miR-222 inhibits cardiac fibrosis in diabetic mice heart via regulating Wnt/β-catenin-mediated endothelium to mesenchymal transition

miR-222 participates in many cardiovascular diseases, but its effect on cardiac remodeling induced by diabetes is unclear. This study evaluated the functional role of miR-222 in cardiac fibrosis in diabetic mice. Streptozotocin (STZ) was used to establish a type 1 diabetic mouse model. After 10 weeks of STZ injection, mice were intravenously injected with Ad-miR-222 to induce the overexpression of miR-222. miR-222 overexpression reduced cardiac fibrosis and improved cardiac function in diabetic mice. Mechanistically, miR-222 inhibited the endothelium to mesenchymal transition (EndMT) in diabetic mouse hearts. Mouse heart fibroblasts and endothelial cells were isolated and cultured with high glucose (HG). An miR-222 mimic did not affect HG-induced fibroblast activation and function but did suppress the HG-induced EndMT process. The antagonism of miR-222 by antagomir inhibited HG-induced EndMT. miR-222 regulated the promoter region of β-catenin, thus negatively regulating the Wnt/β-catenin pathway, which was confirmed by β-catenin siRNA. Taken together, our results indicated that miR-222 inhibited cardiac fibrosis in diabetic mice via negatively regulating Wnt/β-catenin-mediated EndMT.     

Dielectric Properties of Normal and Metastatic Lymph Nodes Ex Vivo From Lung Cancer Surgeries

The dielectric properties of normal and tumor human tissues have been widely reported in recent years. However, the dielectric properties of intrathoracic lymph nodes (LNs) have not been reported. In this communication, we measured the dielectric properties (i.e., permittivity and conductivity) of ex vivo intrathoracic LNs obtained from lung cancer surgeries. Results show that the permittivity and conductivity of metastatic LNs are higher than those of normal LNs over the frequency range of 1 MHz–4 GHz. Statistically significant differences are observed at single specific frequencies (64, 128, 298, 433, and 915 MHz and 2.45 GHz). Our study provides the basic data to support future-related research and fills the research gap on the dielectric properties of LNs in the lungs. Bioelectromagnetics. 2020;41:148–155. © 2020 Bioelectromagnetics Society.     

Integrated bioinformatics analysis revealed the regulation of angiogenesis by tumor cells in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality, metastasis accounts for most of the cases. Angiogenesis plays an important role in cancer metastasis, but how tumor cells affect the function of endothelial cells by dictating their microRNA (miRNA) expression remains largely unknown.Differentially expressed miRNAs (DEMs) were identified through dataset downloaded from the Gene Expression Omnibus (GEO) database and analyzed by GEO2R. We then used online tools to obtain potential targets of candidate miRNAs and functional enrichment analysis, as well as the protein-protein interaction (PPI). Finally, the function of miR-302c-3p was validated through in vitro assay.In the current study, we found that HCC cells altered miRNA expression profiles of human umbilical vein endothelial cells (HUVECs) and miR-302c-3p was the most down-regulated miRNA in HUVECs when they were co-cultured with HCC-LM3 cells. Functional enrichment analysis of the candidate targets revealed that these genes were involved in epigenetic regulation of gene expression, in particular, cytosine methylation. In addition, PPI network demonstrated distinct roles of genes targeted by miR-302c-3p. Importantly, inhibition of angiogenesis, migration and permeability by the most down-regulated miR-302c-3p in HUVECs was confirmed in vitro. These findings brought us novel insight into the regulation of angiogenesis by HCC cells and provided potential targets for the development of therapeutic strategies.     

Prostasomes from four different species are able to produce extracellular adenosine triphosphate (ATP)

Background

Prostasomes are extracellular vesicles. Intracellularly they are enclosed by another larger vesicle, a so called “storage vesicle” equivalent to a multivesicular body of late endosomal origin. Prostasomes in their extracellular context are thought to play a crucial role in fertilization.

Methods

Prostasomes were purified according to a well worked-out schedule from seminal plasmas obtained from human, canine, equine and bovine species. The various prostasomes were subjected to SDS-PAGE separation and protein banding patterns were compared. To gain knowledge of the prostasomal protein systems pertaining to prostasomes of four different species proteins were analyzed using a proteomic approach. An in vitro assay was employed to demonstrate ATP formation by prostasomes of different species.

