A robotic Intelligent Towing Tank for learning complex fluid-structure dynamics

We describe the development of the Intelligent Towing Tank, an automated experimental facility guided by active learning to conduct a sequence of vortex-induced vibration (VIV) experiments, wherein the parameters of each next experiment are selected by minimizing suitable acquisition functions of quantified uncertainties. This constitutes a potential paradigm shift in conducting experimental research, where robots, computers, and humans collaborate to accelerate discovery and to search expeditiously and effectively large parametric spaces that are impracticable with the traditional approach of sequential hypothesis testing and subsequent train-and-error execution. We describe how our research parallels efforts in other fields, providing an orders-of-magnitude reduction in the number of experiments required to explore and map the complex hydrodynamic mechanisms governing the fluid-elastic instabilities and resulting nonlinear VIV responses. We show the effectiveness of the methodology of "explore-and-exploit" in parametric spaces of high dimensions, which are intractable with traditional approaches of systematic parametric variation in experimentation. We envision that this active learning approach to experimental research can be used across disciplines and potentially lead to physical insights and a new generation of models in multi-input/multi-output nonlinear systems.

Twenty Novel Disease Group-Specific and 12 New Shared Macrophage Pathways in Eight Groups of 34 Diseases Including 24 Inflammatory Organ Diseases and 10 Types of Tumors

The mechanisms underlying pathophysiological regulation of tissue macrophage (Mφ) subsets remain poorly understood. From the expression of 207 Mφ genes comprising 31 markers for 10 subsets, 45 transcription factors (TFs), 56 immunometabolism enzymes, 23 trained immunity (innate immune memory) enzymes, and 52 other genes in microarray data, we made the following findings. (1) When 34 inflammation diseases and tumor types were grouped into eight categories, there was differential expression of the 31 Mφ markers and 45 Mφ TFs, highlighted by 12 shared and 20 group-specific disease pathways. (2) Mφ in lung, liver, spleen, and intestine (LLSI-Mφ) express higher M1 Mφ markers than lean adipose tissue Mφ (ATMφ) physiologically. (3) Pro-adipogenic TFs C/EBPα and PPARγ and proinflammatory adipokine leptin upregulate the expression of M1 Mφ markers. (4) Among 10 immune checkpoint receptors (ICRs), LLSI-Mφ and bone marrow (BM) Mφ express higher levels of CD274 (PDL-1) than ATMφ, presumably to counteract the M1 dominant status via its reverse signaling behavior. (5) Among 24 intercellular communication exosome mediators, LLSI- and BM- Mφ prefer to use RAB27A and STX3 than RAB31 and YKT6, suggesting new inflammatory exosome mediators for propagating inflammation. (6) Mφ in peritoneal tissue and LLSI-Mφ upregulate higher levels of immunometabolism enzymes than does ATMφ. (7) Mφ from peritoneum and LLSI-Mφ upregulate more trained immunity enzyme genes than does ATMφ. Our results suggest that multiple new mechanisms including the cell surface, intracellular immunometabolism, trained immunity, and TFs may be responsible for disease group-specific and shared pathways. Our findings have provided novel insights on the pathophysiological regulation of tissue Mφ, the disease group-specific and shared pathways of Mφ, and novel therapeutic targets for cancers and inflammations.

INFLUENCE OF STATIC ELECTRICITY ON RADON MEASUREMENT USING PASSIVE DETECTORS

In order to investigate the influence of the static electricity on the measurement using passive radon detector, detectors were charged at the surface of chamber and its CR-39 elements respectively on purpose before the exposure in this study. The results of in-chamber experiments revealed that the static electricity would lead to critical influence on measurement especially when the CR-39 elements were negatively charged. The static charge would remain for several ten hours, which result in more significant influence on the short-term measurement.

