Reporter Gene Research Articles

Cone-rod homeobox transcriptionally activates TCF7 to promote the proliferation of retinal pigment epithelial and retinoblastoma cells in vitro

AIM: To investigate the proliferation regulatory effect of cone-rod homeobox (CRX) in retinal pigment epithelium (RPE) and retinoblastoma (RB) cells to explore the potential application and side effect (oncogenic potential) of CRX-based gene therapy in RPE-based retinopathies. METHODS: Adult human retinal pigment epithelial (ARPE)-19 and human retinal pigment epithelial (RPE)-1 cells and Y79 RB cell were used in the study. Genetic manipulation was performed by lentivirus-based technology. The cell proliferation was determined by a CellTiter-Glo Reagent. The mRNA and protein levels were determined by quantitative real-time polymerase chain reaction (qPCR) and Western blot assay. The transcriptional activity of the promoter was determined by luciferase reporter gene assay. The bindings between CRX and transcription factor 7 (TCF7) promoter as well as TCF7 and the promoters of TCF7 target genes were examined by chromatin immunoprecipitation (ChIP) assay. The transcription of the TCF7 was determined by a modified nuclear run-on assay. RESULTS: CRX overexpression and knockdown significantly increased (n=3, P<0.05 in all the cells) and decreased (n=3, P<0.01 in all the cells) the proliferation of RPE and RB cells. CRX overexpression and knockdown significantly increased and deceased the mRNA levels of Wnt signaling target genes [including MYC proto-oncogene (MYC), JUN, FOS like 1 (FOSL1), CCND1, cyclin D2 (CCND2), cyclin D3 (CCND3), cellular communication network factor 4 (CCN4), peroxisome proliferator activated receptor delta (PPARD), and matrix metallopeptidase 7 (MMP7)] and the luciferase activity driven by the Wnt signaling transcription factor (TCF7). TCF7 overexpression and knockdown significantly increased and decreased the proliferation of RPE and RB cells and depletion of TCF7 significantly abolished the stimulatory effect of CRX on the proliferation of RPE and RB cells. CRX overexpression and knockdown significantly increased and decreased the mRNA level of TCF7 and the promoter of TCF7 was significantly immunoprecipitated by CRX antibody. CONCLUSION: CRX transcriptionally activates TCF7 to promote the proliferation of RPE and RB cells in vitro. CRX is a potential target for RPE-based regenerative medicine. The potential risk of this strategy, tumorigenic potential, should be considered.

Smads and AP-1 activation of TGF-β signaling upregulate transcription of Osteoprotegerin in Cementoblasts to inhibit osteoclastogenesis.

Orthodontically induced root resorption (OIRR) is a common side effect during orthodontic tooth treatment (OTM). The function of osteoprotegerin (OPG) is considered to protect cementum from excessive resorption to maintain root integrity. In this study, we observed that the expression of TGF-β1 and OPG was upregulated under the loading of orthodontic force in periodontal tissues. However, the specific molecular mechanisms of TGF-β1-induced OPG expression in cementoblasts are not fully elucidated. This study aims to investigate the effect of Smads and AP-1 stimulated by TGF-β signaling on the transcription of OPG in cementoblasts. Invitro, we demonstrated that TGF-β/Smad and AP-1 signaling involved in TGF-β1-induced extracellular secretion of OPG in conditioned media (CM) from cementoblasts, which further inhibited osteoclastogenesis. Reporter gene plasmids containing OPG promoter sequences of different lengths (0.5-3 kb) were constructed to investigate the potential binding sites of Smads and AP-1. We identified nine binding sites of Smads and AP-1 concentrated in the 0-0.5 and 2.3-3 kb regions of OPG promoter in cementoblasts. ChlP results showed that Smad2/3/4 and c-Jun were bound more to the OPG promoter under TGF-β1 stimulation. Invivo, localized administration of TGF-β1 in the OTM model increased OPG expression, which resulted in the inhibition of OIRR. In summary, TGF-β1-induced Smads and AP-1 can bind to the OPG promoter to promote the transcription, expression, and secretion of OPG in cementoblasts, which inhibits osteoclast differentiation and protects cementum from excessive resorption.

Echinochrome A inhibits HMGB1-induced vascular smooth muscle cell migration by suppressing osteopontin expression.

