Multiple Effects of a Novel Epothilone Analog on Cellular Processes and Signaling Pathways Regulated by Rac1 GTPase in the Human Breast Cancer Cells.

The epothilones are a class of microtubule inhibitors that exhibit a strong antitumor activity. UTD2 is a novel epothilone analog generated by genetic manipulation of the polyketide biosynthetic gene cluster. This study investigated the effects of UTD2 on the actin cytoskeleton and its critical regulators, and the signaling pathways which are essential for cell motility, growth and survival in MCF-7 breast cancer cells. Results showed that UTD2 inhibited the cellular functions of actin cytoskeleton, such as wound-closure, migration and invasion, as well as adhesion. Our study further demonstrated that UTD2 suppressed Rac1 GTPase activation and reduced the activity of PAK1, which is a downstream effector of Rac1, while the activity of Cdc42 was not affected. Additionally, the phosphorylation of p38 and ERK were significantly inhibited, but the phosphorylation of JNK remained the same after UTD2 treatment. Moreover, UTD2 inhibited the activity and mRNA expression of MMP-2, which plays a key role in cell motility. UTD2 also reduced the phosphorylation of Akt, which is an important signaling kinase regulating the cell survival through Rac1. Furthermore, UTD2 interrupted the synergy between Rac1 and Raf in focus formation assays. Taken together, these results indicated that UTD2 exerted multiple effects on the actin cytoskeleton and signaling pathways associated with Rac1. This study provided novel insights into the molecular mechanism of the antineoplastic and antimetastatic activities of epothilones. Our findings also suggest that the signaling pathways regulated by Rac1 may be evaluated as biomarkers for the response to therapy in clinical trials of epothilones.

Correlation Between Blood Cadmium Levels and Platelet Characteristics, As Well As Their Impact on Susceptibility to Coronary Heart Disease: Findings from NHANES 2005-2018 Data.

Investigating the correlation between blood cadmium levels, platelet characteristics, and susceptibility to coronary heart disease (CHD). Utilized NHANES 2005-2018 data with covariates such as age, sex, race, marital status, and socio-economic status. Blood cadmium served as the independent variable, while platelet count (PC) and mean platelet volume (MPV) were dependent variables. The average age of the participants was 68.77 ± 11.03 years, and 67.4% of them were male. The mean values for WBC, MPV, PC, and blood cadmium were 7.53 ± 3.36 × 103 cells/µL, 11.33 ± 0.27fL, 57.61 ± 5.34 × 103 cells/µL, and 2.58 ± 0.61 µg/L, respectively. Adjusting for other variables revealed increased MPV and PC with rising blood cadmium levels in cardiac patients, indicating a higher risk of CHD in those with elevated blood cadmium. The average age of the participants was 68.77 ± 11.03 years, and 67.4% of them were male. The mean values for WBC, MPV, PC, and blood cadmium were 7.53 ± 3.36 × 103 cells/µL, 11.33 ± 0.27fL, 57.61 ± 5.34 × 103 cells/µL, and 2.58 ± 0.61 µg/L, respectively. Adjusting for other variables revealed increased MPV and PC with rising blood cadmium levels in cardiac patients, indicating a higher risk of CHD in those with elevated blood cadmium. This study enhances understanding of how cadmium impacts platelet characteristics, contributing to increased CHD risk, providing insights for primary prevention strategies.

Oncogenic fatty acid oxidation senses circadian disruption in sleep-deficiency-enhanced tumorigenesis.

