Enhancing antitumor efficacy of NIR-I region zinc phthalocyanine@upconversion nanoparticle through lysosomal escape and mitochondria targeting.

Accurately visualizing the intracellular trafficking of upconversion nanoparticles (UCNPs) loaded with phthalocyanines and achieving precise photodynamic therapy (PDT) using near-infrared (NIR) laser irradiation still present challenges. In this study, a novel NIR laser-triggered upconversion luminescence (UCL) imaging-guided nanoparticle called FA@TPA-NH-ZnPc@UCNPs (FTU) was developed for PDT. FTU consisted of UCNPs, folic acid (FA), and triphenylamino-phenylaniline zinc phthalocyanine (TPA-NH-ZnPc). Notably, TPA-NH-ZnPc showcases aggregation-induced emission (AIE) characteristic and NIR absorption properties at 741 nm, synthesized initially via molybdenum-catalyzed condensation reaction. The UCL emitted by FTU enable real-time visualization of their subcellular localization and intracellular trafficking within ovarian cancer HO-8910 cells. Fluorescence images revealed that FTU managed to escape from lysosomes due to the "proton sponge" effect of TPA-NH-ZnPc. The FA ligands on the surface of FTU further directed their transport and accumulation within mitochondria. When excited by a 980 nm laser, FTU exhibited UCL and activated TPA-NH-ZnPc, consequently generating cytotoxic singlet oxygen (1O2), disrupted mitochondrial function and induced apoptosis in cancer cells, which demonstrated great potential for tumor ablation.

Asymmetric silicon phthalocyanine based nanoparticle with spatiotemporally targeting of mitochondria for synergistic apoptosis-ferroptosis antitumor treatment.

A promising therapeutic strategy in cancer treatment merges photodynamic therapy (PDT) induced apoptosis with ferroptosis, a form of programmed cell death governed by iron-dependent lipid peroxidation. Given the pivotal role of mitochondria in ferroptosis, the development of photosensitizers that specifically provoke mitochondrial dysfunction and consequentially trigger ferroptosis via PDT is of significant interest. To this end, we have designed and synthesized a novel nanoparticle, termed FECTPN, tailored to address this requisite. FECTPN harnesses a trifecta of critical attributes: precision mitochondria targeting, photoactivation capability, pH-responsive drug release, and synergistic apoptosis-ferroptosis antitumor treatment. This nanoparticle was formulated by conjugating an asymmetric silicon phthalocyanine, Chol-SiPc-TPP, with the ferroptosis inducer Erastin onto a ferritin. The Chol-SiPc-TPP is a chemically crafted entity featuring cholesteryl (Chol) and triphenylphosphine (TPP) functionalities bonded axially to the silicon phthalocyanine, enhancing mitochondrial affinity and leading to effective PDT and subsequent apoptosis of cells. Upon cellular uptake, FECTPN preferentially localizes to mitochondria, facilitated by Chol-SiPc-TPP's targeting mechanics. Photoactivation induces the synchronized release of Chol-SiPc-TPP and Erastin in the mitochondria's alkaline domain, driving the escalation of both ROSs and lipid peroxidation. These processes culminate in elevated antitumor activity compared to the singular application of Chol-SiPc-TPP-mediated PDT. A notable observation is the pronounced enhancement in glutathione peroxidase-4 (GPX4) expression within MCF-7 cells treated with FECTPN and subjected to light exposure, reflecting intensified oxidative stress. This study offers compelling evidence that FECTPN can effectively induce ferroptosis and reinforces the paradigm of a synergistic apoptosis-ferroptosis pathway in cancer therapy, proposing a novel route for augmented antitumor treatments.

A piperazine-substituted phthalocyanine with rapid cellular uptake and dual organelle-targeting for in vitro photodynamic therapy.

