TASL mediates keratinocyte differentiation by regulating intracellular calcium levels and lysosomal function.

Maintaining epidermal homeostasis relies on a tightly organized process of proliferation and differentiation of keratinocytes. While past studies have primarily focused on calcium regulation in keratinocyte differentiation, recent research has shed light on the crucial role of lysosome dysfunction in this process. TLR adaptor interacting with SLC15A4 on the lysosome (TASL) plays a role in regulating pH within the endo-lysosome. However, the specific role of TASL in keratinocyte differentiation and its potential impact on proliferation remains elusive. In our study, we discovered that TASL deficiency hinders the proliferation and migration of keratinocytes by inducing G1/S cell cycle arrest. Also, TASL deficiency disrupts proper differentiation process in TASL knockout human keratinocyte cell line (HaCaT) by affecting lysosomal function. Additionally, our research into calcium-induced differentiation showed that TASL deficiency affects calcium modulation, which is essential for keratinocyte regulation. These findings unveil a novel role of TASL in the proliferation and differentiation of keratinocytes, providing new insights into the intricate regulatory mechanisms of keratinocyte biology.

Silibinin induces oral cancer cell apoptosis and reactive oxygen species generation by activating the JNK/c-Jun pathway.

Background: Oral cancer is one of the most prevalent malignant tumors worldwide. Silibinin has been reported to exert therapeutic effects in various cancer models. However, its mechanism of action in oral cancer remains unclear. We aimed to examine the molecular processes underlying the effects of silibinin in oral cancer in vitro and in vivo as well as its potential anticancer effects. Next, we investigated the molecular processes underlying both in vitro and in vivo outcomes of silibinin treatment on oral cancer. Methods: To investigate the effects of silibinin on the growth of oral cancer cells, cell proliferation and anchorage-independent colony formation tests were conducted on YD10B and Ca9-22 oral cancer cells. The effects of silibinin on the migration and invasion of oral cancer cells were evaluated using transwell assays. Flow cytometry was used to examine apoptosis, cell cycle distribution, and accumulation of reactive oxygen species (ROS). The molecular mechanism underlying the anticancer effects of silibinin was explored using immunoblotting. The in vivo effects of silibinin were evaluated using a Ca9-22 xenograft mouse model. Results: Silibinin effectively suppressed YD10B and Ca9-22 cell proliferation and colony formation in a dose-dependent manner. Moreover, it induced cell cycle arrest in the G0/G1 phase, apoptosis, and ROS generation in these cells. Furthermore, silibinin inhibited the migration and invasion abilities of YD10B and Ca9-22 cells by regulating the expression of proteins involved in the epithelial-mesenchymal transition. Western blotting revealed that silibinin downregulated SOD1 and SOD2 and triggered the JNK/c-Jun pathway in oral cancer cells. Silibinin significantly inhibited xenograft tumor growth in nude mice, with no obvious toxicity. Conclusions: Silibinin considerably reduced the development of oral cancer cells by inducing apoptosis, G0/G1 arrest, ROS generation, and activation of the JNK/c-Jun pathway. Importantly, silibinin effectively suppressed xenograft tumor growth in nude mice. Our findings indicate that silibinin may be a promising option for the prevention or treatment of oral cancer.

20 (S)-ginsenoside Rh2 inhibits colorectal cancer cell growth by suppressing the Axl signaling pathway in vitro and in vivo.

Background: Colorectal cancer (CRC) has a high morbidity and mortality worldwide. 20 (S)-ginsenoside Rh2 (G-Rh2) is a natural compound extracted from ginseng, which exhibits anticancer effects in many cancer types. In this study, we demonstrated the effect and underlying molecular mechanism of G-Rh2 in CRC cells in vitro and in vivo. Methods: Cell proliferation, migration, invasion, apoptosis, cell cycle, and western blot assays were performed to evaluate the effect of G-Rh2 on CRC cells. In vitro pull-down assay was used to verify the interaction between G-Rh2 and Axl. Transfection and infection experiments were used to explore the function of Axl in CRC cells. CRC xenograft models were used to further investigate the effect of Axl knockdown and G-Rh2 on tumor growth in vivo. Results: G-Rh2 significantly inhibited proliferation, migration, and invasion, and induced apoptosis and G0/G1 phase cell cycle arrest in CRC cell lines. G-Rh2 directly binds to Axl and inhibits the Axl signaling pathway in CRC cells. Knockdown of Axl suppressed the growth, migration and invasion ability of CRC cells in vitro and xenograft tumor growth in vivo, whereas overexpression of Axl promoted the growth, migration, and invasion ability of CRC cells. Moreover, G-Rh2 significantly suppressed CRC xenograft tumor growth by inhibiting Axl signaling with no obvious toxicity to nude mice. Conclusion: Our results indicate that G-Rh2 exerts anticancer activity in vitro and in vivo by suppressing the Axl signaling pathway. G-Rh2 is a promising candidate for CRC prevention and treatment.

