A single-cell atlas of Drosophila trachea reveals glycosylation-mediated Notch signaling in cell fate specification.

The Drosophila tracheal system is a favorable model for investigating the program of tubular morphogenesis. This system is established in the embryo by post-mitotic cells, but also undergoes remodeling by adult stem cells. Here, we provide a comprehensive cell atlas of Drosophila trachea using the single-cell RNA-sequencing (scRNA-seq) technique. The atlas documents transcriptional profiles of tracheoblasts within the Drosophila airway, delineating 9 major subtypes. Further evidence gained from in silico as well as genetic investigations highlight a set of transcription factors characterized by their capacity to switch cell fate. Notably, the transcription factors Pebbled, Blistered, Knirps, Spalt and Cut are influenced by Notch signaling and determine tracheal cell identity. Moreover, Notch signaling orchestrates transcriptional activities essential for tracheoblast differentiation and responds to protein glycosylation that is induced by high sugar diet. Therefore, our study yields a single-cell transcriptomic atlas of tracheal development and regeneration, and suggests a glycosylation-responsive Notch signaling in cell fate determination.

PCNP is a novel regulator of proliferation, migration, and invasion in human thyroid cancer.

Thyroid cancer (TC) has increased globally, with a prominent increase in small, papillary thyroid cancers. PEST-containing nuclear protein (PCNP), a nuclear protein, has been found to be associated with human cancers in recent years. However, the role and molecular mechanism of PCNP in thyroid cancer remain underexplored. In the present study, the results showed that the expression levels of PCNP in human thyroid tissues were higher than those in adjacent non-tumor tissues. Overexpression of PCNP reduced the proliferation, migration, and invasion of human thyroid cancer cells and down-regulation of PCNP showed reverse effects. In addition, PCNP regulated cell cycle arrest through modifications in the expression of cell cycle regulating genes and PCNP affected apoptosis via activation of ERK/JNK/p38 pathway in thyroid cancer cells. Moreover, PCNP overexpression promoted autophagy by reducing the expression levels of Wnt/ß-catenin pathway in TC cells, however, PCNP knockdown had opposite effects. Furthermore, PCNP overexpression reduced the growth of xenografted human thyroid cancer, whereas PCNP knockdown showed opposite trends. In conclusion, in vitro and in vivo data demonstrate that PCNP as a tumor suppressor gene may serve as a novel prognostic and potential therapeutic marker in human thyroid cancer.

Metabolic control of progenitor cell propagation during Drosophila tracheal remodeling.

Adult progenitor cells in the trachea of Drosophila larvae are activated and migrate out of niches when metamorphosis induces tracheal remodeling. Here we show that in response to metabolic deficiency in decaying tracheal branches, signaling by the insulin pathway controls the progenitor cells by regulating Yorkie (Yki)-dependent proliferation and migration. Yki, a transcription coactivator that is regulated by Hippo signaling, promotes transcriptional activation of cell cycle regulators and components of the extracellular matrix in tracheal progenitor cells. These findings reveal that regulation of Yki signaling by the insulin pathway governs proliferation and migration of tracheal progenitor cells, thereby identifying the regulatory mechanism by which metabolic depression drives progenitor cell activation and cell division that underlies tracheal remodeling.

PCNP promotes ovarian cancer progression by accelerating ß-catenin nuclear accumulation and triggering EMT transition.

Ever reports showed that PCNP is associated with human cancers including neuroblastoma and lung cancer. However, the role and underlying molecular mechanism of PCNP in ovarian cancer have not been plenty elucidated. Herein, we first investigated the expression of PCNP in ovarian cancer tissues and cells, the effects of PCNP in ovarian cancer proliferation, apoptosis, migration and invasion, and determined the molecular mechanism of PCNP in ovarian cancer progression. The results indicated that PCNP was significantly overexpressed in human ovarian cancer tissues and cells, and related to poor prognosis in ovarian cancer patients. In addition, we also detected that PCNP promoted ovarian cancer cells growth, migration and invasion, as well as inhibited ovarian cancer cells apoptosis. Mechanistically, PCNP binding to ß-catenin promoted ß-catenin nuclear translocation and further activated Wnt/ß-catenin signalling pathway. Moreover, PCNP regulated the expression of genes involved in EMT and further triggered EMT occurrence. Conclusionally, PCNP may promote ovarian cancer progression through activating Wnt/ß-catenin signalling pathway and EMT, acting as a novel and promising target for treating ovarian cancer.

PEST-containing nuclear protein regulates cell proliferation, migration, and invasion in lung adenocarcinoma.

