Silica nanoparticles induce cardiomyocyte apoptosis via the mitochondrial pathway in rats following intratracheal instillation

Oral Release Kinetics, Biodistribution, and Excretion of Dopants from Barium-Containing Bioactive Glass in Rats

Background: Inorganic biomaterials are biologically active and are used as implants and drug delivery system. They have therapeutically active elements present in their framework that are released in the physiological milieu. Release of these dopants above the supraphysiological limit may produce adverse effects and physicochemical interactions with the loaded drugs. Therefore, this necessitates evaluating the in vivo release kinetics, biodistribution, and excretion profiles of dopants from barium-doped bioglass (BaBG) that has potential anti-inflammatory, antiulcer, and regenerative properties. Methods: In vitro leaching of Ca, Si, and Ba from BaBG was analyzed in simulated body fluid. Release kinetics post single-dose oral administration (1, 5, and 10 mg/kg) was performed in rats. Blood was collected at different time points, and pharmacokinetic parameters of released elements were calculated. The routes of excretion and biodistribution in major organs were evaluated using ICP-MS. Results: Elements were released after the oral administration of BaBG into the plasma. They showed dose-dependent release kinetics and mean residence time. Cmax was observed at 24 h for all elements, followed by a downhill fall. There was also a dose-dependent increase in the volume of distribution, and the clearance of dopants was mostly through feces. Ba and Si were biodistributed significantly in the liver, spleen, and kidneys. However, by the end of day 7, there was a leveling-off effect observed for all elements. Conclusion: All of the dopants exhibited a dose-dependent increase in release kinetics and biodistribution in vital organs. This study will help in dose optimization and understanding of various physicochemical and pharmacokinetic interactions when BaBG is used for future pharmacological studies.

lncRNA OIP5-AS1 attenuates the osteoarthritis progression in IL-1β-stimulated chondrocytes

In view of the association between long noncoding RNA OIP5-AS1 and osteoarthritis (OA) pathology, the corresponding potential mechanism is worthy of exploration. Primary chondrocytes were identified by morphological observation and immunohistochemical staining of collagen II. The association between OIP5-AS1 and miR-338-3p was analyzed by StarBase and dual-luciferase reporter assay. After the expression of OIP5-AS1 or miR-338-3p in interleukin (IL)-1β-stimulated primary chondrocytes and CHON-001 cells was manipulated, cell viability, proliferation, apoptosis rate, apoptosis-related protein (cleaved caspase-9, Bax) expressions, extracellular matrix (ECM) (matrix metalloproteinase (MMP)-3, MMP-13, aggrecan, and collagen II), PI3K/AKT pathway, and mRNA expressions of inflammatory factors (IL-6 and IL-8), OIP5-AS1, and miR-338-3p were determined by cell counting kit-8, EdU, flow cytometry, Western blot, and quantitative reverse transcription-polymerase chain reaction. As a result, the expression of OIP5-AS1 was downregulated in IL-1β-activated chondrocytes, while miR-338-3p was overexpressed. OIP5-AS1 overexpression reversed the effects of IL-1β on viability, proliferation, apoptosis, ECM degradation, and inflammation in chondrocytes. However, OIP5-AS1 knockdown exhibited opposite effects. Interestingly, the effects of OIP5-AS1 overexpression were partially offset by miR-338-3p overexpression. Furthermore, OIP5-AS1 overexpression blocked the PI3K/AKT pathway by modulating miR-338-3p expression. In sum, OIP5-AS1 promotes viability and proliferation, and inhibits apoptosis and ECM degradation in IL-1β-activated chondrocytes by targeting miR-338-3p through blocking the PI3K/AKT pathway, indicating an attractive strategy for OA treatment.