The rational design of photosensitizers with rapid cellular uptake and dual-organelle targeting ability is essential for enhancing the efficacy of photodynamic therapy (PDT). However, achieving this goal is a great challenge. In this paper, a novel axial piperazine substituted (PIP) silicon phthalocyanine (PIP-SiPc) has been synthesized. The PIP substitution significantly improved the cellular uptake of PIP-SiPc in MCF-7 breast cancer cells, as demonstrated by two-photon fluorescence imaging combined with fluorescence correlation spectroscopy. Additionally, PIP-SiPc was able to target both mitochondria and lysosomes simultaneously. Notably, PIP-SiPc exhibited remarkable singlet oxygen generation ability, leading to apoptosis in cancer cells upon irradiation, with an IC50 value of only 0.2 µM. These findings highlight the effectiveness of PIP-SiPc as a multifunctional photosensitizer for PDT.

A YOLO-based AI system for classifying calcifications on spot magnification mammograms.

OBJECTIVES: Use of an AI system based on deep learning to investigate whether the system can aid in distinguishing malignant from benign calcifications on spot magnification mammograms, thus potentially reducing unnecessary biopsies. METHODS: In this retrospective study, we included public and in-house datasets with annotations for the calcifications on both craniocaudal and mediolateral oblique vies, or both craniocaudal and mediolateral views of each case of mammograms. All the lesions had pathological results for correlation. Our system comprised an algorithm based on You Only Look Once (YOLO) named adaptive multiscale decision fusion module. The algorithm was pre-trained on a public dataset, Curated Breast Imaging Subset of Digital Database for Screening Mammography (CBIS-DDSM), then re-trained and tested on the in-house dataset of spot magnification mammograms. The performance of the system was investigated by receiver operating characteristic (ROC) analysis. RESULTS: We included 1872 images from 753 calcification cases (414 benign and 339 malignant) from CBIS-DDSM. From the in-house dataset, 636 cases (432 benign and 204 malignant) with 1269 spot magnification mammograms were included, with all lesions being recommended for biopsy by radiologists. The area under the ROC curve for our system on the in-house testing dataset was 0.888 (95% CI 0.868-0.908), with a sensitivity of 88.4% (95% CI 86.9-8.99%), specificity of 80.8% (95% CI 77.6-84%), and an accuracy of 84.6% (95% CI 81.8-87.4%) at the optimal cutoff value. Using the system with two views of spot magnification mammograms, 80.8% benign biopsies could be avoided. CONCLUSION: The AI system showed good accuracy for classification of calcifications on spot magnification mammograms which were all categorized as suspicious by radiologists, thereby potentially reducing unnecessary biopsies.

Morpholinyl silicon phthalocyanine nanoparticles with lysosome cell death and two-photon imaging functions for in vitro photodynamic therapy of cancer cells.

The lysosome is an important target for realizing antitumor therapy. Lysosomal cell death exerts significant therapeutic effects on apoptosis and drug-resistance. The development of lysosome-targeting nanoparticles to obtain efficient cancer treatment is challenging. In this article, nanoparticles composed of DSPE@M-SiPc and possessing bright two-photon fluorescence, lysosome targeting ability, and photodynamic therapy multifunctionalities are prepared by encapsulating morpholinyl-substituted silicon phthalocyanine (M-SiPc) with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (DSPE). Two photon fluorescence bioimaging showed that M-SiPc and DSPE@M-SiPc mainly locate in lysosomes after cellular internalization. Upon irradiation, DSPE@M-SiPc effectively generates reactive oxygen species and damages the function of lysosome, subsequently leading to lysosomal cell death. DSPE@M-SiPc is a promising photosensitizer for cancer treatment.

Regulatory mechanism of immune-related genes in patients with hypertension.