Macrophage miR-34a Is a Key Regulator of Cholesterol Efflux and Atherosclerosis

Macrophages play a crucial role in the pathogenesis of atherosclerosis, but the molecular mechanisms remain poorly understood. Here we show that microRNA-34a (miR-34a) is a key regulator of macrophage cholesterol efflux and reverse cholesterol transport by modulating ATP-binding cassette transporters ATP-binding cassette subfamily A member 1 (ABCA1) and ATP-binding cassette subfamily G member 1 (ABCG1). miR-34a also regulates M1 and M2 macrophage polarization via liver X receptor α. Furthermore, global loss of miR-34a reduces intestinal cholesterol or fat absorption by inhibiting cytochrome P450 enzymes CYP7A1 and sterol 12α-hydroxylase (CYP8B1). Consistent with these findings, macrophage-selective or global ablation of miR-34a markedly inhibits the development of atherosclerosis. Finally, therapeutic inhibition of miR-34a promotes atherosclerosis regression and reverses diet-induced metabolic disorders. Our studies outline a central role of miR-34a in regulating macrophage cholesterol efflux, inflammation, and atherosclerosis, suggesting that miR-34a is a promising target for treatment of cardiometabolic diseases.

Anticancer activity of emodin is associated with downregulation of CD155

Emodin is a Chinese herb-derived compound that exhibits a variety of pharmacological benefits. Although emodin has been shown to inhibit growth of cancer cells, its antineoplastic function is incompletely understood. CD155 is a member of poliovirus receptor-related (PRR) family of adhesion molecules; it is constitutively expressed on many tumor cell lines and tissues and has diverse functions. CD155 has been reported to mediate activation of T cells via CD226 or inhibition of T cells via T-cell immunoreceptor with Ig and ITIM domains (TIGIT). In addition, CD155 may play a critical role through non-immunological mechanisms in cancer. In this study, we tested the ability of emodin to modulate CD155 expression in cancer cells. We found that emodin significantly decreased the expression of CD155 in tumor cells and inhibited tumor cell proliferation and migration, and induced cell-cycle arrest at G2/M phase. The tumor inhibitory effects of emodin were lost with CD155 knockdown. Furthermore, emodin was used to treat mice bearing B16 melanoma. It was shown that emodin attenuated tumor growth accompanied by suppressing CD155 expression. Therefore, we propose that emodin could inhibit tumor growth, and the antineoplastic properties of emodin are at least partially CD155 dependent. Our study provides new insights into the mechanisms by which emodin inhibits tumor growth.

Intraductal Adaptation of the 4T1 Mouse Model of Breast Cancer Reveals Effects of the Epithelial Microenvironment on Tumor Progression and Metastasis

BACKGROUND

Low success rates in oncology drug development are prompting re-evaluation of preclinical models, including orthotopic tumor engraftment. In breast cancer models, tumor cells are typically injected into mouse mammary fat pads (MFP). However, this approach bypasses the epithelial microenvironment, potentially altering tumor properties in ways that affect translational application.

MATERIALS AND METHODS

Tumors were generated by mammary intraductal (MIND) engraftment of 4T1 carcinoma cells. Growth, histopathology, and molecular features were quantified.

RESULTS

Despite growth similar to that of 4T1 MFP tumors, 4T1 MIND tumors exhibit distinct histopathology and increased metastasis. Furthermore, >6,000 transcripts were found to be uniquely up-regulated in 4T1 MIND tumor cells, including genes that drive several cancer hallmarks, in addition to two known therapeutic targets that were not up-regulated in 4T1 MFP tumor cells.

CONCLUSION

Engraftment into the epithelial microenvironment generates tumors that more closely recapitulate the complexity of malignancy, suggesting that intraductal adaptation of orthotopic mammary models may be an important step towards improving outcomes in preclinical drug screening and development.

Preclinical development of natural compound emodin as an agent to halt breast cancer metastasis

Our previous studies demonstrated that a natural compound, emodin, suppresses breast cancer growth and metastasis by modulating tumor-associated macrophages (TAMs), we aim in this study to further develop emodin as an agent to diminish breast cancer post-surgery metastatic recurrence. Using various mouse and human breast cancer cell lines, we demonstrated that emodin not only directly reversed TGF-β1-induced epithelial to mesenchymal transition (EMT), migration and invasion, but also indirectly attenuated EMT by suppressing TAM polarization and TGF-β1 production. Emodin also suppressed the stemness and progenitor properties of tumor-initiating cells (TICs). The EMT process and TIC populations in primary breast tumors were diminished by emodin in vivo, and pretreating tumor cells with emodin suppressed breast cancer lung metastasis in a stem cell-like circulating tumor cell-seeding model. In orthotopic metastasis mouse models, administration of emodin before surgery suppressed the metastatic recurrence of breast cancer and improved the overall survival. Mechanistic study revealed that emodin inhibited both canonical and non-canonical pathways of TGF-β1 signaling in breast cancer cells. Taken together, our study demonstrated that emodin can be developed as a therapeutic agent to prevent post-surgery metastatic recurrence of breast cancer by suppressing TGF-β1-mediated crosstalk between breast cancer cells and TAMs.

