Coupling is the process that links bone resorption to bone formation in a temporally and spatially coordinated manner within the remodeling cycle. Several lines of evidence point to the critical ...roles of osteoclast-derived coupling factors in the regulation of osteoblast performance. Here, we used a fractionated secretomic approach and identified the axon-guidance molecule SLIT3 as a clastokine that stimulated osteoblast migration and proliferation by activating β-catenin. SLIT3 also inhibited bone resorption by suppressing osteoclast differentiation in an autocrine manner. Mice deficient in Slit3 or its receptor, Robo1, exhibited osteopenic phenotypes due to a decrease in bone formation and increase in bone resorption. Mice lacking Slit3 specifically in osteoclasts had low bone mass, whereas mice with either neuron-specific Slit3 deletion or osteoblast-specific Slit3 deletion had normal bone mass, thereby indicating the importance of SLIT3 as a local determinant of bone metabolism. In postmenopausal women, higher circulating SLIT3 levels were associated with increased bone mass. Notably, injection of a truncated recombinant SLIT3 markedly rescued bone loss after an ovariectomy. Thus, these results indicate that SLIT3 plays an osteoprotective role by synchronously stimulating bone formation and inhibiting bone resorption, making it a potential therapeutic target for metabolic bone diseases.
Although autophagy plays a role in melanogenesis by regulating melanosome degradation and biogenesis in melanocytes, a detailed understanding of the regulatory functions of autophagy factors is ...lacking. Here, we report a mechanistic link between microtubule-associated protein light chain 3 (LC3) activation and melanogenesis. We observed high expression of LC3 in melanosome-associated pigment-rich melanocytic nevi of sun-exposed skin, as indicated by patterns of melanosomal protein MART1 expression. Rapamycin-induced autophagy significantly increased the melanin index, tyrosinase activity and expression of several proteins linked to melanosome biogenesis, including microphthalmia transcription factor (MITF), pre-melanosome protein and tyrosinase, in Melan-a melanocytes. siRNA-mediated knockdown of LC3, but not beclin-1 or ATG5, decreased melanin content and tyrosinase activity. LC3 knockdown also markedly inhibited MITF expression and subsequent rapamycin-induced melanosome formation. More importantly, LC3 knockdown suppressed α-MSH-mediated melanogenesis by attenuating cAMP response element-binding protein (CREB) phosphorylation and MITF expression in Melan-a cells via decreased extracellular signal-regulated kinase (ERK) activity. Overexpression of constitutively active ERK reversed the effect of LC3 knockdown on CREB phosphorylation and MITF expression. These findings demonstrate that LC3 contributes to melanogenesis by increasing ERK-dependent MITF expression, thereby providing a mechanistic insight into the signaling network that links autophagy to melanogenesis.
The endoplasmic reticulum (ER) is a subcellular organelle essential for cellular homeostasis. Perturbation of ER functions due to various conditions can induce apoptosis. Chronic ER stress has been ...implicated in a wide range of diseases, including autosomal dominant retinitis pigmentosa (ADRP), which is characterized by age-dependent retinal degeneration caused by mutant rhodopsin alleles. However, the signaling pathways that mediate apoptosis in response to ER stress remain poorly understood. In this study, we performed an unbiased in vivo RNAi screen with a Drosophila ADRP model and found that Wg/Wnt1 mediated apoptosis. Subsequent transcriptome analysis revealed that ER stress-associated serine protease (Erasp), which has been predicted to show serine-type endopeptidase activity, was a downstream target of Wg/Wnt1 during ER stress. Furthermore, knocking down Erasp via RNAi suppressed apoptosis induced by mutant rhodopsin-1 (Rh-1
) toxicity, alleviating retinal degeneration in the Drosophila ADRP model. In contrast, overexpression of Erasp resulted in enhanced caspase activity in Drosophila S2 cells treated with apoptotic inducers and the stabilization of the initiator caspase Dronc (Death regulator Nedd2-like caspase) by stimulating DIAP1 (Drosophila inhibitor of apoptosis protein 1) degradation. These findings helped identify a novel cell death signaling pathway involved in retinal degeneration in an autosomal dominant retinitis pigmentosa model.
