Multifunctional TPP-PEG-biotin self-assembled nanoparticle drug delivery-based combination therapeutic approach for co-targeting of GRP78 and lysosome

Abstract Background In this study, a multifunctional tetraphenylporphyrin (TPP) conjugated polyethylene glycol with biotin (TPP-PEG-biotin) as a photo-dynamic therapy (PDT) material encapsulating a ruthenium complex 1 (Ru-1) was fabricated as self-assembled nanoparticle (Ru-1@TPP-PEG-biotin SAN) to co-target glucose-regulated protein 78 (GRP78) and the lysosome as a new anti-cancer therapeutic strategy. Results The MTT assay results reveals the enhanced anticancer activity of the Ru-1@TPP-PEG-biotin SANs due to the co-targeting of the GRP78 and lysosome. The Ru-1@TPP-PEG-biotin reduced level of GRP78 and lysosomal ceramide that contributed to the stability of the lysosomal membrane. The endoplasmic reticulum (ER) stress concomitant with the inhibition of GRP78 was clearly monitored by the phosphorylation of protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK), and inositol-requiring enzyme 1 α (IRE1α) kinases to indicate the activation of the unfolded protein response (UPR) signaling using immunofluorescence assay. On the other hand, the degradation of the lysosome was observed through PDT action by the Ru-1@TPP-PEG-biotin SAN treatment. This was confirmed by the co-localization assay showing the disappearance of cathepsin D and lysosomal-associated membrane protein 1 (LAMP1) in the lysosome. Conclusions Considering lysosome-mediated autophagy is an effective cancer cell survival mechanism, the degradation of the lysosome along with GRP78 inhibition by the Ru-1@TPP-PEG-biotin SAN combination therapy is suggested as a new co-targeting cancer treatment

A Novel TLR4-Mediated Signaling Pathway Leading to IL-6 Responses in Human Bladder Epithelial Cells

The vigorous cytokine response of immune cells to Gram-negative bacteria is primarily mediated by a recognition molecule, Toll-like receptor 4 (TLR4), which recognizes lipopolysaccharide (LPS) and initiates a series of intracellular NF-κB–associated signaling events. Recently, bladder epithelial cells (BECs) were reported to express TLR4 and to evoke a vigorous cytokine response upon exposure to LPS. We examined intracellular signaling events in human BECs leading to the production of IL-6, a major urinary cytokine, following activation by Escherichia coli and isolated LPS. We observed that in addition to the classical NF-κB–associated pathway, TLR4 triggers a distinct and more rapid signaling response involving, sequentially, Ca(2+), adenylyl cyclase 3–generated cAMP, and a transcriptional factor, cAMP response element–binding protein. This capacity of BECs to mobilize secondary messengers and evoke a more rapid IL-6 response might be critical in their role as first responders to microbial challenge in the urinary tract

Host Adaptation of a Bacterial Toxin from the Human Pathogen Salmonella Typhi

SummarySalmonella Typhi is an exclusive human pathogen that causes typhoid fever. Typhoid toxin is a S. Typhi virulence factor that can reproduce most of the typhoid fever symptoms in experimental animals. Toxicity depends on toxin binding to terminally sialylated glycans on surface glycoproteins. Human glycans are unusual because of the lack of CMAH, which in other mammals converts N-acetylneuraminic acid (Neu5Ac) to N-glycolylneuraminic acid (Neu5Gc). Here, we report that typhoid toxin binds to and is toxic toward cells expressing glycans terminated in Neu5Ac (expressed by humans) over glycans terminated in Neu5Gc (expressed by other mammals). Mice constitutively expressing CMAH thus displaying Neu5Gc in all tissues are resistant to typhoid toxin. The atomic structure of typhoid toxin bound to Neu5Ac reveals the structural bases for its binding specificity. These findings provide insight into the molecular bases for Salmonella Typhi’s host specificity and may help the development of therapies for typhoid fever

GSK-3β inhibition by curcumin mitigates amyloidogenesis via TFEB activation and anti-oxidative activity in human neuroblastoma cells