Circadian disruption predicts poor cancer prognosis, yet how circadian disruption is sensed in sleep-deficiency (SD)-enhanced tumorigenesis remains obscure. Here, we show fatty acid oxidation (FAO) as a circadian sensor relaying from clock disruption to oncogenic metabolic signal in SD-enhanced lung tumorigenesis. Both unbiased transcriptomic and metabolomic analyses reveal that FAO senses SD-induced circadian disruption, as illustrated by continuously increased palmitoyl-coenzyme A (PA-CoA) catalyzed by long-chain fatty acyl-CoA synthetase 1 (ACSL1). Mechanistically, SD-dysregulated CLOCK hypertransactivates ACSL1 to produce PA-CoA, which facilitates CLOCK-Cys194 S-palmitoylation in a ZDHHC5-dependent manner. This positive transcription-palmitoylation feedback loop prevents ubiquitin-proteasomal degradation of CLOCK, causing FAO-sensed circadian disruption to maintain SD-enhanced cancer stemness. Intriguingly, timed ß-endorphin resets rhythmic Clock and Acsl1 expression to alleviate SD-enhanced tumorigenesis. Sleep quality and serum ß-endorphin are negatively associated with both cancer development and CLOCK/ACSL1 expression in patients with cancer, suggesting dawn-supplemented ß-endorphin as a potential chronotherapeutic strategy for SD-related cancer.

Current matching using CdSe quantum dots to enhance the power conversion efficiency of InGaP/GaAs/Ge tandem solar cells.

A III-V multi-junction tandem solar cell is the most efficient photovoltaic structure that offers an extremely high power conversion efficiency. Current mismatching between each subcell of the device, however, is a significant challenge that causes the experimental value of the power conversion efficiency to deviate from the theoretical value. In this work, we explore a promising strategy using CdSe quantum dots (QDs) to enhance the photocurrent of the limited subcell to match with those of the other subcells and to enhance the power conversion efficiency of InGaP/GaAs/Ge tandem solar cells. The underlying mechanism of the enhancement can be attributed to the QD's unique capacity for photon conversion that tailors the incident spectrum of solar light; the enhanced efficiency of the device is therefore strongly dependent on the QD's dimensions. As a result, by appropriately selecting and spreading 7 mg/mL of CdSe QDs with diameters of 4.2 nm upon the InGaP/GaAs/Ge solar cell, the power conversion efficiency shows an enhancement of 10.39% compared to the cell's counterpart without integrating CdSe QDs.

Correlation between systemic inflammatory response index and thyroid function: 2009-2012 NHANES results.

Aims: This study investigates the relationship between the Systemic Inflammatory Response Index (SIRI) and thyroid function. Methods: Utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2009-2012, we excluded participants lacking SIRI or thyroid function data, those under 20 years, and pregnant individuals. SIRI was determined using blood samples. We conducted weighted multivariate regression and subgroup analyses to discern the independent relationship between SIRI and thyroid function. Results: The study included 1,641 subjects, with an average age of 47.26±16.77 years, including 48.65% males and 51.35% females. The population was divided into three SIRI-based groups (Q1-Q3). Q3, compared to Q1, exhibited higher age-at-onset, greater male prevalence, and increased levels of FT3, FT4, TT4, leukocytes, and triglycerides. This group also showed a higher incidence of diabetes, hypertension, and smoking. Notably, Q1 had lower LDL and HDL levels. SIRI maintained a positive association with FT4 (ß = 0.01, 95% CI = 0.00-0.03, P for trend = 0.0071), TT4 (ß = 0.20, 95% CI = 0.10, 0.31, P for trend=0.0001), and TPOAb (ß = 8.0, 95% CI = 1.77-14.30, P for trend = 0.0120), indicating that each quartile increase in SIRI corresponded to a 0.01 ng/dL increase in FT4, a 0.2 g/dL increase in TT4, and an 8.03 IU/mL rise in TPOAb. The subgroup analysis suggested the SIRI-thyroid function correlation was influenced by hypertension. Conclusion: Inflammation may impact the development and progression of thyroid function disorders. Proactive anti-inflammatory treatment might mitigate thyroid abnormalities.

Pyrroline-5-carboxylate reductase 1 reprograms proline metabolism to drive breast cancer stemness under psychological stress.

