Large-Scale Production of Recombinant Noggin and R-Spondin1 Proteins Required for the Maintenance of Stem Cells in Intestinal Organoid Cultures

ELABELA-APJ-Akt/YAP Signaling Axis: A Novel Mechanism of Aerobic Exercise in Cardioprotection of Myocardial Infarction Rats

PURPOSE

The aim of this study was to investigate the function and mechanisms of ELABELA (ELA) in the aerobic exercise-induced antiapoptosis and angiogenesis of ischemic heart.

METHODS

The myocardial infarction (MI) model of Sprague-Dawley rat was established by the ligation of the left anterior descending coronary artery. MI rats underwent 5 wk of Fc-ELA-21 subcutaneous injection and aerobic exercise training using a motorized rodent treadmill. Heart function was evaluated by hemodynamic measures. Cardiac pathological remodeling was evaluated by Masson's staining and the calculation of left ventricular weight index. Cell proliferation, angiogenesis, and Yes-associated protein (YAP) translocation were observed by immunofluorescence staining. Cell apoptosis was analyzed by TUNEL. Cell culture and treatment were used to elucidate the molecular mechanism of ELA. Protein expression was detected by Western blotting. Angiogenesis was observed by tubule formation test. One-way or two-way ANOVA and Student's t -test were used for statistical analysis.

RESULTS

Aerobic exercise stimulated the endogenous ELA expression. Exercise and Fc-ELA-21 intervention significantly activated APJ-Akt-mTOR-P70S6K signaling pathway, kept more cardiomyocytes alive, and increased angiogenesis, so as to inhibit the cardiac pathological remodeling and improved the heart function of MI rats. Fc-ELA-32 also had the cellular and functional cardioprotective activities in vivo . In vitro , ELA-14 peptide regulated the phosphorylation and nucleoplasmic translocation of YAP and activated the APJ-Akt signaling pathway so as to increase the proliferation of H9C2 cells. Moreover, the antiapoptosis and the tubule formation of HUVECs were also enhanced by ELA-14, whereas the inhibition of Akt activity weakened such effects.

CONCLUSIONS

ELA is a potential therapeutic member that plays a key role through APJ-Akt/YAP signaling axis in aerobic exercise-induced cardioprotection of MI rats.

In Vitro and in Vivo Assays for Testing Retinoids Effect on Intestinal Progenitors' Lineage Commitments

The intestine consists of epithelial cells surrounded by a complex environment as mesenchymal cells and the gut microbiota. With its impressive stem cell regeneration capability, the intestine is able to constantly replenish cells lost through apoptosis or abrasion by food passing through. Over the past decade, researchers have identified signaling pathways involved in stem cell homeostasis such as retinoids pathway. Retinoids are also involved in cell differentiation of healthy and cancer cells. In this study, we describe several approaches in vitro and in vivo to further investigate the effect of retinoids on stem cells, progenitors, and differentiated intestinal cells.

A novel protein fusion partner, carbohydrate-binding module family 66, to enhance heterologous protein expression in Escherichia coli

Background

Proteins with novel functions or advanced activities developed by various protein engineering techniques must have sufficient solubility to retain their bioactivity. However, inactive protein aggregates are frequently produced during heterologous protein expression in Escherichia coli. To prevent the formation of inclusion bodies, fusion tag technology has been commonly employed, owing to its good performance in soluble expression of target proteins, ease of application, and purification feasibility. Thus, researchers have continuously developed novel fusion tags to expand the expression capacity of high-value proteins in E. coli.

Results

A novel fusion tag comprising carbohydrate-binding module 66 (CBM66) was developed for the soluble expression of heterologous proteins in E. coli. The target protein solubilization capacity of the CBM66 tag was verified using seven proteins that are poorly expressed or form inclusion bodies in E. coli: four human-derived signaling polypeptides and three microbial enzymes. Compared to native proteins, CBM66-fused proteins exhibited improved solubility and high production titer. The protein-solubilizing effect of the CBM66 tag was compared with that of two commercial tags, maltose-binding protein and glutathione-S-transferase, using poly(ethylene terephthalate) hydrolase (PETase) as a model protein; CBM66 fusion resulted in a 3.7-fold higher expression amount of soluble PETase (approximately 370 mg/L) compared to fusion with the other commercial tags. The intact PETase was purified from the fusion protein upon serial treatment with enterokinase and affinity chromatography using levan-agarose resin. The bioactivity of the three proteins assessed was maintained even when the CBM66 tag was fused.

Conclusions

The use of the CBM66 tag to improve soluble protein expression facilitates the easy and economic production of high-value proteins in E. coli.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01725-w.