Oncogenic EGFR is essential for the development and growth of non-small cell lung cancer (NSCLC), but the precise roles of EGFR in lung cancer metabolism remain unclear. Here, we show that EGFR ...mutation-mediated enhancement of glycolysis is critical for EGFR stability. EGFR knockdown significantly decreased levels of glycolytic pathway intermediates via transcriptional regulation of glycolytic genes. EGFR mutation-enhanced glycolysis was required for fueling the tricarboxylic acid cycle, a critical component of EGFR stability. Nonsustained ATP production enhanced reactive oxygen species accumulation and subsequent JNK-mediated activation of autophagy, which in turn induced EGFR degradation. Our data show that EGFR-mutant NSCLCs require EGFR mutation-enhanced glycolysis to maintain EGFR stability. This pathway may serve as an attractive therapeutic target for EGFR-mutant NSCLCs.
Enhanced glycolysis by EGFR mutation is required for maintaining EGFR levels via inhibition of JNK-induced autophagy. This provides a promising rationale for use of JNK activators in patients with EGFR-mutated NSCLC.
.
Patients with fibro-calcific aortic valve disease (FCAVD) have lipid depositions in their aortic valve that engender a proinflammatory impetus toward fibrosis and calcification and ultimately valve ...leaflet stenosis. Although the lipoprotein(a)-autotaxin (ATX)-lysophosphatidic acid axis has been suggested as a potential therapeutic target to prevent the development of FCAVD, supportive evidence using ATX inhibitors is lacking. We here evaluated the therapeutic potency of an ATX inhibitor to attenuate valvular calcification in the FCAVD animal models.
ATX level and activity in healthy participants and patients with FCAVD were analyzed using a bioinformatics approach using the Gene Expression Omnibus datasets, enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and western blotting. To evaluate the efficacy of ATX inhibitor, interleukin-1 receptor antagonist-deficient (Il1rn
mice and cholesterol-enriched diet-induced rabbits were used as the FCAVD models, and primary human valvular interstitial cells (VICs) from patients with calcification were employed.
The global gene expression profiles of the aortic valve tissue of patients with severe FCAVD demonstrated that ATX gene expression was significantly upregulated and correlated with lipid retention (r = 0.96) or fibro-calcific remodeling-related genes (r = 0.77) in comparison to age-matched non-FCAVD controls. Orally available ATX inhibitor, BBT-877, markedly ameliorated the osteogenic differentiation and further mineralization of primary human VICs in vitro. Additionally, ATX inhibition significantly attenuated fibrosis-related factors' production, with a detectable reduction of osteogenesis-related factors, in human VICs. Mechanistically, ATX inhibitor prohibited fibrotic changes in human VICs via both canonical and non-canonical TGF-β signaling, and subsequent induction of CTGF, a key factor in tissue fibrosis. In the in vivo FCAVD model system, ATX inhibitor exposure markedly reduced calcific lesion formation in interleukin-1 receptor antagonist-deficient mice (Il1rn
, P = 0.0210). This inhibition ameliorated the rate of change in the aortic valve area (P = 0.0287) and mean pressure gradient (P = 0.0249) in the FCAVD rabbit model. Moreover, transaortic maximal velocity (Vmax) was diminished with ATX inhibitor administration (mean Vmax = 1.082) compared to vehicle control (mean Vmax = 1.508, P = 0.0221). Importantly, ATX inhibitor administration suppressed the effects of a high-cholesterol diet and vitamin D2-driven fibrosis, in association with a reduction in macrophage infiltration and calcific deposition, in the aortic valves of this rabbit model.
ATX inhibition attenuates the development of FCAVD while protecting against fibrosis and calcification in VICs, suggesting the potential of using ATX inhibitors to treat FCAVD.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•We have designed and fabricated a sensor system for early lung cancer diagnosis.•Breath gas was collected from lung cancer patients before and after the surgery.•Volatile organic compounds in the ...breath gas were analyzed by the sensor system.•Lung cancer patients were distinguished from healthy controls with 75.0% accuracy.•Breath analysis may develop as a novel diagnostic tool for early lung cancer.
