Complex phenotypic heterogeneity of combined hepatocellular-cholangiocarcinoma with a homogenous TERT promoter mutation.

To clarify the mechanism underlying the development and poor prognosis of combined hepatocellular-cholangiocarcinoma (cHCC-CCA), we characterized liver cancer driver mutations and poor prognostic markers in both the HCC and intrahepatic CCA (iCCA) components of a cHCC-CCA tumor. The telomerase reverse transcriptase (TERT) promoter mutation C228T was quantified by digital polymerase chain reaction using DNA from multiple microdissected cancer components of a single cHCC-CCA nodule. The protein expression of cancer-related markers, including TERT, was examined by serial thin-section immunohistochemistry and double-staining immunofluorescence. TERT promoter mutation and TERT protein expression were detected in all cancer components but not in noncancer regions. TERT promoter mutation frequencies were similar among components; those of TERT protein-positive cancer cells were higher in iCCA and mixed components than in HCC. The frequencies of Ki67- and p53-positive cells were similarly higher in iCCA and mixed components than in HCC. However, double-positive cells for the three proteins were unexpectedly rare; single-positive cells dominated, indicating phenotypic microheterogeneity in cancer cells within a component. Interestingly, HCC and CCA marker protein immunohistochemistry suggested dedifferentiation of HCC and transdifferentiation from HCC to iCCA in HCC and iCCA components, respectively. Such phenotypic intercomponent heterogeneity and intracomponent microheterogeneity were detected in a tumor nodule of cHCC-CCA uniformly carrying the early HCC driver mutation. Moreover, poor prognostic markers were randomly expressed without a regular pattern, consistent with the poor prognosis.

Syntheses of 25-Adamantyl-25-alkyl-2-methylidene-1α,25-dihydroxyvitamin D3 Derivatives with Structure-Function Studies of Antagonistic and Agonistic Active Vitamin D Analogs.

The active form of vitamin D3, 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3], is a major regulator of calcium homeostasis through activation of the vitamin D receptor (VDR). We have previously synthesized vitamin D derivatives with large adamantane (AD) rings at position 24, 25, or 26 of the side chain to study VDR agonist and/or antagonist properties. One of them-ADTK1, with an AD ring and 23,24-triple bond-shows a high VDR affinity and cell-selective VDR activity. In this study, we synthesized novel vitamin D derivatives (ADKM1-6) with an alkyl group substituted at position 25 of ADTK1 to develop more cell-selective VDR ligands. ADKM2, ADKM4, and ADKM6 had VDR transcriptional activity comparable to 1,25(OH)2D3 and ADTK1, although their VDR affinities were weaker. Interestingly, ADKM2 has selective VDR activity in kidney- and skin-derived cells-a unique phenotype that differs from ADTK1. Furthermore, ADKM2, ADKM4, and ADKM6 induced osteoblast differentiation in human dedifferentiated fat cells more effectively than ADTK1. The development of vitamin D derivatives with bulky modifications such as AD at position 24, 25, or 26 of the side chain is useful for increased stability and tissue selectivity in VDR-targeting therapy.

ESS2 controls prostate cancer progression through recruitment of chromodomain helicase DNA binding protein 1.

Molecular targeted therapy using poly (ADP-ribose) polymerase inhibitors has improved survival in patients with castration-resistant prostate cancer (CRPC). However, this approach is only effective in patients with specific genetic mutations, and additional drug discovery targeting epigenetic modulators is required. Here, we evaluated the involvement of the transcriptional coregulator ESS2 in prostate cancer. ESS2-knockdown PC3 cells dramatically inhibited proliferation in tumor xenografts in nude mice. Microarray analysis revealed that ESS2 regulated mRNA levels of chromodomain helicase DNA binding protein 1 (CHD1)-related genes and other cancer-related genes, such as PPAR-γ, WNT5A, and TGF-ß, in prostate cancer. ESS2 knockdown reduced nuclear factor (NF)-κB/CHD1 recruitment and histone H3K36me3 levels on the promoters of target genes (TNF and CCL2). In addition, we found that the transcriptional activities of NF-κB, NFAT and SMAD2/3 were enhanced by ESS2. Tamoxifen-inducible Ess2-knockout mice showed delayed prostate development with hypoplasia and disruption of luminal cells in the ventral prostate. Overall, these findings identified ESS2 acts as a transcriptional coregulator in prostate cancer and ESS2 can be novel epigenetic therapeutic target for CRPC.

