvious luciferase activity in the living animals and in the draining lymph nodes by imaging. Notably, both vectors appeared to leak from the ID injection site and not only modify the draining lymph node but also strongly modify the livers of the mice. Naked DNA and DNA-LNP mediated detectable GFP activation in the skin and draining lymph node in some mice, but this activity was low and did not reach statistical significance when compared to PBS-treated animals. mRNA-LNPs and Ad both mediated significant Cre delivery in CD45⁺, CD3⁺, CD11b⁺, and CD207⁺ immune cells in the skin and in the lymph node, with adenovirus mediating consistently higher levels of expression in all of the tested cells. Conclusions: These data indicate that mRNA-LNP and Ad vectors mediate stronger modification of skin and lymph node immune cells after intradermal injections. Naked DNA and DNA-LNPs were markedly less potent at this activity than the other vectors. These data are consistent with the higher vaccine potency of mRNA-LNP and Ad vectors and suggest that approaches that increase targeting of immune cell subsets may have utility to increase efficacy while also reducing off-target modification of tissues like the liver. Full article

Background: Survivin is an anti-apoptotic protein highly expressed during embryonic development and, in adults, mainly in the gastrointestinal epithelium. Its levels decrease in human gastric tissue and cultured cells upon exposure to Helicobacter pylori gamma-glutamyl transpeptidase (GGT), though the underlying mechanism remains unclear. Objective: We aimed to investigate the role of cap-independent translation driven by the Survivin 5′ untranslated region (5′UTR) in response to H. pylori infection in vitro. Methodology: Human cell lines (AGS, GES-1, HeLa, HEK293T) were used alongside bicistronic and monocistronic (Firefly/Renilla luciferases) reporter assays to assess short and long variants of the Survivin 5′UTR and HIV-1 internal ribosome entry site (IRES) sequences. Additional methods included in vitro transcription/translation, RT-qPCR, agarose gel electrophoresis, Western blotting, coupled/uncoupled translation assays, and siRNA silencing. Results: The short variant of the Survivin 5′ UTR supported cap-independent translation, like the HIV-1 IRES. Notably, H. pylori infection suppressed this translation in a GGT-dependent manner in gastric cells, and a similar reduction was observed following treatment with ATO, a known prooxidant. Conclusion: The Survivin 5′UTR exhibits cap-independent translation activity that is inhibited by H. pylori in a GGT-dependent manner, likely via oxidative stress. This mechanism helps to explain the downregulation of Survivin during gastric infection and indicates that oxidative stress can negatively affect both cellular and viral IRES-mediated translation. Full article

Background/Objectives: A key disadvantage of DNA vaccines is ineffective uptake of plasmid DNA, resulting in low immunogenicity. A way to overcome it is forced DNA delivery, which requires specialized equipment and/or reagents. Effective delivery of plasmids without specialized devices or using commonly available ones would significantly increase DNA vaccine applicability. Here, we delivered DNA by intradermal injections, facilitating them by optimized sonoporation (SP) or electroporation (EP), and we compared these methods by their capacity to support the production of foreign proteins in mice. Methods: DNA delivery was optimized using the plasmid encoding firefly luciferase (Luc) (pVaxLuc). Luc production was assessed by bioluminescence imaging (BLI) (IVIS, PerkinElmer, Shelton, CT, USA; LumoTrace Fluo, Abisense, Dolgoprudny, Russia). Female BALB/c mice were injected intradermally (id) with pVaxLuc in phosphate buffers of varying ionic strengths. Injection sites were subjected to SP (Intelect Mobile, Chattanooga, UK) or EP (CUY21EDITII, BEX Co., Tokyo, Japan) or left untreated. Optimal delivery protocols were selected based on the highest in vivo levels of photon flux according to BLI. Optimal protocols for id injections with/without EP were applied to DNA-immunized mice with HIV-1 clade A reverse transcriptase. Antibody response induced by DNA immunization was assessed by ELISA. Results: The optimal phosphate buffers for id delivery had ionic strengths from 81 to 163 mmol/L. The optimal SP regimen included an acoustic pressure of 2.4 W/cm² applied in a duty cycle of 2%. The optimal EP regimen included bipolar driving pulses of 100 V, a pulse duration of 10 ms, and an interval between the pulses of 20 ms. Optimized DNA delivery by id/SP injection was inferior to both id/EP and id alone. DNA immunization with HIV-1 RT by id injections induced anti-RT antibodies in a titer of 10⁴ and by id/EP in a titer of 10⁵. Conclusions: Electroporation of the sites of id DNA injection provided the highest levels of production of luciferase reporters and induced a strong antibody response against HIV-1 RT. Full article