Lung cancer is the leading cause of cancer deaths in worldwide. There are many challenges to detect early stage lung cancer in accurate, inexpensive, and non-invasive ways. In this study, we have designed, fabricated, and characterized a sensor system as a novel lung cancer diagnosis tool. In order to investigate the clinical feasibility of the system to detect early stage lung cancer, exhaled breath was collected from 37 patients with non-small cell lung cancer (81.1% of stage I and II) and 48 healthy controls. Three types of samples were collected from each patient; 1) before lung cancer surgery, 2) the first outpatient clinic visit after surgery, and 3) the second outpatient clinic visit after surgery. The sampling schedule from the healthy controls matched that of the lung cancer patients. The volatile organic compounds (VOCs) in the exhaled breath were analyzed by the sensor system. The sensor system consisted of an array of seven metal oxide gas sensors, a gas flow controlling module, heating module, gas adsorption-desorption module and classifiers for data analysis. The result obtained for the first set of samples, using a multilayer perceptron (MLP) for classification indicated a total accuracy of 75.0% with 79.0% of sensitivity and 72.0% of specificity. 93.5% of healthy controls showed nearly unchanged data from the first to the third samples, while 45.2% of lung cancer patients showed definitely changed data from the first to the third samples when analyzed the projection results of original data onto the selected principal components (PCs) obtained from principal component analysis (PCA). The study showed that VOCs in exhaled breath potentially discriminated mostly early stage lung cancer patients before the surgery from healthy volunteers with our sensor system. Furthermore, the prognosis of the lung cancer patients after surgery would be predicted by this system. These results suggest that breath analysis may develop as a novel diagnostic tool for early lung cancer.
We tested the use of a deep learning algorithm to classify the clinical images of 12 skin diseases—basal cell carcinoma, squamous cell carcinoma, intraepithelial carcinoma, actinic keratosis, ...seborrheic keratosis, malignant melanoma, melanocytic nevus, lentigo, pyogenic granuloma, hemangioma, dermatofibroma, and wart. The convolutional neural network (Microsoft ResNet-152 model; Microsoft Research Asia, Beijing, China) was fine-tuned with images from the training portion of the Asan dataset, MED-NODE dataset, and atlas site images (19,398 images in total). The trained model was validated with the testing portion of the Asan, Hallym and Edinburgh datasets. With the Asan dataset, the area under the curve for the diagnosis of basal cell carcinoma, squamous cell carcinoma, intraepithelial carcinoma, and melanoma was 0.96 ± 0.01, 0.83 ± 0.01, 0.82 ± 0.02, and 0.96 ± 0.00, respectively. With the Edinburgh dataset, the area under the curve for the corresponding diseases was 0.90 ± 0.01, 0.91 ± 0.01, 0.83 ± 0.01, and 0.88 ± 0.01, respectively. With the Hallym dataset, the sensitivity for basal cell carcinoma diagnosis was 87.1% ± 6.0%. The tested algorithm performance with 480 Asan and Edinburgh images was comparable to that of 16 dermatologists. To improve the performance of convolutional neural network, additional images with a broader range of ages and ethnicities should be collected.
Cold atmospheric plasma (CAP) may have applications in treating various types of malignant tumors. This study assessed the anticancer effects of CAP using melanoma and colon cancer cell lines. CAP ...treatment significantly reduced the in vitro viability of melanoma and colon cancer cell lines and had a negligible effect on the viability of normal human melanocytes. Additionally, CAP and epidermal growth factor receptor (EGFR) inhibitor had an additive anticancer effect in a CAP-resistant melanoma cell line. Reactive oxygen and nitrogen species known to be generated by CAP enhanced the anticancer effects of CAP and EGFR inhibitors. The in vivo anticancer activities of CAP were evaluated by testing its effects against syngeneic tumors induced in mice by melanoma and colon cancer cells. CAP treatment reduced tumor volume and weight in both cancer models, with the extent of tumor reduction dependent on the duration and number of CAP treatments. Histologic examination also revealed the tumoricidal effects of CAP in both tumor models. In conclusion, CAP inhibits the growth of mouse melanoma and colon cancer cell lines in vitro and shows tumoricidal effects against mouse models of melanoma and colon cancer in vivo.