Cancer stem-like cells (CSCs) contribute to cancer metastasis, drug resistance and tumor relapse, yet how amino acid metabolism promotes CSC maintenance remains exclusive. Here, we identify that proline synthetase PYCR1 is critical for breast cancer stemness and tumor growth. Mechanistically, PYCR1-synthesized proline activates cGMP-PKG signaling to enhance cancer stem-like traits. Importantly, cGMP-PKG signaling mediates psychological stress-induced cancer stem-like phenotypes and tumorigenesis. Ablation of PYCR1 markedly reverses psychological stress-induced proline synthesis, cGMP-PKG signaling activation and cancer progression. Clinically, PYCR1 and cGMP-PKG signaling components are highly expressed in breast tumor specimens, conferring poor survival in breast cancer patients. Targeting proline metabolism or cGMP-PKG signaling pathway provides a potential therapeutic strategy for breast patients undergoing psychological stress. Collectively, our findings unveil that PYCR1-enhanced proline synthesis displays a critical role in maintaining breast cancer stemness.

Analyzing Human Periodontal Soft Tissue Inflammation and Drug Responses In Vitro Using Epithelium-Capillary Interface On-a-Chip.

The gingival epithelium-capillary interface is a unique feature of periodontal soft tissue, preserving periodontal tissue homeostasis and preventing microorganism and toxic substances from entering the subepithelial tissue. However, the function of the interface is disturbed in periodontitis, and mechanisms of the breakdown of the interface are incompletely understood. To address these limitations, we developed a microfluidic epithelium-capillary barrier with a thin culture membrane (10 µm) that closely mimics the in vivo gingival epithelial barrier with an immune micro-environment. To test the validity of the fabricated gingival epithelial barrier model, epithelium-capillary interface-on-a-chip was cultured with human gingival epithelial cells (HGECs) and human vascular endothelial cells (HUVEC). Their key properties were tested using optical microscope, transepithelial/transendothelial electrical resistance (TEER), and permeability assays. The clear expression of VE-cadherin revealed the tight junctions in endothelial cells. Live/dead assays indicated a high cell viability, and the astrocytic morphology of HGE cells was confirmed by F-actin immunostaining. By the third day of cell culture, TEER levels typically exceeded in co-cultures. The resultant permeability coefficients showed a significant difference between 70 kDa and 40 kDa FITC-dextran. The expression of protein intercellular cell adhesion molecule (ICAM-1) and human beta defensin-2 (HBD2) decreased when exposed to TNF-α and LPS, but recovered with the NF-κB inhibitor treatment- Pyrrolidinedithiocarbamic acid (PDTC), indicating the stability of the fabricated chip. These results demonstrate that the developed epithelium-capillary interface system is a valid model for studying periodontal soft tissue function and drug delivery.

A microfluidic demonstration of "cluster-sprout-infiltrating" mode for hypoxic mesenchymal stem cell guided cancer cell migration.

Mesenchymal stem cells (MSCs) play a critical role in tumor metastasis. However, the dynamic process of MSCs-mediated cancer cell invasion remains inconclusive. In breast cancer mouse models, we observed that MSCs promoted lung metastasis. We constructed a microfluidic-based 3D co-culture device to monitor MSCs-mediated cancer cell invasion in a nutrient-deficient hypoxic microenvironment. On biomimetic microfluidic devices, MSCs guided cancer cell migration in a "cluster-sprout-infiltrating" mode. Importantly, hypoxic conditions significantly promoted MSCs migration at the infiltration stage, leading to accelerated breast cancer cell invasion. Moreover, hypoxia related LncRNA analysis showed that H19 was dramatically upregulated in response to hypoxic conditions. Conversely, H19 depletion impaired MSCs-directed breast cancer cell invasion. Mechanistically, H19 functions as a competitive endogenous RNA (ceRNA) which sequesters miRNA let-7 to release its target matrix metalloproteinase-1 (MMP1). Intriguingly, aspirin dramatically suppressed H19 and MMP1 expression and blocked MSCs infiltration under hypoxic conditions, resulting in alleviated breast cancer cell invasion. These findings point to the metastatic promoting role of MSCs in tumor stroma and suggest that MSCs might be a therapeutic target for metastatic breast cancer.

Nuclear Aurora kinase A switches m6A reader YTHDC1 to enhance an oncogenic RNA splicing of tumor suppressor RBM4.

