Background and Purpose
Mitochondrial dysfunction plays a role in the progression of cardiovascular diseases including heart failure. 3‐Hydroxy‐3‐methylglutaryl‐CoA reductase inhibitors (statins), ...which inhibit ROS synthesis, show cardioprotective effects in chronic heart failure. However, the beneficial role of statins in mitochondrial protection in heart failure remains unclear.
Experimental Approach
Rats were treated with angiotensin II (1.5 mg·kg−1·day−1) or co‐administered simvastatin (oral, 10 mg·kg−1) for 14 days; and then administration was stopped for the following 14 days. Cardiac structure/function was examined by wheat germ agglutinin staining and echocardiography. Mitochondrial morphology and the numbers of lipid droplets, lysosomes, autophagosomes, and mitophagosomes were determined by transmission electron microscopy. Human cardiomyocytes were stimulated, and intracellular ROS and mitochondrial membrane potential (ΔΨm) changes were measured by flow cytometry and JC‐1 staining, respectively. Autophagy and mitophagy‐related and mitochondria‐regulated apoptotic proteins were identified by immunohistochemistry and western blotting.
Key Results
Simvastatin significantly reduced ROS production and attenuated the disruption of ΔΨm. Simvastatin induced the accumulation of lipid droplets to provide energy for maintaining mitochondrial function, promoted autophagy and mitophagy, and inhibited mitochondria‐mediated apoptosis. These findings suggest that mitochondrial protection mediated by simvastatin plays a therapeutic role in heart failure prevention by modulating antioxidant status and promoting energy supplies for autophagy and mitophagy to inhibit mitochondrial damage and cardiomyocyte apoptosis.
Conclusion and Implications
Mitochondria play a key role in mediating heart failure progression. Simvastatin attenuated heart failure, induced by angiotensin II, via mitochondrial protection and might provide a new therapy to prevent heart failure.
Exosomes are implicated in cancer cell development, migration and invasion. Pigment epithelium-derived factor (PEDF) is a secreted anticancer protein that can regulate lung cancer progression; ...however, the role of PEDF in non-small cell lung cancer (NSCLC), including metastasis and cancer cell-derived exosome secretion, is unclear. In this study, we analyzed the effects of PEDF on exosome-mediated migration, invasion, and tumorigenicity of cultured NSCLC cells. The results showed that PEDF overexpression significantly reduced NSCLC invasion and migration, while inducing cell aggregation, whereas PEDF knockdown had the opposite effects. Exosomes from NSCLC cells treated with recombinant PEDF had a significantly reduced ability to promote cancer cell motility, migration, and invasion compared to exosomes from untreated cells. Exosomes from PEDF-treated cells contained thrombospondin 1 (THBS1), which inhibited cytoskeletal remodeling and exosome-induced lung cancer cell motility, migration, and invasion. Furthermore, PEDF-overexpressing NSCLC cells formed smaller xenograft tumors with higher THBS1 expression compared to control tumors. Our findings indicate that PEDF decreases the metastatic potential of NSCLC cells through regulation of THBS1 release in cancer cell-derived exosomes, thus uncovering a new mechanism of lung cancer progression.
•PEDF induces aggregation and reduces invasion and migration of lung cancer cells.•Exosomes from PEDF-treated cancer cells inhibit metastatic behavior of NSCLC cells.•PEDF-expressing NSCLC cells have reduced tumorigenicity in vivo.•PEDF increases thrombospondin 1 content in lung cancer cell-derived exosomes.•Thrombospondin 1 inhibits exosome-induced lung cancer cell migration and invasion.
Tumor-derived extracellular vesicles (TEVs) are membrane-bound, nanosized vesicles released by cancer cells and taken up by cells in the tumor microenvironment to modulate the molecular makeup and ...behavior of recipient cells. In this report, we summarize the pivotal roles of TEVs involved in bladder cancer (BC) development, progression and treatment resistance through transferring their bioactive cargos, including proteins and nucleic acids. We also report on the molecular profiling of TEV cargos derived from urine and blood of BC patients as non-invasive disease biomarkers. The current hurdles in EV research and plausible solutions are discussed.