Vitamin D Receptor Mediates Attenuating Effect of Lithocholic Acid on Dextran Sulfate Sodium Induced Colitis in Mice.

Bile acids are major components of bile; they emulsify dietary lipids for efficient digestion and absorption and act as signaling molecules that activate nuclear and membrane receptors. The vitamin D receptor (VDR) is a receptor for the active form of vitamin D and lithocholic acid (LCA), a secondary bile acid produced by the intestinal microflora. Unlike other bile acids that enter the enterohepatic circulation, LCA is poorly absorbed in the intestine. Although vitamin D signaling regulates various physiological functions, including calcium metabolism and inflammation/immunity, LCA signaling remains largely unknown. In this study, we investigated the effect of the oral administration of LCA on colitis in a mouse model using dextran sulfate sodium (DSS). Oral LCA decreased the disease activity of colitis in the early phase, which is a phenotype associated with the suppression of histological injury, such as inflammatory cell infiltration and goblet cell loss. These protective effects of LCA were abolished in VDR-deleted mice. LCA decreased the expression of inflammatory cytokine genes, but this effect was at least partly observed in VDR-deleted mice. The pharmacological effect of LCA on colitis was not associated with hypercalcemia, an adverse effect induced by vitamin D compounds. Therefore, LCA suppresses DSS-induced intestinal injury in its action as a VDR ligand.

Transcriptional coregulator Ess2 controls survival of post-thymic CD4+ T cells through the Myc and IL-7 signaling pathways.

Ess2, also known as Dgcr14, is a transcriptional co-regulator of CD4+ T cells. Ess2 is located in a chromosomal region, the loss of which has been associated with 22q11.2 deletion syndrome (22q11DS), which causes heart defects, skeletal abnormalities, and immunodeficiency. However, the specific association of Ess2 with 22q11DS remains unclear. To elucidate the role of Ess2 in T-cell development, we generated Ess2 floxed (Ess2fl/fl) and CD4+ T cell-specific Ess2 KO (Ess2ΔCD4/ΔCD4) mice using the Cre/loxP system. Interestingly, Ess2ΔCD4/ΔCD4 mice exhibited reduced naïve T-cell numbers in the spleen, while the number of thymocytes (CD4-CD8-, CD4+CD8+, CD4+CD8-, and CD4-CD8+) in the thymus remained unchanged. Furthermore, Ess2ΔCD4/ΔCD4 mice had decreased NKT cells and increased γδT cells in the thymus and spleen. A genome-wide expression analysis using RNA-seq revealed that Ess2 deletion alters the expression of many genes in CD4 single-positive thymocytes, including genes related to the immune system and Myc target genes. In addition, Ess2 enhanced the transcriptional activity of c-Myc. Some genes identified as Ess2 targets in mice show expressional correlation with ESS2 in human immune cells. Moreover, Ess2ΔCD4/ΔCD4 naïve CD4+ T cells did not maintain survival in response to IL-7. Our results suggest that Ess2 plays a critical role in post-thymic T-cell survival through the Myc and IL-7 signaling pathways.

Dec2 negatively regulates bone resorption in periodontitis.