TRIM14 promotes endothelial activation via NF-κB signaling pathway

Endothelial activation induced by proinflammatory cytokines is closely associated to the pathogenesis of atherosclerosis and other vascular diseases, however, the molecular mechanisms controlling endothelial activation are not fully understood. Here we report that TRIM14 promotes endothelial activation by enhancing cytokine-induced NF-κB activation. TRIM14 is highly expressed in human vascular endothelial cells, and markedly induced by TNF-α, IL-1β and LPS in both HUVECs and aortas of LPS-injected mice. Overexpression of TRIM14 significantly increased TNF-induced expression of adhesion molecules such as VCAM-1, ICAM-1, E-Selectin and cytokines in human endothelial cells, and by which it facilitated monocyte adhesion to the activated endothelial cells. Conversely, its silencing has opposite effect on endothelial activation. We further found that TRIM14 interacted with TAK1 and NEMO to facilitate the IKK complex formation and enhanced cytokine-induced phosphorylation of IκBα and NF-κB nuclear translocation. Moreover, we found that TRIM14 underwent K63-linked ubiquitination during TNF-induced endothelial activation, which is required for its positive role in the regulation of NF-κB signaling and endothelial inflammation. Meanwhile, NF-κB can directly bind to the promoter regions of TRIM14 gene and control its mRNA transcription. Finally, TRIM14 protein levels were significantly up-regulated in mouse and human atheroma compared to normal arteries. Taken together, the current study demonstrates the new role of TRIM14 in the regulation of endothelial activation and suggests that TRIM14 may be a potential therapeutic target for vascular inflammatory diseases such as atherosclerosis.

Utility of Dynamic Susceptibility Contrast Perfusion-Weighted MR Imaging and 11C-Methionine PET/CT for Differentiation of Tumor Recurrence from Radiation Injury in Patients with High-Grade Gliomas

BACKGROUND AND PURPOSE

Both ¹¹C-methionine PET/CT and DSC-PWI could be used to differentiate radiation injury from recurrent brain tumors. Our aim was to assess the performance of MET PET/CT and DSC-PWI for differentiation of recurrence and radiation injury in patients with high-grade gliomas and to quantitatively analyze the diagnostic values of PET and PWI parameters.

MATERIALS AND METHODS

Forty-two patients with high-grade gliomas were enrolled in this study. The final diagnosis was determined by histopathologic analysis or clinical follow-up. PWI and PET parameters were recorded and compared between patients with recurrence and those with radiation injury using Student t tests. Receiver operating characteristic and logistic regression analyses were used to determine the diagnostic performance of each parameter.

RESULTS

The final diagnosis was recurrence in 33 patients and radiation injury in 9. PET/CT showed a patient-based sensitivity and specificity of 0.909 and 0.556, respectively, while PWI showed values of 0.667 and 0.778, respectively. The maximum standardized uptake value, mean standardized uptake value, tumor-to-background maximum standardized uptake value, and mean relative CBV were significantly higher for patients with recurrence than for patients with radiation injury. All these parameters showed a high discriminative power in receiver operating characteristic analysis. The optimal cutoff values for the tumor-to-background maximum standardized uptake value and mean relative CBV were 1.85 and 1.83, respectively, and corresponding sensitivities and specificities for the diagnosis of recurrence were 0.97 and 0.667 and 0.788 and 0.88, respectively. Areas under the curve for the tumor-to-background maximum standardized uptake value and mean relative CBV were 0.847 ± 0.077 and 0.845 ± 0.078, respectively. Combined assessment of the tumor-to-background maximum standardized uptake value and mean relative CBV showed the largest area under the curve (0.953 ± 0.031), with corresponding sensitivity and specificity of 0.848 and 1.0, respectively.

CONCLUSIONS

Both ¹¹C-methionine PET/CT and PWI are equally accurate in the differentiation of recurrence from radiation injury in patients with high-grade gliomas, and a combination of the 2 modalities could result in increased diagnostic accuracy.