Echinochrome A (Ech A) isolated from marine organisms is a therapeutic effector for various cardiovascular diseases, but its precise mechanisms are unclear. This study identified the role and mechanisms mediating the effects of Ech A on the migration of vascular smooth muscle cells (VSMCs) induced by high-mobility group box 1 (HMGB1). Compared to the control cells, the migration of VSMCs stimulated with HMGB1 (100 ng/ml) was markedly increased, which was significantly attenuated in cells pretreated with MPIIIB10 (100 ng/ml), a neutralizing monoclonal antibody for osteopontin (OPN). In VSMCs stimulated with HMGB1, the increased expression of OPN mRNA and protein was accompanied by an increased OPN promoter activity. In reporter gene assays using OPN promoter-luciferase constructs, the promoter region 538-234 bp of the transcription start site containing the binding sites for activator protein 1 (AP-1) was shown to be responsible for the increased transcriptional activity by HMGB1. In addition, the binding activity of AP-1 was increased in HMGB1-stimulated cells, highlighting the pivotal role of AP-1 on OPN expression in HMGB1-stimulated VSMCs. An examination of the vascular effects of Ech A showed that the increased AP-1 binding/promoter activities and OPN expression induced by HMGB1 were attenuated in cells pretreated with Ech A (3 or 10 μM). Similarly, Ech A inhibited HMGB1-induced VSMC migration in a concentration-dependent manner. These findings suggest that Ech A inhibits VSMC migration by suppressing OPN expression. Hence, Ech A is suggested as a potential therapeutic strategy for vascular remodeling in the injured vasculatures.

Astilbin improves the therapeutic effects of mesenchymal stem cells in AKI-CKD mice by regulating macrophage polarization through PTGS2-mediated pathway.

Although mesenchymal stem cells (MSCs) have been proven to be appropriate candidates for the treatment of AKI-CKD, their efficacy is limited and variable. Astilbin (AST) had a protective effect on MSCs from oxidative stress via ROS-scavenging, however, whether it can improve MSCs' renoprotection and the underlying mechanism need to be elucidated. AST-pretreated MSCs were administered intravenously into the ischemia-reperfusion injury mice models and the renal function, pathological changes and inflammation. Were evaluated. In addition, DARTS, molecular docking, surface plasma resonance(SPR), dual-luciferase reporter gene assay and the ChIP-PCR were utilized to explore the potential signaling pathways through which AST exert renal protective effects on MSCs. AST-pretreated MSCs markedly improved kidney function, reduced kidney pathological injury and inflammation in AKI and AKI-CKD mice. RNA-seq results showed that PTGS2 related pathway was significantly up-regulated in MSCs after AST pretreatment. DARTS assay, molecular docking and SPR assay revealed that AST could bind with the transcriptional factor of Kruppel-Like Factor 4(KLF4) protein. The promoter of PTGS2 had the binding and transcriptional activation by KLF4. Furthermore, AST pretreatment promoted the secretion of PGE2 in MSCs. And then the westren blot results showed that the protein levels of CD163 and CD206 were upregulated after coculture in AST-pretreated MSCs, indicating that the polarization of RAW264.7 cells towards M2-like macrophages was induced. Knockdown of PTGS2 reversed the ability of AST-pretreated MSCs in converting macrophages to M2 phenotype and reducing their therapeutic effects on AKI-CKD mice. AST pretreatment enhances the efficacy of MSCs on AKI and AKI-CKD mice by inducing of M2-like phenotype polarization in macrophages through the PTGS2-mediated pathway. This approach not only provides a novel strategy to strengthen the capability of MSCs but also helps elucidate the beneficial effects of the Chinese herbal medicine AST.

ZFP36, an RNA-binding protein promotes hBMSCs osteogenic differentiation via binding with JUN.

Osteoporosis (OP) is a metabolic bone disease characterized by progressive decline of bone mass and bone quality, leading to bone fragility and an increased risk of fracture. The osteogenic differentiation of bone mesenchymal stem cells (BMSCs) is crucial to maintain the balance of osteoblast and osteoclast. Bioinformatics prediction indicates that ZFP36 ring finger protein (ZFP36), an RNA-binding protein, is a potential target of OP. Herein, we sought to probe the regulatory role and mechanisms of ZFP36 in the progression of OP. Overexpression of ZFP36 enhanced osteoblast viability, differentiation and mineralization of human BMSCs (hBMSCs). RNA immunoprecipitation qPCR (RIP-qPCR) assays demonstrated that ZFP36 could inhibit the translation of JUN, which was also verified with dual luciferase reporter gene assay. Furthermore, administration with T-5224, a transcription factor c-Fos/activator protein (AP)-1 inhibitor, which specifically inhibits the DNA binding activity of c-Fos/JUN, abolished the effect of ZFP36 knockdown on the behaviors of hBMSCs, suggesting that ZFP36 might promotes osteogenic differentiation through regulating JUN. These findings provide insights into the progression and a potential therapeutic target of OP.