The PER2 gene is a crucial component responsible for the proper functioning of the mammalian core circadian clock. The circadian nature of the murine Per2 (mPer2) promoter’s activity has been thoroughly investigated to identify important elements responsible for its oscillatory behavior; however, its human counterpart has not. While there are similarities between murine and human core clocks, there are differences and unconserved elements between their promoter sequences that may influence the nature of rhythms. Further, most studies to date have used murine-based sequences in human cell lines. To fully understand the role(s) of and factors involved in the human PER2 (hPER2) gene, human-derived sequences should be used. To this end, we developed two lentiviral luciferase reporters in well-established, circadian model U2OS cells using different hPER2 promoter regions. Their rhythmic nature was compared to that of the standard mPer2 promoter reporter. We found that hPER2 reporters exhibited stronger oscillations than the mPer2 reporter, and that the frame of the hPER2 promoter affected the period and phase. This work introduces a human sequence-based PER2 promoter in U2OS cells, which should be used for further in vitro tracking of hPER2 activity and to understand PER2 gene dynamics, in lieu of the murine iteration. Full article

In rice (Oryza sativa L.), the short-chain dehydrogenase protein OsABA2 plays a crucial role in regulating abscisic acid (ABA) biosynthesis. However, little is known about the other proteins that interact with OsABA2 to regulate ABA biosynthesis. Using yeast two-hybrid screening, we identified a novel OsABA2 interacting protein OsPP2C55, which contains a serine/threonine phosphatase (family 2C) catalytic domain. The yeast two-hybrid (Y2H) assay and firefly luciferase complementary imaging (LCI) assay confirmed these interactions. Subsequent studies revealed that saline–alkaline stress significantly downregulated OsPP2C55 gene expression. Meanwhile, we constructed ospp2c55 CRISPR gene knockout (ospp2c55-KO) plants using Agrobacterium genetic transformation. Compared with wild-type plants, ospp2c55-KO plants under saline–alkaline stress exhibited significantly elevated OsABA2 protein levels, leading to substantial increases in ABA content. In addition, ospp2c55-KO plants demonstrated heightened sensitivity to ABA during seed germination. Moreover, ospp2c55-KO plants improved the survival rate and stress-related indices of rice seedlings under saline–alkaline stress, and upregulated the expression of genes related to adversity stress (OsNCED1, OsNCED3, OsABA2, OsSODCc2, and OsCatB). We found that OsPP2C55 plays a negative regulatory role in ABA biosynthesis and saline–alkaline stress tolerance in rice. Full article

The current study examined the in vitro antineoplastic potentials of centrapalus coumarin F (CCF) obtained from aerial parts of Centrapalus pauciflorus (Willd.) H.Rob. (Asteraceae). Cytotoxic activity was tested against a panel of human adherent cancer cell lines, including breast, cervical, and oropharyngeal cancer and glioblastoma. Cell cycle analyses using flow cytometry and Hoechst 33258-propidium iodide (HOPI) fluorescent double staining were used to describe the proapoptotic property of CCF. Wound healing assessment and the Boyden chamber assay were performed to characterize the antimetastatic action of the compound. The firefly luciferase assay was applied to clarify the action of CCF on estrogenic receptors. CCF demonstrated remarkable selective growth inhibition against the HPV-18-positive human cervical cancer cell line HeLa (IC₅₀ = 2.28 µM). The compound elicited crucial markers of apoptosis, inhibited the migration and invasion capacity of HeLa cells, and demonstrated an antiestrogenic property. Our current data indicate that the meroterpenoid scaffold presented here displays remarkable antiproliferative and antimetastatic effects on HeLa cells and can be considered a valuable model for designing further analogs targeting cervical carcinoma. Full article

Cedar virus (CedV), closely related to the Hendra and Nipah viruses, is a novel Henipavirus that was originally isolated from flying foxes in Australia in 2012. Although its glycoprotein G exhibits relatively low sequence similarity with its counterparts of the Hendra and Nipah viruses, CedV also uses ephrin receptors, i.e., ephrins B1, B2, A2 and A5, to enters human cells. Nevertheless, the entry mechanism of CedV into bat cells remains unexplored. Considering that Rousettus aegyptiacus (Egyptian Rousette bat, ERB) is postulated to be a reservoir host for henipaviruses, we aim to reveal the receptors utilized by CedV to enable its entry into ERB cells. To this end, we cloned the class A and B ephrins of ERB and generated CHO-K1 cells stably expressing individual ephrins. We also developed a lentivirus-based pseudovirus system containing the firefly luciferase reporter. Assessment of the luciferase activity in cells expressing single ephrins demonstrated that the ERB ephrin B1 and B2 mediated CedV pseudovirus entry. Further, we generated a recombinant CedV expressing the fluorescent protein TurboFP635 (rCedV-nTurbo635). By performing high-content microscopy and flow cytometry, we unveiled that, in addition to ephrin B1 and B2, ephrin A5 was also able to mediate rCedV-nTurbo635 entry, although to a much lesser extent. In contrast to human ephrin A2, ERB ephrin A2 failed to mediate rCedV-nTurbo635 entry. Finally, we generated ERB epithelial cells with ephrin B1 and/or ephrin B2 knockdown (KD). The entry of rCedV-nTurbo635 into ERB epithelial cells was drastically impaired by ephrin B1/B2 KD, validating the importance of ephrin B1 and B2 in its entry. Altogether, we conclude that CedV primarily employs ERB ephrin B1, B2 and, possibly, A5 for its entry into ERB cells. Full article