BACKGROUND AND OBJECTIVES: The potential role of the transcription factor Differentiated embryo-chondrocyte 2 (Dec2) in the progression of inflammatory diseases such as periodontitis has been unclear. Here, the effect of Dec2 on the expression of RANKL and on osteoclastogenesis was determined. MATERIAL AND METHODS: Wild-type (WT) and Dec2 knockout (KO) mice as a model for periodontitis were used to assess alveolar bone resorption by microcomputed tomography (CT). Western blot, flow cytometry, quantitative real-time PCR, and immunohistochemical analyses were utilized to detect inflammation and osteoclasts. Luciferase reporter and Chromatin immunoprecipitation (ChIP) assays examined the interaction between Dec2 and RANKL. RESULTS: Micro-CT showed that the alveolar bone resorption of Dec2KO mice was more severe than WT mice after treatment with P. gingivalis. Immunohistochemistry and Tartrate-resistant acid phosphatase staining showed active osteoclast differentiation in Dec2KO mice. There was an increase in CD11b+ F4/80+ and CD4+ RANKL+ T cells in Dec2KO mice treated with P. gingivalis. Moreover, inflammatory and immune markers were expressed at significantly higher levels in gingival mononuclear cells in Dec2KO mice. Furthermore, luciferase reporter and ChIP assays confirmed the direct binding of Dec2 protein to the RANKL gene. CONCLUSION: Dec2 has an immune regulation ability that modulates P. gingivalis-induced periodontitis via RANKL.

Prediction of the need for emergency endoscopic treatment for upper gastrointestinal bleeding and new score model: a retrospective study.

BACKGROUND: Gastrointestinal bleeding is one of the major gastrointestinal diseases. In this study, our objective was to compare Glasgow-Blatchford score (GBS), AIMS65 score, MAP score, Modified GBS, and Iino score as outcome measures for upper gastrointestinal bleeding. In addition, we extracted factors associated with hemostatic procedures including endoscopy, and proposed a new robust score model. METHODS: From January 2015 to December 2019, 675 patients with symptoms such as hematemesis who visited the National Hospital Organization Disaster Medical Center and underwent urgent upper endoscopy with diagnosis of suspected non-variceal upper gastrointestinal bleeding were retrospectively reviewed. We evaluated the GBS, AIMS65 score, MAP score, Modified GBS, and Iino score, and assessed the outcomes of patients requiring hemostatic treatments at the subsequent emergency endoscopy. We performed logistic regression analysis of factors related to endoscopic hemostasis and upper gastrointestinal bleeding, created a new score model, and evaluated the prediction of hemostatic treatment and mortality in the new score and the existing scores. RESULTS: The factors associated with endoscopic treatment were hematemesis, heart rate, HB (hemoglobin), blood pressure, blood urea nitrogen (BUN). Based on these predictors and the partial regression coefficients, a new score named H3B2 (using the initial letters of hematemesis, heart rate, HB, blood pressure, and BUN) was generated. H3B2 score was slightly more discriminatory compared to GBS and Modified GBS (area under the receiver operating characteristic curves (AUROC): 0.73 versus 0.721 and 0.7128, respectively) in predicting hemostatic treatment in emergency endoscopy. The H3B2 score also showed satisfactory prediction accuracy for subsequent deaths (AUROC: 0.6857. P < 0.001). CONCLUSIONS: We proposed a new score, the H3B2 score, consisting of simple and objective indices in cases of suspected upper gastrointestinal bleeding. The H3B2 score is useful in identifying high-risk patients with suspected upper gastrointestinal bleeding who require urgent hemostatic treatment including emergency endoscopy.

Molecular Basis of Bile Acid-FXR-FGF15/19 Signaling Axis.

Bile acids (BAs) are a group of amphiphilic molecules consisting of a rigid steroid core attached to a hydroxyl group with a varying number, position, and orientation, and a hydrophilic side chain. While BAs act as detergents to solubilize lipophilic nutrients in the small intestine during digestion and absorption, they also act as hormones. Farnesoid X receptor (FXR) is a nuclear receptor that forms a heterodimer with retinoid X receptor α (RXRα), is activated by BAs in the enterohepatic circulation reabsorbed via transporters in the ileum and the colon, and plays a critical role in regulating gene expression involved in cholesterol, BA, and lipid metabolism in the liver. The FXR/RXRα heterodimer also exists in the distal ileum and regulates production of fibroblast growth factor (FGF) 15/FGF19, a hormone traveling via the enterohepatic circulation that activates hepatic FGF receptor 4 (FGFR4)-ß-klotho receptor complex and regulates gene expression involved in cholesterol, BA, and lipid metabolism, as well as those regulating cell proliferation. Agonists for FXR and analogs for FGF15/19 are currently recognized as a promising therapeutic target for metabolic syndrome and cholestatic diseases.

