Cytoplasmic vacuolation with endoplasmic reticulum stress directs sorafenib induced non-apoptotic cell death in hepatic stellate cells

Godanti bhasma (anhydrous CaSO4) induces massive cytoplasmic vacuolation in mammalian cells: A model for phagocytosis assay

Phagocytosis is an essential physiological mechanism; its impairment is associated with many diseases. A highly smart particle is required for understanding detailed sequential cellular events in phagocytosis. Recently, we identified an Indian traditional medicine named Godanti Bhasma (GB), a bioactive calcium sulfate particle prepared by thermo-transformation ofgypsum. Thermal processing of the gypsum transforms its native physicochemical properties by removing water molecules into the anhydrous GB, which was confirmed by Raman and FT-IR spectroscopy. GB particle showed a 0.5-5 µm size range and a neutral surface charge. Exposure of mammalian cells to GB particles showed a rapid cellular uptake through phagocytosis and induced massive cytoplasmic vacuolation in cells. Interestingly, no cellular uptake and cytoplasmic vacuolation were observed with the parent gypsum particle. The presence of the GB particles in intra-vacuolar space was confirmed using FESEM coupled with EDX. Flow cytometry analysis and live tracking of GB-treated cells showed particle internalization, vacuole formation, particle dissolution, and later vacuolar turnover. Quantification of GB-induced vacuolation was done using neutral red uptake assay in cells. Treatment of lysosomal inhibitors (BFA1 or CQ) with GB could not induce vacuolation, suggesting the requirement of an acidic environment for the vacuolation. In the mimicking experiment, GB particle dissolution in acidic cell-free solution suggested that degradation of GB occurs by acidic pH inside the cell vacuole. Vacuole formation generally accompanies with cell death, whereas GB-induced massive vacuolation does not cause cell death. Moreover, the cell divides and proliferates with the vacuolar process, intra-vacuolar cargo degradation, and eventually vacuolar turnover. Taken together, the sequential cellular events in this study suggest that GB can be used as a smart particle for phagocytosis assay development in animal cells.

Kinetic Effects of Transferrin-Conjugated Gold Nanoparticles on the Antioxidant Glutathione-Thioredoxin Pathway

Nanoparticle-based therapeutics are being clinically translated for treating cancer. Even when thought to be biocompatible, nanoparticles are being increasingly identified as altering cell regulation and homeostasis. Antioxidant pathways are important for maintaining cell redox homeostasis and play important roles by maintaining ROS levels within tolerable ranges. Here, we sought to understand how a model of a relatively inert nanoparticle without any therapeutic agent itself could antagonize a cancer cell lines' antioxidant mechanism. A label-free protein expression approach was used to assess the glutathione-thioredoxin antioxidative pathway in a prostate cancer cell line (PC-3) after exposure to gold nanoparticles conjugated with a targeting moiety (transferrin). The impact of the nanoparticles was also corroborated through morphological analysis with TEM and classification of pro-apoptotic cells by way of the sub-G0/G1 population via the cell cycle and annexin V apoptosis assay. After a two-hour exposure to nanoparticles, major proteins associated with the glutathione-thioredoxin antioxidant pathway were downregulated. However, this response was acute, and in terms of protein expression, cells quickly recovered within 24 h once nanoparticle exposure ceased. The impact on PRDX-family proteins appears as the most influential factor in how these nanoparticles induced an oxidative stress response in the PC-3 cells. An apparent adaptive response was observed if exposure to nanoparticles continued. Acute exposure was observed to have a detrimental effect on cell viability compared to continuously exposed cells. Nanoparticle effects on cell regulation likely provide a compounding therapeutic advantage under some circumstances, in addition to the action of any cytotoxic agents; however, any therapeutic advantage offered by nanoparticles themselves with regard to vulnerabilities specific to the glutathione-thioredoxin antioxidative pathway is highly temporal.