Hypertension (HT) is among the most common cardiovascular diseases in the world and is an important risk factor for stroke, myocardial infarction, heart failure, and kidney failure. Recent studies have demonstrated that activation of the immune system plays an important role in the occurrence and maintenance of HT. Thus, this research aimed to determine the immune-related biomarkers in HT. In this study, RNA sequencing data of the gene expression profiling datasets (GSE74144) were downloaded from the Gene Expression Omnibus database. Differentially expressed genes between HT and normal samples were identified using the software limma. The immune-related genes associated with HT were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed using the program "clusterProfiler" of the R package. The protein-protein interaction network of these differentially expressed immune-related genes (DEIRGs) was constructed based on the information from the STRING database. Finally, the TF-hub and miRNA-hub gene regulatory networks were predicted and constructed using the miRNet software. Fifty-nine DEIRGs were observed in HT. The Gene Ontology analysis indicated that DEIRGs were mainly enriched in the positive regulation of cytosolic calcium ions, peptide hormones, protein kinase B signaling, and lymphocyte differentiation. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis indicated that these DEIRGs were significantly involved in the intestinal immune network for IgA production, autoimmune thyroid disease, JAK-STAT signaling pathway, hepatocellular carcinoma, and Kaposi sarcoma-associated herpesvirus infection, among others. From the protein-protein interaction network, 5 hub genes (insulin-like growth factor 2, cytokine-inducible Src homology 2-containing protein, suppressor of cytokine signaling 1, cyclin-dependent kinase inhibitor 2A, and epidermal growth factor receptor) were identified. The receiver operating characteristic curve analysis was performed in GSE74144, and all genes with an area under the curve of > 0.7 were identified as the diagnostic genes. Moreover, miRNA-mRNA and TF-mRNA regulatory networks were constructed. Our study identified 5 immune-related hub genes in patients with HT and demonstrated that they were potential diagnostic biomarkers for HT.

Immediate clip migration after breast biopsy: a meta-analysis for potential risk factors.

OBJECTIVES: Immediate clip migration following breast biopsy is not a rare condition but its impact on future cancer management can be profound. However, there is limited knowledge on what causes the phenomenon and how to prevent it. METHODS: A systematic search was performed to identify articles discussing factors associated with clip migration, and a meta-analysis for each risk factor was conducted to determine the risk ratio. RESULTS: The most significant risk factor for immediate clip migration is globally fatty breast (RR = 2.00 [1.43-2.80], P<0.00001), while local heterogeneity has a moderate but insignificant protective effect (RR=0.68 [0.45-1.04], P=0.07). Clips with bioabsorbable carriers and biopsy along the superior/inferior breast axis do not change the rate of clip migration. CONCLUSION: Intrinsic breast composition is the most important determinant for accurate clip placement. Further research to identify potentially modifiable factors, such as clip design and biopsy techniques, is needed. ADVANCES IN KNOWLEDGE: Fatty breast composition has the highest risk of clip migration. Research on potentially modifiable factors such as clip design and biopsy techniques is needed.

Chronic disease management practices and factors associated with health-related quality-of-life for persons with chronic myeloid leukemia receiving tyrosine kinase inhibitor therapy.

BACKGROUND: The main objective of this study was to explore health-related quality of life (HRQoL) profiles, chronic disease management practices and key factors associated with HRQoL in 540 patients with chronic myeloid leukemia in chronic phase (CML-CP) administered tyrosine kinase inhibitors (TKIs). METHODS: Adult CML-CP patients treated with TKIs in Henan Cancer Hospital from March 2015 to October 2019 were assessed via questionnaires, including demographic characteristics, TKI medications, participation in CML disease management, and HRQoL, in a cross-sectional investigation. Respondents were anonymous. Functional Assessment of Cancer Therapy-Leukemia (FACT-Leu) was used to measure HRQoL. A multivariate linear regression model with stepwise entry was used to investigate variables independently associated with HRQoL domain and total scores. RESULTS: Totally, 540 respondents were included; 302 (55.93%) were male. Mean participant age was 42.90±13.00 years; 169 (31.3%), 178 (32.9%) and 193 (35.7%) individuals had a low, moderate or high disease management level, respectively. Except for insignificant event-free survival information, participants with higher disease management levels also had significantly higher rates of completing re-examination, drug withdrawal, cytogenetic response (CcyR) and/or major molecular response (MMR) (all P<0.01). Moreover, higher disease management level was accompanied by eight significantly higher HRQoL domains (all P<0.01). In multivariate linear regression analysis, variables significantly associated with a higher HRQoL included: (I) high disease management level (B=3.68, P=0.046); (II) transportation convenience (B=6.67, P<0.001); (III) family annual income >10,000 CNY (B=5.97, P<0.001); (IV) completed re-examination (B=4.58, P=0.036); (V) MMR (B=3.75, P=0.021) and CcyR (B=5.15, P=0.035). Female sex (B=-3.53, P=0.010), single status or divorce (B=-1.89 and -2.94, P=0.005 and 0.011), and low education level (B=-1.44, P=0.019) were significantly associated with lower HRQoL. CONCLUSIONS: Higher disease management level was significantly associated with higher elevated treatment efficacy and HRQoL in Chinese individuals with CML-CP administered TKIs. These data indicate the importance of chronic disease management on people's HRQoL and clinical outcome.