Myeloid LXR (Liver X Receptor) Deficiency Induces Inflammatory Gene Expression in Foamy Macrophages and Accelerates Atherosclerosis.

BACKGROUND: Cholesterol loaded macrophage foam cells are a prominent feature of atherosclerotic plaques. Single-cell RNA sequencing has identified foam cells as TREM2 (triggering receptor expressed on myeloid cells 2) positive populations with low expression of inflammatory genes, resembling the TREM2 positive microglia of neurodegenerative diseases. Cholesterol loading of macrophages in vitro results in activation of LXR (liver X receptor) transcription factors and suppression of inflammatory genes. METHODS: To test the hypothesis that LXRs mediate anti-inflammatory effects in Trem2 expressing atherosclerotic plaque foam cells, we performed RNA profiling on plaque cells from hypercholesterolemic mice with myeloid LXR deficiency. RESULTS: Myeloid LXR deficiency led to a dramatic increase in atherosclerosis with increased monocyte entry, foam cell formation, and plaque inflammation. Bulk cell-RNA profiling of plaque myeloid cells showed prominent upregulation of inflammatory mediators including oxidative, chemokine, and chemotactic genes. Single-cell RNA sequencing revealed increased numbers of foamy TREM2-expressing macrophages; however, these cells had reduced expression of the Trem2 gene expression module, including phagocytic and cholesterol efflux genes, and had switched to a proinflammatory and proliferative phenotype. Expression of Trem2 was suppressed by inflammatory signals but not directly affected by LXR activation in bone marrow-derived macrophages. CONCLUSIONS: Our current studies reveal the key role of macrophage LXRs in promoting the Trem2 gene expression program and in suppressing inflammation in foam cells of atherosclerotic plaques.

Oral benzo[a]pyrene administration attenuates dextran sulfate sodium-induced colitis in mice.

Benzo[a]pyrene (BaP) is an environmental pollutant produced by combustion processes and is present in grilled foods as well as in tobacco smoke. BaP acts as an agonist for the aryl hydrocarbon receptor (AHR), and is metabolized by AHR-inducing enzymes. BaP metabolism can result in either detoxification or metabolic activation, the latter leads to an increased risk of disease, particularly lung cancer and cardiovascular disease, in a context-dependent manner. Although AHR activation has been thought to protect against inflammatory bowel disease, it remains unknown whether BaP exerts a protective or deleterious effect on colitis. In this study, we examined the effect of oral BaP administration on colitis induced by dextran sulfate sodium (DSS) in mice, an animal model of inflammatory bowel disease. BaP administration attenuated weight loss, shortening of the colon, disease activity index scores, and histological damage in DSS-induced colitis mice. BaP also suppressed colonic expression of inflammation-associated genes and plasma interleukin-6 secretion induced by DSS treatment. BaP-DNA adduct formation, a marker of BaP metabolic activation, was not enhanced in the colon after DSS treatment. Thus, oral BaP exerts an anti-inflammatory effect on DSS-induced colitis, without the toxicity associated with metabolic activation. The results provide insights into the disease-specific roles of BaP.

Lithocholic Acid Amides as Potent Vitamin D Receptor Agonists.