A toxicological profile of silica nanoparticles

Humans are regularly exposed to silica nanoparticles in environmental and occupational contexts, and these exposures have been implicated in the onset of adverse health effects. Existing reviews on silica nanoparticle toxicity are few and not comprehensive. There are natural and synthetic sources by which crystalline and amorphous silica nanoparticles are produced. These processes influence physiochemical properties, which are factors that can dictate toxicological effects. Toxicological assessment includes exposure scenario (e.g. environmental, occupational), route of exposure, toxicokinetics, and toxicodynamics. Broader considerations include pathology, risk assessment, regulation, and treatment after injury. This review aims to consolidate the most relevant and up-to-date research in these areas to provide an exhaustive toxicological profile of silica nanoparticles.

Fluid Mechanics of Fetal Left Ventricle During Aortic Stenosis with Evolving Hypoplastic Left Heart Syndrome

In cases of fetal aortic stenosis and evolving Hypoplastic Left Heart Syndrome (feHLHS), aortic stenosis is associated with specific abnormalities such as retrograde or bidirectional systolic transverse arch flow. Many cases progressed to hypoplastic left heart syndrome (HLHS) malformation at birth, but fetal aortic valvuloplasty can prevent the progression in many cases. Since both disease and intervention involve drastic changes to the biomechanical environment, in-vivo biomechanics likely play a role in inducing and preventing disease progression. However, the fluid mechanics of feHLHS is not well-characterized. Here, we conduct patient-specific echocardiography-based flow simulations of normal and feHLHS left ventricles (LV), to understand the essential fluid dynamics distinction between the two cohorts. We found high variability across feHLHS cases, but also the following unifying features. Firstly, feHLHS diastole mitral inflow was in the form of a narrowed and fast jet that impinged onto the apical region, rather than a wide and gentle inflow in normal LVs. This was likely due to a malformed mitral valve with impaired opening dynamics. This altered inflow caused elevated vorticity dynamics and wall shear stresses (WSS) and reduced oscillatory shear index at the apical zone rather than mid-ventricle. Secondly, feHLHS LV also featured elevated systolic and diastolic energy losses, intraventricular pressure gradients, and vortex formation numbers, suggesting energy inefficiency of flow and additional burden on the LV. Thirdly, feHLHS LV had poor blood turnover, suggesting a hypoxic environment, which could be associated with endocardial fibroelastosis that is often observed in these patients.

Silica Nanoparticles Induce Hepatotoxicity by Triggering Oxidative Damage, Apoptosis, and Bax-Bcl2 Signaling Pathway

The increase in the usage of silica nanoparticles (SiNPs) in the industrial and medical fields has raised concerns about their possible adverse effects on human health. The present study aimed to investigate the potential adverse effects of SiNPs at daily doses of 25 and 100 mg/kg body weight intraperitoneally (i.p.) for 28 consecutive days on markers of liver damage in adult male rats. Results revealed that SiNPs induced a marked increase in serum markers of liver damage, including lactate dehydrogenase (LDH), alanine aminotransferase (ALAT), and aspartate aminotransferase (ASAT). SiNPs also induced an elevation of reactive oxygen species (ROS) production in liver, along with an increase in oxidative stress markers (NO, MDA, PCO, and H₂O₂), and a decrease in antioxidant enzyme activities (CAT, SOD, and GPx). Quantitative real-time PCR showed that SiNPs also induced upregulation of pro-apoptotic gene expression (including Bax, p53, Caspase-9/3) and downregulation of anti-apoptotic factors Bcl-2. Moreover, histopathological analysis revealed that SiNPs induced hepatocyte alterations, which was accompanied by sinusoidal dilatation, Kupffer cell hyperplasia, and the presence of inflammatory cells in the liver. Taken together, these data showed that SiNPs trigger hepatic damage through ROS-activated caspase signaling pathway, which plays a fundamental role in SiNP-induced apoptosis in the liver.

Pan-cancer analysis of necroptosis-related gene signature for the identification of prognosis and immune significance

BACKGROUND

Necroptosis is a novel programmed cell death mode independent on caspase. A number of studies have revealed that the induction of necroptosis could act as an alternative therapeutic strategy for drug-resistant tumors as well as affect tumor immune microenvironment.