© 2020 Informa UK Limited, trading as Taylor & Francis Group.The translocation of transcription factor EB (TFEB) to the nucleus plays a pivotal role in the regulation of basic cellular processes, such as lysosome biogenesis and autophagy. Autophagy is an intracellular degradation system that delivers cytoplasmic constituents to the lysosome, which is important in maintaining cellular homeostasis during environmental stress. Furthermore, oxidative stress is a critical cause for the progression of neurodegenerative diseases. Curcumin has anti-oxidative and anti-inflammatory activities, and is expected to have potential therapeutic effects in various diseases. In this study, we demonstrated that curcumin regulated TFEB export signalling via inhibition of glycogen synthase kinase-3β (GSK-3β); GSK-3β was inactivated by curcumin, leading to reduced phosphorylation of TFEB. We further showed that H2O2-induced oxidative stress was reduced by curcumin via the Nrf2/HO-1 pathway in human neuroblastoma cells. In addition, we showed that curcumin induced the degradation of amyloidogenic proteins, including amyloid-β precursor protein and α-synuclein, through the TFEB-autophagy/lysosomal pathway. In conclusion, curcumin regulates autophagy by controlling TFEB through the inhibition of GSK-3β, and increases antioxidant gene expression in human neuroblastoma cells. These results contribute to the development of novel cellular therapies for neurodegenerative diseases.

CO ameliorates cellular senescence and aging by modulating the miR-34a/Sirt1 pathway

Oxidative stress is recognised as a key factor that can lead to cellular senescence and aging. Carbon monoxide (CO) is produced by haemoxygenase-1 (HO-1), which exerts cytoprotective effects in aging-related diseases, whereas the effect of CO on cellular senescence and aging has not been elucidated. In the current study, we clearly demonstrated that CO delays the process of cellular senescence and aging through regulation of miR-34a and Sirt1 expression. CO reduced H2O2-induced premature senescence in human diploid fibroblast WI-38 cells measured with SA-beta-Gal-staining. Furthermore, CO significantly decreased the expression of senescence-associated secretory phenotype (SASP), including TNF-alpha IL-6, and PAI-1 and increased the transcriptional levels of antioxidant genes, such as HO-1 and NQO1. Moreover, CO apparently enhanced the expression of Sirt1 through down-regulation of miR-34a. Next, to determine whether Sirt1 mediates the inhibitory effect of CO on cellular senescence, we pre-treated WI-38 cells with the Sirt1 inhibitor Ex527 and a miR-34a mimic followed by the administration of H2O2 and evaluated the expression of SASP and antioxidant genes as well as ROS production. According to our results, Sirt1 is crucial for the antiaging and antioxidant effects of CO. Finally, CO prolonged the lifespan of Caenorhabditis elegans and delayed high-fat diet-induced liver aging. Taken together, these findings demonstrate that CO reduces cellular senescence and liver aging through the regulation of miR-34a and Sirt1.

Porphyra tenera Extracts Have Immune Stimulation Activity via Increasing Cytokines in Mouse Primary Splenocytes and RAW264.7 Macrophages

Abstract Porphyra tenera has long been consumed as food in Korea and Asia. The effects of Porphyra tenera extracts on the immune system are largely unknown. Therefore, this study investigated the immune-stimulating effects of ethanol and water extracts of P. tenera. The immunomodulatory potential of P. tenera was evaluated by determining its effect on cell viability and cytokine expression of mouse RAW264.7 cells and splenocytes. We investigated the effect of 10% ethanol extracts of laver (P. tenera) on the RAW264.7 cells. Production of nitric oxide (NO) and cytokines (interleukin [IL]-1β, IL-2, and IL-4, inducible NO synthase, and interferon-γ) in RAW264.7 macrophages was slightly higher after treatment with P. tenera extracts. Ethanol extracts upregulated and enhanced the functions of macrophages, such as NO and cytokines (IL-1β, IL-2, and IL-4, inducible NO synthase, and interferon-γ) production. In addition, cytokine concentrations were significantly increased in cells treated with different doses of P. tenera ethanol extracts compared to the control group. Overall, the results demonstrated that P. tenera extracts enhanced cytokine secretion in mouse splenocytes and macrophages. From these findings, it can be concluded that P. tenera possess a natural compound with immune-stimulatory activity. P. tenera extract is a good immunostimulant from natural compounds

A mouse model for the human pathogen Salmonella typhi

Salmonella enterica serovar Typhi (S. Typhi) causes typhoid fever, a life-threatening human disease. The lack of animal models due to S. Typhi's strict human host specificity has hindered its study and vaccine development. We find that immunodeficient Rag2(-/-) γc(-/-) mice engrafted with human fetal liver hematopoietic stem and progenitor cells are able to support S. Typhi replication and persistent infection. A S. Typhi mutant in a gene required for virulence in humans was unable to replicate in these mice. Another mutant unable to produce typhoid toxin exhibited increased replication, suggesting a role for this toxin in the establishment of persistent infection. Furthermore, infected animals mounted human innate and adaptive immune responses to S. Typhi, resulting in the production of cytokines and pathogen-specific antibodies. We expect that this mouse model will be a useful resource for understanding S. Typhi pathogenesis and for evaluating potential vaccine candidates against typhoid fever