Label-free and enzyme-free fluorescence detection of microRNA based on sulfydryl-functionalized carbon dots via target-initiated hemin/G-quadruplex-catalyzed oxidation.

Carbon dots (CDs)-based biosensors have attracted considerable interest in reliable and sensitive detection of microRNA (miRNA) because of their merits of ultra-small size, excellent biosafety and tunable emission, whereas complicated labeling procedure and expensive bioenzyme associated with current strategies significantly limit their practical application. Herein, we developed a label-free and enzyme-free fluorescence strategy based on strand displaced amplification (SDA) for highly sensitive detection of miRNA using sulfydryl-functionalized CDs (CDs-SH) as probe. CDs-SH displayed excellent response to G-quadruplex DNA against other DNAs based on based on the catalytic oxidation of -SH into -S-S- by hemin/G-quadruplex. Further, CDs-SH were employed to detect miRNA, using miRNA-21 as target model, which triggered the SDA reaction of P1 and P2 to generate hemin/G-quadruplex, subsequently making CDs-SH transform from dot to aggresome along with the quenched fluorescence. Therefore, label-free, enzyme-free, and highly sensitive analysis of miRNA-21 was readily acquired with a limit of detection at 0.03 pM. This proposed biosensor couples the advantages of CDs and label-free/enzyme-free strategy, and thus has a significant potential to be used in early and accurate diagnosis of cancer.

Prediction of survival according to kinetic changes of cytokines and hepatitis status following radioembolization with yttrium-90 microspheres.

BACKGROUND/PURPOSE: Yttrium-90 radioembolization (Y90-RE) may exert an immunomodulatory effect on the tumor microenvironment of hepatocellular carcinoma (HCC). Whether the host immune alterations after Y90-RE correlated with outcomes and whether Y90-RE affects viral hepatitis reactivation remains unclear. METHODS: Between July 2014 and July 2015, 18 patients undergoing Y90-RE for HCC were prospectively enrolled. Serum levels of virological markers, cytokines and chemokines were measured at baseline, 2, 4, and 12 weeks after Y90-RE. Factors associated with the clinical outcomes were evaluated. RESULTS: The disease control rate of Y90-RE was 44.4% (8 of 18) at 12 weeks, including 1 case with complete response, 4 cases with partial response, and 3 cases with stable disease. Significant elevation from baseline to week 2 and week 4 were noted in IL-10 level (8.4 ± 33.8, 15.7 ± 31.6, and 16.0 ± 41.7 pg/mL, P = 0.041 and 0.013, respectively) and IP-10 level (113.5 ± 97.8, 189.1 ± 164.4, and 168.6 ± 150.5 pg/mL, P = 0.027 and 0.026, respectively). After Y90-RE, transient HBV reactivation occurred in 2 patients, and 1 out of 3 HCV-infected patients exhibited HCV reactivation. Univariate analysis revealed that lower baseline IP-10 (≤200 pg/mL) and alanine aminotransferase (ALT) (≤50 U/L) levels were associated with better overall survival. Multivariate analysis identified an IP-10 level of 200 pg/mL (HR = 4.374, P = 0.045) as a predictor of overall survival. CONCLUSION: Baseline serum IP-10 level is a predictor of survival for HCC patients undergoing Y90-RE. HBV and HCV reactivation may develop after Y90-RE treatment.