Bioactivity of Grape Pomace Extract and Sodium Selenite, Key Components of the OenoGrape Advanced Complex, on Target Human Cells: Intracellular ROS Scavenging and Nrf2/ARE Induction Following In Vitro Intestinal Absorption

Oenobiol Sun Expert, a food formulation designed to enhance skin health prior to sun exposure, has been optimized by incorporating the OenoGrape Advanced Complex, which includes grape pomace extract, increased selenium content and 10% lycopene-rich tomato extract, with these constituents exhibiting high antioxidant potential. To evaluate the effects of these individual ingredients and the overall formulation at the cellular level, the AOP1 cell antioxidant efficacy assay was employed to measure the intracellular free radical scavenging activity, while the Cell Antioxidant Assay (CAA or DCFH-DA) assay was used to assess peroxidation scavenging at the plasma membrane level. The indirect antioxidant activity was examined using stably transfected cell lines containing a luciferase reporter gene controlled by the Antioxidant Response Element (ARE), which activates the endogenous antioxidant system via the Nrf2/Keap1-ARE pathway. Our results indicate that among the individual components, grape pomace extract and sodium selenite possess high and complementary antioxidant properties. Grape pomace extract was particularly effective in inhibiting free radicals (AOP1 EC50 = 6.80 μg/mL) and activating the ARE pathway (ARE EC50 = 231.1 μg/mL), whereas sodium selenite exerted its effects through potent ARE activation at sub-microgram levels (EC50 = 0.367 μg/mL). In contrast, the lycopene-rich tomato extract did not show a notable contribution to the antioxidant effects. The antiradical activity of the OenoGrape Advanced Complex, comprising these three ingredients, was very efficient and consistent with the results obtained for the individual components (AOP1 EC50 = 15.78 µg/mL and ARE EC50 of 707.7 μg/mL). Similarly, the free radical scavenging activity still persisted in the Oenobiol Sun Expert formulation (AOP1 EC50 = 36.63 µg/mL). Next, in vitro intestinal transepithelial transfer experiments were performed. The basolateral compartments of cells exposed to the ingredients were collected and assessed using the same antioxidant cell assays. The direct and indirect antioxidant activities were measured on both hepatocytes and keratinocytes, demonstrating the bioavailability and bioactivity of grape pomace extract and sodium selenite. These finding suggest that the ingredients of this food supplement contribute to enhanced cytoprotection following ingestion.

Iterative Bleaching Extends Multiplexity (IBEX) facilitates simultaneous identification of all major retinal cell types.

To understand the multicellular composition of tissues, and how it is altered during development, ageing and/or disease, we must visualise the complete cellular landscape. Currently, this is hindered by our limited ability to combine multiple cellular markers. To overcome this, we adapted a highly multiplexed immunofluorescence (IF) technique called Iterative Bleaching Extends Multiplexity (IBEX) to the zebrafish retina. We optimised fluorescent antibody micro-conjugation to perform sequential rounds of labelling on a single tissue to simultaneously visualise all major retinal cell types with 11 cell-specific antibodies. We further adapted IBEX to be compatible with fluorescent transgenic reporter lines, in situ hybridisation chain reaction (HCR), and wholemount immunofluorescence (WMIF). We applied IBEX at multiple stages to study the spatial and temporal relationships between glia and neurons during retinal development. Finally, we demonstrate the utility of IBEX across species by testing it on the turquoise killifish (Nothobranchius furzeri) and African clawed frog (Xenopus laevis) to glean large amounts of information from precious tissues. These techniques will revolutionise our ability to visualise multiple cell types in any organism where antibodies are readily available.

Identification and functional validation of variants in the promoter region of HAND1 gene in sporadic tetralogy of Fallot.

Tetralogy of Fallot (TOF) is a common congenital heart disease (CHD) but the impact of the variants of the HAND1 gene promoter region has not been explored. DNA from blood samples of 612 subjects (300 sporadic TOF patients and 312 healthy controls) was sequenced to identify variants in the HAND1 gene promoter region that were further tested by cellular function experiments including dual-luciferase reporter gene assays, electrophoretic mobility shift analysis (EMSA), and bioinformatics analysis using JASPAR, a transcription factor binding site database. Eight variants in HAND1 gene promoter region were identified with 3 only found in TOF patients including one novel g.3639 G > T. All 3 variants significantly reduced the transcriptional activity of HAND1 gene promoter in an in vitro reporter assay (p < 0.05). JASPAR analysis indicated that these variants may alter the binding sites of transcription factors, potentially associated with TOF formation. In the promoter region of HAND1gene of TOF patients, 3 variants were found only in the patients including one found for the first time. These variants decreased transcription factor activity. Therefore, the present study implies the role of HAND1 gene in the pathogenesis of TOF and further provides new insights into the genetic basis of TOF formation. Sequencing of DNA from 612 human subjects (300 TOF patients and 312 healthy controls) identified 8 variants in the promoter region of HAND1 gene with 3 found only in TOF including 1 newly identified. Reduced transcriptional activity at these 3 variants was confirmed by dual-luciferase reporter gene assay and EMSA assay. Predictions from the JASPAR database suggest altered binding sites of transcription factors by the variants. We for the first time demonstrate variants in the HAND1 promoter and that cause cellular dysfunction. The variants identified may have a pathological role in the formation of TOF.

