Effects of the Extracts from Fruit and Stem of Camellia japonica on Induced Pluripotency and Wound Healing

Development of pluripotent stem cell-derived epidermal organoids that generate effective extracellular vesicles in skin regeneration

Cellular skin substitutes such as epidermal constructs have been developed for various applications, including wound healing and skin regeneration. These cellular models are mostly derived from primary cells such as keratinocytes and fibroblasts in a two-dimensional (2D) state, and further development of three-dimensional (3D) cultured organoids is needed to provide insight into the in vivo epidermal phenotype and physiology. Here, we report the development of epidermal organoids (EpiOs) generated from induced pluripotent stem cells (iPSCs) as a novel epidermal construct and its application as a source of secreted biomolecules recovered by extracellular vesicles (EVs) that can be utilized for cell-free therapy of regenerative medicine. Differentiated iPSC-derived epidermal organoids (iEpiOs) are easily cultured and expanded through multiple organoid passages, while retaining molecular and functional features similar to in vivo epidermis. These mature iEpiOs contain epidermal stem cell populations and retain the ability to further differentiate into other skin compartment lineages, such as hair follicle stem cells. By closely recapitulating the epidermal structure, iEpiOs are expected to provide a more relevant microenvironment to influence cellular processes and therapeutic response. Indeed, iEpiOs can generate high-performance EVs containing high levels of the angiogenic growth factor VEGF and miRNAs predicted to regulate cellular processes such as proliferation, migration, differentiation, and angiogenesis. These EVs contribute to target cell proliferation, migration, and angiogenesis, providing a promising therapeutic tool for in vivo wound healing. Overall, the newly developed iEpiOs strategy as an organoid-based approach provides a powerful model for studying basic and translational skin research and may also lead to future therapeutic applications using iEpiOs-secreted EVs.

Txnip regulates the Oct4-mediated pluripotency circuitry via metabolic changes upon differentiation

Thioredoxin interacting protein (Txnip) is a stress-responsive factor regulating Trx1 for redox balance and involved in diverse cellular processes including proliferation, differentiation, apoptosis, inflammation, and metabolism. However, the biological role of Txnip function in stem cell pluripotency has yet to be investigated. Here, we reveal the novel functions of mouse Txnip in cellular reprogramming and differentiation onset by involving in glucose-mediated histone acetylation and the regulation of Oct4, which is a fundamental component of the molecular circuitry underlying pluripotency. During reprogramming or PSC differentiation process, cellular metabolic and chromatin remodeling occur in order to change its cellular fate. Txnip knockout promotes induced pluripotency but hinders initial differentiation by activating pluripotency factors and promoting glycolysis. This alteration affects the intracellular levels of acetyl-coA, a final product of enhanced glycolysis, resulting in sustained histone acetylation on active PSC gene regions. Moreover, Txnip directly interacts with Oct4, thereby repressing its activity and consequently deregulating Oct4 target gene transcriptions. Our work suggests that control of Txnip expression is crucial for cell fate transitions by modulating the entry and exit of pluripotency.

Zymolytic grain extract facilitates the conversion of liver tumor cells to hepatocyte-like cells through hepatocyte nuclear factors

At present, malignant tumors are an urgent global threat to human health. Conversion of cancer cells to normal-like or normal cells will open new therapeutic avenues for eradicating cancer. It has been reported that compounds extracted from grains display biological activities, such as antioxidant, antiviral and antitumor activities. In this study, we identified clear changes in a liver tumor cell line (HepG2) after stimulation with zymolytic grain extract (ZGE) supernatants. The expression levels of hepatocyte nuclear factor 1A (HNF1A), hepatocyte nuclear factor 4A (HNF4A) and forkhead box protein A3 (FOXA3) were significantly increased. Eukaryotic transcriptome analyses revealed that trends in the transcriptional changes for genes were similar in HepG2 cells stimulated with ZGE (zHeps) and the normal hepatocyte cell line L02. Changes in the expression levels of genes involved in drug transport, metabolism and the malignant characteristics of cancer cells in nude mice further indicated that ZGE regulated the expression of HNF1A, HNF4A and FOXA3, which altered the expression of a series of hepatocyte-specific genes. It was also confirmed that zHeps acquired some of the characteristics of hepatocyte-like cells. Our results not only provide new ideas for the treatment of liver tumors but also lay a solid foundation for the application of combination therapy.

