Low selenium and T-2 toxin may be involved in the pathogenesis of Kashin-Beck disease by affecting AMPK/mTOR/ULK1 pathway mediated autophagy.

Kashin-Beck disease (KBD) is an endemic, environmentally associated cartilage disease. Previous studies have shown that the environmental suspected pathogenic factors of KBD, T-2 toxin and low selenium, are involved in the regulation of inflammation, oxidative stress and autophagy in some tissues and organs. In cartilage diseases, the level of cellular autophagy determines the fate of the chondrocytes. However, whether autophagy is involved in KBD cartilage lesions, and the role of low selenium and T-2 toxins in KBD cartilage injury and autophagy are still unclear. This work took the classical AMPK/mTOR/ULK1 autophagy regulatory pathway as the entry point to clarify the relationship between the environmental suspected pathogenic factors and chondrocyte autophagy. Transmission electron microscopy was used to observe the autophagy of chondrocytes in KBD patients. qRT-PCR and western blot were used to analyze the expression of AMPK/mTOR/ULK1 pathway and autophagy markers. The rat model of KBD was established by low selenium and T-2 toxin, the autophagy in rat cartilage was detected after 4- and 12-week interventions. Chondrocyte autophagy was found in KBD, and the AMPK/mTOR/ULK1 pathway was down-regulated. In the rat model, the pathway showed an up-regulated trend when low selenium and T-2 toxin, were treated for a short time or low concentration, and autophagy level increased. However, when low selenium and T-2 toxin were treated for a long time or at high concentrations, the pathway showed a down-regulated trend, and the autophagy level was reduced and even defective. In conclusion, in the process of KBD cartilage lesion, chondrocyte autophagy level may increase in the early stage, and decrease in the late stage with the progression of lesion. Low selenium and T-2 toxins may affect autophagy by AMPK/mTOR/ULK1 pathway.

Chondrocyte autophagy mediated by T-2 toxin via AKT/TSC/Rheb/mTOR signaling pathway and protective effect of CSA-SeNP.

OBJECTIVE: Kashin-Beck disease (KBD) is an endemic, degenerative, and cartilage-damaging disease for which low selenium and T-2 toxins are considered environmental pathogenic factors. This study aimed to investigate the molecular mechanisms of autophagy in cartilage damage caused by T-2 toxin and the protective effect of chondroitin sulfate A nano-elemental selenium (CSA-SeNP) on the cartilage. METHODS: KBD chondrocytes and C28/I2 human chondrocyte cell lines were used. T-2 toxin, AKT inhibitor, and CSA-SeNP treatment experiments were conducted separately, with a treatment time of 24 h. Autophagy was monitored using MDC staining, and mRFP-GFP-LC3 adenovirus, respectively. RT-qPCR and western blotting were used to detect the expression of the relevant genes and proteins. RESULTS: The suppression of autophagy observed in KBD chondrocytes was replicated by applying 10 ng/mL T-2 toxin to C28/I2 chondrocytes for 24 h. The AKT/TSCR/Rheb/mTOR signaling pathway was activated by T-2 toxin, which inhibits autophagy. The supplementation with CSA-SeNP alleviated the inhibition of autophagy by T-2 toxin through the AKT/TSCR/Rheb/mTOR signaling pathway. CONCLUSIONS: Loss of autophagy regulated by the AKT/TSCR/Rheb/mTOR signaling pathway plays an important role in cartilage damage caused by T-2 toxin. CSA-SeNP supplementation attenuated inhibition of autophagy in chondrocytes by T-2 toxin by modulating this signaling pathway. These findings provide promising new targets for the prevention and treatment of cartilage disease.

Protective effects of functional Nano-Selenium supplementation on spleen injury through regulation of p38 MAPK and NF-κB protein expression.