Abstract
Background
Toll-like receptor 4 (TLR4) conducts a highly regulated inflammatory process by limiting the extent of inflammation to avoid toxicity and tissue damage, even in bone tissues. ...Thus, it is plausible that strategies for the maintenance of normal bone-immunity to prevent undesirable bone damage by TLR4 activation can exist, but direct evidence is still lacking.
Methods
Osteoclast precursors (OCPs) obtained from
WT
or
Slit3
-deficient mice were differentiated into osteoclast (OC) with macrophage colony-stimulating factor (M-CSF), RANK ligand (RANKL) and lipopolysaccharide (LPS) by determining the number of TRAP-positive multinuclear cells (TRAP
+
MNCs). To determine the alteration of OCPs population, fluorescence-activated cell sorting (FACS) was conducted in bone marrow cells in mice after LPS injection. The severity of bone loss in LPS injected
WT
or
Slit3
-deficient mice was evaluated by micro-CT analysis.
Result
We demonstrate that TLR4 activation by LPS inhibits OC commitment by inducing the concomitant expression of
miR-218–2-3p
and its host gene,
Slit3
, in mouse OCPs. TLR4 activation by LPS induced SLIT3 and its receptor ROBO1 in BMMs, and this SLIT3-ROBO1 axis hinders RANKL-induced OC differentiation by switching the protein levels of C/EBP-β isoforms. A deficiency of SLIT3 resulted in increased RANKL-induced OC differentiation, and the elevated expression of OC marker genes including
Pu.1
,
Nfatc1
, and
Ctsk
. Notably,
Slit3
-deficient mice showed expanded OCP populations in the bone marrow. We also found that miR-218–2 was concomitantly induced with SLIT3 expression after LPS treatment, and that this miRNA directly suppressed
Tnfrsf11a
(RANK) expression at both gene and protein levels, linking it to a decrease in OC differentiation. An endogenous
miR-218–2
block rescued the expression of RANK and subsequent OC formation in LPS-stimulated OCPs. Aligned with these results,
SLIT3
-deficient mice displayed increased OC formation and reduced bone density after LPS challenge.
Conclusion
Our findings suggest that the TLR4-dependent concomitant induction of
Slit3
and
miR-218–2
targets RANK in OCPs to restrain OC commitment, thereby avoiding an uncoordinated loss of bone through inflammatory processes. These observations provide a mechanistic explanation for the role of TLR4 in controlling the commitment phase of OC differentiation.
Although deep learning algorithms have demonstrated expert-level performance, previous efforts were mostly binary classifications of limited disorders. We trained an algorithm with 220,680 images of ...174 disorders and validated it using Edinburgh (1,300 images; 10 disorders) and SNU datasets (2,201 images; 134 disorders). The algorithm could accurately predict malignancy, suggest primary treatment options, render multi-class classification among 134 disorders, and improve the performance of medical professionals. The area under the curves for malignancy detection were 0.928 ± 0.002 (Edinburgh) and 0.937 ± 0.004 (SNU). The area under the curves of primary treatment suggestion (SNU) were 0.828 ± 0.012, 0.885 ± 0.006, 0.885 ± 0.006, and 0.918 ± 0.006 for steroids, antibiotics, antivirals, and antifungals, respectively. For multi-class classification, the mean top-1 and top-5 accuracies were 56.7 ± 1.6% and 92.0 ± 1.1% (Edinburgh) and 44.8 ± 1.2% and 78.1 ± 0.3% (SNU), respectively. With the assistance of our algorithm, the sensitivity and specificity of 47 clinicians (21 dermatologists and 26 dermatology residents) for malignancy prediction (SNU; 240 images) were improved by 12.1% (P < 0.0001) and 1.1% (P < 0.0001), respectively. The malignancy prediction sensitivity of 23 non-medical professionals was significantly increased by 83.8% (P < 0.0001). The top-1 and top-3 accuracies of four doctors in the multi-class classification of 134 diseases (SNU; 2,201 images) were increased by 7.0% (P = 0.045) and 10.1% (P = 0.0020), respectively. The results suggest that our algorithm may serve as augmented intelligence that can empower medical professionals in diagnostic dermatology.
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