Aberrant RNA splicing produces alternative isoforms of genes to facilitate tumor progression, yet how this process is regulated by oncogenic signal remains largely unknown. Here, we unveil that non-canonical activation of nuclear AURKA promotes an oncogenic RNA splicing of tumor suppressor RBM4 directed by m6A reader YTHDC1 in lung cancer. Nuclear translocation of AURKA is a prerequisite for RNA aberrant splicing, specifically triggering RBM4 splicing from the full isoform (RBM4-FL) to the short isoform (RBM4-S) in a kinase-independent manner. RBM4-S functions as a tumor promoter by abolishing RBM4-FL-mediated inhibition of the activity of the SRSF1-mTORC1 signaling pathway. Mechanistically, AURKA disrupts the binding of SRSF3 to YTHDC1, resulting in the inhibition of RBM4-FL production induced by the m6A-YTHDC1-SRSF3 complex. In turn, AURKA recruits hnRNP K to YTHDC1, leading to an m6A-YTHDC1-hnRNP K-dependent exon skipping to produce RBM4-S. Importantly, the small molecules that block AURKA nuclear translocation, reverse the oncogenic splicing of RBM4 and significantly suppress lung tumor progression. Together, our study unveils a previously unappreciated role of nuclear AURKA in m6A reader YTHDC1-dependent oncogenic RNA splicing switch, providing a novel therapeutic route to target nuclear oncogenic events.

Nuclear Aurora kinase A triggers programmed death-ligand 1-mediated immune suppression by activating MYC transcription in triple-negative breast cancer.

BACKGROUND: Increasing studies have reported that oncogenes regulate components of the immune system, suggesting that this is a mechanism for tumorigenesis. Aurora kinase A (AURKA), a serine/threonine kinase, is involved in cell mitosis and is essential for tumor cell proliferation, metastasis, and drug resistance. However, the mechanism by which AURKA is involved in immune response regulation is unclear. Therefore, this study aimed to investigate the role of AURKA in immune regulation in triple-negative breast cancer (TNBC). METHODS: Peripheral blood mononuclear cells (PBMCs) were co-cultured with TNBC cells. The xCELLigence Real-Time Cell Analyzer-MP system was used to detect the killing efficiency of immune cells on TNBC cells. The expression of immune effector molecules was tested by quantitative real-time polymerase chain reaction (qRT-PCR) to evaluate immune function. Furthermore, to validate AURKA-regulated immune response in vivo, 4T1 murine breast cancer cell line with AURKA overexpression or downregulation was engrafted into BALB/c mice. The distribution and proportion of immune cells in tumors were further evaluated by immunohistochemistry and flow cytometry. RESULTS: Downregulation of AURKA in TNBC cells increased immune response by activating CD8+ T cell proliferation and activity. Nuclear rather than cytoplasmic AURKA-derived programmed death-ligand 1 (PD-L1) expression was independent of its kinase activity. Mechanistic investigations showed that nuclear AURKA increased PD-L1 expression via an MYC-dependent pathway. PD-L1 overexpression mostly reversed AURKA silencing-induced expression of immune effector molecules, including interleukin- (IL-2), interferon-γ (IFN-γ), and perforin. Moreover, AURKA expression was negatively correlated with the enrichment and activity of tumor-infiltrating CD8+ T cells in 4T1 engrafted BALB/c mouse model. CONCLUSIONS: Nuclear AURKA elevated PD-L1 expression via an MYC-dependent pathway and contributed to immune evasion in TNBC. Therapies targeting nuclear AURKA may restore immune responses against tumors.

Lactobacillus spp. create a protective micro-ecological environment through regulating the core fucosylation of vaginal epithelial cells against cervical cancer.