Selenium (Se) is a trace element necessary for humans to maintain normal physiological activities, and Se deficiency may lead to splenic injury, while Se supplementation can alleviate splenic injury. However, the mechanism is unclear. In this study, we constructed a Se deficiency animal model by feeding Sprague-Dawley (SD) rats with low Se feed. Meanwhile, we observed the repairing effect of Se supplementation on splenic injury with two doses of novel nano-selenium (Nano-Se) supplement by gavage. We measured the Se content in the spleens of the rats by atomic fluorescence spectroscopy (AFS) method and combined the results of hematoxylin-eosin (HE) and Masson staining to observe the splenic injury, comprehensively evaluating the construction of the animal model of low selenium-induced splenic injury. We measured the mRNA and protein expression levels of p38 mitogen-activated protein kinase (p38 MAPK), nuclear factor kappa-B (NF-κB), and interleukin-6 (IL-6) in the spleen by Real-time quantitative polymerase chain reaction (qPCR), western blot (WB), and immunohistochemistry (IHC). We found that the Se deficiency group exhibited lower Se content, splenic fibrosis, and high expression of p38 MAPK, NF-κB, and IL-6 compared to the normal group. The Se supplement groups exhibited higher Se content, attenuated splenic injury, and down-regulated expression of p38 MAPK, NF-κB, and IL-6 relative to the Se deficiency group. This study suggests that Se deficiency leads to splenic injury in rats, and Se supplementation may attenuate splenic injury by inhibiting the expression of p38 MAPK, NF-κB and IL-6.

Synergistic effects of T-2 toxin and selenium deficiency exacerbate renal fibrosis through modulation of the ERα/PI3K/Akt signaling pathway.

As common pathogenic agents in the world and widely distributed globally, T-2 toxin and selenium deficiency might exacerbate toxic effects by combined exposure, posing a dramatic health hazard to humans and animals. In this study, we aim to elucidate the underlying mechanisms of renal fibrosis triggered by T-2 toxin and selenium deficiency exposure. A total of thirty-two rats are randomly divided into the normal control, T-2 toxin, selenium deficiency, and combined intervention groups. T-2 toxin (100 ng/g) is intragastric gavaged to the rats in compliance with the body weight. Both the standard (containing selenium 0.20 mg/Kg) and selenium-deficient (containing selenium 0.02 mg/Kg) diets were manufactured adhering to the AIN-93 formula. After 12 weeks of intervention, renal tissue ultrastructural and pathological changes, inflammatory infiltration, epithelial mesenchymal transition (EMT), and extracellular matrix (ECM) deposition are evaluated, respectively. Metabolomics analysis is conducted to explore the underlying pathology of renal fibrosis, followed by the validation of potential mechanisms at gene and protein levels. T-2 toxin and selenium deficiency exposure results in podocyte foot process elongation or fusion, tubular vacuolization and dilatation, and collagen deposition in the kidneys. Additionally, it also increases inflammatory infiltration, EMT conversion, and ECM deposition. Metabolomics analysis suggests that T-2 toxin and selenium deficiency influence amino acid and cholesterol metabolism, respectively, and the estrogen signaling pathway is probably engaged in renal fibrosis progression. Moreover, T-2 toxin and selenium deficiency are found to regulate the expressions of the ERα/PI3K/Akt signaling pathway. In conclusion, T-2 toxin and selenium deficiency synergistically exacerbate renal fibrosis through regulating the ERα/PI3K/Akt signaling pathway, and inflammatory infiltration, EMT and ECM deposition are involved in this process.

Noninvasive diagnosis of AIH/PBC overlap syndrome based on prediction models.

Autoimmune liver diseases (AILDs) are life-threatening chronic liver diseases, mainly including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and AIH-PBC overlap syndrome (OS), which are difficult to distinguish clinically at early stages. This study aimed to establish model to achieve the purpose of the diagnosis of AIH/PBC OS in a noninvasive way. A total of 201 AILDs patients were included in this retrospective study who underwent liver biopsy during January 2011 to December 2020. Serological factors significantly associated with OS were determined by the univariate analysis. Two multivariate models based on these factors were constructed to predict the diagnosis of AIH/PBC OS using logistic regression and random forest analysis. The results showed that immunoglobulins G and M had significant importance in both models. In logistic regression model, anti-Sp100, anti-Ro-52, anti-SSA, or antinuclear antibody positivity were risk factors for OS. In random forest model, activated partial thromboplastin time and ɑ-fetoprotein level were important. To distinguish PBC and OS, the sensitivity and specificity of logistic regression model were 0.889 and 0.727, respectively, and the sensitivity and specificity of random forest model were 0.944 and 0.818, respectively. In conclusion, we established two predictive models for the diagnosis of AIH/PBC OS in a noninvasive method and they showed better performance than Paris criteria for the definition of AIH/PBC OS.

The basis and advances in clinical application of boron neutron capture therapy.