METHODS

Gene expression profiles and clinical data were downloaded from XENA-UCSC (including The Cancer Genome Atlas and Genotype-Tissue Expression), Gene Expression Omnibus, International Cancer Genome Consortium and Chinese Glioma Genome Atlas. We used non-negative matrix factorization method to conduct tumor classification. The least absolute shrinkage and selection operator regression was applied to establish risk models, whose prognostic effectiveness was examined in both training and testing sets with Kaplan-Meier analysis, time-dependent receiver operating characteristic curves as well as uni- and multi-variate survival analysis. Principal Component Analysis, t-distributed Stochastic Neighbor Embedding and Uniform Manifold Approximation and Projection were conducted to check the risk group distribution. Gene Set Enrichment Analyses, immune infiltration analysis based on CIBERSORT, EPIC, MCPcounter, ssGSEA and ESTIMATE, gene mutation and drug sensitivity between the risk groups were also taken into consideration.

RESULTS

There were eight types of cancer with at least ten differentially expressed necroptosis-related genes which could influence patients' prognosis, namely, adrenocortical carcinoma (ACC), cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC), acute myeloid leukemia (LAML), brain lower grade glioma (LGG), pancreatic adenocarcinoma (PAAD), liver hepatocellular carcinoma (LIHC), skin cutaneous melanoma (SKCM) and thymoma (THYM). Patients could be divided into different clusters with distinct overall survival in all cancers above except for LIHC. The risk models could efficiently predict prognosis of ACC, LAML, LGG, LIHC, SKCM and THYM patients. LGG patients from high-risk group had a higher infiltration level of M2 macrophages and cancer-associated fibroblasts. There were more CD8+ T cells, Th1 cells and M1 macrophages in low-risk SKCM patients' tumor microenvironment. Gene mutation status and drug sensitivity are also different between low- and high-risk groups in the six cancers.

CONCLUSIONS

Necroptosis-related genes can predict clinical outcomes of ACC, LAML, LGG, LIHC, SKCM and THYM patients and help to distinguish immune infiltration status for LGG and SKCM.

Inhibition of Bruton's Tyrosine Kinase Protects Against Burn Sepsis-Induced Intestinal Injury

This study aimed to investigate the role and molecular mechanisms of Bruton's tyrosine kinase (BTK), a member of the Tec family in burn sepsis-induced intestinal injury. Eighty C57BL/6 mice were randomly divided into four groups: the sham group, the burn group, the burn + sepsis group, and the burn + sepsis + LFM-A13 (a selective BTK inhibitor) group. The dynamic expression profiles of BTK and p-BTK in the intestine were measured by Western blot analysis. Intestinal histopathological changes and cellular apoptosis were determined. Inflammatory cytokines in serum and intestinal tissue were examined through enzyme-linked immunosorbent assay. Myeloperoxidase (MPO) activity was determined via a colorimetric assay. Intestinal p-BTK expression in the burn+sepsis group was significantly increased compared with that in the sham and burn groups. In the burn + sepsis group, the p-BTK expression level increased over time, peaked at 12, and then decreased at 24 h. LFM-A13 administration significantly inhibited p-BTK expression in the intestine. In contrast to the sham and burn groups, the burn + sepsis group exhibited obvious histopathological changes, which gradually aggravated over time. LFM-A13 also reduced the histopathological changes and cellular apoptosis in intestinal tissues, inhibited the inflammatory cytokines IL-4, IL-6, and TNF-α in serum and intestinal tissues, and significantly inhibited the increase in intestinal MPO activity induced by burn sepsis. BTK activation is one important aspect of the signaling event that may mediate the release of the anti-inflammatory cytokine IL-4 and the pro-inflammatory cytokines IL-6 and TNF-α; oxidative stress; and intestinal cell apoptosis. Thus, it contributes to burn sepsis-induced intestinal injury.