Vaginal dysbiosis often occurs in patients with cervical cancer. The fucosylation of mucosal epithelial cells is closely related to microbial colonization, and play an important role in protecting the vaginal mucosal epithelial cells. However, no reports on the relationship between vaginal dysbiosis and abnormal mucosal epithelial cell fucosylation, and their roles in the occurrence and development of cervical cancer are unavailable. Here we report that core fucosylation levels were significantly lower in the serum, exfoliated cervical cells and tumor tissue of cervical cancer patients. Core fucosyltransferase gene (Fut8) knockout promoted the proliferation and migration of cervical cancer cells. In patients with cervical cancer, the vaginal dysbiosis, and the abundance of Lactobacillus, especially L. iners, was significantly reduced. Meanwhile, the abundance of L.iners was positively correlated with core fucosylation levels. The L. iners metabolite lactate can activate the Wnt pathway through the lactate-Gpr81 complex, which increases the level of core fucosylation in epidermal cells, inhibiting the proliferation and migration of cervical cancer cells, and have application prospects in regulating the vaginal microecology and preventing cervical cancer.

Oncogenic AURKA-enhanced N6-methyladenosine modification increases DROSHA mRNA stability to transactivate STC1 in breast cancer stem-like cells.

RNase III DROSHA is upregulated in multiple cancers and contributes to tumor progression by hitherto unclear mechanisms. Here, we demonstrate that DROSHA interacts with ß-Catenin to transactivate STC1 in an RNA cleavage-independent manner, contributing to breast cancer stem-like cell (BCSC) properties. DROSHA mRNA stability is enhanced by N6-methyladenosine (m6A) modification which is activated by AURKA in BCSCs. AURKA stabilizes METTL14 by inhibiting its ubiquitylation and degradation to promote DROSHA mRNA methylation. Moreover, binding of AURKA to DROSHA transcript further strengthens the binding of the m6A reader IGF2BP2 to stabilize m6A-modified DROSHA. In addition, wild-type DROSHA, but not an m6A methylation-deficient mutant, enhances BCSC stemness maintenance, while inhibition of DROSHA m6A modification attenuates BCSC traits. Our study unveils the AURKA-induced oncogenic m6A modification as a key regulator of DROSHA in breast cancer and identifies a novel DROSHA transcriptional function in promoting the BCSC phenotype.

Stress-induced epinephrine enhances lactate dehydrogenase A and promotes breast cancer stem-like cells.

Chronic stress triggers activation of the sympathetic nervous system and drives malignancy. Using an immunodeficient murine system, we showed that chronic stress-induced epinephrine promoted breast cancer stem-like properties via lactate dehydrogenase A-dependent (LDHA-dependent) metabolic rewiring. Chronic stress-induced epinephrine activated LDHA to generate lactate, and the adjusted pH directed USP28-mediated deubiquitination and stabilization of MYC. The SLUG promoter was then activated by MYC, which promoted development of breast cancer stem-like traits. Using a drug screen that targeted LDHA, we found that a chronic stress-induced cancer stem-like phenotype could be reversed by vitamin C. These findings demonstrated the critical importance of psychological factors in promoting stem-like properties in breast cancer cells. Thus, the LDHA-lowering agent vitamin C can be a potential approach for combating stress-associated breast cancer.

A nephron model for study of drug-induced acute kidney injury and assessment of drug-induced nephrotoxicity.

In this study, we developed a multilayer microfluidic device to simulate nephron, which was formed by "glomerulus", "Bowman's capsule", "proximal tubular lumen" and "peritubular capillary". In this microdevice, artificial renal blood flow was circulating and glomerular filtrate flow was single passing through, mimicking the behavior of a nephron. In this dynamic artificial nephron, we observed typical renal physiology, including the glomerular size-selective barrier, glomerular basement membrane charge-selective barrier, glucose reabsorption and para-aminohippuric acid secretion. To demonstrate the capability of our microdevice, we used it to investigate the pathophysiology of drug-induced acute kidney injury (AKI) and give assessment of drug-induced nephrotoxicity, with cisplatin and doxorubicin as model drugs. In the experiment, we loaded the doxorubicin or cisplatin in the "renal blood flow", recorded the injury of primary glomerular endothelial cells, podocytes, tubular epithelial cells and peritubular endothelial cells by fluorescence imaging, and identified the time-dependence, dose-dependence and the death order of four types of renal cells. Then by measuring multiple biomarkers, including E-cadherin, VEGF, VCAM-1, Nephrin, and ZO-1, we studied the mechanism of cell injuries caused by doxorubicin or cisplatin. Also, we investigated the effect of BSA in the "renal blood flow" on doxorubicin-or-cisplatin-induced nephrotoxicity, and found that BSA enhanced the tight junctions between cells and eased cisplatin-induced nephrotoxicity. In addition, we compared the nephron model and traditional tubule models for assessment of drug-induced nephrotoxicity. And it can be inferred that our biomimetic microdevice simulated the complex, dynamic microenvironment of nephron, yielded abundant information about drug-induced-AKI at the preclinical stage, boosted the drug safety evaluation, and provided a reliable reference for clinical therapy.