LncRNA CASC9 facilitates papillary thyroid cancer development and doxorubicin resistance via miR-28-3p/BCL-2 axis and PI3K/AKT signaling pathway.

Papillary thyroid cancer (PTC) is a malignant tumor that poses a serious threat to human health. LncRNA CASC9 serves as an oncogene in numerous tumors. The purpose of this study was to explore the mechanism of lncRNA CASC9 regulating doxorubicin (Dox) resistance in PTC. The expression of CASC9, miR-28-3p and BCL-2 in PTC tissues or dox-resistant cells was determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot (WB). CCK-8, colony formation assay, flow cytometry and transwell assay were used to measure the semi-inhibitory concentration (IC50) of dox, cell proliferation, apoptosis and migration, respectively. Dual luciferase reporter gene assays were performed to verify the targeting relationship between miR-28-3p and CASC9 or BCL-2. Rescue experiments were applied to verify the mechanism of CASC9. Finally, the role of CASC9 was verified by xenograft modeling in vivo. We discovered that CASC9 was enhanced in PTC tissues, cells and Dox-resistant cells (BCPAP/Dox and K1/Dox). Furthermore, CASC9 inhibition markedly restrained the proliferation, migration and facilitated apoptosis of Dox cells. In vivo experiments also showed that silencing of CASC9 inhibited tumor growth. Meanwhile, knockdown of CASC9 sensitized PTC cells to Dox. CASC9 enhanced tumor progression by activating the PI3K/AKT signaling pathway. Furthermore, bioinformatics analysis identified miR-28-3p as a downstream target of CASC9. MiR-28-3p inhibitor reversed the impact of CASC9 knockdown in BCPAP/Dox and K1/Dox. Further studies showed that CASC9 positively regulated BCL-2 expression through miR-28-3p. miR-28-3p weakened Dox resistance, proliferation, migration and accelerated apoptosis of PTC cells via BCL-2. CASC9, as an oncogenic lncRNA, has a promotional effect on Dox resistance and PTC progression via miR-28-3p/BCL-2 axis and PI3K/AKT signaling pathway.

Inhibition of Sat1 alleviates myocardial ischemia-reperfusion injury through regulation of ferroptosis via MAPK/ERK pathway

IntroductionMyocardial ischemia-reperfusion injury (MIRI) is a prevalent complication in patients with myocardial infarction. The pathological mechanism of MIRI remains elusive. Ferroptosis plays a critical role in MIRI. This study aimed to investigate the role of spermidine/spermine N1-acetyltransferase 1 (Sat1) in MIRI by regulation of ferroptosis.MethodsRats and H9C2 cells were used to perform MIRI model. The extent of myocardial damage and associated pathological changes were evaluated. Protein expression was detected by western blot. Then we observed the mitochondrial morphology and measured cell viability and damage. The levels of lipid peroxide and glutathione were measured, and lipid reactive oxygen species (ROS) was quantified. Differentially expressed genes (DEGs) in MIRI were analyzed. Moreover, to explore the role of Sat1 in MIRI, this study utilized adeno-associated virus 9 and lentiviral transduction to modulate Sat1 expression in rats and H9C2 cells, respectively. The transcription factor that regulates Sat1 expression was predicated. Luciferase reporter gene experiment was conducted to reveal the potential sites of Sox2 binding to Sat1.ResultsThis study revealed that ferroptosis was involved in MIRI. Through bioinformatic analysis, Sat1 was identified as a significant gene in MIRI, which has been reported as an inducer of ferroptosis. Our results showed that Sat1 expression was significantly increased in MIRI. Next, the study showed that inhibition of Sat1 alleviated MIRI by suppressing ferroptosis in vivo and in vitro, and over-expression of Sat1 promoted MIRI via activation of ferroptosis. Furthermore, Sat1 and its interacting genes were enriched in several signaling pathways, including ferroptosis and the MAPK signaling pathway. The results showed that Sat1 regulated MIRI through ferroptosis via MAPK/ERK pathway. Moreover, it is found that Sox2 can suppress Sat1 expression at the transcriptional level. The potential binding site was TAACAAAGGAA.ConclusionIn sum, this study demonstrated Sat1 expression was increased in MIRI, inhibition of Sat1 can alleviate MIRI by regulating ferroptosis via MAPK/ERK pathway, and Sat1 was negatively regulated by Sox2. These findings suggested that Sat1 may serve as a potential therapeutic target for the treatment of MIRI.