Boron neutron capture therapy (BNCT) was first proposed as early as 1936, and research on BNCT has progressed relatively slowly but steadily. BNCT is a potentially useful tool for cancer treatment that selectively damages cancer cells while sparing normal tissue. BNCT is based on the nuclear reaction that occurs when 10B capture low-energy thermal neutrons to yield high-linear energy transfer (LET) α particles and recoiling 7Li nuclei. A large number of 10B atoms have to be localized within the tumor cells for BNCT to be effective, and an adequate number of thermal neutrons need to be absorbed by the 10B atoms to generate lethal 10B (n, α)7Li reactions. Effective boron neutron capture therapy cannot be achieved without appropriate boron carriers. Improvement in boron delivery and the development of the best dosing paradigms for both boronophenylalanine (BPA) and sodium borocaptate (BSH) are of major importance, yet these still have not been optimized. Here, we present a review of this treatment modality from the perspectives of radiation oncology, biology, and physics. This manuscript provides a brief introduction of the mechanism of cancer-cell-selective killing by BNCT, radiobiological factors, and progress in the development of boron carriers and neutron sources as well as the results of clinical study.

Shielding effect of a lead apron on the peripheral radiation dose outside the applicator of electron beams from an Elekta linear accelerator.

PURPOSE: To evaluate the shielding effect of lead aprons (LAs) on peripheral radiation doses outside the applicator of electron beams from a linear accelerator. METHODS: Out-of-field radiation doses of 4-, 6-, 8-, 10-, 12-, and 15-MeV electron beams from an Elekta Synergy linear accelerator (linac) were measured by thermoluminescence dosimeters (TLD) at different depths (0, 0.5, 1.0, and 2.0 cm) and distances from the applicator edge (0-58 cm) in a water-equivalent slab phantom with a different number of layers of LA shielding (0-5 layers). Measurements were performed by 6 × 6, 10 × 10, 14 × 14, and 20 × 20-cm2 applicators at a gantry and collimator angle of 0°. The out-of-field radiation dose profiles were normalized to the maximum dose of every energy and measuring depth. RESULTS: The out-of-field radiation doses (beyond 3 cm away from the field edge) decreased with an increase in the number of LA layers and distance away from the central beam axis (CAX). After shielding with the LA, the out-of-field doses decreased by up to approximately 99% compared with the no shielding group. For 4-MeV electron beams, there was a peak at 24.5 cm from the CAX, which weakened with an increasing number of LA layers. CONCLUSION: The shielding effect of the LA varied for a different number of LA layers as well as different depths and distances away from the CAX. Four LA layers were sufficient for shielding out-of-field doses of 4-15-MeV electron beams.

Decreased serum complement component 4 levels in patients with schizophrenia.

Dysregulation of the immune system in mental disease, particularly complement component 4 (C4), which may be associated with schizophrenia, has been repeatedly observed. This study investigated the association between the level of serum component 4 and schizophrenia. Data were derived from a case-control association study of 40 unrelated adult patients with schizophrenia and 40 matched healthy controls. The component 4 level in serum was measured for comparative analysis by a component 4 enzyme-linked immunosorbent assay kit. Our findings suggest that the serum component 4 level is lower in patients with schizophrenia than in the controls, and the results apply to both males and females. Our results will lay an important foundation for establishing diagnostic methods and provide feasible and reliable evidence for the clinical treatment of schizophrenia.

Imaging elemental events of store-operated Ca2+ entry in invading cancer cells with plasmalemmal targeted sensors.

STIM1- and Orai1-mediated store-operated Ca2+ entry (SOCE) constitutes the major Ca2+ influx in almost all electrically non-excitable cells. However, little is known about the spatiotemporal organization at the elementary level. Here, we developed Orai1-tethered or palmitoylated biosensor GCaMP6f to report subplasmalemmal Ca2+ signals. We visualized spontaneous discrete and long-lasting transients ('Ca2+ glows') arising from STIM1-Orai1 in invading melanoma cells. Ca2+ glows occurred preferentially in single invadopodia and at sites near the cell periphery under resting conditions. Re-addition of external Ca2+ after store depletion elicited spatially synchronous Ca2+ glows, followed by high-rate discharge of asynchronous local events. Knockout of STIM1 or expression of the dominant-negative Orai1-E106A mutant markedly decreased Ca2+ glow frequency, diminished global SOCE and attenuated invadopodial formation. Functionally, invadopodial Ca2+ glows provided high Ca2+ microdomains to locally activate Ca2+/calmodulin-dependent Pyk2 (also known as PTK2B), which initiates the SOCE-Pyk2-Src signaling cascade required for invasion. Overall, the discovery of elemental Ca2+ signals of SOCE not only unveils a previously unappreciated gating mode of STIM1-Orai1 channels in situ, but also underscores a critical role of the spatiotemporal dynamics of SOCE in orchestrating complex cell behaviors such as invasion. This article has an associated First Person interview with the first author of the paper.