Lung cancer is the leading cause of cancer-related mortality worldwide. PEST-containing nuclear protein (PCNP) has been found in the nucleus of cancer cells. Whether PCNP plays a role in the growth of lung adenocarcinoma is still unknown. In the present study, the results indicated that the level of PCNP in lung adenocarcinoma tissue was significantly higher than that in corresponding adjacent non-tumor tissue. Over-expression of PCNP promoted the proliferation, migration, and invasion of lung adenocarcinoma cells, while down-regulation of PCNP exhibited opposite effects. PCNP over-expression decreased apoptosis through up-regulating the expression levels of phospho (p)-signal transducers and activators of transcription (STAT) 3 and p-STAT5 in lung adenocarcinoma cells, whereas PCNP knockdown showed opposite trends. PCNP overexpression enhanced autophagy by increasing the expression levels of p-phosphatidylinositol 3-kinase (PI3K), p-Akt, and p-mammalian target of rapamycin (mTOR) in lung adenocarcinoma cells, however an opposite trend was observed in the sh-PCNP group. In addition, overexpression of PCNP showed the tumor-promoting effect on xenografted lung adenocarcinoma, while PCNP knockdown reduced the growth of lung adenocarcinoma via regulating angiogenesis. Our study elucidates that PCNP can regulate the procession of human lung adenocarcinoma cells via STAT3/5 and PI3K/Akt/mTOR signaling pathways. PCNP may be considered as a promising biomarker for the diagnosis and prognosis in patients with lung adenocarcinoma. Furthermore, PCNP can be a novel therapeutic target and potent PCNP inhibitors can be designed and developed in the treatment of lung adenocarcinoma.

Tumour necrosis factor-α-induced protein 8-like 2 is a novel regulator of proliferation, migration, and invasion in human rectal adenocarcinoma cells.

Tumour necrosis factor-α-induced protein 8-like 2 (TIPE2) is a tumour suppressor in many types of cancer. However, the mechanism of action of TIPE2 on the growth of rectal adenocarcinoma is unknown. Our results showed that the expression levels of TIPE2 in human rectal adenocarcinoma tissues were higher than those in adjacent non-tumour tissues. Overexpression of TIPE2 reduced the proliferation, migration, and invasion of human rectal adenocarcinoma cells and down-regulation of TIPE2 showed reverse effects. TIPE2 overexpression increased apoptosis through down-regulating the expression levels of Wnt3a, phospho (p)-ß-Catenin, and p-glycogen synthase kinase-3ß in rectal adenocarcinoma cells, however, TIPE2 knockdown exhibited reverse trends. TIPE2 overexpression decreased autophagy by reducing the expression levels of p-Smad2, p-Smad3, and transforming growth factor-beta (TGF-ß) in rectal adenocarcinoma cells, however, TIPE2 knockdown showed opposite effects. Furthermore, TIPE2 overexpression reduced the growth of xenografted human rectal adenocarcinoma, whereas TIPE2 knockdown promoted the growth of rectal adenocarcinoma tumours by modulating angiogenesis. In conclusion, TIPE2 could regulate the proliferation, migration, and invasion of human rectal adenocarcinoma cells through Wnt/ß-Catenin and TGF-ß/Smad2/3 signalling pathways. TIPE2 is a potential therapeutic target for the treatment of rectal adenocarcinoma.

Hydrogen Sulfide Alleviates Lipopolysaccharide-Induced Diaphragm Dysfunction in Rats by Reducing Apoptosis and Inflammation through ROS/MAPK and TLR4/NF-κB Signaling Pathways.

Diaphragm dysfunction is an important clinical problem worldwide. Hydrogen sulfide (H2S) is involved in many physiological and pathological processes in mammals. However, the effect and mechanism of H2S in diaphragm dysfunction have not been fully elucidated. In this study, we detected that the level of H2S was decreased in lipopolysaccharide- (LPS-) treated L6 cells. Treatment with H2S increased the proliferation and viability of LPS-treated L6 cells. We found that H2S decreased reactive oxygen species- (ROS-) induced apoptosis through the mitogen-activated protein kinase (MAPK) signaling pathway in LPS-treated L6 cells. Administration of H2S alleviated LPS-induced inflammation by mediating the toll-like receptor-4 (TLR-4)/nuclear factor-kappa B (NF-κB) signaling pathway in L6 cells. Furthermore, H2S improved diaphragmatic function and structure through the reduction of inflammation and apoptosis in the diaphragm of septic rats. In conclusion, these findings indicate that H2S ameliorates LPS-induced diaphragm dysfunction in rats by reducing apoptosis and inflammation through ROS/MAPK and TLR4/NF-κB signaling pathways. Novel slow-releasing H2S donors can be designed and applied for the treatment of diaphragm dysfunction.