Surface Immobilization of Anti-VEGF Peptide on SPIONs for Antiangiogenic and Targeted Delivery of Paclitaxel in Non-Small-Cell Lung Carcinoma

A design has been established for the surface decoration of superparamagnetic iron oxide nanoparticles (SPIONs) with anti-vascular endothelial growth factor peptide, HRH, to formulate a targeted paclitaxel (PTX) delivery nanosystem with notable tumor targetability and antiangiogenic activity. The design methodology included (i) tandem surface functionalization via coupling reactions, (ii) pertinent physicochemical characterization, (iii) in vitro assessment of drug release, anti-proliferative activity, and quantification of vascular endothelial growth factor A (VEGF-A) levels, and (iv) in vivo testing using a lung tumor xenograft mouse model. Formulated CLA-coated PTX-SPIONs@HRH depicted a size and surface charge of 108.5 ± 3.5 nm and -30.4 ± 2.3 mV, respectively, and a quasi-spherical shape relative to pristine SPIONs. Fourier transform infrared (FTIR) analysis and estimation of free carboxylic groups supported the preparation of the CLA-coated PTX-SPIONs@HRH. CLA-coated PTX-SPIONs@HRH exhibited high PTX loading efficiency (98.5%) and sustained release in vitro, with a marked dose dependent anti-proliferative activity in A549 lung adenocarcinoma cells, complimented by an enhanced cellular uptake. CLA-coated PTX-SPIONs@HRH significantly reduced secretion levels of VEGF-A in human dermal microvascular endothelial cells from 46.9 to 35.6 pg/mL compared to untreated control. A 76.6% tumor regression was recorded in a lung tumor xenograft mouse model following intervention with CLA-coated PTX-SPIONs@HRH, demonstrating tumor targetability and angiogenesis inhibition. CLA-coated PTX-SPIONs@HRH enhanced the half-life of PTX by almost 2-folds and demonstrated a prolonged PTX plasma circulation time from a subcutaneous injection (SC). Thus, it is suggested that CLA-coated PTX-SPIONs@HRH could provide a potential effective treatment modality for non-small-cell lung carcinoma as a nanomedicine.

Primary assessment of medicines for expected migrastatic potential with holographic incoherent quantitative phase imaging

Solid tumor metastases cause most cancer-related deaths. The prevention of their occurrence misses suitable anti-metastases medicines newly labeled as migrastatics. The first indication of migrastatics potential is based on an inhibition of in vitro enhanced migration of tumor cell lines. Therefore, we decided to develop a rapid test for qualifying the expected migrastatic potential of some drugs for repurposing. The chosen Q-PHASE holographic microscope provides reliable multifield time-lapse recording and simultaneous analysis of the cell morphology, migration, and growth. The results of the pilot assessment of the migrastatic potential exerted by the chosen medicines on selected cell lines are presented.

Inhibition of FGFR2 Signaling by Cynaroside Attenuates Liver Fibrosis

Liver fibrosis represents a significant health hazard with a high morbidity rate and an increased risk of liver cancer. Targeting overactivated Fibroblast growth factor receptor 2 (FGFR2) is a promising strategy to counteract collagen accumulation during liver fibrosis. However, there is a shortage of drugs to specifically block the activation of FGFR2 in liver fibrosis patients. Data mining, cell validation, and animal studies showed a positive correlation between FGFR2 overexpression and liver fibrosis development. Novel FGFR2 inhibitors were screened using a microarray-based high-throughput binding analysis. The effectiveness of each candidate was validated through simulated docking, binding affinity verification, single-point mutation validation, and in vitro kinase inhibition measurements to demonstrate the ability of each inhibitor to block the catalytic pocket and reverse FGFR2 overactivation. A specific FGFR2 inhibitor, cynaroside (CYN, also known as luteoloside), was screened based on the finding that FGFR2 promotes hepatic stellate cell (HSC) activation and collagen secretion in hepatocytes. The results from cellular assays showed that CYN can inhibit FGFR2 hyperactivation resulting from its overexpression and excessive basic fibroblast growth factor (bFGF), reducing HSC activation and collagen secretion in hepatocytes. Animal experiments on a carbon tetrachloride (CCl4) mouse model and a nonalcoholic steatohepatitis mouse model indicate that CYN treatment reduces liver fibrosis during fibrosis formation. These findings suggest that CYN prevents liver fibrosis formation at the cell level and in mouse models.