Increased Piezo1 channel activity in interstitial Cajal-like cells induces bladder hyperactivity by functionally interacting with NCX1 in rats with cyclophosphamide-induced cystitis.

The Piezo1 channel is a mechanotransduction mediator, and Piezo1 abnormalities have been linked to several clinical disorders. However, the role of the Piezo1 channel in cystitis-associated bladder dysfunction has not been documented. The current study aimed to discover the functional role of this channel in regulating bladder activity during cyclophosphamide (CYP)-induced cystitis. One hundred four female rats were randomly assigned to the control, CYP-4h, CYP-48h and CYP-8d groups. CYP successfully induced acute or chronic cystitis in these rats. CYP treatment for 48h or 8d significantly increased Piezo1 channel expression in bladder interstitial Cajal-like cells (ICC-LCs), and the increase in CYP-8d rats was more prominent. In addition, 2.5 µM Grammostola spatulata mechanotoxin 4 (GsMTx4) significantly attenuated bladder hyperactivity in CYP-8d rats by inhibiting the Piezo1 channel in bladder ICC-LCs. Furthermore, by using GsMTx4 and siRNA targeting the Piezo1 channel, we demonstrated that hypotonic stress-induced Piezo1 channel activation significantly triggered Ca2+ and Na+ influx into bladder ICC-LCs during CYP-induced chronic cystitis. In addition, the Piezo1 channel functionally interacted with the relatively activated reverse mode of Na+/Ca2+ exchanger 1 (NCX1) in bladder ICC-LCs from CYP-8d rats. In conclusion, we suggest that the functional role of the Piezo1 channel in CYP-induced chronic cystitis is based on its synergistic effects with NCX1, which can significantly enhance [Ca2+]i and result in Ca2+ overload in bladder ICC-LCs, indicating that the Piezo1 channel and NCX1 are potential novel therapeutic targets for chronic cystitis-associated bladder hyperactivity.

A Laminated Microfluidic Device for Comprehensive Preclinical Testing in the Drug ADME Process.

New techniques are urgently needed to replace conventional long and costly pre-clinical testing in the new drug administration process. In this study, a laminated microfluidic device was fabricated to mimic the drug ADME response test in vivo. This proposed device was loaded and cultured with functional cells for drug response investigation and organ tissues that are involved in ADME testing. The drug was introduced from the top of the device and first absorbed by the Caco-2 cell layer, and then metabolized by the primary hepatocyte layer. It subsequently interacted with the MCF-7 cell layer, distributed in the lung, heart and fat tissues, and was finally eliminated through the dialysis membrane. Throughout this on-chip ADME process, the proposed device can be used as a reliable tool to simultaneously evaluate the drug anti-tumor activity, hepatotoxicity and pharmacokinetics. Furthermore, this device was proven to be able to reflect the hepatic metabolism of a drug, drug distribution in the target tissues, and the administration method of a drug. Furthermore, this microdevice is expected to reduce the number of drug candidates and accelerate the pre-clinical testing process subject to animal testing upon adaptation in new drug discovery.

A novel microfluidic model can mimic organ-specific metastasis of circulating tumor cells.