Cell morphology and migration depend critically on the adhesions on the extracellular matrix (ECM), determined by the transmembrane protein integrins. The epithelial to mesenchymal transition (EMT) ...is a prominent transformation process in which adherent cells acquire a mesenchymal phenotype and a promoted migration. EMT plays important roles in embryonic development and cancer metastasis, and its hallmarks include the acquisition of front‐back cell polarity and loss of cell–cell contact. However, how integrins dynamically regulate cell‐ECM adhesions and cellular behaviors during EMT is still unclear. Using single‐particle tracking of β1‐integrins labeled with quantum dots, the temporal‐spatial on‐membrane dynamics of integrins in the EMT of MCF10A cells is revealed. β1‐integrins exhibit significantly enhanced dynamics, which temporally behave more diffusive and less immobilized, and spatially become distributed asymmetrically with front regions being more dynamic. These dynamic alterations are shown to arise from microtubule remodeling in EMT. The results shed new light on the EMT mechanism from the cell‐ECM adhesion perspective, and suggest that the enhanced integrin diffusion may represent as a new hallmark of EMT.
Transmembrane protein integrins, as a key component of cell adhesions connecting cells to extracellular matrix, are labeled with single quantum dots through an antibody–biotin–streptavidin strategy. By single‐particle tracking of integrins on living‐cell membranes, a significant enhancement in integrin diffusion dynamics during the epithelial‐mesenchymal transformation (EMT) is discovered. This enables better identification of EMT at the single‐cell level than traditional biological methods.
In this paper, we apply the Turán sieve and the simple sieve developed by R. Murty and the first author to study problems in random graph theory. In particular, we obtain upper and lower bounds on ...the probability of a graph on
n
vertices having diameter 2 (or diameter 3 in the case of bipartite graphs) with edge probability
p
where the edges are chosen independently. An interesting feature revealed in these results is that the Turán sieve and the simple sieve “almost completely” complement each other. As a corollary to our result, we note that the probability of a random graph having diameter 2 approaches 1 as
n
→
∞
for constant edge probability
p
=
1
/
2
.
Immunogenicity is critical for biologics. However, reference biologics labeling documents do not necessarily mention immunogenicity impact, rendering the development of biosimilars more challenging. ...We aimed to investigate the comparative assessment of immunogenicity profiles between biosimilars and their respective reference biologics in the review reports of the biosimilar monoclonal antibody applications approved by the Center for Drug Evaluation and Research (CDER), US Food and Drug Administration (FDA) as of March 13, 2022, covering 22 applications approved between April 5, 2016, and December 17, 2021. The maximum differences in anti-drug antibody (ADA) and neutralizing antibody (NAb) incidences between biosimilars and reference products mostly fell within ± 15% (-13.6% to 12%) and ± 20% (-17.4% to 17.1%, except extreme values of -23.4% and 66.7%), respectively. In comparison with antineoplastic agents, more immunosuppressants had ADA-positive (11/11, 100.0% vs. 8/10, 80.0%)/NAb-positive (11/11, 100.0% vs. 3/10, 30.0%) subjects, and the distribution of the aforementioned incidence differences was wider. The investigated biosimilars with available data for analysis demonstrated a high degree of consistency with their reference products in terms of the impact on pharmacokinetic parameters. No increase in immunogenicity was found in available switching studies. Most (16/22, 72.7%) biosimilars were issued post-marketing requirements that were not directly related to immunogenicity concerns. The FDA considered the totality of evidence assessing clinical consequences of immunogenicity differences, if any. Additional information on titers and subgroup analysis may be warranted to elucidate the critical attributes of immunogenicity impact and to aid in forming cost-effective strategies for biosimilar development.