1α,25-Dihydroxyvitamin D3 [1α,25(OH)2D3, 1] is an active form of vitamin D3 and regulates various biological phenomena, including calcium and phosphate homeostasis, bone metabolism, and immune response via binding to and activation of vitamin D receptor (VDR). Lithocholic acid (LCA, 2) was identified as a second endogenous agonist of VDR, though its potency is very low. However, the lithocholic acid derivative 3 (Dcha-20) is a more potent agonist than 1α,25(OH)2D3, (1), and its carboxyl group has similar interactions to the 1,3-dihydroxyl groups of 1 with amino acid residues in the VDR ligand-binding pocket. Here, we designed and synthesized amide derivatives of 3 in order to clarify the role of the carboxyl group. The synthesized amide derivatives showed HL-60 cell differentiation-inducing activity with potency that depended upon the substituent on the amide nitrogen atom. Among them, the N-cyanoamide 6 is more active than either 1 or 3.

Biphasic Functions of Sodium Fluoride (NaF) in Soft and in Hard Periodontal Tissues.

Sodium fluoride (NaF) is widely used in clinical dentistry. However, the administration of high or low concentrations of NaF has various functions in different tissues. Understanding the mechanisms of the different effects of NaF will help to optimize its use in clinical applications. Studies of NaF and epithelial cells, osteoblasts, osteoclasts, and periodontal cells have suggested the significant roles of fluoride treatment. In this review, we summarize recent studies on the biphasic functions of NaF that are related to both soft and hard periodontal tissues, multiple diseases, and clinical dentistry.

Direct molecular evidence for both multicentric and monoclonal carcinogenesis followed by transdifferentiation from hepatocellular carcinoma to cholangiocarcinoma in a case of metachronous liver cancer.

Frequent recurrence is a major issue in liver cancer and histological heterogeneity frequently occurs in this cancer type. However, it has remained elusive whether such cancers are multicentric or monoclonal. To elucidate the clonal evolution of hepatocellular carcinoma (HCC) recurrence and combined hepatocellular-cholangiocarcinoma (cHCC-CCA) development, the somatic mutation frequency and signatures in a patient with triple occurrence of liver cancer every three years were examined, with samples designated as #1HCC, #2HCC and #3cHCC-CCA, respectively. A total of four tumor regions, including HCC (#3HCC) and intrahepatic CCA (#3iCCA) components of #3cHCC-CCA, and three nontumor regions (#1N, #2N and #3N) were precisely dissected from formalin-fixed paraffin-embedded tissues of each surgical specimen. DNA was extracted and subjected to tumor-specific somatic mutation determination. Of note, five nonsynonymous single-nucleotide variants (SNVs), namely those of KMT2D, TP53, DNMT3A, PKHD1 and TLR4, were identified in #3cHCC-CCA. All five SNVs were detected in both #3HCC and #3iCCA and #2HCC but not in #1HCC. The telomerase reverse transcriptase (TERT) promoter mutation C228T, but not C250T, was observed in all tumors. Digital PCR of C228T also indicated the presence of the TERT promoter mutation C228T in nontumorous liver tissues (#1N, #2N and #3N) at a frequency of 0.11-0.83% compared with normal liver and blood samples. These results suggest the following phylogenetic evolution of three metachronous liver cancers: #1HCC was not related to #2HCC, #3HCC and #3iCCA; both #3HCC and #3iCCA arose from #2HCC. From the above, three novel findings were deduced: i) Both multicentric occurrence and intrahepatic metastasis may be involved in liver cancer in a three-year interval; ii) transdifferentiation from HCC to iCCA is a possible pathogenic mechanism of cHCC-CCA; and iii) a nontumorous, noncirrhotic liver may contain a preneoplastic region with a cancer driver mutation in the TERT promoter.

FGFR2 loss sensitizes MYCN-amplified neuroblastoma CHP134 cells to CHK1 inhibitor-induced apoptosis.

