ATP6V0A1-dependent cholesterol absorption in colorectal cancer cells triggers immunosuppressive signaling to inactivate memory CD8+ T cells.

Obesity shapes anti-tumor immunity through lipid metabolism; however, the mechanisms underlying how colorectal cancer (CRC) cells utilize lipids to suppress anti-tumor immunity remain unclear. Here, we show that tumor cell-intrinsic ATP6V0A1 drives exogenous cholesterol-induced immunosuppression in CRC. ATP6V0A1 facilitates cholesterol absorption in CRC cells through RAB guanine nucleotide exchange factor 1 (RABGEF1)-dependent endosome maturation, leading to cholesterol accumulation within the endoplasmic reticulum and elevated production of 24-hydroxycholesterol (24-OHC). ATP6V0A1-induced 24-OHC upregulates TGF-ß1 by activating the liver X receptor (LXR) signaling. Subsequently, the release of TGF-ß1 into the tumor microenvironment by CRC cells activates the SMAD3 pathway in memory CD8+ T cells, ultimately suppressing their anti-tumor activities. Moreover, we identify daclatasvir, a clinically used anti-hepatitis C virus (HCV) drug, as an ATP6V0A1 inhibitor that can effectively enhance the memory CD8+ T cell activity and suppress tumor growth in CRC. These findings shed light on the potential for ATP6V0A1-targeted immunotherapy in CRC.

Immunotoxicity Evaluation of Trihalophenolic Disinfection By-Products in Mouse and Human Mononuclear Macrophage Systems: The Role of RNA Epitranscriptomic Modification in Mammalian Immunity.

BACKGROUND: 2,4,6-Trichlorophenol (TCP), 2,4,6-tribromophenol (TBP) and 2,4,6-triiodophenol (TIP) are three widely detected trihalophenolic disinfection by-products (DBPs). Previous studies have mainly focused on the carcinogenic risk and developmental toxicity of 2,4,6-trihalophenols. Very little is known about their immunotoxicity in mammals. OBJECTIVES: We investigated the effects of 2,4,6-trihalophenols on mammalian immunity using a mouse macrophage model infected with bacteria or intracellular parasites and aimed to elucidate the underlying mechanisms from an epitranscriptomic perspective. The identified mechanisms were further validated in human peripheral blood mononuclear cells (PBMCs). METHODS: The mouse macrophage cell line RAW264.7 and primary mouse peritoneal macrophages were exposed to different concentrations of TCP, TBP, and TIP. The pro-inflammatory marker Ly6C, the survival of the bacterium Escherichia coli (E. coli), and the parasite burden of Toxoplasma gondii (T. gondii) were assessed. Furthermore, the global gene expression profiling of macrophages following exposure to 2,4,6-trihalophenols was obtained through RNA-sequencing (RNA-seq). The effects of 2,4,6-trihalophenols on RNA N6-methyladenosine (m6A) methyltransferases and total RNA m6A levels were evaluated using Western blotting and dot blot, respectively. Transcriptome-wide m6A methylome was analyzed by m6A-seq. In addition, expression of m6A regulators and total RNA m6A levels in human PBMCs exposed to 2,4,6-trihalophenols were detected using quantitative reverse transcriptase polymerase chain reaction and dot blot, respectively. RESULTS: Mouse macrophages exposed to TCP, TBP, or TIP had lower expression of the pro-inflammatory marker Ly6C, with a greater difference from control observed for TIP-exposed cells. Consistently, macrophages exposed to such DBPs, especially TIP, were susceptible to infection with the bacterium E. coli and the intracellular parasite T. gondii, indicating a compromised ability of macrophages to defend against pathogens. Intriguingly, macrophages exposed to TIP had significantly greater m6A levels, which correlated with the greater expression levels of m6A methyltransferases. Macrophages exposed to each of the three 2,4,6-trihalophenols exhibited transcriptome-wide redistribution of m6A. In particular, the m6A peaks in genes associated with immune-related pathways were altered after exposure. In addition, differences in m6A were also observed in human PBMCs after exposure to 2,4,6-trihalophenols. DISCUSSION: These findings suggest that 2,4,6-trihalophenol exposure impaired the ability of macrophages to defend against pathogens. This response might be associated with notable differences in m6A after exposure. To the best of our knowledge, this study presents the first m6A landscape across the transcriptome of immune cells exposed to pollutants. However, significant challenges remain in elucidating the mechanisms by which m6A mediates immune dysregulation in infected macrophages after 2,4,6-trihalophenol exposure. https://doi.org/10.1289/EHP11329.

Low-Dose Cyclophosphamide Induces Nerve Injury and Functional Overactivity in the Urinary Bladder of Rats.