Cyclic AMP and Polyamines Overcome Inhibition by Myelin-Associated Glycoprotein through eIF5A-Mediated Increases in p35 Expression and Activation of Cdk5.

Inhibitory molecules associated with CNS myelin, such as myelin-associated glycoprotein (MAG), represent major obstacles to axonal regeneration following CNS injury. Our laboratory has shown that elevating levels of intracellular cAMP, via application of the nonhydrolyzable analog dibutyryl cAMP (dbcAMP), can block the inhibitory effects of MAG and myelin. We have also shown that elevation of cAMP results in upregulation of arginase I and increased polyamine synthesis. Treatment with putrescine or spermidine blocks myelin-mediated inhibition of neurite outgrowth, but the mechanism underlying this effect has not yet been elucidated. Here we show that cyclin-dependent kinase 5 (Cdk5) is required for dbcAMP and putrescine to overcome MAG-mediated inhibition. The ability of dbcAMP and putrescine to overcome inhibition by MAG is abolished in the presence of roscovitine, a Cdk inhibitor that has greater selectivity for Cdk5, and expression of dominant negative Cdk5 abolishes the ability of dbcAMP or putrescine to enhance neurite outgrowth in the presence of MAG. Importantly, dbcAMP and putrescine increase expression of p35, the neuron-specific activator of Cdk5, and rat DRG neurons transduced with HSV overexpressing p35 can overcome inhibition by MAG. The upregulation of p35 by putrescine is also reflected in increased localization of p35 to neurites and growth cones. Last, we show that putrescine upregulates p35 expression by serving as a substrate for hypusine modification of eIF5A, and that this hypusination is necessary for putrescine's ability to overcome inhibition by MAG. Our findings reveal a previously unknown mechanism by which polyamines may encourage regeneration after CNS injury.

STIM1- and Orai1-mediated Ca(2+) oscillation orchestrates invadopodium formation and melanoma invasion.

Ca(2+) signaling has been increasingly implicated in cancer invasion and metastasis, and yet, the underlying mechanisms remained largely unknown. In this paper, we report that STIM1- and Orai1-mediated Ca(2+) oscillations promote melanoma invasion by orchestrating invadopodium assembly and extracellular matrix (ECM) degradation. Ca(2+) oscillation signals facilitate invadopodial precursor assembly by activating Src. Disruption of Ca(2+) oscillations inhibited invadopodium assembly. Furthermore, STIM1 and Orai1 regulate the proteolysis activity of individual invadopodia. Mechanistically, Orai1 blockade inhibited the recycling of MT1-matrix metalloproteinase (MMP) to the plasma membrane and entrapped MT1-MMP in the endocytic compartment to inhibit ECM degradation. STIM1 knockdown significantly inhibited melanoma lung metastasis in a xenograft mouse model, implicating the importance of this pathway in metastatic dissemination. Our findings provide a novel mechanism for Ca(2+)-mediated cancer cell invasion and shed new light on the spatiotemporal organization of store-operated Ca(2+) signals during melanoma invasion and metastasis.

GATA3 transcription factor abrogates Smad4 transcription factor-mediated fascin overexpression, invadopodium formation, and breast cancer cell invasion.

Transforming growth factor ß (TGFß) is a potent and context-dependent regulator of tumor progression. TGFß promotes the lung metastasis of basal-like (but not the luminal-like) breast cancer. Here, we demonstrated that fascin, a pro-metastasis actin bundling protein, was a direct target of the canonical TGFß-Smad4 signaling pathway in basal-like breast cancer cells. TGFß and Smad4 induced fascin overexpression by directly binding to a Smad binding element on the fascin promoter. We identified GATA3, a transcription factor crucial for mammary gland morphogenesis and luminal differentiation, as a negative regulator of TGFß- and Smad4-induced fascin overexpression. When ectopically expressed in basal-like breast cancer cells, GATA-3 abrogated TGFß- and Smad4-mediated overexpression of fascin and other TGFß response genes, invadopodium formation, cell migration, and invasion, suggesting suppression of the canonical TGFß-Smad signaling axis. Mechanistically, GATA3 abrogated the canonical TGFß-Smad signaling by abolishing interactions between Smad4 and its DNA binding elements, potentially through physical interactions between the N-terminal of GATA3 and Smad3/4 proteins. Our findings provide mechanistic insight into how TGFß-mediated cell motility and invasiveness are differentially regulated in breast cancer.