A comparative study of four Bowie-Dick test under the condition of pressure steam sterilizer simulating gas leakage.

We aimed to understand the evaluation of different Bowie-Dick test (B-D test) on the performance of pressure steam sterilization equipment in the case of simulated gas leakage, and we selected a pulsating vacuum steam sterilizer to set 4 different gas leakage levels: 1.1, 1.3, 1.5, and 1.7 mbar/min during the B-D test phase. In terms of methods, 4 different brands of B-D test kits (devices) were tested at 4 different leakage rates, and a total of 48 experiments were conducted. The results from univariate analysis revealed that there are statistically significant differences in the judgment of test results among different personnel and brands. The results from multivariate logistic regression analysis displayed that the difference between different personnel was statistically significant (χ = 45.34, P < .001); the difference between different products was statistically significant (χ = 129.37, P < .001); and there was no statistically significant difference between different degree of leakage (χ = 6.99, P > .05). Result judgments of brand 1 and brand 2 are susceptible to subjective factors. The judgment of brand 3 is intuitive and consistent with the evaluation result of brand 4. In conclusion, the order of capacity to evaluate air leakage from best to worst is brand 4→brand 3→brand 1→brand 2.

TRPM7 Upregulate the Activity of SMAD1 through PLC Signaling Way to Promote Osteogenesis of hBMSCs.

TRPM7 is a member of the transient receptor potential cation channel (TRP channel) subfamily M and possesses both an ion channel domain and a functional serine/threonine α-kinase domain. It has been proven to play an essential role in the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). However, the signaling pathway and molecular mechanism for TRPM7 in regulating osteogenic differentiation remain largely unknown. In this study, the potential role and mechanism of TRPM7 in the osteogenic differentiation of hBMSCs were investigated. The results showed that the expression of TRPM7 mRNA and protein increased, as did the osteogenic induction time. Upregulation or inhibition of TRPM7 could promote or inhibit the osteogenic differentiation of hBMSCs for 14 days. It was also found that the upregulation or inhibition of TRPM7 promoted or inhibited the activity of PLC and SMAD1, respectively, during osteogenic differentiation. PLC could promote osteogenic differentiation by upregulating the activity of SMAD1. However, inhibition of PLC alone could reduce the activity of SMAD1 but not inhibit completely the activation of SMAD1. Therefore, we inferred that it is an important signaling pathway for TRPM7 to upregulate the activity of SMAD1 through PLC and thereby promote the osteogenic differentiation of hBMSCs, but it is not a singular pathway. TRPM7 may also regulate the activation of SMAD1 through other ways, except for PLC, during osteogenic differentiation of hBMSCs.

Outcome analysis in 270 radiologically guided implantations of totally implantable venous access ports via basilic vein.

BACKGROUND: Totally implantable venous access ports (TIVAPs) are widely applied in patients who require chemotherapy, parenteral nutrition, or frequent intravenous drug infusion. Although various venous access routes are possible for TIVAP insertion, the best method remains a topic of controversy. We present a single-center retrospective study of radiologically guided placement of TIVAPs through the basilic vein, with analysis of technical feasibility, patient safety, and device-related complications. METHODS: We retrospectively reviewed 270 patients who received TIVAP implantation through the basilic vein from November 2013 to July 2016, under imaging guidance by an interventional radiology team at our institution. Fluoroscopic images, chest radiographs, computed tomography scans, and medical records were reviewed after port implantation. Catheter maintenance days were calculated and catheter-related complications were recorded. RESULTS: The procedural success rate was 99.3%. In total, 270 TIVAPs were implanted in 270 patients, of which 150 remained functional at the end of the study period. The total catheter maintenance days was 77 543 days, and the mean catheter indwelling duration was 287 ± 207 days. In 20 (7.4%) patients, TIVAP-related complications occurred during the follow-up period, resulting in a postprocedural complication rate of 0.26 incidences per 1000 catheter days. No significant relationship was observed between complications and gender (p = 0.188), age (p = 0.528), body mass index (p = 0.547), the type of primary malignancy (p = 0.914), or between the left and right basilic veins (p = 0.319). CONCLUSION: Real-time ultrasound and fluoroscopic guidance provides a safe method for TIVAP implantation through the basilic vein, with a high technical success rate and few device-related complications.