Process Optimization Based on Biological Effects and Biomarker Contents of Camellia japonica L. for the Development of Anti-Hyperuricemic and Anti-Wrinkle Source

The purpose of this study was to simultaneously develop anti-hyperuricemic and anti-wrinkle source using Camellia japonica leaf (CJ). CJ extract was prepared. Its contents of biomarkers and biological activities were then analyzed. First, we investigated the extraction efficiency. The extraction rate was 10% or less with hot water or 80% ethanol. HPLC analysis revealed that CJ extract contained rutin, hyperoside, isoquercitrin, chlorogenic acid (CGA), gallocatechin gallate (GCG), and phillygenin. As a result of measuring contents of biomarkers in the extract, CGA was detected in 20, 40, and 60% ethanol extracts. GCG showed the highest content in the hot water extract. Hyperoside and isoquercitrin showed the highest contents in the 80% ethanol extract. Philligenin showed an even content of 0.1% or more in all samples except for 40% ethanol extract. Rutin showed the highest content in 80% ethanol extract. Elastase inhibitory abilities of six extracts and PPRM were investigated at a concentration of 0.5 mg/mL. Results revealed that PPRM and 80% ethanol extract showed about 80% and 62% inhibition, respectively. As a result of comparing elastase inhibitory activities of biomarkers, hyperoside, isoquercitrin, and philligenin showed higher activities. Among six extracts, the extract that could be used as an anti-hyperuricemic source was 80% ethanol extract. When xanthine oxidase (XO) inhibitory activities of biomarkers were evaluated, rutin and hyperoside showed excellent activities. In particular, when XO activity was measured by mixing rutin and hyperoside with 80% ethanol extract, the same efficacy as 80% ethanol extract was obtained. It was predicted that 80% ethanol extract could be used simultaneously as an anti-hyperuricemic and anti-wrinkle source. Further studies are needed to determine anti-hyperuricemic activities of rutin and hyeproside in vivo.

Camellia japonica: A phytochemical perspective and current applications facing its industrial exploitation

In response to the increased popularity of medicinal plants, a number of conservation groups are recommending the investigation on poorly characterized and widely distributed species, as it is the case of camellias. In particular, Camellia japonica L. is a widespread species found in Galicia (NW Spain), where it has been largely exploited with ornamental purposes. Recent findings on its phytochemical characterization showed thousands of bioactive ingredients, mostly represented by phenolic compounds, together with terpenoids, and fatty acids. These molecules present associated biological activities, acting as antioxidant, antimicrobial, anti-inflammatory, and anticancer agents. This review is aimed at describing the main bioactive compounds of C. japonica, as well as the health-enhancing properties attributed to this medicinal plant. Novel strategies are needed to implement an efficient industrialization process for C. japonica, ranging from small-scale approaches to the establishment of large plantations, thus involving important sectors, such as the food, pharmaceutical and cosmetic industries.

Inhibition of O-GlcNAcylation protects from Shiga toxin-mediated cell injury and lethality in host

Shiga toxins (Stxs) produced by enterohemorrhagic Escherichia coli (EHEC) are the major virulence factors responsible for hemorrhagic colitis, which can lead to life-threatening systemic complications including acute renal failure (hemolytic uremic syndrome) and neuropathy. Here, we report that O-GlcNAcylation, a type of post-translational modification, was acutely increased upon induction of endoplasmic reticulum (ER) stress in host cells by Stxs. Suppression of the abnormal Stx-mediated increase in O-GlcNAcylation effectively inhibited apoptotic and inflammatory responses in Stx-susceptible cells. The protective effect of O-GlcNAc inhibition for Stx-mediated pathogenic responses was also verified using three-dimensional (3D)-cultured spheroids or organoids mimicking the human kidney. Treatment with an O-GlcNAcylation inhibitor remarkably improved the major disease symptoms and survival rate for mice intraperitoneally injected with a lethal dose of Stx. In conclusion, this study elucidates O-GlcNAcylation-dependent pathogenic mechanisms of Stxs and demonstrates that inhibition of aberrant O-GlcNAcylation is a potential approach to treat Stx-mediated diseases.

Anticancer properties of dried-pericarp water extracts of Camellia japonica L. fermented with Aspergillus oryzae through regulation of IGFBP-2/mTOR pathway

This study aimed to investigate the anticancer activity of dried-pericarp water extract of fermented C. japonicus (CJ). The dried-pericarp water extracts of CJ were fermented using Aspergillus oryzae and Saccharomyces cerevisiae at 30 °C and 35 °C. The anticancer activities of both water extracts fermented at 30 °C and 35 °C using A. oryzae against FaDu cells were remarkably changed compared with unfermented dried-pericarp water extract of CJ, which has no anticancer activity. Cleaved-PARP, caspase 3, and apoptotic cells stained with annexin V/PI were significantly increased by treatment with A. oryzae extracts fermented at 30 °C. The insulin-like growth factor-binding protein 2 (IGFBP-2) protein level and mTOR phosphorylation by A. oryzae fermented extracts (AOFE) were dramatically reduced, and the expression levels of IGFBP-2 and phosphorylated mTOR were significantly increased depending on the glucose concentrations in FaDu cells. These results suggested that the cell viabilities in AOFE were restored as the glucose concentrations increased. Furthermore, it was confirmed LC/MS/MS that the content of gallic acid was increased by fermentation of Aspergillus oryzae (5.596 ± 0.1746 μg/mg) compared to the unfermented extract (1.620 ± 0.0432 μg/mg). Based on these results, the anticancer effect of AOFE was achieved through inhibition of the IGFBP-2/mTOR signaling pathway. These results suggest that AOFE may be a potential treatment for head and neck cancer.

