Producing highly effective extracellular vesicles using IBAR and talin F3 domain fusion.

Extracellular vesicles (EVs), transporting diverse cellular components, play a crucial role in intercellular communication in numerous physiological and pathological processes. EVs have also been recognized as a drug delivery platform for therapeutic purposes and cell-free regenerative medicine. While various approaches have focused on increasing EV production for efficient use therapeutic use of EVs, enhancing the quality of EVs, such as ensuring efficient uptake by their target cells, has not been widely explored. In this study, we linked a negative membrane curvature-forming inverse BAR (IBAR) domain with an integrin ß tail-binding talin F3 domain to create the IBAR-F3 fusion protein. We observed that IBAR-F3 can trigger filopodia-like membrane protrusions and attract integrins to those protrusion-rich regions, when expressed in Chinese hamster ovary cells expressing integrin αIIbß3. Surprisingly, the expression of IBAR-F3 also induced a robust production of EVs, which were then efficiently taken up by nearby cells in an integrin-dependent manner. Moreover, IBAR triggered integrin activation, presumably by inducing negative membrane curvature that likely disrupts the interaction between the integrin α and ß transmembrane domain. Therefore, we suggest that IBAR-F3 should be utilized to promote both EV production and efficient uptake mediated by integrins. Furthermore, the negative curvature-inducing integrin activation suggests that integrins on EVs can be activated by the nanoscale change in the curvature of the EV without the need for conventional machinery to activate integrin inside the EVs.

Recognition of atomic-level difference in porphyrin dyads for self-sorted supramolecular polymer growth.

Porphyrin dyads (PDMs, where M = Zn and Cu) composed of diphenylporphyrin and tetraphenylporphyrin units, designated as DPDMs and TPDMs, respectively, exhibited remarkable differences in the molecular assemblies depending on the coordination metal ion. Furthermore, TPDMs showed self-sorting behavior during the formation of supramolecular assemblies through the recognition of atomic-level difference.

AHR rs4410790 genotype and IgG levels: Effect modification by lifestyle factors.

Inflammation is a multifaceted marker resulting from complex interactions between genetic and lifestyle factors. Emerging evidence suggests Aryl hydrocarbon receptor (AHR) protein may be implicated in the regulation of immune system and inflammatory responses. To investigate whether rs4410790 genotype (TT, TC, CC) near AHR gene is related to serum IgG levels, a marker of chronic inflammation, and whether lifestyle factors modifies the relationship, we conducted a cross-sectional study by recruiting 168 Korean adults. Participants responded to a lifestyle questionnaire and provided oral epithelial cells and blood samples for biomarker assessment. Among these participants, C allele was the minor allele, with the minor allele frequency of 40%. The rs4410790 TT genotype was significantly associated with elevated IgG levels compared with TC/CC genotypes, after adjusting for potential confounders (p = 0.04). The relationship varied significantly by levels of alcohol consumption (P interaction = 0.046) and overweight/obese status (P interaction = 0.02), but not by smoking status (P interaction = 0.64) and coffee consumption (P interaction = 0.55). Specifically, higher IgG levels associated with the TT genotype were evident in frequent drinkers and individuals with BMI≥23kg/m2, but not in their counterparts. Thus, rs4410790 genotype may be associated with IgG levels and the genetic predisposition to higher IgG levels may be mitigated by healthy lifestyle factors like infrequent drinking and healthy weight.

Durability and strength degradation of xanthan gum based biopolymer treated soil subjected to severe weathering cycles.

Biopolymer-based soil treatments have shown effectiveness in soil improvement, with successful field-scale implementation. In this study, we explored the effect of cyclic wetting-drying (W-D) and freezing-thawing (F-T) on the strength durability of biopolymer-treated soils. The results indicate that cyclic W-D and F-T gradually degrade soil strength owing to water adsorption and local biopolymer dilution. Poorly graded sand was highly vulnerable to these weathering effects; however, this problem was mitigated when the soil contained a fines content of 15-25%. These biopolymer-treated soils effectively resisted numerous cycles of both W-D and F-T, indicating that biopolymer-treated soils are suitable for earthen slope reinforcement.

Systematic and mechanistic analysis of AuNP-induced nanotoxicity for risk assessment of nanomedicine.

For decades, nanoparticles (NPs) have been widely implemented in various biomedical fields due to their unique optical, thermal, and tunable properties. Particularly, gold nanoparticles (AuNPs) have opened new frontiers in sensing, targeted drug delivery, imaging, and photodynamic therapy, showing promising results for the treatment of various intractable diseases that affect quality of life and longevity. Despite the tremendous achievements of AuNPs-based approaches in biomedical applications, few AuNP-based nanomedicines have been evaluated in clinical trials, which is likely due to a shortage of understanding of the biological and pathological effects of AuNPs. The biological fate of AuNPs is tightly related to a variety of physicochemical parameters including size, shape, chemical structure of ligands, charge, and protein corona, and therefore evaluating the effects of these parameters on specific biological interactions is a major ongoing challenge. Therefore, this review focuses on ongoing nanotoxicology studies that aim to characterize the effect of various AuNP characteristics on AuNP-induced toxicity. Specifically, we focus on understanding how each parameter alters the specific biological interactions of AuNPs via mechanistic analysis of nano-bio interactions. We also discuss different cellular functions affected by AuNP treatment (e.g., cell motility, ROS generation, interaction with DNA, and immune response) to understand their potential human health risks. The information discussed herein could contribute to the safe usage of nanomedicine by providing a basis for appropriate risk assessment and for the development of nano-QSAR models.