Background/Objectives: Murine models play a key role in guiding formulation and immunogenicity studies across various vaccine platforms, including mRNA-based vaccines. Typically, a narrow age range (6 to 8 weeks) is used in these studies. Here, we investigated whether widening this age range could provide greater flexibility in experimental design without impacting pre-clinical outcomes. Methods: To achieve this, we evaluated two commonly used lipid nanoparticle (LNP) formulations (based on SM102 and ALC-0315 ionizable lipids) containing either firefly luciferase or ovalbumin mRNA in female BALB/c mice aged 4, 8, and 16 weeks. LNPs were prepared and purified via microfluidics, and their size, polydispersity, zeta potential, and encapsulation efficiency were measured. Mice were injected intramuscularly, and the in vivo bioluminescence and antibody titers were measured to evaluate mRNA expression profiles and immunogenicity across the three age groups. Results: Our findings show that the 4-week-old mice exhibited higher protein expression following mRNA administration compared to the older groups; however, no significant differences were observed between the 8- and 16-week-old mice. Despite the initial higher protein expression, the antibody responses after the prime dose were lower in the 4-week-old mice compared to the other two groups. However, following the booster dose, antibody levels were comparable across all three age groups. Conclusions: By identifying a broader age range window, we provide greater flexibility in study design, enhance data comparability across studies, and promote more efficient use of animal resources, all while maintaining reliable and representative results in these murine models. Full article

Heavy metal contamination of soil and water is a growing environmental concern, especially mercury, lead, and cadmium. Therefore, fast and reliable methodologies to assess contamination in the field are in demand. However, many methodologies require laborious, expensive, and cumbersome equipment that is not convenient for rapid field analysis. Mobile phone technology coupled with bioluminescent assays provides accessible hands-on alternatives that has already been shown to be feasible. Previously, we demonstrated that firefly luciferases can be harnessed as luminescence color-tuning sensors for toxic metals. An assay based on such a principle was already successfully applied for teaching biochemistry laboratory lessons, which demonstrates the effect of cadmium on enzyme function based on bioluminescence color change. For analytical detection of cadmium in water, here, we developed a novel bioluminescence assay using the cadmium-sensitive Amydetes vivianii firefly luciferase coupled with a cell phone provided with a program to quantify cadmium concentration based on luminescence color discrimination. The application has proven to be efficient with high precision between 0.10 and 2 mM of cadmium, being appliable to diluted water samples (0.1–2 µM) upon concentration and relying on reference cadmium standards values. The light emitted by the reference standards and samples in a dark box is captured by the smartphone’s camera, which, using computer vision, automatically quantifies cadmium according to the RGB color. CadmiLume is a simple and easy luminescent enzymatic biosensor for cadmium contamination in water samples, which instantaneously can provide results with the convenience of a smartphone in the palm of one’s hands. Full article

Background: Irrespective of the rapid development of AAV-based gene therapy, the production of clinical-grade vectors has a bottleneck resulting from product-related impurities such as empty and partially filled capsids, which lack a functional recombinant genome. Methods: In the current study, we applied the sequential affinity chromatography (AC)- and anion-exchange chromatography (AEX)-based method for purification of AAV9 vector harboring single-stranded genome encoding the fusion of firefly luciferase (fLuc)-yellow fluorescent protein (YFP) under chicken beta actin (CBA) promoter. We assessed the efficiency of two different pre-packed cross-linked sepharose and one monolithic AEX columns following AC purification to separate fully encapsulated with recombinant DNA AAV vectors from byproducts. Results: We showed the possibility to achieve approximately 20–80% recovery and over 90% calculated DNA-containing/empty capsid ratio depending on column and buffers composition. Additionally, we confirmed the infectivity of AAV by in vitro luciferase assay regardless of recovery method from different AEX columns. Conclusions: Our purification data indicate the effectiveness of dual chromatography method to obtain rAAV9 vectors with DNA-containing capsid content over 90%. Full article