Visualization photofragmentation-induced rhodamine B release from gold nanorod delivery system by combination two-photon luminescence imaging with correlation spectroscopy.

Plasmon-enhanced gold nanorod (AuNR) with high photothermal conversion efficiency is a promising light-controllable nanodrug delivery system for cancer therapy. Understanding the mechanism for the light-controllable drug release of AuNR delivery systems is important for the development of nanomedicine. In this study, the rhodamine B (RB) released from AuNR-RB nanodelivery system was quantitated and visualized by using two-photon luminescence (TPL) imaging combined with correlation spectroscopy. The photofragmentation of AuNR induced by femtosecond pulsed laser was revealed by TPL correlation spectroscopy when the laser energy was above the thermal damage threshold of AuNR, and the RB released from this nanodrug delivery system was visualized by TPL imaging. Furthermore, the photofragmentation-induced release of RB from AuNR-RB nanodelivery system was visualized in living MCF-7 breast cancer cells by TPL imaging combined with correlation spectroscopy. These results provided a novel optical approach to quantify the release of drugs from gold nanocarriers in complex biological media.

Self-assembly of lipid rafts revealed by fluorescence correlation spectroscopy in living breast cancer cells.

Lipids and proteins in the plasma membrane are laterally heterogeneous and formalised as lipid rafts featuring unique biophysical properties. However, the self-assembly mechanism of lipid raft cannot be revealed even its physical properties and components were determined in specific physiological processes. In this study, two-photon generalised polarisation imaging and fluorescence correlation spectroscopy were used to study the fusion of lipid rafts through the membrane phase and the lateral diffusion of lipids in living breast cancer cells. A self-assembly model of lipid rafts associated with lipid diffusion and membrane phase was proposed to demonstrate the lipid sorting ability of lipid rafts in the plasma membrane. The results showed that the increased proportion of slow subdiffusion of GM1 -binding cholera toxin B-subunit (CT-B) was accompanied with an increased liquid-ordered domain during the ß-estradiol-induced fusion of lipid rafts. And slow subdiffusion of CT-B was vanished with the depletion of lipid rafts. Whereas the dialkylindocarbocyanine (DiIC18 ) diffusion was not specifically regulated by lipid rafts. This study will open up a new insight for uncovering the self-assembly of lipid rafts in specific pathophysiological processes.

Amphiphilic Polymer-Mediated Aggregation-Induced Emission Nanoparticles for Highly Sensitive Organophosphorus Pesticide Biosensing.

Biosensing applications require signal reporters to be sufficiently stable and biosafe as well as highly efficient. Aggregation-induced emission (AIE) nanoparticles have proven to be capable of cell-imaging and cancer therapy; however, realizing sensitive detection of biomolecules remains a great challenge because of their instability, biotoxicity, and lack of modifiable functional groups. Herein, we report a self-assembling strategy to fabricate AIE nanoparticles (PTDNPs) through the dispersion of amphiphilic polymers (PTDs) in phosphate-buffered saline. The PTDs were prepared through radical copolymerization of N-(1,2,2-triphenylvinyl)-4-acetylaniline and dimethyl diallyl ammonium chloride. We found that the particle size, morphology, functional groups, and fluorescence property of PTDNPs can be fine-tuned. Further, PTDNPs-0.10 were chosen as signal reporters to detect organophosphorus pesticides (OPs) with the aid of gold nanoparticles. Their sensing performance on OPs is superior to that using C-dot/quantum dot/rhodamine B as the signal reporter. This study not only provides new possibilities to fabricate novel AIE nanoparticles with exceptional properties, but also facilitates the AIE nanoparticle's application for target analyte biosensing.