Altered Gene Expression Profiles in Neural Stem Cells Derived from Duchenne Muscular Dystrophy Patients with Intellectual Disability

Intellectual disability (ID) is a neurodevelopmental disorder defined by below-average intelligence (intelligence quotient of <70) accompanied by adaptive behavior deficits. Defects in the functions of neural stem cells during brain development are closely linked to the pathogenesis of ID. To understand the molecular etiology of ID, we examined neural stem cells from individuals with Duchenne muscular dystrophy (DMD), a genetic disorder in which approximately one-third of the patients exhibit ID. In this study, we generated induced pluripotent stem cells from peripheral blood mononuclear cells from a normal individual and DMD patients with and without ID to identify ID-specific functional and molecular abnormalities. We found defects in neural ectoderm formation in the group of DMD patients with ID. Our transcriptome analysis of patient-derived neural stem cells revealed altered expression of genes related to the hippo signaling pathway and neuroactive ligand-receptor interaction, implicating these in the pathogenesis of ID in patients with DMD.

A Review on the Biological Activity of Camellia Species

Medicinal plants have been used since antiquity to cure illnesses and injuries. In the last few decades, natural compounds extracted from plants have garnered the attention of scientists and the Camellia species are no exception. Several species and cultivars are widespread in Asia, namely in China, Japan, Vietnam and India, being also identified in western countries like Portugal. Tea and oil are the most valuable and appreciated Camellia subproducts extracted from Camellia sinensis and Camellia oleifera, respectively. The economic impact of these species has boosted the search for additional information about the Camellia genus. Many studies can be found in the literature reporting the health benefits of several Camellia species, namely C. sinensis, C. oleifera and Camellia japonica. These species have been highlighted as possessing antimicrobial (antibacterial, antifungal, antiviral) and antitumoral activity and as being a huge source of polyphenols such as the catechins. Particularly, epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and specially epigallocatechin-3-gallate (EGCG), the major polyphenols of green tea. This paper presents a detailed review of Camellia species’ antioxidant properties and biological activity.

Therapeutic efficacy of catalpol against apoptosis in cardiomyocytes derived from human induced pluripotent stem cells

Cardiac arrhythmia is an irregular heart rhythm that can lead to serious heart conditions and various organ disorders, and may cause sudden cardiac death. Catalpol belongs to the iridoid glycoside family and is highly abundant in Rehmannia glutinosa Libosch. The study included five groups such as group I (normal control), group II (treatment control), group III (low-dose treatment), group IV (medium-dose treatment) and group V (high-dose treatment). We investigated the therapeutic effects of catalpol on cardiac arrhythmia in human-induced pluripotent stem cells (iPSCs). Cell viability, lactate dehydrogenase (LDH) levels, lipid peroxidation, antioxidant activity, and caspase-3 and caspase-9 activities and protein levels were measured in normal control, treatment control, and treated (1, 10, and 100 µM) iPSC groups. Compared with the treatment control group, catalpol supplementation (1, 10, and 100 µM) increased iPSC cell viability by 7.5, 27.3, and 65.8%, respectively; reduced the LDH levels by 10.4, 31.3, and 75.2%, respectively; and reduced the lipid peroxidation levels by 7.7, 33.0, and 62.6%, respectively. The antioxidant levels were significantly higher in the treatment control group than in the normal control group. Catalpol (100 µM) reduced the caspase-3 and caspase-9 activities by more than 30% and increased expression of the corresponding proteins by more than 50%. These findings suggest that the naturally occurring iridoid glycoside catalpol is effective against aconitine-induced cardiac arrhythmia in iPSCs.

Protein Kinases and Their Inhibitors in Pluripotent Stem Cell Fate Regulation

Protein kinases modulate the reversible postmodifications of substrate proteins to their phosphorylated forms as an essential process in regulating intracellular signaling transduction cascades. Moreover, phosphorylation has recently been shown to tightly control the regulatory network of kinases responsible for the induction and maintenance of pluripotency, defined as the particular ability to differentiate pluripotent stem cells (PSCs) into every cell type in the adult body. In particular, emerging evidence indicates that the balance between the self-renewal and differentiation of PSCs is regulated by the small molecules that modulate kinase signaling pathways. Furthermore, new reprogramming technologies have been developed using kinase modulators, which have provided novel insight of the mechanisms underlying the kinase regulatory networks involved in the generation of induced pluripotent stem cells (iPSCs). In this review, we highlight the recent progress made in defining the roles of protein kinase signaling pathways and their small molecule modulators in regulating the pluripotent states, self-renewal, reprogramming process, and lineage differentiation of PSCs.