Sparstolonin B (SsnB) attenuates liver fibrosis via a parallel conjugate pathway involving P53-P21 axis, TGF-beta signaling and focal adhesion that is TLR4 dependent

SsnB previously showed a promising role to lessen liver inflammation observed in a mouse model of NAFLD. Since NAFLD can progress to fibrosis, studies were designed to unravel its role in attenuating NAFLD associated fibrosis. Using both in vivo and in vitro approaches, the study probed the possible mechanisms that underlined the role of SsnB in mitigating fibrosis. Mechanistically, SsnB, a TLR4 antagonist, decreased TLR4-PI3k akt signaling by upregulating PTEN protein expression. It also decreased MDM2 protein activation and increased p53 and p21 gene and protein expression. SsnB also downregulated pro-fibrogenic hedgehog signaling pathway, inhibited hepatic stellate cell proliferation and induced apoptosis in hepatic stellate cells, a mechanism that was LPS dependent. Further, SsnB decreased fibrosis by antagonizing TLR4 induced TGFβ signaling pathway. Alternatively, SsnB augmented BAMBI (a TGFβ pseudo-receptor) expression in mice liver by inhibiting TLR4 signaling pathway and thus reduced TGFβ signaling, resulting in decreased hepatic stellate cell activation and extracellular matrix deposition. In vitro experiments on human hepatic stellate cell line showed that SsnB increased gene and protein expression of BAMBI. It also decreased nuclear co-localization of phospho SMAD2/3 and SMAD4 protein and thus attenuated TGFβ signaling in vitro. We also observed a significant decrease in phosphorylation of SMAD2/3 protein, decreased STAT3 activation, alteration of focal adhesion protein and stress fiber disassembly upon SsnB administration in hepatic stellate cells which further confirmed the antagonistic effect of SsnB on TLR4-induced fibrogenesis.

Protein markers of dysfunctional HDL in scavenger receptor class B type I deficient mice

Background

Scavenger receptor class B type I (SR-BI) plays a key role in high density lipoproteins (HDL) metabolism. SR-BI deficiency in mice results in enhanced susceptibility to atherosclerosis with abnormal large, cholesterol enriched, and functional impaired HDL. This study was to characterize the protein markers of dysfunctional HDL in SR-BI deficient (SR-BI^−/−) mice and to test if the defective of HDL might be affected by probucol treatment.

Methods

Shotgun proteomics and 2-D gel electrophoresis were performed to examine the profile of HDL protein and distribution of HDL particles isolated from SR-BI^−/− mice. HDL’s cell-function, paraoxonase 1 (PON1) and myeloperoxidase activity were assessed. The mice were treated with 1.2 mg/g/day probucol for 6 weeks and the impact on HDL protein markers was analyzed. The differential proteins were quantified by Western blotting.

Results

The relative amount of protein in SR-BI^−/− HDL was decreased by about 25% compared to that in HDL from wild type (WT) mice. Compared to WT HDL, relative protein abundance of representative apoAI and PON1 in SR-BI^−/− HDL were significantly reduced, whereas acute-phase protein serum amyloid A (SAA) and apoAIV, proteinase inhibitor proteins α-1-antitrypsin (A1AT) were increased. The distribution of plasma apoAI-containing HDL particles in SR-BI^−/− mice was also dramatically altered, although plasma apoAI level was no difference. The protein alterations were accompanied with dysfunction of SR-BI^−/− HDL, evidenced by impaired cholesterol homeostasis in macrophages, and reduced anti-oxidative and anti-inflammatory effects. Probucol treatment of SR-BI^−/− mice could restored the relative contents of critical proteins including apoAI, PON1, SAA, apoAIV and A1AT on HDL, and improve HDL dysfunction despite decreased HDL-C level.

Conclusion

SR-BI deficiency leading to dysfunctional HDL is closely related to alteration of HDL protein, suggesting that identification of apoAI, PON1, SAA, apoAIV, and A1AT may serve as the valuable protein markers for diagnosis and therapeutics of dysfunctional HDL-related metabolic diseases.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1502-y) contains supplementary material, which is available to authorized users.