Potential role of the apelin-APJ pathway in sex-related differential cardiotoxicity induced by doxorubicin in mice

Preclinical and clinical findings suggest sexual dimorphism in cardiotoxicity induced by a chemotherapeutic drug, doxorubicin (DOX). However, molecular alterations leading to sex-related differential vulnerability of heart to DOX toxicity are not fully explored. In the present study, RNA sequencing in hearts of B6C3F₁ mice indicated more differentially expressed genes in males than females (224 vs. 19; ≥1.5-fold, False Discovery Rate [FDR] < 0.05) at 1 week after receiving 24 mg/kg total cumulative DOX dose that induced cardiac lesions only in males. Pathway analysis further revealed probable inactivation of cardiac apelin fibroblast signaling pathway (p = 0.00004) only in DOX-treated male mice that showed ≥1.25-fold downregulation in the transcript and protein levels of the apelin receptor, APJ. In hearts of DOX-treated females, the transcript levels of apelin (1.24-fold) and APJ (1.47-fold) were significantly (p < 0.05) increased compared to saline-treated controls. Sex-related differential DOX effect was also observed on molecular targets downstream of the apelin-APJ pathway in cardiac fibroblasts and cardiomyocytes. In cardiac fibroblasts, upregulation of Tgf-β2, Ctgf, Sphk1, Serpine1, and Timp1 (fibrosis; FDR < 0.05) in DOX-treated males and upregulation of only Tgf-β2 and Timp1 (p < 0.05) in females suggested a greater DOX toxicity in hearts of males than females. Additionally, Ryr2 and Serca2 (calcium handling; FDR < 0.05) were downregulated in conjunction with 1.35-fold upregulation of Casp12 (sarcoplasmic reticulum-mediated apoptosis; FDR < 0.05) in DOX-treated male mice. Drug effect on the transcript level of these genes was less severe in female hearts. Collectively, these data suggest a likely role of the apelin-APJ axis in sex-related differential DOX-induced cardiotoxicity in our mouse model.

Divergent effect of Birinapant, and BV6 SMAC mimetic on TNFα induced NF-κB signaling and cell viability in activated hepatic stellate cells

BACKGROUND

Tumor necrosis factor-α (TNFα) is a pleiotropic cytokine involved in nuclear factor kappa B (NF-κB) mediated cell survival as well as cell death. High serum TNFα levels correlate with liver fibrosis and enhance hepatic stellate cell (HSC) viability. However, the regulatory role of cellular inhibitor of apoptosis-1/2 (cIAP1/2) during TNFα induced NF-κB signaling in activated HSCs is largely unknown.

METHOD AND RESULTS

Activated HSCs were treated with cIAP1/2 inhbitiors i.e., SMAC mimetic BV6, and Birinapant in the presence of TNFα and macrophage conditioned media. TNFα cytokine increased cIAP2 expression and enhanced cell viability through the canonical NF-κB signaling in activated HSCs. cIAP2 inhibition via BV6 decreased the TNFα induced canonical NF-κB signaling, and reduced cell viability in activated HSCs. SMAC mimetic, Birinapant alone did not affect the cell viability but treatment of TNFα sensitized HSCs with Birinapant induced cell death. While BV6 mediated cIAP2 ablation was able to decrease the TNFα induced canonical NF-κB signaling, this effect was not observed with Birinapant treatment. Secreted TNFα from M1 polarized macrophages sensitized activated HSCs to BV6 or Birinapant mediated cell death. However, M2 polarized macrophage conditioned medium rescued the activated HSCs from BV6 mediated cytotoxicity.

CONCLUSION

In this study, we describe the regulatory role of cIAP2 in TNFα induced NF-κB signaling in activated HSCs. Targeting cIAP2 may be a promising approach for liver fibrosis treatment via modulating NF-κB signaling in activated HSCs.

Transcriptomic profiling on localized gastric cancer identified CPLX1 as a gene promoting malignant phenotype of gastric cancer and a predictor of recurrence after surgery and subsequent chemotherapy

BACKGROUND

Localized gastric cancer (GC) becomes fatal once recurring. We still have room for improving their prognoses.