Physical activity and reduced risk of fracture in thyroid cancer patients after thyroidectomy — a nationwide cohort study

ObjectivesLevothyroxine suppressive therapy following thyroidectomy for thyroid cancer patients is considered as a risk factor for osteoporosis and fragility fractures. We evaluated the association of regular exercise and exercise habit change with fracture risk in adults older than 40 years who underwent thyroidectomy for thyroid cancer.MethodsWe enrolled the patients who underwent thyroidectomy for thyroid cancer older than 40 years between 2010 and 2016 from the Korean National Health Insurance Service data, and they were followed through 2019. Based on the questionnaire of health examination within 2 years before and after surgery, whether regular exercise once a week was evaluated. The reference group for the statistical analysis was the continuing lack of physical activity group that did not exercise before or after surgery. For fractures newly diagnosed during the follow-up period, univariate and multivariate Cox regression analyses were performed for risk evaluation.ResultsWe evaluated 74,774 subjects, of whom 2,924 (3.9%) experienced any fractures during a median follow-up of 4.5 years. Compared with the group consistently lack of physical activity, the group that exercised before and after surgery showed a significant decrease in the risk of any fracture, vertebral fracture, and hip fracture: adjusted hazard ratio 0.848 (95% Confidence Interval 0.771–0.932), 0.703 (0.591–0.836), and 0.405 (0.224–0.732), respectively. For vertebral fracture, a significant reduction in fracture risk was confirmed even in patients who started their regular exercise after surgery: adjusted hazard ratio 0.779 (0.648–0.936). The risk reduction for vertebral fractures upon the initiation of exercise was found to be significant in the high-risk groups of patients: women and total thyroidectomy patients.ConclusionWe suggest that maintaining or starting regular exercise after surgery may help prevent fractures in thyroid cancer patients older than 40 years who have undergone thyroidectomy

Carbon Nanotubes Based 3-D Matrix for Enabling Three-Dimensional Nano-Magneto-Electronics

This letter describes the use of vertically aligned carbon nanotubes (CNT)-based arrays with estimated 2-nm thick cobalt (Co) nanoparticles deposited inside individual tubes to unravel the possibility of using the unique templates for ultra-high-density low-energy 3-D nano-magneto-electronic devices. The presence of oriented 2-nm thick Co layers within individual nanotubes in the CNT-based 3-D matrix is confirmed through VSM measurements as well as an energy-dispersive X-ray spectroscopy (EDS)

황금 뿌리 메탄올 추출물의 경구투여에 의한 옥사졸론 유도 아토피 피부염 마우스에의 효과 연구

학위논문 (석사)-- 서울대학교 대학원 : 식품영양학과, 2012. 2. 지근억.Atopic dermatitis (AD) is a relapsing skin disease associated with chronic inflammation and its prevalence has been increased especially in industrialized countries. Recently, several studies have reported that oral administration of herbal extracts has preventive or therapeutic effects on AD. We investigated the effects of several food materials on oxazolone-induced AD murine model. Among them, Scutellaria baicalensis root extract showed lower total IgE level in serum in the preliminary studies. Scutellaria baicalensis is a widely used traditional herbal medicine in China and Korea. The root of Scutellaria baicalensis contains flavonoids and exhibits various beneficial bioactivities such as anti-inflammatory and anti-allergic effects. Therefore, we evaluated the effect of oral administration of methanolic extract from Scutellaria baicalensis root (SB) on the development of atopic dermatitis-like skin lesions in hairless mice induced by discontinuous oxazolone application. Mice were orally administered SB 250, 500 mg/kg b.w. per day, or dexamethasone 1 mg/kg b.w. per day for 33 days. Oral administration of SB inhibited the development of clinical symptoms, and reduced dermal mast cell infiltration. However, SB administration did not show definite suppressive effect on the elevation of serum total IgE level in the experimental condition. Furthermore, IL-6 level in serum and the mRNA expressions of IL-4, IL-13, IL-12, IFN-γ, TGF-β, and Foxp3 in draining lymph nodes were not significantly affected by SB administration. In conclusion, SB may alleviate atopic dermatitis via the inhibition of mast cell infiltration.Maste