Construction and Analysis of miRNA–mRNA Interaction Network in Ovarian Tissue of Wanxi White Geese Across Different Breeding Stages

Ovarian development significantly influences the laying performance of geese. In this study, the transcriptome analysis was conducted on the ovarian tissues of Wanxi White Geese during the pre-laying (KL), laying (CL), and ceased-laying period (XL). Short Time-series Expression Miner (STEM) analysis and miRNA–mRNA regulatory network construction were performed to identify the key genes and miRNAs regulating laying traits. Comparative analysis of KL vs. CL, CL vs. XL, and XL vs. KL groups resulted in the identification of 337, 136, and 525 differentially expressed genes (DEGs), and 258, 1131, and 909 differentially expressed miRNAs (DEMs), respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis (p &lt; 0.05) revealed that the main enrichment pathways of DEGs and DEMs at different breeding periods were Neuroactive ligand–receptor interaction, GnRH signaling pathway and Wnt signaling pathway, all associated with ovarian development. According to the three groups of common pathways, four DEGs were screened out, including INHBB, BMP5, PRL, and CGA, along with five DEMs, including let-7-x, miR-124-y, miR-1-y, and miR-10926-z, all of them may affect ovarian development. A miRNA–mRNA regulatory network was constructed through integrated analysis of DEGs and DEMs, revealing nine miRNAs highly associated with ovarian development: miR-101-y, let-7-x, miR-1-x, miR-17-y, miR-103-z, miR-204-x, miR-101-x, miR-301-y, and miR-151-x. The dual-luciferase reporter gene verified the target relationship between WIF1 and miR-204-x, suggesting that these miRNAs may influence ovarian development in Wanxi White Goose by regulating the expression levels of their target genes within ovarian tissue. This study provides a theoretical foundation for analyzing the mechanisms of ovarian development across different breeding periods and accelerating the cultivation of new breeds through post-transcriptional regulation levels.

Minimally Invasive Transthoracic Intramyocardial Cellular Transplantation Under Echocardiographic Guidance for Myocardial Impairment

Abstract Objective: To explore the approach of minimally invasive transthoracic intramyocardial cellular transplantation under echocardiographic guidance to promote ischemic myocardial repair in a preclinical big-animal study. Methods: Female Guangxi Bama miniature pigs (weight: 25–30 kg) were randomly allocated into the sham group, untreated myocardial infarction (MI) group (MI group), the MI and surgical intramyocardial injection (SIM) group (MI-SIM group), and the MI and transthoracic echocardiography-guided percutaneous intramyocardial injection (TTEPIM) group (MI-TTEPIM group) (n = 4 each) using a lottery method. A swine MI model was established in the 3 groups excluding the sham group, and human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) labeled with the herpes simplex virus type-1 thymidine kinase reporter gene (hiPS-CMTK+) were transplanted by SIM in MI-SIM group and TTEPIM in MI-TTEPIM group. The operation time, postoperative recovery time of animals and volume of blood loss were collected for comparison between MI-SIM group and MI-TTEPIM group. 9-(4-[18F] fluoro-3-(hydroxymethyl) butyl) guanine positron emission tomography/computed tomography imaging was performed to track the hiPS-CMTK+ in vivo. Cardiac function and morphology were evaluated by echocardiography. Results: The operation time and postoperative recovery time of MI-TTEPIM group were significantly shorter than those of MI-SIM group ((28.3 ± 3.6) min vs. (97.0 ± 6.7) min, P &lt; 0.001; (1.3 ± 0.3) d vs. (7.5 ± 0.9) d, P &lt; 0.001). MI-TTEPIM also showed significantly lesser volume of blood loss during cell transplantation than MI-SIM group ((4.3 ± 0.8) mL vs. (47.0 ± 4.1) mL, P &lt; 0.001). The transplanted cells could be traced more accurately in vivo in MI-TTEPIM than in MI-SIM. The circumferential strain of intervention region in the MI-TTEPIM group (–25.07% ± 0.27%) was significantly higher than that of the MI-SIM (–20.39% ± 0.67%) and MI groups (–19.68% ± 0.67%), respectively (P &lt; 0.01). Conclusion: A minimally invasive TTEPIM protocol with stem cells for treating the ischemic myocardium was established in this study. Transplantation of hiPS-CMTK+ with this method could promote the recovery of the circumferential strain of the ischemic myocardium. The findings of this study lay a foundation for the clinical transformation of this auxiliary means of treatment in the future.

MiR-204-5p regulates SIRT1 to promote the endoplasmic reticulum stress-induced apoptosis of inner ear cells in C57BL/6 mice with hearing loss.