METHODS

Transcriptomic analysis was done on surgically resected specimens of 16 patients with UICC stage III GC who underwent curative gastrectomy and adjuvant oral fluoropyrimidine monotherapy. Four of them were free from disease for longer than 5 years, and the others experienced metachronous metastasis within 2 years after surgery. Quantitative RT-PCR determined mRNA expression levels of primary gastric cancer tissues, which were collected from 180 patients who underwent gastric resection for stage II-III GC without preoperative treatment between 2001 and 2014. We tested alteration of malignant phenotypes including drug resistance of GC cell lines by siRNA and shRNA-mediated knockdown and forced expression experiments.

RESULTS

CPLX1 was identified as a candidate biomarker for GC recurrence among 57,749 genes. Inhibiting and forced expression experiments indicated that CPLX1 promotes proliferation, motility, and invasiveness of GC cells, and decreases apoptosis and sensitivity to fluorouracil. Subcutaneous xenograft mouse models revealed that shRNA-mediated knockdown of CPLX1 also attenuated tumor growth of MKN1 cells in vivo. Overexpression of CPLX1 in gastric cancer tissue correlated with worse prognosis and was an independent risk factor for peritoneal recurrence in subgroups receiving adjuvant chemotherapy.

CONCLUSIONS

CPLX1 may represent a biomarker for recurrence of gastric cancer and a target for therapy.

Differences in the characteristics and pulmonary toxicity of nano- and micron-sized respirable coal dust

BACKGROUND

The characteristics of coal dust (CD) particles affect the inhalation of CD, which causes coal worker's pneumoconiosis (CWP). CD nanoparticles (CD-NPs, < 500 nm) and micron particles (CD-MPs, < 5 μm) are components of the respirable CD. However, the differences in physicochemical properties and pulmonary toxicity between CD-NPs and CD-MPs remain unclear.

METHODS

CD was analyzed by scanning electron microscopy, Malvern nanoparticle size potentiometer, energy dispersive spectroscopy, infrared spectroscopy, and electron paramagnetic resonance spectroscopy. CCK-8 assay, ELISA, transmission electron microscope, JC-1 staining, reactive oxygen species activity probe, calcium ion fluorescent probe, AO/EB staining, flow cytometry, and western blot were used to determine the differences between CD-NPs and CD-MPs on acute pulmonary toxicity. CCK-8, scratch healing and Transwell assay, hematoxylin-eosin and Masson staining, immunohistochemistry, immunofluorescence, and western blot were applied to examine the effects of CD-NPs and CD-MPs on pneumoconiosis.

RESULTS

Analysis of the size distribution of CD revealed that the samples had been size segregated. The carbon content of CD-NPs was greater than that of CD-MPs, and the oxygen, aluminum, and silicon contents were less. In in vitro experiments with A549 and BEAS-2B cells, CD-NPs, compared with CD-MPs, had more inflammatory vacuoles, release of pro-inflammatory cytokines (IL-6, IL-1β, TNFα) and profibrotic cytokines (CXCL2, TGFβ1), mitochondrial damage (reactive oxygen species and Ca2+ levels and decreased mitochondrial membrane potential), and cell death (apoptosis, pyroptosis, and necrosis). CD-NPs-induced fibrosis model cells had stronger proliferation, migration, and invasion than did CD-MPs. In in vivo experiments, lung coefficient, alveolar inflammation score, and lung tissue fibrosis score (mean: 1.1%, 1.33, 1.33) of CD-NPs were higher than those of CD-MPs (mean: 1.3%, 2.67, 2.67). CD-NPs accelerated the progression of pulmonary fibrosis by upregulating the expression of pro-fibrotic proteins and promoting epithelial-mesenchymal transition. The regulatory molecules involved were E-cadherin, N-cadherin, COL-1, COL-3, ZO-1, ZEB1, Slug, α-SMA, TGFβ1, and Vimentin.

CONCLUSIONS

Stimulation with CD-NPs resulted in more pronounced acute and chronic lung toxicity than did stimulation with CD-MPs. These effects included acute inflammatory response, mitochondrial damage, pyroptosis, and necrosis, and more pulmonary fibrosis induced by epithelial-mesenchymal transition.