[Investigation on snails Achatina fulica and Pomacea canaliculata infected with Angiostrongylus cantonensis in Panyu region of Guangzhou City].

OBJECTIVE: To understand the natural infection status of Angiostrongylus cantonensis in snails Achatina fulica and Pomacea canaliculata from Panyu region of Guangzhou City. METHODS: The snails Achatina fulica and Pomacea canaliculata captured from the field were digested with the artificial stomach fluid. The third-stage larvae of A. cantonensis were examined and counted under a microscope. The collected third-stage larvae were used to infect SD rats. RESULTS: A total of 367 Achatina fulica and 357 Pomacea canaliculata were examined. The infection rate of A. cantonensis in Achatina fulica was 22.62%, with a mean intensity of 57.00 larvae per positive snail. The infection rate of A. cantonensis in Pomacea canaliculata was 3.08%, with a mean intensity of 1.64 larvae per positive snail. The infection rates of A. cantonensis in Achatina fulica from Dagang, Shiqi, Hualong, and Lanhe towns and Nansha District, were 13.33%, 15.00%, 20.93%, 73.68% and 8.41%, respectively. Those in Pomacea canaliculata were 5.88%, 2.88%, 1.89%, 0% and 3.96%, respectively. CONCLUSIONS: A. cantonensis infection exists in Achatina fulica and Pomacea canaliculata from Panyu region of Guangzhou City, and the infection in Achatina fulica is more serious than that in Pomacea canaliculata. The infection rates of the snails among five sites are different.

Fascin protein is critical for transforming growth factor ß protein-induced invasion and filopodia formation in spindle-shaped tumor cells.

Fascin, an actin-bundling protein overexpressed in all carcinomas, has been associated with poor prognosis, shorter survival, and more metastatic diseases. It is believed that fascin facilitates tumor metastasis by promoting the formation of invasive membrane protrusions. However, the mechanisms by which fascin is overexpressed in tumors are not clear. TGFß is a cytokine secreted by tumor and mesenchymal cells and promotes metastasis in many late stage tumors. The pro-metastasis mechanisms of TGFß remain to be fully elucidated. Here we demonstrated that TGFß induced fascin expression in spindle-shaped tumor cells through the canonical Smad-dependent pathway. Fascin was critical for TGFß-promoted filopodia formation, migration, and invasion in spindle tumor cells. More importantly, fascin expression significantly correlates with TGFß1 and TGFß receptor I levels in a cohort of primary breast tumor samples. Our results indicate that elevated TGFß level in the tumor microenvironment may be responsible for fascin overexpression in some of the metastatic tumors. Our data also suggest that fascin could play a central role in TGFß-promoted tumor metastasis.

Increased synthesis of spermidine as a result of upregulation of arginase I promotes axonal regeneration in culture and in vivo.

Adult spinal axons do not spontaneously regenerate after injury. However, if the peripheral branch of dorsal root ganglion neurons is lesioned before lesioning the central branch of the same neurons in the dorsal column, these central axons will regenerate and, if cultured, are not inhibited from extending neurites by myelin-associated inhibitors of regeneration such as myelin-associated glycoprotein (MAG). This effect can be mimicked by elevating cAMP and is transcription dependent. The ability of cAMP to overcome inhibition by MAG in culture involves the upregulation of the enzyme arginase I (Arg I) and subsequent increase in synthesis of polyamines such as putrescine. Now we show that a peripheral lesion also induces an increase in Arg I expression and synthesis of polyamines. We also show that the conditioning lesion effect in overcoming inhibition by MAG is initially dependent on ongoing polyamine synthesis but, with time after lesion, becomes independent of ongoing synthesis. However, if synthesis of polyamines is blocked in vivo the early phase of good growth after a conditioning lesion is completely blocked and the later phase of growth, when ongoing polyamine synthesis is not required during culture, is attenuated. We also show that putrescine must be converted to spermidine both in culture and in vivo to overcome inhibition by MAG and that spermidine can promote optic nerve regeneration in vivo. These results suggest that spermidine could be a useful tool in promoting CNS axon regeneration after injury.