This study investigated the effect of miR-204-5p-mediated silencing of SIRT1 on the development of deafness in C57BL/6 mice and the roles of miR-204-5p and SIRT1 in deafness. Auditory brainstem response recordings, H&E staining, and immunohistochemistry were used to observe changes in hearing function and cochlear tissue morphology in 2-month-old and 15-month-old C57BL/6 mice. A senescence model was induced using H2O2 in inner ear cells (HEI-OC1). Changes in HEI-OC1 cell proliferation were detected using the CCK-8 assay, whereas flow cytometry was used to detect changes in apoptosis. MiR-204-5p expression was measured via RT‒qPCR. The SIRT1 agonist RSV and a miR-204-5p inhibitor were used to study changes in ER stress (ERS), proliferation, and apoptosis in HEI-OC1 cells. Western blotting was performed to detect changes in ATF4, CHOP, SIRT1, PERK, p-PERK, Bax, and Bcl-2 protein levels. A dual-luciferase reporter gene assay was carried out to assess the ability of miR-204-5p to target SIRT1. Relative miR-204-5p expression levels in the cochleae of aged C57BL/6 mice increased, whereas SIRT1 expression levels decreased, and miR-204-5p and SIRT1 expression levels were negatively correlated. ERS and increased 8-OHDG levels were observed in aged C57BL/6 mice. In a model of inner ear cell aging, H2O2 treatment induced increases in miR-204-5p expression and ERS-mediated apoptosis. MiR-204-5p was found to target SIRT1 and inhibit its expression. SIRT1 activation and a miR-204-5p inhibitor promoted HEI-OC1 cell proliferation and reduced apoptosis. The miR-204-5p inhibitor regulated expression of the ERS proteins PERK, ATF4, and CHOP to upregulate Bcl-2 and downregulate Bax. This study identified the roles of miR-204-5p and SIRT1 in deafness in C57BL/6 mice and investigated the loss of cochlear outer hair cells and the involvement of apoptosis and ERS in deafness.

A generic cell-based biosensor converts bacterial infection signals into chemoattractants for immune cells

Bacterial infections are a major challenge to human health. Although various potent antibiotics have emerged in the last decades, current challenges arise from an increasing number of multi-drug-resistant species. Infections associated with implants represent a particular challenge since they are usually diagnosed at an advanced state, and are difficult to treat with antibiotics due to the formation of protecting biofilms. In this study, we designed and explored a synthetic biology-inspired, cell-based bio-sensor/actor for the detection and counteraction of bacterial infections. The system is generic as it senses diverse types of infections and acts by enhancement of the endogenous immune system. The strategy is based on genetically engineered sensor/actor cells that can sense type I interferons (IFNs), which are released by immune cells at the early stages of infections. IFN signalling activates a synthetic circuit to induce reporter genes with a sensitivity of only 5 pg/ml of IFN and leads to a therapeutic protein output of 100ng/ml, resulting in theranostic cells that visualize and fight infections. Robustness and resilience were achieved by the implementation of a positive feedback loop. We show that diverse gram-positive and gram-negative implant-associated pathogenic bacteria activate the cascade in co-culture systems in a dose-dependent manner. Finally, we show that this system can be used to secrete chemoattractants facilitating the infiltration of immune cells in response to bacterial triggers. Together, the system is not only universal to bacterial infections but at the same time hypersensitive allowing the sensing of infections at initial stages.

Harmonic imaging for nonlinear detection of acoustic biomolecules.

Gas vesicles (GVs) based on acoustic reporter genes have emerged as potent contrast agents for cellular and molecular ultrasound imaging. These air-filled, genetically encoded protein nanostructures can be expressed in a variety of cell types in vivo to visualize cell location and activity or injected systemically to label and monitor tissue function. Distinguishing GV signal from tissue deep inside intact organisms requires imaging approaches such as amplitude modulation (AM) or collapse-based pulse sequences. However, these approaches have limitations either in sensitivity or require the destruction of GVs, restricting the imaging of dynamic cellular processes. To address these limitations, we developed harmonic imaging to enhance the sensitivity of nondestructive GV imaging. We hypothesized that harmonic imaging, integrated with AM, could significantly elevate GV detection sensitivity by leveraging the nonlinear acoustic response of GVs. We tested this hypothesis by imaging tissue-mimicking phantoms embedded with purified GVs, mammalian cells genetically modified to express GVs, and mice liver in vivo post-systemic infusion of GVs. Our findings reveal that harmonic cross-propagating wave AM (HxAM) imaging markedly surpasses traditional xAM in isolating GVs' nonlinear acoustic signature, demonstrating significant (p < 0.05) enhancements in imaging performance. HxAM imaging improves detection of GV producing cells up to three folds in vitro, enhances in vivo imaging performance by over 10 dB, while extending imaging depth by up to 20%. Investigation into the backscattered spectra further elucidates the advantages of harmonic imaging. These advancements bolster ultrasound's capability in molecular and cellular imaging, underscoring the potential of harmonic signals to improve GV detection.

Unveiling Novel Regulatory Mechanisms of miR-5195-3p in Pelvic Organ Prolapse Pathogenesis†.