Pulmonary artery hypertension (PAH) pathology involves extracellular matrix (ECM) remodeling in cardiac tissues, thus promoting cardiac fibrosis progression. miR-29a-3p reportedly inhibits lung ...progression and liver fibrosis by regulating ECM protein expression; however, its role in PAH-induced fibrosis remains unclear. In this study, we aimed to investigate the role of miR-29a-3p in cardiac fibrosis progression in PAH and its influence on ECM protein thrombospondin-2 (THBS2) expression. The diagnostic and prognostic values of miR-29a-3p and THBS2 in PAH were evaluated. The expressions and effects of miR-29a-3p and THBS2 were assessed in cell culture, monocrotaline-induced PAH mouse model, and patients with PAH. The levels of circulating miR-29a-3p and THBS2 in patients and mice with PAH decreased and increased, respectively. miR-29a-3p directly targets THBS2 and regulates THBS2 expression via a direct anti-fibrotic effect on PAH-induced cardiac fibrosis. The circulating levels of miR-29a-3p and THBS2 were correlated with PAH diagnostic parameters, suggesting their independent prognostic value. miR-29a-3p targeted THBS2 expression via a direct anti-fibrotic effect on PAH-induced cardiac fibrosis, indicating miR-29a-3p acts as a messenger with promising therapeutic effects.
Intracellular transport of cellular proteins and organelles is critical for establishing and maintaining intracellular organization and cell physiology. Apoptosis is a process of programmed cell ...death with dramatic changes in cell morphology and organization, during which signaling molecules are transported between different organelles within the cells. However, how the intracellular transport changes in cells undergoing apoptosis remains unknown. Here, we study the dynamics of intracellular transport by using the single-particle tracking method and find that both directed and diffusive motions of endocytic vesicles are accelerated in early apoptotic cells. With careful elimination of other factors involved in the intracellular transport, the reason for the acceleration is attributed to the elevation of adenosine triphosphate (ATP) concentration. More importantly, we show that the accelerated intracellular transport is critical for apoptosis, and apoptosis is delayed when the dynamics of intracellular transport is regulated back to the normal level. Our results demonstrate the important role of transport dynamics in apoptosis and shed light on the apoptosis mechanism from a physical perspective.
Let
$k\geqslant 1$
be a natural number and
$\omega _k(n)$
denote the number of distinct prime factors of a natural number n with multiplicity k. We estimate the first and second moments of the ...functions
$\omega _k$
with
$k\geqslant 1$
. Moreover, we prove that the function
$\omega _1(n)$
has normal order
$\log \log n$
and the function
$(\omega _1(n)-\log \log n)/\sqrt {\log \log n}$
has a normal distribution. Finally, we prove that the functions
$\omega _k(n)$
with
$k\geqslant 2$
do not have normal order
$F(n)$
for any nondecreasing nonnegative function F.
Thrombospondin‐1 (TSP1) is involved in corneal wound healing caused by chemical injury. Herein, we examined the effects of TSP1 on hypoxia‐induced damages and wound‐healing activity in human corneal ...epithelial (HCE) cells. Exosomal protein expression was determined using liquid chromatography‐tandem mass spectrometry, and HCE cell migration and motility were examined through wound‐healing assay and time‐lapse microscopy. Reestablishment of cell junctions by TSP1 was assessed through confocal microscopy and 3D image reconstruction. Our results show that CoCl2‐induced hypoxia promoted HCE cell death by paraptosis. TSP1 protected these cells against paraptosis by attenuating mitochondrial membrane potential depletion, swelling and dilation of endoplasmic reticulum and mitochondria, and mitochondrial fission. Exosomes isolated from HCE cells treated with TSP1 contained wound healing‐associated proteins that were taken up by HCE cells to promote tissue remodeling and repair. TSP1 protected HCE cells against hypoxia‐induced damages and inhibited paraptosis progression by promoting cell migration, cell‐cell adhesion, and extracellular matrix remodeling. These findings indicate that TSP1 ameliorates hypoxia‐induced paraptosis in HCE cells and promotes wound healing and remodeling by regulating exosomal protein expression. TSP1 may, therefore, play important roles in the treatment of hypoxia‐associated corneal diseases.
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