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Ghrelin is an orexigenic peptide released by gastric ghrelin cells that contributes to obesity and hepatic steatosis. The mechanosensitive ion channel Piezo1 in gastric ghrelin cells inhibits the synthesis and secretion of ghrelin in response to gastric mechanical stretch. We sought to modulate hepatic lipid metabolism by manipulating Piezo1 in gastric ghrelin cells. Mice with a ghrelin cell–specific deficiency of Piezo1 (Ghrl-Piezo1−/−) had hyperghrelinemia and hepatic steatosis when fed a low-fat or high-fat diet. In these mice, hepatic lipid accumulation was associated with changes in gene expression and in protein abundance and activity expected to increase hepatic fatty acid synthesis and decrease lipid β-oxidation. Pharmacological inhibition of the ghrelin receptor improved hepatic steatosis in Ghrl-Piezo1−/− mice, thus confirming that the phenotype of these mice was due to overproduction of ghrelin caused by inactivation of Piezo1. Gastric implantation of silicone beads to induce mechanical stretch of the stomach inhibited ghrelin synthesis and secretion, thereby helping to suppress fatty liver development induced by a high-fat diet in wild-type mice but not in Ghrl-Piezo1−/− mice. Our study elucidates the mechanism by which Piezo1 in gastric ghrelin cells regulate hepatic lipid accumulation, providing insights into potential treatments for fatty liver. Editor's summary: The appetite-stimulating hormone ghrelin promotes hepatic lipid accumulation. Zhang et al. investigated the regulation of hepatic lipid homeostasis by Piezo1, a mechanosensitive ion channel that is activated when food ingestion stretches the stomach and that suppresses ghrelin production. Mice lacking Piezo1 in ghrelin-producing cells in the stomach developed hepatic steatosis, which was reversed by pharmacologically blocking the ghrelin receptor. Gastric bead implantation, which mimicked the mechanical stretch induced by food intake, reduced hepatic steatosis in control mice on a normal diet or with diet-induced obesity but not in the conditional knockout mice. Thus, Piezo1 in ghrelin-producing cells could be targeted to treat metabolic dysfunction–associated steatotic liver disease, the most prevalent liver disorder worldwide. —Wei Wong [ABSTRACT FROM AUTHOR]

Background and aims: Evaluation of the programmed cell death ligand‐1 (PD‐L1) combined positive score (CPS) is vital to predict the efficacy of the immunotherapy in triple‐negative breast cancer (TNBC), but pathologists show substantial variability in the consistency and accuracy of the interpretation. It is of great importance to establish an objective and effective method which is highly repeatable. Methods: We proposed a model in a deep learning‐based framework, which at the patch level incorporated cell analysis and tissue region analysis, followed by the whole‐slide level fusion of patch results. Three rounds of ring studies (RSs) were conducted. Twenty‐one pathologists of different levels from four institutions evaluated the PD‐L1 CPS in TNBC specimens as continuous scores by visual assessment and our artificial intelligence (AI)‐assisted method. Results: In the visual assessment, the interpretation results of PD‐L1 (Dako 22C3) CPS by different levels of pathologists have significant differences and showed weak consistency. Using AI‐assisted interpretation, there were no significant differences between all pathologists (P = 0.43), and the intraclass correlation coefficient (ICC) value was increased from 0.618 [95% confidence interval (CI) = 0.524–0.719] to 0.931 (95% CI = 0.902–0.955). The accuracy of interpretation result is further improved to 0.919 (95% CI = 0.886–0.947). Acceptance of AI results by junior pathologists was the highest among all levels, and 80% of the AI results were accepted overall. Conclusion: With the help of the AI‐assisted diagnostic method, different levels of pathologists achieved excellent consistency and repeatability in the interpretation of PD‐L1 (Dako 22C3) CPS. Our AI‐assisted diagnostic approach was proved to strengthen the consistency and repeatability in clinical practice. [ABSTRACT FROM AUTHOR]

Neoadjuvant therapy (NAT) treats early‐stage breast cancers, especially triple‐negative breast cancers (TNBCs). NAT improves pathological complete response (pCR) rates for different breast cancer patients. Recently, immune checkpoint inhibitors that target programmed death 1 (PD‐1) or programmed death ligand 1 (PD‐L1) in combination with NAT have shown antitumor activity in patients with early breast cancer. However, the tumor immune microenvironment (TME) in different subtypes of breast cancers, like TNBC, hormone receptor‐positive (HR+), and human epidermal growth factor receptor 2 amplified (HER2+) and its changes by NAT remain to be fully characterized. We analyzed pre‐NAT tumor biopsies from TNBC (n = 27), HR+ (n = 24), and HER2+ (n = 30) breast cancer patients who received NAT, followed by surgery. The different immune makers (PD‐1, PD‐L1, CD3, and CD8) of tumor‐infiltrating lymphocytes (TILs) were identified with immunofluorescence‐based microenvironment analysis. TILs within cancer parenchyma (iTILs) and in cancer stroma (sTILs) were counted separately. We found that PD‐L1+ cells in tumor and stroma were significantly higher in TNBC patients than in others. PD‐L1+ sTILs were significantly higher in pCR than in non‐pCR patients of all the subtypes. The infiltration scores of B‐cell memory, T‐cell CD4+ memory activated, T‐cell follicular helper, and Macrophage M0 and M1 were relatively higher in TNBC patients, indicating immunoreactive TME in TNBC. Analysis of TCGA‐BRCA RNA‐seq indicated that PD‐L1 was highly expressed in TNBC patients compared with HR+ and HER2+ patients. Higher PD‐L1 expression in TNBC patients was associated with significantly longer overall survival (OS). Our results demonstrated that PD‐L1 expression level of iTILs and sTILs is highest in TNBC among breast cancers. TNBC patients had significantly different immunoreactive TME compared with HR+ and HER2+ patients, suggesting potentially favorable outcomes for immunotherapy in these patients. Also, PD‐L1+ could be a powerful predictor of pCR in TNBC patients after NAT. [ABSTRACT FROM AUTHOR]