Results

The SDS-PAGE banding pattern of prostasomes from the four species revealed a richly faceted picture with most protein bands within the molecular weight range of 10–150 kDa. Some protein bands seemed to be concordant among species although differently expressed and the number of protein bands of dog prostasomes seemed to be distinctly fewer. Special emphasis was put on proteins involved in energy metabolic turnover. Prostasomes from all four species were able to form extracellular adenosine triphosphate (ATP). ATP formation was balanced by ATPase activity linked to the four types of prostasomes.

Conclusion

These potencies of a possession of functional ATP-forming enzymes by different prostasome types should be regarded against the knowledge of ATP having a profound effect on cell responses and now explicitly on the success of the sperm cell to fertilize the ovum.

General significance

This study unravels energy metabolic relationships of prostasomes from four different species.     

Electrically tunable organic bioelectronics for spatial and temporal manipulation of neuron-like pheochromocytoma (PC-12) cells

Background

Organic bioelectronic devices consisting of alternating poly(3,4-ethylenedioxythiophene) (PEDOT) and reduced graphite oxide (rGO) striped microelectrode arrays were fabricated by lithography technology. It has been demonstrated that the organic bioelectronic devices can be used to spatially and temporally manipulate the location and proliferation of the neuron-like pheochromocytoma cells (PC-12 cells).

Methods

By coating an electrically labile contact repulsion layer of poly(l-lysine-graft-ethylene glycol) (PLL-g-PEG) on the PEDOT electrode, the location and polarity of the PC-12 cells were confined to the rGO electrodes.

Results

The outgrowth of spatially confined bipolar neurites was found to align along the direction of the 20 μm wide electrode. The location of the PC-12 cells can also be manipulated temporally by applying electrical stimulation during the neurite differentiation of PC-12 cells, allowing the PC-12 cells to cross over the boundary between the PEDOT and the rGO regions and construct neurite networks in an unconfined manner where the contact repulsive coating of PLL-g-PEG was removed.

Conclusions

This adsorption and desorption of the PLL-g-PEG without and with electrical stimulation can be attributed to the tunable surface properties of the PEDOT microelectrodes, whose surface charge can switch from being negative to positive under electrical stimulation.

General significance

The electrically tunable organic bioelectronics reported here could potentially be applied to tissue engineering related to the development and regeneration of mammalian nervous systems. The spatial and temporal control in this device would also be used to study the synapse junctions of neuron–neuron contacts in both time and space domains. This article is part of a Special Issue entitled Organic Bioelectronics — Novel Applications in Biomedicine.     

Stimulation of σ1-receptor restores abnormal mitochondrial Ca mobilization and ATP production following cardiac hypertrophy

Background

We previously reported that the σ₁-receptor (σ₁R) is down-regulated following cardiac hypertrophy and dysfunction in transverse aortic constriction (TAC) mice. Here we address how σ₁R stimulation with the selective σ₁R agonist SA4503 restores hypertrophy-induced cardiac dysfunction through σ₁R localized in the sarcoplasmic reticulum (SR).

Methods

We first confirmed anti-hypertrophic effects of SA4503 (0.1–1 μM) in cultured cardiomyocytes exposed to angiotensin II (Ang II). Then, to confirm the ameliorative effects of σ₁R stimulation in vivo, we administered SA4503 (1.0 mg/kg) and the σ₁R antagonist NE-100 (1.0 mg/kg) orally to TAC mice for 4 weeks (once daily).

Results

σ₁R stimulation with SA4503 significantly inhibited Ang II-induced cardiomyocyte hypertrophy. Ang II exposure for 72 h impaired phenylephrine (PE)-induced Ca^2 + mobilization from the SR into both the cytosol and mitochondria. Treatment of cardiomyocytes with SA4503 largely restored PE-induced Ca^2 + mobilization into mitochondria. Exposure of cardiomyocytes to Ang II for 72 h decreased basal ATP content and PE-induced ATP production concomitant with reduced mitochondrial size, while SA4503 treatment completely restored ATP production and mitochondrial size. Pretreatment with NE-100 or siRNA abolished these effects. Chronic SA4503 administration also significantly attenuated myocardial hypertrophy and restored ATP production in TAC mice. SA4503 administration also decreased hypertrophy-induced impairments in LV contractile function.

Conclusions

σ₁R stimulation with the specific agonist SA4503 ameliorates cardiac hypertrophy and dysfunction by restoring both mitochondrial Ca^2 + mobilization and ATP production via σ₁R stimulation.

General significance

Our observations suggest that σ₁R stimulation represents a new therapeutic strategy to rescue the heart from hypertrophic dysfunction.