Checkpoint kinase 1 (CHK1) plays a key role in genome surveillance and integrity throughout the cell cycle. Selective inhibitors of CHK1 (CHK1i) are undergoing clinical evaluation for various human malignancies, including neuroblastoma. In this study, one CHK1i-sensitive neuroblastoma cell line, CHP134, was investigated, which characteristically carries MYCN amplification and a chromosome deletion within the 10q region. Among several cancer-related genes in the chromosome 10q region, mRNA expression of fibroblast growth factor receptor 2 (FGFR2) was altered in CHP134 cells and associated with an unfavorable prognosis of patients with neuroblastoma. Induced expression of FGFR2 in CHP134 cells reactivated downstream MEK/ERK signaling and resulted in cells resistant to CHK1i-mediated cell growth inhibition. Consistently, the MEK1/2 inhibitor, trametinib, potentiated CHK1 inhibitor-mediated cell death in these cells. These results suggested that FGFR2 loss might be prone to highly effective CHK1i treatment. In conclusion, extreme cellular dependency of ERK activation may imply a possible application for the MEK1/2 inhibitor, either as a single inhibitor or in combination with CHK1i in MYCN-amplified neuroblastomas.

Zinc Inhibits Cadherin 1 Expression Induced by 1α,25-Dihydroxyvitamin D3 in Colon Cancer Cells.

BACKGROUND: Zinc is a mineral that is essential for biological molecules, such as transcription factors, and is involved in the maintenance of intestinal homeostasis. Vitamin D signaling is mediated by vitamin D receptor (VDR) activated by 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] and is also important in intestinal functions, such as calcium absorption and epithelial barrier maintenance. However, the crosstalk between vitamin D signaling and zinc signaling in intestinal cells remains poorly understood. MATERIALS AND METHODS: Colon cancer SW480 and HCT116 cells were treated with zinc chloride (ZnCl2) with/without 1,25(OH)2D3 Expression of zinc-inducible genes [metallothionein 1A (MT1A) and MT2A] and VDR target genes [cytochrome P450 family 24 subfamily A member 1 (CYP24A1), transient receptor potential cation channel subfamily V member 6 (TRPV6) and cadherin 1 (CDH1)] was examined. RESULTS: Treatment of cells with ZnCl2 effectively induced MT1A and MT2A mRNA expression, and interestingly suppressed mRNA expression of CDH1, which was induced by 1,25(OH)2D3 in both cell lines. ZnCl2 also reduced the CDH1 protein level in HCT116 cells. CONCLUSION: Zinc signaling suppresses VDR-induced expression of CDH1.

Liver X receptors regulate natural killer T cell population and antitumor activity in the liver of mice.

The nuclear receptors liver X receptor α (LXRα) and LXRß are lipid sensors that regulate lipid metabolism and immunity. Natural killer T (NKT) cells, a T cell subset expressing surface markers of both natural killer cells and T lymphocytes and involved in antitumor immunity, are another abundant immune cell type in the liver. The potential function of the metabolic regulators LXRα/ß in hepatic NKT cells remains unknown. In this study, we examined the role of LXRα and LXRß in NKT cells using mice deficient for LXRα and/or LXRß, and found that hepatic invariant NKT (iNKT) cells are drastically decreased in LXRα/ß-KO mice. Cytokine production stimulated by the iNKT cell activator α-galactosylceramide was impaired in LXRα/ß-KO hepatic mononuclear cells and in LXRα/ß-KO mice. iNKT cell-mediated antitumor effect was also disturbed in LXRα/ß-KO mice. LXRα/ß-KO mice transplanted with wild-type bone marrow showed decreased iNKT cells in the liver and spleen. The thymus of LXRα/ß-KO mice showed a decreased population of iNKT cells. In conclusion, LXRα and LXRß are essential for NKT cell-mediated immunity, such as cytokine production and hepatic antitumor activity, and are involved in NKT cell development in immune tissues, such as the thymus.

The Potential Roles of Dec1 and Dec2 in Periodontal Inflammation.

Periodontal inflammation is a common inflammatory disease associated with chronic inflammation that can ultimately lead to alveolar attachment loss and bone destruction. Understanding autophagy and pyroptosis has suggested their significant roles in inflammation. In recent years, studies of differentiated embryo-chondrocyte expressed genes 1 and 2 (Dec1 and Dec2) have shown that they play important functions in autophagy and in pyroptosis, which contribute to the onset of periodontal inflammation. In this review, we summarize recent studies on the roles of clock genes, including Dec1 and Dec2, that are related to periodontal inflammation and other diseases.