Distribution, Trafficking, and in Vitro Photodynamic Therapy Efficacy of Cholesterol Silicon(IV) Phthalocyanine and Its Nanoparticles in Breast Cancer Cells.

A cholesterol silicon(IV) phthalocyanine (Chol-Pc) and a water-soluble Chol-Pc based nanoparticle (DSPE@Chol-Pc), which was prepared using 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (DSPE-PEG2000) as a nanocarrier were developed. Chol-Pc readily distributed within the cholesterol-rich domains and was preferentially localized in the Golgi apparatus after being transported into the cells. The trafficking of DSPE@Chol-Pc in breast cancer cells was visualized by tracking the fluorescence of Chol-Pc and FITC-labeled DSPE-PEG2000 through two-photonic imaging in real-time. It was discovered that Chol-Pc disassociated from the DSPE-PEG2000 on the plasma membrane and traveled to the cholesterol-rich domains soon afterward. Both DSPE@Chol-Pc and Chol-Pc effectively mediated photodynamic therapy to kill the breast cancer cells. After light irradiation, we found that the organizations of clustered cholesterol-rich domains in cells were destroyed, presumably leading to the death of cells for photodynamic therapy. It should be noted that DSPE@Chol-Pc is highly soluble in aqueous solution and has strong red fluorescence under two-photon excitation. Thus, it could be an excellent probe for detecting cholesterol-rich domains and studying transport processes of cholesterol in living cells.

Effects of simulated microgravity on the expression profiles of RNA during osteogenic differentiation of human bone marrow mesenchymal stem cells.

OBJECTIVES: Exposure to microgravity induces many adaptive and pathological changes in human bone marrow mesenchymal stem cells (hBMSCs). However, the underlying mechanisms of these changes are poorly understood. We revealed the gene expression patterns of hBMSCs under normal ground (NG) and simulated microgravity (SMG), which showed an interpretation for these changes by gene regulation and signal pathways analysis. MATERIALS AND METHODS: In this study, hBMSCs were osteogenically induced for 0, 2, 7 and 14 days under normal ground gravity and simulated microgravity, followed by analysis of the differences in transcriptome expression during osteogenic differentiation by RNA sequencing and some experimental verification for these results. RESULTS: The results indicated that 837, 399 and 894 differentially expressed genes (DEGs) were identified in 2, 7 and 14 days samples, respectively, out of which 13 genes were selected for qRT-PCR analysis to confirm the RNA-sequencing results. After analysis, we found that proliferation was inhibited in the early stage of induction. In the middle stage, osteogenic differentiation was inhibited, whereas adipogenic differentiation benefited from SMG. Moreover, SMG resulted in the up-regulation of genes specific for tumorigenesis in the later stage. CONCLUSION: Our data revealed that SMG inhibits the proliferation and inhibits the differentiation towards osteoblasts but promotes adipogenesis. SMG also selects highly tumorigenic cells for survival under prolonged SMG.

Differentiation and transplantation of human induced pluripotent stem cell-derived otic epithelial progenitors in mouse cochlea.