Pelvic organ prolapse (POP) is a condition that significantly affects women's quality of life. The pathological mechanism of POP is not yet fully understood, and its pathogenesis is often caused by multiple factors, including the metabolic imbalance of the extracellular matrix (ECM). This study aims to investigate the role of miR-5195-3p, a microRNA, in the pathology of POP and its regulatory mechanism. Using various molecular biology techniques such as qRT-PCR, FISH, immunohistochemistry, and western blot, miR-5195-3p expression was examined in vaginal wall tissues obtained from POP patients. Results revealed an up-regulation of miR-5195-3p expression in these tissues, showing a negative correlation with the expression of ECM-related proteins. Further analysis using bioinformatics tools identified LOX as a potential target in POP. Dual luciferase reporter gene experiments confirmed LOX as a direct target of miR-5195-3p. Interestingly, regulating the expression of LOX also influenced the TGF-β1 signaling pathway and had an impact on ECM metabolism. This finding suggests that miR-5195-3p controls ECM metabolism by targeting LOX and modulating the TGF-β1 signaling pathway. In conclusion, this study unveils the involvement of miR-5195-3p in the pathological mechanism of POP by regulating ECM metabolism through the LOX/TGF-β1 axis. These findings reveal new mechanisms in the pathogenesis of pelvic POP, providing a theoretical foundation and therapeutic targets for further research on POP treatment.

Abstract 4143267: Bicaudal-C Homolog 1 Plays a Significant Role in Cardiac Development and Congenital Heart Defects

Background: Congenital heart defects (CHDs) are the most common birth defects globally and often require palliative surgical interventions with limited long-term effectiveness. Prenatal detection of CHDs is challenging due to the absence of heart failure signs in most fetuses. Thus, early detection methods and therapeutic drugs to correct abnormal heart development are crucial. We have discovered that the RNA-binding protein Bicaudal-C homolog 1 (Bicc1) influences normal and abnormal heart development. Bicc1 is involved in post-transcriptional regulation and interacts with RNA interference (RNAi) components. While its role in left-right patterning, kidney development, and the interaction with PKD genes ( Pkd1 and Pkd2 ) is documented, the role of Bicc1 and its expression in heart development and whether it relies on interaction with Pkd1/Pkd2 are not understood. Methods and Results: To start addressing these knowledge gaps, we used a transgenic mouse line with an in-frame fusion of Bicc1 and the LacZ reporter gene to perform β-galactosidase staining, RNAscope and immunostaining to identify the cardiac cell types expressing Bicc1 . High Bicc1 expression was observed in embryonic and neonatal hearts, particularly in the ventricles, atria, and endothelial cells of blood vessels. Expression decreased in adulthood but persisted at basal levels. We observed that Bicc1 knockout (KO) developed heterotaxy of the heart and enlarged atria. Next, to elucidate the gene and miRNA regulatory networks involved in cardiac development disrupted by the absence of Bicc1, we carried out RNA- and miRNA-seq on hearts from wild-type and Bicc1 KO embryonic hearts at different developmental stages. Several genes and miRNAs associated with ciliopathy and heterotaxy, including miR-196 , Hand1 , and Lefy2, were significantly altered in Bicc1 KO mice. Moreover, as reported for the kidney, Pkd2 mRNA expression was altered in Bicc1 KO mice, while Pkd1 expression remained unchanged. Finally, we detected changes linked to lipid metabolism and related pathways, such as members of aldehyde dehydrogenase ( Adlh1a ) and cytochrome P450 family ( Cyp5a1 ), that were altered in the absence of Bicc1 . Conclusions: Our study reveals additional role(s) for Bicc1 in heart development suggesting its involvement in regulating heart metabolism in fetuses. These findings provide a conceptual basis for future investigations into the function of Bicc1 in heart development and how its disruption contributes to CHDs.

EXTH-59. ESTABLISHING GAUSSIA LUCIFERASE REPORTER AS A BIOMARKER FOR ESTIMATING THERAPEUTIC RESPONSE AND PROGRESSION-FREE SURVIVAL IN PATIENT-DERIVED XENOGRAFT MODELS OF GLIOBLASTOMA