Protective Effect of GIP against Monosodium Glutamate-Induced Ferroptosis in Mouse Hippocampal HT-22 Cells through the MAPK Signaling Pathway.

The effect of glucose-dependent insulinotropic polypeptide (GIP) on cells under oxidative stress induced by glutamate, a neurotransmitter, and the underlying molecular mechanisms were assessed in the present study. We found that in the pre-treatment of HT-22 cells with glutamate in a dose-dependent manner, intracellular ROS were excessively generated, and additional cell damage occurred in the form of lipid peroxidation. The neurotoxicity caused by excessive glutamate was found to be ferroptosis and not apoptosis. Other factors (GPx-4, Nrf2, Nox1 and Hspb1) involved in ferroptosis were also identified. In other words, it was confirmed that GIP increased the activity of sub-signalling molecules in the process of suppressing ferroptosis as an antioxidant and maintained a stable cell cycle even under glutamate-induced neurotoxicity. At the same time, in HT-22 cells exposed to ferroptosis as a result of excessive glutamate accumulation, GIP sustained cell viability by activating the mitogen-activated protein kinase (MAPK) signalling pathway. These results suggest that the overexpression of the GIP gene increases cell viability by regulating mechanisms related to cytotoxicity and reactive oxygen species production in hippocampal neuronal cell lines.

[6]-Gingerol Suppresses Oral Cancer Cell Growth by Inducing the Activation of AMPK and Suppressing the AKT/mTOR Signaling Pathway.

BACKGROUND/AIM: [6]-Gingerol, a compound extracted from ginger, has been studied for its therapeutic potential in various types of cancers. However, its effects on oral cancer remain largely unknown. Here, we aimed to investigate the potential anticancer activity and underlying mechanisms of [6]-gingerol in oral cancer cells. MATERIALS AND METHODS: We analyzed the antigrowth effects of [6]-gingerol in oral cancer cell lines by cell proliferation, colony formation, migration, and invasion assays. We detected cell cycle and apoptosis with flow cytometry and further explored the mechanisms of action by immunoblotting. RESULTS: [6]-Gingerol significantly inhibited oral cancer cell growth by inducing apoptosis and cell cycle G2/M phase arrest. [6]-Gingerol also inhibited oral cancer cell migration and invasion by up-regulating E-cadherin and down-regulating N-cadherin and vimentin. Moreover, [6]-gingerol induced the activation of AMPK and suppressed the AKT/mTOR signaling pathway in YD10B and Ca9-22 cells. CONCLUSION: [6]-Gingerol exerts anticancer activity by activating AMPK and suppressing the AKT/mTOR signaling pathway in oral cancer cells. Our findings highlight the potential of [6]-gingerol as a therapeutic drug for oral cancer treatment.

Overexpression of Lin28a Aggravates Psoriasis-Like Phenotype by Regulating the Proliferation and Differentiation of Keratinocytes.

PURPOSE: Psoriasis is a common and well-studied autoimmune skin disease, which is characterized by plaques. The formation of psoriasis plaques occurs through the hyperproliferation and abnormal differentiation of keratinocytes, infiltration of numerous immune cells into the dermis, increased subepidermal angiogenesis, and various autoimmune-associated cytokines and chemokines. According to previous research, Lin28 regulates the let-7 family, and let-7b is associated with psoriasis. However, the link between Lin28 and psoriasis is unclear. In this study, an association was identified between Lin28a and psoriasis progression, which promoted the pathological characteristic of psoriasis in epidermal keratinocytes. PATIENTS AND METHODS: This study aims to investigate the role of Lin28a and its underlying mechanism in psoriasis through in vivo and in vitro models, which include the Lin28a-overexpressing transgenic (TG) mice and Lin28a-overexpressing human keratinocyte (HaCaT) cell lines, respectively. RESULTS: In vivo and in vitro results revealed that overexpression of Lin28a downregulated microRNA let-7 expression levels and caused hyperproliferation and abnormal differentiation in keratinocytes. In imiquimod (IMQ)-induced psoriasis-like inflammation, Lin28a overexpressing transgenic (TG) mice exhibited more severe symptoms of psoriasis. CONCLUSION: Mechanistically, Lin28a exacerbated psoriasis-like inflammation through the activation of the extracellular-signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 signaling (STAT 3) by targeting proinflammatory cytokine interleukin-6 (IL-6).