Macrophage depletion results in anemia, neutrophilia, and is not an effective therapy for rescuing obesity-linked metabolic impairments

Low-grade, chronic inflammation is thought to play a role in obesity-associated metabolic dysfunction. In obesity, macrophages account for approximately 50% of adipose tissue cells and can secrete a variety of proinflammatory cytokines. In this study, we sought to deplete macrophages in order to decrease macrophage-mediated inflammation and rescue metabolic dysfunction. Following 16 weeks of high-fat diet (HFD) (40% of total kcal from fat) or AIN-76A control diet consumption (n=30), male C57BL/6J mice within each diet cohort were assigned to either a clodronate (CLD)-liposome or PBS-liposome-treatment (n=15/group). Mice received 200 μl (1mg) i.p. injections of CLD or PBS-encapsulated liposomes (control group) twice weekly for 4 weeks to deplete macrophages. Metabolic function was assessed via the HOMA-IR, glucose and insulin tolerance tests, and serum free fatty acids. Adipose tissue, liver, and blood were analyzed for macrophage infiltration, inflammatory mediators and circulating cell populations. HFD-fed mice exhibited an obese phenotype compared to the control diet; however, macrophage depletion was unable to rescue metabolic dysfunction. Interestingly, macrophage-depleted mice had >35% increase in circulating neutrophils and adipose tissue Ly6G content. The increase in neutrophils, likely a compensation for the depletion of macrophages, was linked to an increase in the proinflammatory cytokines, IL-6 and IL1β, in the adipose tissue. Additionally, the decrease in macrophages resulted in iron-deficient anemia. Our study suggests that depleting macrophages in an obese setting is not an effective therapy for rescuing metabolic dysfunction and may increase the risk for anemia and adipose tissue inflammation.

TFEB regulates tumor-associated macrophages in breast cancer through autophagy-dependent and independent pathways

Tumor-associated macrophages (TAMs) play a key role in tumor development in breast cancer, as they are educated in the tumor microenvironment to assist tumor growth and metastasis. We identified an important role of TFEB, a master regulator of autophagy and lysosome biogenesis, in phenotypic regulation of TAMs. In human breast cancer and mouse orthotopic breast tumors, TFEB expression and activation are down-regulated in TAMs. Previously we showed that TFEB inhibits macrophage M2 polarization through a SOCS3-STAT3 pathway. Our new microarray analysis and qPCR confirmation demonstrate that TFEB overexpression in macrophages not only significantly suppresses the induction of typical M2 genes Arg1 and IL-10 by breast cancer cell conditioned medium, but also significantly inhibits the induction of inflammatory response axis NLRP3/IL1β/IL6 and PGE2 generation axis HIF-1α/MIF/cPLA2/COX2. These two axes are known to be tumor-promoting. Further analyses indicate that TFEB regulates these two axes through both autophagy-dependent and autophagy-independent pathways. Animal studies show that macrophage-specific TFEB overexpression inhibits, while macrophage-specific TFEB deficiency enhances breast tumor growth and metastasis. Furthermore, activation of TFEB using two natural compounds halts breast cancer development in mice. Taken together, our data suggest that activation of macrophage TFEB could be developed as a therapeutic strategy against breast cancer.

Diaheliotropic leaf movement enhances leaf photosynthetic capacity and photosynthetic light and nitrogen use efficiency via optimising nitrogen partitioning among photosynthetic components in cotton (Gossypium hirsutum L.)

Phototropic leaf movement of plants is an effective mechanism for adapting to light conditions. Light is the major driver of plant photosynthesis. Leaf N is also an important limiting factor on leaf photosynthetic potential. Cotton (Gossypium hirsutum L.) exhibits diaheliotropic leaf movement. Here, we compared the long-term photosynthetic acclimation of fixed leaves (restrained) and free leaves (allowed free movement) in cotton. The fixed leaves and free leaves were used for determination of PAR, leaf chlorophyll concentration, leaf N content and leaf gas exchange. The measurements were conducted under clear sky conditions at 0, 7, 15 and 30 days after treatment (DAT). The results showed that leaf N allocation and partitioning among different components of the photosynthetic apparatus were significantly affected by diaheliotropic leaf movement. Diaheliotropic leaf movement significantly increased light interception per unit leaf area, which in turn affected leaf mass per area (LMA), leaf N content (N_A ) and leaf N allocation to photosynthesis (N_P ). In addition, cotton leaves optimised leaf N allocation to the photosynthetic apparatus by adjusting leaf mass per area and N_A in response to optimal light interception. In the presence of diaheliotropic leaf movement, cotton leaves optimised their structural tissue and photosynthetic characteristics, such as LMA, N_A and leaf N allocation to photosynthesis, so that leaf photosynthetic capacity was maximised to improve the photosynthetic use efficiency of light and N under high light conditions.