BACKGROUND: Inner ear hair cells as mechanoreceptors are extremely important for hearing. Defects in hair cells are a major cause of deafness. Induced pluripotent stem cells (iPSCs) are promising for regenerating inner ear hair cells and treating hearing loss. Here, we investigated migration, differentiation, and synaptic connections of transplanted otic epithelial progenitors (OEPs) derived from human iPSCs in mouse cochlea. METHODS: Human urinary cells isolated from a healthy donor were reprogramed to form iPSCs that were induced to differentiate into OEPs and hair cell-like cells. Immunocytochemistry, electrophysiological examination, and scanning electron microscopy were used to examine characteristics of induced hair cell-like cells. OEP-derived hair cell-like cells were cocultured with spiral ganglion neurons (SGNs), and the markers of synaptic connections were detected using immunocytochemistry and transmission electron microscope. In vivo, OEPs derived from iPSCs were transplanted into the cochlea of mice by injection through the round window. Migration, differentiation, and synaptic connections of transplanted cells were also examined by thin cochlear sectioning and immunohistochemistry. RESULTS: The induced hair cell-like cells displayed typical morphological characteristics and electrophysiological properties specific to inner hair cells. In vitro, OEP-derived hair cell-like cells formed synaptic connections with SGNs in coculture. In vivo, some of the transplanted cells migrated to the site of the resident hair cells in the organ of Corti, differentiated into hair cell-like cells, and formed synaptic connections with native SGNs. CONCLUSIONS: We conclude that the transplantation of OEPs is feasible for the regeneration of hair cells. These results present a substantial reference for a cell-based therapy for the loss of hair cells.

Space microgravity drives transdifferentiation of human bone marrow-derived mesenchymal stem cells from osteogenesis to adipogenesis.

Bone formation is linked with osteogenic differentiation of mesenchymal stem cells (MSCs) in the bone marrow. Microgravity in spaceflight is known to reduce bone formation. In this study, we used a real microgravity environment of the SJ-10 Recoverable Scientific Satellite to examine the effects of space microgravity on the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hMSCs). hMSCs were induced toward osteogenic differentiation for 2 and 7 d in a cell culture device mounted on the SJ-10 satellite. The satellite returned to Earth after going through space experiments in orbit for 12 d, and cell samples were harvested and analyzed for differentiation potentials. The results showed that space microgravity inhibited osteogenic differentiation and resulted in adipogenic differentiation, even under osteogenic induction conditions. Under space microgravity, the expression of 10 genes specific for osteogenesis decreased, including collagen family members, alkaline phosphatase ( ALP), and runt-related transcription factor 2 ( RUNX2), whereas the expression of 4 genes specific for adipogenesis increased, including adipsin ( CFD), leptin ( LEP), CCAAT/enhancer binding protein ß ( CEBPB), and peroxisome proliferator-activated receptor-γ ( PPARG). In the analysis of signaling pathways specific for osteogenesis, we found that the expression and activity of RUNX2 was inhibited, expression of bone morphogenetic protein-2 ( BMP2) and activity of SMAD1/5/9 were decreased, and activity of focal adhesion kinase (FAK) and ERK-1/2 declined significantly under space microgravity. These data indicate that space microgravity plays a dual role by decreasing RUNX2 expression and activity through the BMP2/SMAD and integrin/FAK/ERK pathways. In addition, we found that space microgravity increased p38 MAPK and protein kinase B (AKT) activities, which are important for the promotion of adipogenic differentiation of hMSCs. Space microgravity significantly decreased the expression of Tribbles homolog 3 ( TRIB3), a repressor of adipogenic differentiation. Y15, a specific inhibitor of FAK activity, was used to inhibit the activity of FAK under normal gravity; Y15 decreased protein expression of TRIB3. Therefore, it appears that space microgravity decreased FAK activity and thereby reduced TRIB3 expression and derepressed AKT activity. Under space microgravity, the increase in p38 MAPK activity and the derepression of AKT activity seem to synchronously lead to the activation of the signaling pathway specifically promoting adipogenesis.-Zhang, C., Li, L., Jiang, Y., Wang, C., Geng, B., Wang, Y., Chen, J., Liu, F., Qiu, P., Zhai, G., Chen, P., Quan, R., Wang, J. Space microgravity drives transdifferentiation of human bone marrow-derived mesenchymal stem cells from osteogenesis to adipogenesis.