JAZF1 heterozygous knockout mice show altered adipose development and metabolism.

BACKGROUND: Juxtaposed with another zinc finger protein 1 (JAZF1) is associated with metabolic disorders, including type 2 diabetes mellitus (T2DM). Several studies showed that JAZF1 and body fat mass are closely related. We attempted to elucidate the JAZF1 functions on adipose development and related metabolism using in vitro and in vivo models. RESULTS: The JAZF1 expression was precisely regulated during adipocyte differentiation of 3T3-L1 preadipocyte and mouse embryonic fibroblasts (MEFs). Homozygous JAZF1 deletion (JAZF1-KO) resulted in impaired adipocyte differentiation in MEF. The JAZF1 role in adipocyte differentiation was demonstrated by the regulation of PPARγ-a key regulator of adipocyte differentiation. Heterozygous JAZF1 deletion (JAZF1-Het) mice fed a normal diet (ND) or a high-fat diet (HFD) had less adipose tissue mass and impaired glucose homeostasis than the control (JAZF1-Cont) mice. However, other metabolic organs, such as brown adipose tissue and liver, were negligible effect on JAZF1 deficiency. CONCLUSION: Our findings emphasized the JAZF1 role in adipocyte differentiation and related metabolism through the heterozygous knockout mice. This study provides new insights into the JAZF1 function in adipose development and metabolism, informing strategies for treating obesity and related metabolic disorders.

Overexpression of cathepsin S exacerbates lupus pathogenesis through upregulation TLR7 and IFN-α in transgenic mice.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects multiple organs. Recent studies suggest relevance between cysteine protease cathepsin S (CTSS) expression and SLE. To investigate the mechanism of CTSS in SLE, CTSS-overexpressing transgenic (TG) mice were generated, and induced lupus-like symptoms. Eight months later, the TG mice spontaneously developed typical SLE symptoms regardless of the inducement. Furthermore, we observed increased toll-like receptor 7 (TLR7) expression with increased monocyte and neutrophil populations in the TG mice. In conclusion, overexpression of CTSS in mice influences TLR7 expression, autoantibodies and IFN-α, which leads to an autoimmune reaction and exacerbates lupus-like symptoms.

Rhein Suppresses Colorectal Cancer Cell Growth by Inhibiting the mTOR Pathway In Vitro and In Vivo.

Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. Rhein has demonstrated therapeutic effects in various cancer models. However, its effects and underlying mechanisms of action in CRC remain poorly understood. We investigated the potential anticancer activity and underlying mechanisms of rhein in CRC in vitro and in vivo. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of rhein on CRC cells. Wound-healing and Transwell assays were conducted to assess cell migration and invasion capacity. Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. A tissue microarray was used to detect mTOR expression in CRC patient tissues. Gene overexpression and knockdown were done to analyze the function of mTOR in CRC. The anticancer effect of rhein in vivo was assessed in a CRC xenograft mouse model. The results show that rhein significantly inhibited CRC cell growth by inducing S-phase cell cycle arrest and apoptosis. Rhein inhibited CRC cell migration and invasion through the epithelial-mesenchymal transition (EMT) process. mTOR was highly expressed in CRC cancer tissues and cells. Overexpression of mTOR promoted cell growth, migration, and invasion, whereas mTOR knockdown diminished these phenomena in CRC cells in vitro. In addition, rhein directly targeted mTOR and inhibited the mTOR signaling pathway in CRC cells. Rhein promoted mTOR degradation through the ubiquitin-proteasome pathway. Intraperitoneal administration of rhein inhibited HCT116 xenograft tumor growth through the mTOR pathway. In conclusion, rhein exerts anticancer activity in vitro and in vivo by targeting mTOR and inhibiting the mTOR signaling pathway in CRC. Our results indicate that rhein is a potent anticancer agent that may be useful for the prevention and treatment of CRC.

Overexpression of hepatic serum amyloid A1 in mice increases IL-17-producing innate immune cells and decreases bone density.