A biomimetic microsystem might compensate costly and time-consuming animal metastatic models. Herein we developed a biomimetic microfluidic model to study cancer metastasis. Primary cells isolated from different organs were cultured on the microlfuidic model to represent individual organs. Breast and salivary gland cancer cells were driven to flow over primary cell culture chambers, mimicking dynamic adhesion of circulating tumor cells (CTCs) to endothelium in vivo. These flowing artificial CTCs showed different metastatic potentials to lung on the microfluidic model. The traditional nude mouse model of lung metastasis was performed to investigate the physiological similarity of the microfluidic model to animal models. It was found that the metastatic potential of different cancer cells assessed by the microfluidic model was in agreement with that assessed by the nude mouse model. Furthermore, it was demonstrated that the metastatic inhibitor AMD3100 inhibited lung metastasis effectively in both the microfluidic model and the nude mouse model. Then the microfluidic model was used to mimick liver and bone metastasis of CTCs and confirm the potential for research of multiple-organ metastasis. Thus, the metastasis of CTCs to different organs was reconstituted on the microfluidic model. It may expand the capabilities of traditional cell culture models, providing a low-cost, time-saving, and rapid alternative to animal models.

Organ-on-a-Chip: New Platform for Biological Analysis.

Direct detection and analysis of biomolecules and cells in physiological microenvironment is urgently needed for fast evaluation of biology and pharmacy. The past several years have witnessed remarkable development opportunities in vitro organs and tissues models with multiple functions based on microfluidic devices, termed as "organ-on-a-chip". Briefly speaking, it is a promising technology in rebuilding physiological functions of tissues and organs, featuring mammalian cell co-culture and artificial microenvironment created by microchannel networks. In this review, we summarized the advances in studies of heart-, vessel-, liver-, neuron-, kidney- and Multi-organs-on-a-chip, and discussed some noteworthy potential on-chip detection schemes.

Concentration-dependent differential effects of an epothilone analog on cell cycle and p53 signaling.

The tumor-suppressor protein p53 is considered to be one of the most important transport hubs of cell signal transduction, playing critical roles in the control of cell cycle arrest, apoptosis and many other processes as a nuclear transcription factor. p53 also acts in the cytoplasm to trigger apoptosis. Paclitaxel and other microtubule inhibitors can inhibit the growth of different types of cancer cells and induce apoptosis which is believed to be p53-independent. In the present study, we demonstrated that UTD1, a genetically engineered epothilone analog and a new microtubule inhibitor, activated p53 as a transcription factor at low concentrations demonstrated by its enhanced transcriptional activity and accumulation of p21, which led to cell cycle arrest. However, at high concentrations of UTD1, p53 was accumulated in the cytoplasm which contributed to induction of apoptosis. These observations indicate that the epothilone analog has differential effects on intracellular signaling and implies that p53 plays different roles in cells exposed to different concentrations of the anticancer agent.

Restoration of arterial baroreflex function contributes to organ protection in spontaneously hypertensive rats treated with long-term hydrochlorothiazide mixture.

1. Hydrochlorothiazide mixture (HCTM) is widely used in China for the treatment of hypertension. This mixture consists of hydrochlorothiazide, triamterene, reserpine, hydralazine and chlordiazpoxide, with small (one-third to one-fifth of normal) doses of each drug. The present study was designed to investigate the effects of this mixture on blood pressure, blood pressure variability (BPV), baroreflex sensitivity (BRS) and end-organ damage in spontaneously hypertensive rats (SHR). 2. The HCTM was mixed in the rat chow and rats were treated for 4 months. After treatment, rats were catheterized and their blood pressure, BPV and BRS were measured in the conscious state. Organ damage was examined after these measurements had been completed. 3. It was found that HCTM not only decreased blood pressure and BPV, but also ameliorated impaired BRS in SHR. The HCTM had an obvious effect on organ protection in SHR. 4. The HCTM prevented left ventricular hypertrophy and this effect was mainly related to a decrease in systolic blood pressure. The effects of HCTM on preventing renal atrophy were mainly determined by BRS. Baroreflex sensitivity was the most important determinant for predicting organ damage in HCTM-treated SHR. 5. In conclusion, long-term treatment of rats with HCTM prevented hypertensive organ damage. Restoration of arterial baroreflex function contributes to organ protection in SHR treated in the long term with HCTM.