Does the laparoscopic treatment of paediatric hydroceles represent a better alternative to the traditional open repair technique? A retrospective study of 1332 surgeries performed at two centres in China

Purpose

To evaluate the safety, efficacy and merits of laparoscopic repair in children with hydroceles by comparing the outcomes of laparoscopic repair and the traditional open repair (OR) procedure. The outcomes of the following three laparoscopic percutaneous extra-peritoneal closure (LPEC) approaches were also compared: conventional two-port surgery, transumbilical single-site two-port surgery and single-port surgery.

Methods

We retrospectively compared the demographic, perioperative and follow-up data from the consecutive records obtained for 382 boys who underwent OR and 950 boys who underwent LPEC at two children’s medical centres in China. In the LPEC group, regardless of the hydrocele form, one of the three approaches with percutaneous aspiration was performed: conventional two-port surgery was performed in 387 cases, single-site two-port surgery was performed in 468 cases and single-port surgery was performed in 95 cases. The clinical data and complications were statistically analysed.

Results

Postoperative follow-up data were obtained for all the patients. The mean follow-up time was 36 months (24–48 months) in the OR group and 32.5 months (20–44 months) in the LPEC group. Significant differences in recurrence were not observed between the groups (five in the OR and 10 in the LPEC; P = 0.69). However, the operation time, postoperative hospital stay, incidence of scrotal oedema, incision infection and contralateral metachronous hernia or hydrocele were significantly higher in the OR group than those in the LPEC group (P < 0.01). Eighteen children (4.71%) had a negative exploration of the patent processus vaginalis (PPV) in the OR group. Fourteen children (1.47%) in the LPEC group had a closed internal ring and were converted to a scrotal procedure. Significant differences in the clinical data or complications were not observed between the two centres for the laparoscopic procedure (P > 0.05). Contralateral PPV (cPPV) was found in 18 patients in the single-port group (18.9%). Of the patients affected with cPPV, significant differences were observed between the single-port group and the two-port LPEC group (122 patients, 31.5%, P = 0.016) and the single-site two-port group (the 148 patients, 31.6%, P = 0.013). A contralateral metachronous hernia or hydrocele was found in zero, zero and two cases in these groups, respectively, and significant differences were observed (P < 0.01) between the single-site surgery and the other two laparoscopic approaches.

Conclusions

LPEC is safe, feasible and effective for treating hydroceles in children and has the same recurrence rate as OR. However, LPEC is superior in operation time, hospital stay, occurrence of scrotal oedema, incision infection and occurrence of metachronous hernia or hydrocele. The transumbilical single-site two-port procedure has the same cosmetic effect as the single-port LPEC. According to our experience, the two-port LPEC approach is better for diagnosing cPPV and reducing metachronous hernia or hydrocele than the single-port LPEC procedure.

miR155 deficiency aggravates high-fat diet-induced adipose tissue fibrosis in male mice

Noncoding RNAs are emerging as regulators of inflammatory and metabolic processes. There is evidence to suggest that miRNA155 (miR155) may be linked to inflammation and processes associated with adipogenesis. We examined the impact of global miRNA-155 deletion (miR155-/-) on the development of high-fat diet (HFD)-induced obesity. We hypothesized that loss of miR155 would decrease adipose tissue inflammation and improve the metabolic profile following HFD feedings. Beginning at 4-5 weeks of age, male miR155-/- and wild-type (WT) mice (n = 13-14) on a C57BL/6 background were fed either a HFD or low-fat diet for 20 weeks. Body weight was monitored throughout the study. Baseline and terminal body composition was assessed by DEXA analysis. Adipose tissue mRNA expression (RT-qPCR) of macrophage markers (F4/80, CD11c, and CD206) and inflammatory mediators (MCP-1 and TNF-α) as well as adiponectin were measured along with activation of NFκB-p65 and JNK and PPAR-γ Adipose tissue fibrosis was assessed by picrosirius red staining and western blot analysis of Collagen I, III, and VI. Glucose metabolism and insulin resistance were assessed by Homeostatic Model Assessment - Insulin Resistance (HOMA-IR), and a glucose tolerance test. Compared to WT HFD mice, miR155-/- HFD mice displayed similar body weights, yet reduced visceral adipose tissue accumulation. However, miR155-/- HFD displayed exacerbated adipose tissue fibrosis and decreased PPAR-γ protein content. The loss of miR155 did not affect adipose tissue inflammation or glucose metabolism. In conclusion, miR155 deletion did not attenuate the development of the obese phenotype, but adipose tissue fibrosis was exacerbated, possibly through changes to adipogenic processes.

