bims-tuchim 2021-02-28 papers

Int J Biochem Cell Biol. 2021 Feb 23. pii: S1357-2725(21)00044-3. [Epub ahead of print] 105960

Netrin-4 expression by human endothelial cells inhibits endothelial inflammation and senescence.

Huayu Zhang, Dianne Vreeken, Danielle G Leuning, Caroline S Bruikman, Abidemi Junaid, Wendy Stam, Ruben G de Bruin, Wendy M P J Sol, Ton J Rabelink, Bernard M van den Berg, Anton Jan van Zonneveld, Janine M van Gils.

Netrin-4, recognized in neural and vascular development, is highly expressed by mature endothelial cells. The function of this netrin-4 in vascular biology after development has remained unclear. We found that the expression of netrin-4 is highly regulated in endothelial cells and is important for quiescent healthy endothelium. Netrin-4 expression is upregulated in endothelial cells cultured under laminar flow conditions, while endothelial cells stimulated with tumor necrosis factor alpha resulted in decreased netrin-4 expression. Targeted reduction of netrin-4 in endothelial cells resulted in increased expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1. Besides, these endothelial cells were more prone to monocyte adhesion and showed impaired barrier function, measured in electric cell-substrate impedance sensing system, as well as in an 'organ-on-a-chip' microfluidic system. Importantly, endothelial cells with reduced levels of netrin-4 showed increased expression of the senescence-associated markers cyclin-dependent kinase inhibitor-1 and -2A, an increased cell size and decreased ability to proliferate. Consistent with the gene expression profile, netrin-4 reduction was accompanied with more senescent associated β-galactosidase activity, which could be rescued by adding netrin-4 protein. Finally, using human decellularized kidney extracellular matrix scaffolds, we found that pre-treatment of the scaffolds with netrin-4 increased numbers of endothelial cells adhering to the matrix, showing a pro-survival effect of netrin-4. Taken together, netrin-4 acts as an anti-senescence and anti-inflammation factor in endothelial cell function and our results provide insights as to maintain endothelial homeostasis and supporting vascular health.

Keywords: barrier function; endothelial cells; inflammation; netrin-4; senescence

DOI: https://doi.org/10.1016/j.biocel.2021.105960

Nat Immunol. 2021 Mar;22(3): 274-276

BAtCHing stem-like T cells during exhaustion.

Lara Labarta-Bajo, Elina I Zúñiga.

DOI: https://doi.org/10.1038/s41590-021-00891-8

Carcinogenesis. 2021 Feb 24. pii: bgab011. [Epub ahead of print]

LAMC2 promotes cancer progression and gemcitabine resistance through modulation of EMT and ATP-binding cassette transporters in pancreatic ductal adenocarcinoma.

Yasuyuki Okada, Naoki Takahashi, Tetsuji Takayama, Ajay Goel.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease with poor prognosis. Gemcitabine remains an effective option for the majority of PDAC patients. Unfortunately, currently no reliable prognostic and predictive biomarkers of therapeutic response are available for the patients with PDAC. Laminin γ2 (LAMC2) is overexpressed in several cancers, and its high expression facilitates cancer development and chemoresistance. However, its functional role in PDAC remains unclear, and a better understanding of this will likely help improve the prognosis of PDAC patients. This study aimed to elucidate the clinical and biological role of LAMC2 in PDAC. We first analyzed the expression levels of LAMC2 by real-time reverse transcription PCR in a cohort of 114 PDAC patients. Interestingly, higher expression of LAMC2 significantly correlated with poor survival in PDAC cohort. In addition, elevated LAMC2 expression served as a potential prognostic marker for survival. Subsequently, functional characterization for the role of LAMC2 in PDAC was performed by small interfering RNA (siRNA) knockdown in pancreatic cancer (PC) cell lines. Interestingly, inhibition of LAMC2 in PC cells enhanced the gemcitabine sensitivity and induction of apoptosis. Moreover, it inhibited colony formation ability, migration, and invasion potential. Furthermore, LAMC2 regulated the expression of epithelial-mesenchymal transition (EMT) phenotype. In addition, LAMC2 significantly correlated with genes associated with the expression of ATP-binding cassette (ABC) transporters in PC cells and PDAC patients. In conclusion, these results suggest that LAMC2 regulates gemcitabine sensitivity through EMT and ABC transporters in PDAC and may be a novel therapeutic target in PDAC patients.

Keywords: ABC transporter; EMT; LAMC2; gemcitabine; pancreatic ductal adenocarcinoma

DOI: https://doi.org/10.1093/carcin/bgab011