Understanding ER homeostasis and the UPR to enhance treatment efficacy of acute myeloid leukemia

Protein biogenesis, maturation and degradation are tightly regulated processes that are governed by a complex network of signaling pathways. The endoplasmic reticulum (ER) is responsible for biosynthesis and maturation of secretory proteins. Circumstances that alter cellular protein homeostasis, determine accumulation of misfolded and unfolded proteins in the ER, a condition defined as ER stress. In case of stress, the ER activates an adaptive response called unfolded protein response (UPR), a series of pathways of major relevance for cancer biology. The UPR plays a preeminent role in adaptation of tumor cells to the harsh conditions that they experience, due to high rates of proliferation, metabolic abnormalities and hostile environment scarce in oxygen and nutrients. Furthermore, the UPR is among the main adaptive cell stress responses contributing to the development of resistance to drugs and chemotherapy. Clinical management of Acute Myeloid Leukemia (AML) has improved significantly in the last decade, thanks to development of molecular targeted therapies. However, the emergence of treatment-resistant clones renders the rate of AML cure dismal. Moreover, different cell populations that constitute the bone marrow niche recently emerged as a main determinant leading to drug resistance. Herein we summarize the most relevant literature regarding the role played by the UPR in expansion of AML and ability to develop drug resistance and we discuss different possible modalities to overturn this adaptive response against leukemia. To this aim, we also describe the interconnection of the UPR with other cellular stress responses regulating protein homeostasis. Finally, we review the newest findings about the crosstalk between AML cells and cells of the bone marrow niche, under physiological conditions and in response to therapies, discussing in particular the importance of the niche in supporting survival of AML cells by favoring protein homeostasis.

Antioxidant Effects of Irisin in Liver Diseases: Mechanistic Insights

Oxidative stress is a crucial factor in the development of various liver diseases. Irisin, a metabolic hormone discovered in 2012, is mainly produced by proteolytic cleavage of fibronectin type III domain containing 5 (FNDC5) in skeletal muscles. Irisin is induced by physical exercise, and a rapidly growing body of literature suggests that irisin is, at least partially, responsible for the beneficial effects of regular exercise. The major biological function of irisin is believed to be involved in the maintenance of metabolic homeostasis. However, recent studies have suggested the therapeutic potential of irisin against a variety of liver diseases involving its antioxidative function. In this review, we aim to summarize the accumulating evidence demonstrating the antioxidative effects of irisin in liver diseases, with an emphasis on the current understanding of the potential molecular mechanisms.

Survivin expression is essential for early activation of hepatic stellate cells and fibrosis progression in chronic liver injury

AIM

Hepatic fibrosis in injured liver is characterized by the activation of hepatic stellate cells (HSCs) from their quiescent state. Survivin (BIRC5) is one of the key genes that are upregulated during activation of HSCs but their role in HSC activation and fibrosis progression is unknown. Here, we have investigated the role of survivin protein in early fibrogenic activation of HSCs and fibrosis progression in chronic liver injury.

MATERIALS & METHODS

Primary quiescent HSCs were isolated from healthy mice liver through perfusion and cultured for fibrogenic activation. Survivin expression was suppressed by its pharmacological suppressant, YM155. We developed chronic liver injury induced fibrotic mice model through administrating repeated dose of CCl₄ for 2 weeks and 4 weeks. Mice were pre-treated with YM155 a week before CCl₄ administration till 2nd week of dosing and then discontinued. Hepatic parameters were characterized and underlying mechanisms were investigated.

KEY FINDINGS

Survivin expression gradually increased along with the expression of αSMA, collagen I activation maker in HSCs during their activation from quiescent state. Survivin suppression through YM155 downregulated αSMA, collagen I. Pre-treatment of YM155 in mice ceased the early activation of HSCs and onset of fibrosis in injured liver. However, discontinuation of YM155 initiated the activation of HSCs and fibrosis progression that shows survivin expression in HSCs is essential for their early activation and onset of liver fibrosis.

SIGNIFICANCE

Survivin expression induces with activation of HSCs and drives onset of liver fibrosis in injured liver. Targeting survivin protein in activated HSCs could be a potential anti-fibrotic therapeutic approach in chronic liver injury.