Design and Fabrication of a Three-Dimensional In Vitro System for Modeling Vascular Stenosis

Vascular stenosis, the abnormal narrowing of blood vessels, arises from defective developmental processes or atherosclerosis-related adult pathologies. Stenosis triggers a series of adaptive cellular responses that induces adverse remodeling, which can progress to partial or complete vessel occlusion with numerous fatal outcomes. Despite its severity, the cellular interactions and biophysical cues that regulate this pathological progression are poorly understood. Here, we report the design and fabrication of a three-dimensional (3D) in vitro system to model vascular stenosis so that specific cellular interactions and responses to hemodynamic stimuli can be investigated. Tubular cellularized constructs (cytotubes) were produced, using a collagen casting system, to generate a stenotic arterial model. Fabrication methods were developed to create cytotubes containing co-cultured vascular cells, where cell viability, distribution, morphology, and contraction were examined. Fibroblasts, bone marrow primary cells, smooth muscle cells (SMCs), and endothelial cells (ECs) remained viable during culture and developed location- and time-dependent morphologies. We found cytotube contraction to depend on cellular composition, where SMC-EC co-cultures adopted intermediate contractile phenotypes between SMC- and EC-only cytotubes. Our fabrication approach and the resulting artery model can serve as an in vitro 3D culture system to investigate vascular pathogenesis and promote the tissue engineering field.

Administration of Sparstolonin B- a TLR4 antagonist, attenuates hepatic fibrosis by inhibiting TLR4 mediated hepatic fibroblast proliferation

Previous studies have shown that TLR4 activation accentuates hepatic inflammation and fibrosis in nonalcoholic steatohepatitis (NASH). Here we report an anti-fibrotic activity of Sparstolonin B (SsnB)-a TLR4 antagonist, derived from Chinese herb Sparganium stoloniferum. We hypothesize that, SsnB decreases TLR4 induced inflammation and fibrosis in liver by inhibiting TLR4 signaling, TGFβ signaling and by inducing senescence in fibrogenic hepatic stellate cells. Here we used Bromodichloromethane (BDCM) induced liver fibrosis model where diet induced obese (DIO) mice were administered with BDCM (a CYP2E1 activator) for 4 weeks. A similar group were administered SsnB for 4 weeks along with BDCM. Picrosirius stain and IHC of fibronectin images showed a robust decrease of extracellular matrix deposition upon SsnB administration. Mechanistically, we found that SsnB decreased fibroblast proliferation by inhibiting TLR4-PI3K akt mediated fibroblast proliferation-as was shown by increased PTEN, p53, p21 and decreased cyclin D1, MDM2 protein expression in SsnB treated mice. Interestingly, we found a parallel mechanism in which SsnB increased BAMBI (a TGFβ pseudo-receptor) protein expression. Inhibition was possibly mediated by targeting the TLR4 dependent MYD88-NfkB pathway and TGFβ signaling was decreased following attenuated SMAD2/3-SMAD4 co-localization in the nucleus. SsnB increased gene expression of cell senescence markers (p53, p21), decreased alpha SMA gene expression and increased anti-fibrotic matrix metallo protease 2 (MMP2) gene expression in rat stellate cells in vitro. BAMBI gene and protein expression- a negative regulator of pro-fibrogenic TGFβ signaling, were also increased by SsnB treatment in vitro.