Aim: This research aimed to investigate the neurotoxicity of low-dose cyclophosphamide (CYP) on the urinary bladder of rats by in vivo and in vitro studies. Methods: To establish CYP-induced cystitis rat model, rats were treated with three intraperitoneal injections of CYP (25 mg/kg) in a week. During treatment, the up-down method was used to assess the mechanical withdrawal threshold. On day 8, urodynamic test and bladder smooth muscle contractility study, including the contraction of bladder strips to electrical field stimulation (EFS, 2-64 Hz), carbachol (CCh, 10-8-10-5 M) and KCl (120 mM), were performed to evaluate the function of bladder function. Body weight and bladder weight were also recorded. Morphometric analysis using an optical microscope and transmission electron microscope was performed to observe the changes of microstructure and submicrostructure of the bladder. The major pelvic neurons were isolated and treated with acrolein (the main CYP metabolite) to assess apoptosis in vitro. RT-PCR assays were used to quantify the mRNA expression levels of Nlrp6, Asc, Casp11 and Casp1 in bladder tissues and primary neurons. Results: After CYP injections, the body weights decreased, but the bladder weights increased in the model group. The mechanical withdrawal threshold of the cystitis model remained at a low level. The morphometric analysis suggested bladder inflammation and neuroinflammation in the bladder of the cystitis rat model. Urodynamic test revealed that, the amplitude, the pressure baseline, the peak pressure and pressure threshold of model rats significantly increased after CYP treatment. The muscle strips of model rats exhibited significantly higher contractility caused by EFS and CCh than the controls. Apoptotic cells appeared at the highest concentration group (100 µM acrolein) after 6 h of acrolein incubation in apoptosis assay of primary neurons. The mRNA expression levels of Nlrp6 and Casp11 were significantly increased in the cystitis rat model and in the acrolein-treated neurons. Conclusions: Low-dose CYP treatment was confirmed to induce nerve injury, which leading to bladder pain and overactive bladder in female rats, and the up-regulation of Nlrp6 and Casp11 may contribute to these pathological changes.

Identification and Target-Modification of SL-BBI: A Novel Bowman-Birk Type Trypsin Inhibitor from Sylvirana latouchii.

The peptides from the ranacyclin family share similar active disulphide loop with plant-derived Bowman-Birk type inhibitors, some of which have the dual activities of trypsin inhibition and antimicrobial. Herein, a novel Bowman-Birk type trypsin inhibitor of the ranacyclin family was identified from the skin secretion of broad-folded frog (Sylvirana latouchii) by molecular cloning method and named as SL-BBI. After chemical synthesis, it was proved to be a potent inhibitor of trypsin with a Ki value of 230.5 nM and showed weak antimicrobial activity against tested microorganisms. Modified analogue K-SL maintains the original inhibitory activity with a Ki value of 77.27 nM while enhancing the antimicrobial activity. After the substitution of active P1 site to phenylalanine and P2' site to isoleucine, F-SL regenerated its inhibitory activity on chymotrypsin with a Ki value of 309.3 nM and exhibited antiproliferative effects on PC-3, MCF-7 and a series of non-small cell lung cancer cell lines without cell membrane damage. The affinity of F-SL for the ß subunits in the yeast 20S proteasome showed by molecular docking simulations enriched the understanding of the possible action mode of Bowman-Birk type inhibitors. Further mechanistic studies have shown that F-SL can activate caspase 3/7 in H157 cells and induce apoptosis, which means it has the potential to become an anticancer agent.

Evaluating the Bioactivity of a Novel Antimicrobial and Anticancer Peptide, Dermaseptin-PS4(Der-PS4), from the Skin Secretion of Phyllomedusa sauvagii.

Dermaseptins belonging to a large family of cationic membrane-disruption antimicrobial peptides display extensive antibacterial and antiproliferative activities depending on a coil-to-helix transition and the specific structural parameters. Herein, a novel dermaseptin peptide named Der-PS4 was discovered from the skin secretion of the waxy monkey tree frog, Phyllomedusa sauvagii. The complementary DNA (cDNA)-encoding precursor was obtained relying on "shotgun" cloning, and afterwards, a mature peptide amino acid sequence was identified by reverse-phase high performance liquid chromatography (RP-HPLC) and MS/MS. Specimens were chemically synthesized and applied for further functional studies. Structural analysis demonstrated a higher α-helical content in the membrane-mimetic environment compared with that in the ammonium acetate/water circumstance. Der-PS4 displayed a broad spectrum of antimicrobial activities against tested pathogenic microorganisms, however, exhibiting slight membrane-damaging effectiveness towards horse red blood cells. Coincident with the inhibitory activities on pathogens, Der-PS4 also showed considerable biofilm eradicating impact. Also, Der-PS4 penetrated cell membrane in a relative short period under each minimum bactericidal concentration. In addition, Der-PS4 possessed antiproliferative capacity against five cancer cell lines, while presenting slight suppressing effect on human microvascular endothelial, HMEC-1. These findings provide a promising insight for the discovery and development of novel drugs from a natural source.

Dietary quality linkage to overall competence at school and emotional disturbance in representative Taiwanese young adolescents: dependence on gender, parental characteristics and personal behaviors.