Serum amyloid A (SAA) is an acute-phase protein produced primarily in the liver that plays a key role in both the initiation and maintenance of inflammation. Rapidly secreted SAA induces neutrophilia at inflammatory sites, initiating inflammation and inducing the secretion of various cytokines, including TNF-α, IL-6, and IL-17. IL-17 is expressed in several inflammatory cells, including innate immune cells such as γδT cells, ILC3 cells, and neutrophils. Increased IL-17 levels exacerbate various inflammatory diseases. Among other roles, IL-17 induces bone loss by increasing receptor activator of nuclear factor-κB ligand (RANKL) secretion, which stimulates osteoclast differentiation. Several studies have demonstrated that chronic inflammation induces bone loss, suggesting a role for SAA in bone health. To test this possibility, we observed an increase in IL-17-producing innate immune cells, neutrophils, and γδT cells in these mice. In 6-month-old animals, we detected increased osteoclast-related gene expression and IL-17 expression in bone lysates. We also observed an increase in neutrophils that secreted RANKL in the bone marrow of TG mice. Finally, we demonstrated decreased bone mineral density in these transgenic (TG) mice. Our results revealed that the TG mice have increased populations of IL-17-producing innate immune cells, γδT cells, and neutrophils in TG mice. We additionally detected increased RANKL and IL-17 expression in the bone marrow of 6-month-old TG mice. Furthermore, we confirmed significant increases in RANKL-expressing neutrophils in TG mice and decreased bone mineral density. Our results provide evidence that chronic inflammation induced by SAA1 causes bone loss via IL-17-secreting innate immune cells.

Jazf1 acts as a regulator of insulin-producing ß-cell differentiation in induced pluripotent stem cells and glucose homeostasis in mice.

Genetic susceptibility of type 2 diabetes and Juxtaposed with another zinc finger protein 1 (Jazf1) has been reported; however, the precise role of Jazf1 in metabolic processes remains elusive. In this study, using Jazf1-knockout (KO)-induced pluripotent stem cells (iPSC), pancreatic beta cell line MIN6 cells, and Jazf-1 heterozygous KO (Jazf1+/- ) mice, the effect of Jazf1 on gradual differentiation was investigated. We checked the alterations of the genes related with ß-cell specification, maturation, and insulin release against glucose treatment by the gain and loss of the Jazf1 gene in the MIN6 cells. Because undifferentiated Jazf1-KO iPSC were not significantly different from wild-type (WT) iPSC, the size and endoderm marker expression after embryoid body (EB) and teratoma formation were investigated. Compared to EB and teratomas formed with WT iPSC, the EB and teratomas from with Jazf1-KO iPSC were smaller, and in teratomas, the expression of proliferation markers was reduced. Moreover, the expression of the gene sets for ß-cell differentiation and the levels of insulin and C-peptide secreted by insulin precursor cells were notably reduced in ß-cells differentiated from Jazf1-KO iPSC compared with those differentiated from WT iPSC. A comparison of Jazf1+/- and WT mice showed that Jazf1+/- mice had lower levels of serum insulin, pancreatic insulin expression, and decreased pancreatic ß-cell size, which resulted in defects in the glucose homeostasis. These findings suggest that Jazf1 plays a pivotal role in the differentiation of ß-cells and glucose homeostasis.

Anti-inflammatory effects of a methanol extract of Dictamnus dasycarpus Turcz. root bark on imiquimod-induced psoriasis.

BACKGROUND: The root bark of Dictamnus dasycarpus Turcz. has been successfully used for the treatment of inflammatory skin conditions such as eczema and pruritus. However, the anti-psoriatic effect of this plant has not until now been investigated. METHODS: The aim of this project was to investigate whether a methanol extract of Dictamnus dasycarpus Turcz. root bark (MEDD) can be used as a therapeutic agent for psoriasis in C57BL/6 mice model of imiquimod (IMQ)-induced psoriasis. IMQ and MEDD was applied to mouse skin continuously for 7 days. The skin phenotype and the levels of inflammatory cytokines, such as interferon (IFN)-γ and interleukin (IL)-17, were analyzed. The immune cell population was determined by flow cytometry, and STAT1 and 3 protein levels were measured. RESULTS: An alleviation of scaly skin phenotype, immune cell infiltration in the dermis, and epidermal hyperplasia was observed after daily MEDD treatment in the lesion-affected area. It was also found that MEDD reduced IL-17 cytokine levels decreased by 44.37% (p < 0.05), the number of IL-17-producing Th17 cells and γδT cells, and the size of the Th1 population secreting IFN-γ decreased by 45.98, 62.21, and 44.42%, respectively (p < 0.05), compared with the vehicle control group. STAT3 signals, associated with IL-17 are also reduced by MEDD. CONCLUSIONS: An anti-psoriatic effect of MEDD was observed, as determined by decreased skin inflammation, reduced number of inflammatory cytokines, and a smaller population of inflammatory cells. These results contribute to the validation of the use of MEDD in the treatment of psoriasis.