The role of TFEB in tumor-associated macrophages

Alternatively activated (M2-like) tumor-associated macrophages (TAMs) have been shown to promote immune suppression, invasion, angiogenesis, the establishment of distant metastases, and maintain the breast cancer stem cell population. However, the mechanisms governing TAM polarization are not fully understood. Transcription factor EB (TFEB) has been recently investigated due to its role as the master regulator of autophagy, but little is known regarding its role in governing macrophage activation or other immune response pathways. We show here that TFEB transcription and activation are reduced in TAMs, and TGF-β-induced activation of ERK signaling is the driving force behind this phenomenon. siRNA knockdown of TFEB in macrophages significantly enhances their alternative activation. Co-inoculation of these macrophages with breast tumor cells results in an increase of both tumor growth and infiltration of M2-like TAMs. Further mechanistic studies reveal that TFEB knockdown regulates M2 polarization by decreasing activation of SOCS3, which acts as an inhibitor of STAT3. These findings led us to further investigate whether increasing TFEB activation in TAMs could decrease their alternative activation and their tumor promoting properties. We found that activation of macrophage TFEB suppresses alternative activation, and introduction of these macrophages at the time of tumor initiation decreases tumor growth in multiple murine models. Therefore, our data demonstrate that the downregulation of TFEB is an integral part of immune editing in the tumor microenvironment, and provides a rationale for a new cancer treatment strategy involving the modulation of TAM polarization through activating TFEB.

Transcriptional factor EB regulates macrophage polarization in the tumor microenvironment

Tumor microenvironment (TME) contains a variety of infiltrating immune cells. Among them, tumor-associated macrophages (TAMs) and their alternative activation contribute greatly to the progression of tumors. The mechanisms governing macrophage polarization in the TME are unclear. Here, we show that in TAMs or macrophages under tumor-conditioned medium treatment, the expression of transcription factor EB (TFEB) is reduced and more of the TFEB protein is in an inactive cytosolic form. Transforming growth factor (TGF)-β is identified as a main driving force for the reduced TFEB expression and activity in TAMs via activating ERK signaling. TFEB interference in macrophages significantly enhanced their alternative activation, with reduced expression of MHC-II and co-stimulatory molecule CD80, decreased ability to activate T cells, and increased ability to attract tumor cells. When co-inoculated with tumor cells, macrophages with TFEB knockdown significantly enhanced tumor growth with increased infiltration of M2-like macrophages, reduced infiltration of CD8⁺ T cells, and enhanced angiogenesis in the tumors. Mechanistic studies revealed that TFEB downregulation resulted in macrophage M2 polarization through reducing SOCS3 production and enhancing STAT3 activation. We further demonstrate that the activation of TFEB by hydroxypropyl-β-cyclodextrin in macrophages suppressed their M2 polarization and tumor-promoting capacity, and that macrophage-specific TFEB overexpression inhibited breast tumor growth in mice. Therefore, our data suggest that TFEB plays critical roles in macrophage polarization, and the downregulation of TFEB expression and activation is an integral part of tumor-induced immune editing in the TME. This study provides a rationale for a new cancer treatment strategy by modulating macrophage polarization through activating TFEB.

High-mobility group box 1 regulates cytoprotective autophagy in a mouse spermatocyte cell line (GC-2spd) exposed to cadmium

BACKGROUND

Cadmium (Cd) is an environmental and industrial pollutant that induces a broad spectrum of toxicological effects, influences a variety of human organs, and is associated with poor semen quality and male infertility. Increasing evidence demonstrates that Cd induces testicular germ cell apoptosis in rodent animals. However, the specific effect of Cd exposure on autophagy in germ cells is poorly understood.

METHODS

We investigate the role of high-mobility group box 1 protein (HMGB1), a ubiquitous nuclear protein, on Cd-evoked autophagy in a mouse spermatocyte cell line (GC-2spd).

RESULTS

Our data have shown that autophagy was significantly elevated in GC-2spd cells exposed to Cd. Furthermore, there was a reduction in rapamycin (RAP)-mediated apoptosis. In addition, Cd exposure reduced cell viability, which is an effect that could be significantly inhibited by RAP treatment. These results indicate that autophagy appears to serve a positive function in reducing Cd-induced cytotoxicity. In addition, HMGB1 increased coincident with the processing of LC3-I to LC3-II. Thus, the upregulation of HMGB1 increases LC3-II levels.

CONCLUSIONS

Our data suggest that HMGB1-induced autophagy appears to act as a defense/survival mechanism against Cd cytotoxicity in GC-2spd cells.