TM4SF5-mediated liver malignancy involves NK cell exhaustion-like phenotypes.

Aberrant extracellular matrix and immune cell alterations within the tumor microenvironment promote the pathological progression of liver carcinogenesis. Although transmembrane 4 L six family member 5 (TM4SF5) is involved in liver fibrosis and cancer, its mechanism avoiding immune surveillance during carcinogenesis remains unknown. We investigated how TM4SF5-mediated signaling caused immune evasion using in vitro primary cells and in vivo liver tissues from genetic or chemically induced mouse models. TM4SF5-transgenic and diethylnitrosamine (DEN)-induced liver cancer mouse models exhibited fibrotic and cancerous livers, respectively, with enhanced TM4SF5, pY705STAT3, collagen I, and laminin γ2 levels. These TM4SF5-mediated effects were abolished by TM4SF5 inhibitor, 4'-(p-toluenesulfonylamido)-4-hydroxychalcone (TSAHC). TM4SF5-dependent tumorigenesis involved natural killer (NK) cell exhaustion-like phenotypes including the reduction of NK cell number or function, which were blocked with TSAHC treatment. TM4SF5 expression in cancer cells downregulated stimulatory ligands and receptors for NK cell cytotoxicity, including SLAMF6, SLAMF7, MICA/B, and others. TM4SF5 suppression or inhibition reduced STAT3 signaling activity and recovered the receptor levels and NK cell surveillance, leading to reduced fibrotic and cancerous phenotypes, and longer survival. Altogether, these findings suggest that TM4SF5-mediated STAT3 activity for extracellular matrix modulation is involved in the progression of liver disease to HCC and that TM4SF5 appears to suppress NK cells during liver carcinogenesis.

Genetically Encoded Sensor Cells for the Screening of Glucocorticoid Receptor (GR) Effectors in Herbal Extracts.

Although in vitro sensors provide facile low-cost ways to screen for biologically active targets, their results may not accurately represent the molecular interactions in biological systems. Cell-based sensors have emerged as promising platforms to screen targets in biologically relevant environments. However, there are few examples where cell-based sensors have been practically applied for drug screening. Here, we used engineered cortisol-detecting sensor cells to screen for natural mimetics of cortisol. The sensor cells were designed to report the presence of a target through signal peptide activation and subsequent fluorescence signal translocation. The developed sensor cells were able to detect known biological targets from human-derived analytes as well as natural product extracts, such as deer antlers and ginseng. The multi-use capability and versatility to screen in different cellular environments were also demonstrated. The sensor cells were used to identify novel GR effectors from medicinal plant extracts. Our results suggest that decursin from dongquai had the GR effector function as a selective GR agonist (SEGRA), making it a potent drug candidate with anti-inflammatory activity. We demonstrated the superiority of cell-based sensing technology over in vitro screening, proving its potential for practical drug screening applications that leads to the function-based discovery of target molecules.

Rapid Screening of Glucocorticoid Receptor (GR) Effectors Using Cortisol-Detecting Sensor Cells.

Cortisol, a stress hormone, plays key roles in mediating stress and anti-inflammatory responses. As abnormal cortisol levels can induce various adverse effects, screening cortisol and cortisol analogues is important for monitoring stress levels and for identifying drug candidates. A novel cell-based sensing system was adopted for rapid screening of cortisol and its functional analogues under complex cellular regulation. We used glucocorticoid receptor (GR) fused to a split intein which reconstituted with the counterpart to trigger conditional protein splicing (CPS) in the presence of targets. CPS generates functional signal peptides which promptly translocate the fluorescent cargo. The sensor cells exhibited exceptional performance in discriminating between the functional and structural analogues of cortisol with improved sensitivity. Essential oil extracts with stress relief activity were screened using the sensor cells to identify GR effectors. The sensor cells responded to peppermint oil, and L-limonene and L-menthol were identified as potential GR effectors from the major components of peppermint oil. Further analysis indicated L-limonene as a selective GR agonist (SEGRA) which is a potential anti-inflammatory agent as it attenuates proinflammatory responses without causing notable adverse effects of GR agonists.

Molecular origin of AuNPs-induced cytotoxicity and mechanistic study.

Gold nanoparticles (AuNPs) with diverse physicochemical properties are reported to affect biological systems differently, but the relationship between the physicochemical properties of AuNPs and their biological effects is not clearly understood. Here, we aimed to elucidate the molecular origins of AuNP-induced cytotoxicity and their mechanisms, focusing on the surface charge and structural properties of modified AuNPs. We prepared a library of well-tailored AuNPs exhibiting various functional groups and surface charges. Through this work, we revealed that the direction or the magnitude of surface charge is not an exclusive factor that determines the cytotoxicity of AuNPs. We, instead, suggested that toxic AuNPs share a common structural characteristics of a hydrophobic moiety neighbouring the positive charge, which can induce lytic interaction with plasma membrane. Mechanistic study showed that the toxic AuNPs interfered with the formation of cytoskeletal structure to slow cell migration, inhibited DNA replication and caused DNA damage via oxidative stress to hinder cell proliferation. Gene expression analysis showed that the toxic AuNPs down-regulated genes associated with cell cycle processes. We discovered structural characteristics that define the cytotoxic AuNPs and suggested the mechanisms of their cytotoxicity. These findings will help us to understand and to predict the biological effects of modified AuNPs based on their physicochemical properties.