Dermoscopic features of actinic keratosis and follow up with dermoscopy: a pilot study.

Actinic keratosis (AK) is a common precursor of sun-related squamous cell carcinoma. AK is difficult to be differentiated from other malignancies with the naked eyes. Dermoscopic features of AK were previously described in some studies, but not extensively investigated. We investigated the dermoscopic features of AK in Asians and assessed dermoscopy as a post-treatment monitoring tool of AK. We retrospectively examined 34 AK lesions which had been diagnosed by histology. The changes of dermoscopic features and histopathological findings were assessed in all these lesions before and after treatment. Before treatment, 18 lesions were pigmented and 16 lesions were non-pigmented AK dermoscopically. The frequent dermoscopic features of AK were keratin/ scales (79.4%), red pseudonetwork (73.5%), targetoid-like appearance (55.9%), rosette sign (38.2%) and absent fissures/ridges, crypts and milia-like cysts. All the lesions had been treated with either photodynamic therapy, cryotherapy or 5% imiquimod cream. After treatment, dermoscopic features of 33 AK lesions were decreased or disappeared, and skin biopsies confirmed that atypical keratinocytes disappeared. One lesion showed accentuated and new dermoscopic features after treatment, and skin biopsy also showed progressing squamous cell carcinoma. In conclusion, scales, red pseudonetwork, targetoid-like appearance and rosette sign were common dermoscopic findings of AK in Asians. In most cases, the treatment response correlated with the changes in dermoscopic features. These findings suggest that dermoscopy is a useful tool to monitor AK.

Clinical characteristics of cholinergic urticaria in Korea.

BACKGROUND: Cholinergic urticaria is a type of physical urticaria characterized by heat-associated wheals. Several reports are available about cholinergic urticaria; however, the clinical manifestations and pathogenesis are incompletely understood. OBJECTIVE: The purpose of this study was to investigate the clinical characteristics of cholinergic urticaria in Korea. METHODS: We performed a retrospective study of 92 patients with cholinergic urticaria who were contacted by phone and whose diagnoses were confirmed by the exercise provocation test among those who had visited The Catholic University of Korea, Catholic Medical Center from January 2001 to November 2010. RESULTS: All 92 patients were male, and their average age was 27.8 years (range, 17~51 years). Most of the patients had onset of the disease in their 20s and 30s. Non-follicular wheals were located on the trunk and upper extremities of many patients, and the symptoms were aggravated by exercise. Eight patients showed general urticaria symptoms and 15 had accompanying atopic disease. Forty-three patients complained of seasonal aggravation. Most patients were treated with first and second-generation antihistamines. CONCLUSION: Dermatologists should consider these characteristics in patients with cholinergic urticaria. Further investigation and follow-up studies are necessary to better understand the epidemiological and clinical findings of cholinergic urticaria.

Downregulation of erythroid differentiation regulator 1 as a novel marker of skin tumors.

BACKGROUND: Erythroid differentiation regulator 1 is decreased in malignant melanoma. However, the expression of erythroid differentiation regulator 1 has not been reported in normal epidermis, vessel, nerve, dermal adnexae, and various skin tumors. METHODS: To investigate the expression of erythroid differentiation regulator 1 in normal skin and various skin tumors, immunohistochemical analysis of normal skin, epidermal tumors, sebaceous tumors, and eccrine tumors was performed. The image analysis was quantitatively performed using HistoQuant(™) software. RESULTS: Erythroid differentiation regulator 1 was strongly expressed in the nuclei of normal epidermis, sebaceous gland, eccrine gland, vessel, and nerve. Expression of erythroid differentiation regulator 1 was weak in seborrheic keratosis, sebaceous hyperplasia, and eccrine spiradenoma. Erythroid differentiation regulator 1 was rarely observed in malignant skin tumors, including squamous cell carcinoma, basal cell carcinoma, malignant melanoma, sebaceous carcinoma, and eccrine porocarcinoma. CONCLUSIONS: The expression of erythroid differentiation regulator 1 was negatively correlated with the malignant potential in various skin tumors. The results support the role of erythroid differentiation regulator 1 in cutaneous carcinogenesis and indicate its potential as a novel marker of skin tumors.