Wearable strain sensors with water repellency can enable the monitoring of human health and body motions when in contact with water; however, realization of such sensors with both high sensitivity and dynamic wetting behaviors simultaneously in air and underwater environment is a challenging task. Herein, a superhydrophobic, breathable, and wearable microfiber composite (SBWMC) strain sensor is fabricated using a stearic acid functionalized multi‐walled carbon nanotubes/TiO2 modified textile. The resultant network of hierarchical micro/nano structure endows the SBWMC surface with excellent conductivity and water damage prevention, and it maintains superhydrophobicity after mechanical abrasion, illumination, and water soaking. More importantly, the SBWMC strain sensor simultaneously achieves the wide sensing ranges (strain over 100%) and superior sensitivity (gauge factor of 461.5) in air, and it can efficiently monitor real‐time bending of human joints in air. Compared to traditional sensors, this SBWMC strain sensor also exhibits superior sensitivity in underwater environment, even comparable to that in air. Undoubtedly, such smart sensor offers broad application prospects in next generation of wearable electronic devices in extremely humid environments. [ABSTRACT FROM AUTHOR]

Theanine content is highly correlated with sensory quality and health benefits of tea infusion. The tender shoots of etiolated and albino tea plants contain higher theanine than the normal green tea plants and are valuable materials for high quality green tea processing. However, why these etiolated or albino tea plants can highly accumulate theanine is largely unknown. In this study, we observed an Arabidopsis etiolated mutant hy1–100 (mutation in Haem Oxygenase 1 , HO1) that accumulated higher levels of glutamine (an analog of theanine). We therefore identified CsHO1 in tea plants and found CsHO1 is conserved in amino acid sequences and subcellular localization with its homologs in other plants. Importantly, CsHO1 expression in the new shoots was much lower in an etiolated tea plants 'Huangkui' and an albino tea plant 'Huangshan Baicha' than that in normal green tea plants. The expression levels of CsHO1 were negatively correlated with theanine contents in these green, etiolated and albino shoots. Moreover, CsHO1 expression levels in various organs and different time points were also negatively correlated with theanine accumulation. The hy1–100 was hypersensitive to high levels of theanine and accumulated more theanine under theanine feeding, and these phenotypes were rescued by the expression of CsHO1 in this mutant. Transient knockdown CsHO1 expression in the new shoots of tea plant using antisense oligonucleotides (asODN) increased theanine accumulation. Collectively, these results demonstrated CsHO1 negatively regulates theanine accumulation in tea plants, and that low expression CsHO1 likely contributes to the theanine accumulation in etiolated/albino tea plants. [ABSTRACT FROM AUTHOR]

Root-synthesized secondary metabolites are critical quality-conferring compounds of foods, plant-derived medicines, and beverages. However, information at a single-cell level on root-specific secondary metabolism remains largely unexplored. L-Theanine, an important quality component of tea, is primarily synthesized in roots, from which it is then transported to new shoots of tea plant. In this study, we present a single-cell RNA sequencing (scRNA-seq)-derived map for the tea plant root, which enabled cell-type-specific analysis of glutamate and ethylamine (two precursors of theanine biosynthesis) metabolism, and theanine biosynthesis, storage, and transport. Our findings support a model in which the theanine biosynthesis pathway occurs via multicellular compartmentation and does not require high co-expression levels of transcription factors and their target genes within the same cell cluster. This study provides novel insights into theanine metabolism and regulation, at the single-cell level, and offers an example for studying root-specific secondary metabolism in other plant systems., Competing Interests: SL, YZ, SZ, YW, MH, YD, JG, BZ, TY, EX, XW, WL, ZZ No competing interests declared, (© 2024, Lin, Zhang et al.)

Background: Most of its issues are still undecided on the relationship between tumour mutation burden (TMB) and immune-related genes in the breast cancer. This study explores their relationship based on gene mutation and transcription data in The Cancer Genome Atlas (TCGA) database, and the effects of immune cells in TMB and tumour microenvironments on prognosis of breast cancer patients., Methods: Cases were divided into low-TMB and high-TMB subgroups. Differentially expressed immune-related genes were identified in different TMB subgroups, and patient prognosis was predicted by gene function enrichment analysis, invasive immune cells and different clinical pathological features were compared among different TMB subgroups., Results: A total of 986 mutation data from breast cancer patients were obtained. Compared with low-TMB group, the survival period of high-TMB group was relatively longer. A total of 337 differential expression genes were identified in this study. Of these genes, seven differentially expressed immune-related genes were associated with prognosis. In the high-TMB group, activated CD4+ memory T cells and other cells had high expression, the expression ratio of memory B cells and other cells in low-TMB group was high., Conclusions: TMB-related immunological infiltration characteristics showed meaningful value for prognosis prediction for breast cancer patients. Differentially expressed immune-related genes in TMB subgroups provide important information on the survival prediction., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tcr.amegroups.com/article/view/10.21037/tcr-23-2195/coif). The authors have no conflicts of interest to declare., (2024 Translational Cancer Research. All rights reserved.)