Abstract Serial monitoring of tumor burden in patient-derived xenograft (PDX) models used for testing new cancer drugs via MRI and other imaging techniques can be costly. We theorized that transducing the Gaussia luciferase (GLuc) reporter gene into glioma PDX models (GliomaPDOX) allows for GLuc to be used as a biomarker for tumor burden. This current study investigates whether changes in the rate of GLuc secretion over time (i.e., “growth rate” changes) can predict survival in GliomaPDOX. Optimal cutoff values to define disease progression via GLuc measurements were established resulting in a strong association between progression-free survival (PFS) and overall survival (OS). The pLenti-CMV-sGluc-T2A-EGFP plasmid was packaged into a second-generation lentiviral system via HEK293FT cells, and the resulting virus transduced into directly-isolated glioma patient cells to establish the MGMT-Unmethylated and MGMT-Methylated GliomaPDOX. MGMT-Unmethylated GliomaPDOX were treated with placebo or Temozolomide (TMZ) until endpoint. MGMT-Methylated GliomaPDOX were treated with placebo or TMZ for three weeks or TMZ for six weeks until endpoint. Treatment response was monitored through GLuc measurements obtained via tail blood collection. The optimal cutoff for time to progression was a 30% increase in GLuc, which yielded a significant positive association between PFS and OS across all models and treatments (R2 = 0.8177, p&amp;lt;0.0001). Compared to the MGMT-Methylated placebo and MGMT-Unmethylated groups, the MGMT-Methylated treatment groups exhibited substantial changes in GLuc growth rates and significantly longer PFS and OS (p&amp;lt;0.0001). More specifically, the six-week MGMT-Methylated TMZ-treated group demonstrated a significant difference in GLuc growth rates and a considerable PFS (p&amp;lt;0.0038) and OS increase (p&amp;lt;0.0049) when compared to the three-week MGMT-Methylated TMZ-treated group. Therefore, GLuc measurement is a valuable biomarker for PDX tumor burden and can be used to estimate treatment response and PFS.

An In Vitro RNA Editing-Based Reporter Assay for Transcriptional Activity of Therapeutic Gene in Gene Therapy Products

The expression of therapeutic genes is critical for the efficacy of gene therapy products. However, existing methods such as immunological analysis at the protein level or reverse-transcription PCR at the RNA level are unable to accurately quantify the expression activity of the target gene. Herein, an in vitro RNA editing-based reporter assay was developed to detect specific mRNA. The designed sensor RNA could specifically identify the target mRNA, and the reporter gene was activated in a dose-dependent manner because of RNA editing mediated by endogenous adenosine deaminases acting on RNA. Of note, all sensors that targeted different regions, including the gene of interest, tag sequence, and 3′ untranslated region, showed a dose-dependent response pattern. The sensor reporter assay, which was used for quantifying the transcriptional activity of recombinant adeno-associated virus-based gene therapy products, revealed excellent performance in terms of assay specificity, precision (inter-assay relative standard deviation &lt; 15%), accuracy (90–115% recovery), and linearity (R2 &gt; 0.99). The reporter assay could also be employed for other gene therapy vectors, including mRNA and recombinant lentivirus. Thus, a robust and reliable platform was developed for assessing the transcriptional activity of therapeutic genes, thereby offering a powerful tool for the quality control of gene therapy products.

Establishing a dominant early larval sex-selection strain in the Asian malaria vector Anopheles stephensi

BackgroundGenetic biocontrol interventions targeting mosquito-borne diseases require the release of male mosquitoes exclusively, as only females consume blood and transmit pathogens. Releasing only males eliminates the risk of increasing mosquito bites and spreading pathogens while enabling effective population control. The aim of this study is to develop robust sex-sorting methods for early larval stages in mosquitoes, enabling scalable male-only releases for genetic biocontrol interventions.MethodsTo address the challenge of sex-sorting in the Asian malaria vector Anopheles stephensi, we engineer Sexing Element Produced by Alternative RNA-splicing of a Transgenic Observable Reporter (SEPARATOR). This dominant fluorescent-based method, previously proven effective in Aedes aegypti, exploits sex-specific alternative splicing of a reporter to ensure exclusive male-specific expression early in development. The sex-specific alternative RNA splicing of the doublesex gene was selected as a target for engineering SEPARATOR due to its evolutionary conservation in insects. To expand SEPARATOR’s applicability for genetic sexing, we assessed the cross-species sex-specific RNA splicing activity of the An. gambiae doublesex (AngDsx) splicing module in An. stephensi. Male-specific enhanced green fluorescent protein (EGFP) expression was verified throughout the mosquito life cycle using a fluorescent stereomicroscope.ResultsOur results confirm that SEPARATOR regulates male-specific EGFP expression in An. stephensi and enables reliable positive male selection from the first instar larval stages. Molecular analysis demonstrates that male-specific EGFP expression is dependent on doublesex sex-specific splicing events. Additionally, the splicing module from An. gambiae operates effectively in An. stephensi, demonstrating evolutionary conservation in sex-specific splicing events between these species.ConclusionsSEPARATOR’s independence from sex-chromosome linkage provides resistance to breakage that could be mediated by meiotic recombination and chromosomal rearrangements, making it highly suitable for mass male releases. By enabling precise male selection from the first instar larval stages, SEPARATOR represents a significant advancement that will aid in the genetic biocontrol for Anopheles mosquitoes.Graphical