Engineered-extracellular vesicles as an optimistic tool for microRNA delivery for osteoarthritis treatment

Worldwide, osteoarthritis (OA) is one of the most common chronic diseases. In OA, profiling gene expression changes occur and cartilage tissue homeostasis is lost. Suggestions for OA treatment include regulation of gene expressions via the use of microRNAs (miRNAs). However, problems exist with the use of miRNAs, the most important of which is the delivery of sufficient amounts of effective miRNAs to save cartilage tissue. The engineering of extracellular vesicles (EVs) with the use of advanced techniques would be an efficient OA treatment. Therefore, we discuss the importance of miRNAs in terms of cartilage tissue regeneration and review recent advances in production of enriched EVs and miRNA delivery by EVs for future clinical applications.

Ventricular Tachycardia: A Rare Case of Myocardial Silicosis

Chronic exposure to silica is a recognized health hazard. Manifestations of pulmonary and extrapulmonary silicosis are well described. Secondary pulmonary arterial hypertension and pericardial involvement are described, but myocardial involvement has not been reported. In this case of newly diagnosed pulmonary silicosis, ventricular tachycardia results are shown from pathological involvement of ventricular myocardium. (Level of Difficulty: Beginner.).

Nanomaterial-mediated autophagy: coexisting hazard and health benefits in biomedicine

BACKGROUND

Widespread biomedical applications of nanomaterials (NMs) bring about increased human exposure risk due to their unique physicochemical properties. Autophagy, which is of great importance for regulating the physiological or pathological activities of the body, has been reported to play a key role in NM-driven biological effects both in vivo and in vitro. The coexisting hazard and health benefits of NM-mediated autophagy in biomedicine are nonnegligible and require our particular concerns.

MAIN BODY

We collected research on the toxic effects related to NM-mediated autophagy both in vivo and in vitro. Generally, NMs can be delivered into animal models through different administration routes, or internalized by cells through different uptake pathways, exerting varying degrees of damage in tissues, organs, cells, and organelles, eventually being deposited in or excreted from the body. In addition, other biological effects of NMs, such as oxidative stress, inflammation, necroptosis, pyroptosis, and ferroptosis, have been associated with autophagy and cooperate to regulate body activities. We therefore highlight that NM-mediated autophagy serves as a double-edged sword, which could be utilized in the treatment of certain diseases related to autophagy dysfunction, such as cancer, neurodegenerative disease, and cardiovascular disease. Challenges and suggestions for further investigations of NM-mediated autophagy are proposed with the purpose to improve their biosafety evaluation and facilitate their wide application. Databases such as PubMed and Web of Science were utilized to search for relevant literature, which included all published, Epub ahead of print, in-process, and non-indexed citations.

CONCLUSION

In this review, we focus on the dual effect of NM-mediated autophagy in the biomedical field. It has become a trend to use the benefits of NM-mediated autophagy to treat clinical diseases such as cancer and neurodegenerative diseases. Understanding the regulatory mechanism of NM-mediated autophagy in biomedicine is also helpful for reducing the toxic effects of NMs as much as possible.

Astrocytes Are More Vulnerable than Neurons to Silicon Dioxide Nanoparticle Toxicity in Vitro

Some studies have shown that silicon dioxide nanoparticles (SiO₂-NPs) can reach different regions of the brain and cause toxicity; however, the consequences of SiO₂-NPs exposure on the diverse brain cell lineages is limited. We aimed to investigate the neurotoxic effects of SiO₂-NP (0–100 µg/mL) on rat astrocyte-rich cultures or neuron-rich cultures using scanning electron microscopy, Attenuated Total Reflection-Fourier Transform Infrared spectroscopy (ATR-FTIR), FTIR microspectroscopy mapping (IQ mapping), and cell viability tests. SiO₂-NPs were amorphous particles and aggregated in saline and culture media. Both astrocytes and neurons treated with SiO₂-NPs showed alterations in cell morphology and changes in the IR spectral regions corresponding to nucleic acids, proteins, and lipids. The analysis by the second derivative revealed a significant decrease in the signal of the amide I (α-helix, parallel β-strand, and random coil) at the concentration of 10 µg/mL in astrocytes but not in neurons. IQ mapping confirmed changes in nucleic acids, proteins, and lipids in astrocytes; cell death was higher in astrocytes than in neurons (10–100 µg/mL). We conclude that astrocytes were more vulnerable than neurons to SiO₂-NPs toxicity. Therefore, the evaluation of human exposure to SiO₂-NPs and possible neurotoxic effects must be followed up.