[Prediction of Prognosis in Breast Carcinoma Using Klotho Immunohistochemistry].

Klotho is one of the known anti-aging genes, and functions as an inhibitor of the insulin-like growth factor 1(IGF-1) pathway. However, the clinical significance of Klotho expression in cancer tissues have not been elucidated yet. In this study, we aimed to investigate the clinical significance of Klotho expression in breast cancer patients. We evaluated Klotho expression through immunohistochemical analysis and evaluating Ki-67 positive cell index in 142 patients who underwent surgery for breast cancer in our hospital. There was no significant correlation between age, menopausal state, historical type, hormone status, HER2 status, and distant metastases. High expression of Klotho was observed in the non-invasive compared to the invasive ductal carcinomas. The number of metastatic lymph nodes, clinical stage, and tumor size were correlated to Klotho expression level in the cancer tissues. The Klotho positive group exhibited low score for Ki-67 positive cell index than the Klotho negative group. No significant correlation in cumulative survival rates between Klotho positive and Klotho negative groups was observed. The Klotho negative group exhibited good prognosis than the Klotho positive group for the disease- free survival after the operation. These results suggest that the analysis Klotho expression in the breast cancer tissues using immunohistochemistry is a useful tool to assess the disease-free survival for breast cancer patients.

Contrasting functional responses of resident Kupffer cells and recruited liver macrophages to irradiation and liver X receptor stimulation.

In the murine liver, there are two major macrophage populations, namely resident Kupffer cells (resKCs) with phagocytic activity and recruited macrophages (recMφs) with cytokine-producing capacity. This study was performed to clarify the functional differences between these two populations, focusing on their susceptibility to radiation and response to stimulation via liver X receptors (LXRs), which are implicated in cholesterol metabolism and immune regulation. Liver mononuclear cells (MNCs) were obtained from C57BL/6 (WT) mice with or without 2 Gy irradiation, and the phagocytic activity against Escherichia coli (E. coli) as well as TNF-α production were compared between the two macrophage populations. To assess LXR functions, phagocytosis, TNF-α production, and endocytosis of acetylated low-density lipoprotein (LDL) were compared after synthetic LXR ligand stimulation. Furthermore, LXRα/ß knockout (KO) mice and LXRα KO mice were compared with WT mice. Irradiation decreased intracellular TNF-α production by recMφs but did not affect the phagocytic activity of resKCs. In vitro LXR stimulation enhanced E. coli phagocytosis by resKCs but decreased E. coli-stimulated TNF-α production by recMφs. Phagocytic activity and acetylated LDL endocytosis were decreased in both LXRα/ß KO mice and LXRα KO mice, with serum TNF-α levels after E. coli injection in the former being higher than those in WT mice. In conclusion, resKCs and recMφs exhibited different functional features in response to radiation and LXR stimulation, highlighting their distinct roles liver immunity and lipid metabolism.

Improvement in aqueous solubility of achiral symmetric cyclofenil by modification to a chiral asymmetric analog.

Decreasing the partition coefficient (LogP) by the introduction of a hydrophilic group is the conventional approach for improving the aqueous solubility of drug candidates, but is not always effective. Since melting point is related to aqueous solubility, we and other groups have developed alternative strategies to improve solubility by means of chemical modification to weaken intermolecular interaction in the solid state, thereby lowering the melting point and increasing the solubility. Here, we show that converting the symmetrical molecular structure of the clinically used estrogen receptor (ER) antagonist cyclofenil (1) into asymmetrical form by introducing an alkyl group enhances the aqueous solubility. Among the synthesized analogs, the chiral methylated analog (R)-4c shows the highest solubility, being 3.6-fold more soluble than 1 even though its hydrophobicity is increased by the methylation. Furthermore, (R)-4c also showed higher membrane permeability than 1, while retaining a comparable metabolic rate, and equivalent biological activity of the active forms (R)-13a to 2. Further validation of this strategy using lead compounds having symmetric structures is expected.