BACKGROUND: Child school performance during puberty may be at increased risk through emotional disturbance. It is hypothesized that this may be mitigated by dietary quality. METHODS: In a nationally representative sample (Nutrition and Health Survey in Taiwan, NAHSIT), 1371 Taiwanese aged 11-16 years, overall competence at school, (OCS) and emotional status have been assessed by teachers with the SAED (Scale for Assessing Emotional Disturbance). Parents provided family socio-demographics and students completed a behavioral and dietary questionnaire (Youth Healthy Eating Index - Taiwan, YHEI-TW). Associations between emotional disturbance (ED), OCS and dietary quality (YHEI-TW) were assessed in multiple linear regression models with adjustments for covariates including parental characteristics, personal behaviors, body fatness and puberty. RESULTS: Boys or girls with ED had a less favorable OCS (p < 0.001), minimally dependent on YHEI-TW. On multivariable analysis there was a more positive association between OCS and YHEI-TW among boys (ß = 0.05, p < 0.01) and girls (ß = 0.07, p < 0.001). Poor dietary quality was associated with ED, especially in girls (ß = - 0.06, p < 0.001). Additionally, parental characteristics, body fatness, and personal behaviors are associated with OCS. Puberty is associated with ED and may be indirectly linked to OCS. CONCLUSIONS: Unsatisfactory food intake is associated with the link between emotional disturbance and impaired school performance, as assessed by OCS, especially among girls. For both genders, socio-economic and behavioral factors including parenteral income, reading, screen viewing and smoking are modulators of this association. Puberty was a modifying factor in girls. Dietary quality is a relevant factor for health (ED) as well as education (OCS) during early adolescence.

Dermaseptin-PH: A Novel Peptide with Antimicrobial and Anticancer Activities from the Skin Secretion of the South American Orange-Legged Leaf Frog, Pithecopus (Phyllomedusa) hypochondrialis.

The dermaseptin peptides, mainly derived from the skin secretions of Hylidae frogs, belong to a superfamily of antimicrobial peptides and exhibit diverse antimicrobial and anticancer activities with low cytotoxicity. Here, we reported a novel dermaseptin peptide, from the South American orange-legged leaf frogs, Pithecopus (Phyllomedusa) hypochondrialis, processing the shortest peptide length, namely Dermaseptin-PH. The complementary DNA (cDNA) encoding biosynthetic precursor of Dermaseptin-PH was initially identified by the rapid amplification of cDNA ends PCR (RACE-PCR) technique from the skin secretion. The predicted primary structure was confirmed by a combination of reverse-phase high performance liquid chromatography (RP-HPLC) and MS/MS fragmentation from the skin secretion. Chemically-synthetic Dermaseptin-PH was investigated using a range of bioactivity assessment assays to evaluate the biological activities and cytotoxicity of Dermaseptin-PH. Dermaseptin-PH inhibited the growth of Gram-negative bacteria, Gram-positive bacteria, and pathogenic yeast Candidaalbicans. In addition, Dermaseptin-PH showed a broad-spectrum of anticancer activities against several cancer cell lines including MCF-7, H157, U251MG, MDA-MB-435S, and PC-3. The potent antimicrobial and anticancer activities of Dermaseptin-PH make it a promising candidate in the discovery of new drugs for clinical applications, and the relatively short sequence of Dermaseptin-PH can provide new insight for the research and structural modification of new peptide drugs.

Optimal dairy intake is predicated on total, cardiovascular, and stroke mortalities in a Taiwanese cohort.

OBJECTIVE: Dairy foods help achieve essential nutrient adequacy. This role may be conflicted where so-called chronic diseases prevail. We have examined associations between dairy intake and mortality where dairy foods have not been traditional. METHODS: A representative Taiwanese cohort of 3810 subjects, aged 19-64 years, derived from the Nutrition and Health Survey in Taiwan (NAHSIT, 1993-1996) was linked to death registration (1993-2008). Participants were categorized by 4 dairy weekly intake frequencies from 0 to >7 times. Mortality hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using Cox proportional-hazards models. RESULTS: Nonconsumers of dairy products included 30.7% of the men and 22.1% of the women. Adverse sociodemographic and personal behaviors were generally significantly associated with lower dairy consumption. After adjustment for covariates, together with body mass index (BMI) and supplement use, those with 3-7 times/week intakes had an HR (95% CI) for all-cause mortality of 0.61 (0.39-0.96) with a significant dose-response trend (p = 0.043). Similarly, the HR for cardiovascular disease (CVD) mortality with dairy weekly intake frequency >7 was 0.14 (0.02-0.97) with a significant linear trend (p = 0.007). For stroke, the corresponding HR (95% CI) was 0.03 (0.00-0.28) with a linear trend. By age and with adjustment for dietary quality, food, and calcium or vitamin D intake, significance and dose-response relationships remained. Dairy intake and cancer mortality were not associated. CONCLUSION: In a Chinese food culture, a dairy foods intake in adults up to 7 times a week does not increase mortality and may have favorable effects on stroke.