Silica nanomaterials induce organ injuries by Ca2+-ROS-initiated disruption of the endothelial barrier and triggering intravascular coagulation

Background

The growing use of silica nanoparticles (SiNPs) in many fields raises human toxicity concerns. We studied the toxicity of SiNP-20 (particle diameter 20 nm) and SiNP-100 (100 nm) and the underlying mechanisms with a focus on the endothelium both in vitro and in vivo.

Methods

The study was conducted in cultured human umbilical vein endothelial cells (HUVECs) and adult female Balb/c mice using several techniques.

Results

In vitro, both SiNP-20 and SiNP-100 decreased the viability and damaged the plasma membrane of cultured HUVECs. The nanoparticles also inhibited HUVECs migration and tube formation in a concentration-dependent manner. Both SiNPs induced significant calcium mobilization and generation of reactive oxygen species (ROS), increased the phosphorylation of vascular endothelial (VE)-cadherin at the site of tyrosine 731 residue (pY731-VEC), decreased the expression of VE-cadherin expression, disrupted the junctional VE-cadherin continuity and induced F-actin re-assembly in HUVECs. The injuries were reversed by blocking Ca²⁺ release activated Ca²⁺ (CRAC) channels with YM58483 or by eliminating ROS with N-acetyl cysteine (NAC). In vivo, both SiNP-20 and SiNP-100 (i.v.) induced multiple organ injuries of Balb/c mice in a dose (range 7–35 mg/kg), particle size, and exposure time (4–72 h)-dependent manner. Heart injuries included coronary endothelial damage, erythrocyte adhesion to coronary intima and coronary coagulation. Abdominal aorta injury exhibited intimal neoplasm formation. Lung injuries were smaller pulmonary vein coagulation, bronchiolar epithelial edema and lumen oozing and narrowing. Liver injuries included multifocal necrosis and smaller hepatic vein congestion and coagulation. Kidney injuries involved glomerular congestion and swelling. Macrophage infiltration occurred in all of the observed organ tissues after SiNPs exposure. SiNPs also decreased VE-cadherin expression and altered VE-cadherin spatial distribution in multiple organ tissues in vivo. The largest SiNP (SiNP-100) and longest exposure time exerted the greatest toxicity both in vitro and in vivo.

Conclusions

SiNPs, administrated in vivo, induced multiple organ injuries, including endothelial damage, intravascular coagulation, and secondary inflammation. The injuries are likely caused by upstream Ca²⁺-ROS signaling and downstream VE-cadherin phosphorylation and destruction and F-actin remodeling. These changes led to endothelial barrier disruption and triggering of the contact coagulation pathway.

Nanoparticle delivery of cardioprotective therapies

Acute myocardial infarction (AMI), and the heart failure (HF) that often follows, are leading causes of death and disability worldwide. Crucially, there are currently no effective treatments, other than myocardial reperfusion, for reducing myocardial infarct (MI) size and preventing HF following AMI. Thus, there is an unmet need to discover novel cardioprotective therapies to reduce MI size, and prevent HF in AMI patients. Although a large number of therapies have been shown to reduce MI size in experimental studies, the majority have failed to benefit AMI patients. Failure to deliver cardioprotective therapy to the ischemic heart in sufficient concentrations following AMI is a major factor for the lack of success observed in previous clinical cardioprotection studies. Therefore, new strategies are needed to improve the delivery of cardioprotective therapies to the ischemic heart following AMI. In this regard, nanoparticles have emerged as drug delivery systems for improving the bioavailability, delivery, and release of cardioprotective therapies, and should result in improved efficacy in terms of reducing MI size and preventing HF. In this article, we provide a review of currently available nanoparticles, some of which have been FDA-approved, in terms of their use as drug delivery systems in cardiovascular disease and cardioprotection.