5-Fluorouracil upregulates the activity of Wnt signaling pathway in CD133-positive colon cancer stem-like cells

Background and Objective:CD133-positive colon cancer stem like cells (CSLCs) are resistant to the conventional cytotoxic drug 5-fluorouracil (5-FU).Wnt signaling pathway plays important roles in colon cancer carcinogenesis and metastasis, and regulates the self-renewal capacity of CSLCs.In the present study, we explored the impact of 5-FU on Wnt signaling pathway of CD133-positive colon CSLCs, and the relation between Wnt signaling pathway and drug resistance of CD133-positive colon CSLCs.Methods:Magnetic activation cell separation was used to collect CD133-positive cells from colon cancer cell line DLD1, which was transfected with luciferase reporter for Wnt signaling activity.The activity of Wnt signaling pathway was compared between CD133-positive and CD133-negative cells.After the treatment with 1 μg/mL of 5-FU, the cell proliferation rates of DLD1 cells, CD133-positive cells, and CD133-negative cells were compared.After the treatment with 1 μg/mL and 10 μg/mL of 5-FU for 48 h, Wnt activity was compared between CD133-positive and CD133-negative cells.The expression of CD133 and cell apoptosis of CD133-positive cells was detected after exposure to 50 ng/mL of dickkopf (DKK)-1, a Wnt pathway inhibitor.Results:After the treatment with 5-FU, the cell proliferation rate of CD133-positive cells was higher than that of CD133-negative cells and the sensitivity of CD133-positive cells to 5-FU decreased.Wnt activity was higher in CD133-positive cells than in CD133-negative cells [(46.3±0.3)% vs.(33.9±2.7)%, P=0.009].After the treatment with 1 μg/mL and 10 μg/mL of 5-FU, Wnt activity of CD133-positive cells was (90.1±10.0)% (P=0.012) and (52.9±2.5)% (P=0.047), respectively, whereas that of CD133-negative cells was (35.5±3.3)% (P=0.434) and (26.5±0.4)% (P=0.046), respectively.CD133 expression in CD133-positive cells decreased from (87.2±5.3)% to (60.6±3.1)% (P=0.022) after treatment with DKK-1, whereas the cell apoptosis rate increased from (11.8±0.2)% to (28.3±0.6)% (P=0.013).Conclusions:Wnt activity is higher in CD133-positive DLD1 cells than in CD133-negative DLD1 cells.5-FU can upregulate Wnt activity of CD133-positive colon CSLCs.Blocking Wnt activity may reverse drug sensitivity of CD133-positive cells to 5-FU.

Three-dimensional visualization of the functional fascicular groups of a long-segment peripheral nerve

The three-dimensional（3D） visualization of the functional bundles in the peripheral nerve provides direct and detailed intraneural spatial information. It is useful for selecting suitable surgical methods to repair nerve defects and in optimizing the construction of tissue-engineered nerve grafts. However, there remain major technical hurdles in obtaining, registering and interpreting 2D images, as well as in establishing 3D models. Moreover, the 3D models are plagued by poor accuracy and lack of detail and cannot completely reflect the stereoscopic microstructure inside the nerve. To explore and help resolve these key technical problems of 3D reconstruction, in the present study, we designed a novel method based on re-imaging techniques and computer image layer processing technology. A 20-cm ulnar nerve segment from the upper arm of a fresh adult cadaver was used for acetylcholinesterase（ACh E） staining. Then, 2D panoramic images were obtained before and after ACh E staining under the stereomicroscope. Using layer processing techniques in Photoshop, a space transformation method was used to fulfill automatic registration. The contours were outlined, and the 3D rendering of functional fascicular groups in the long-segment ulnar nerve was performed with Amira 4.1 software. The re-imaging technique based on layer processing in Photoshop produced an image that was detailed and accurate. The merging of images was accurate, and the whole procedure was simple and fast. The least square support vector machine was accurate, with an error rate of only 8.25%. The 3D reconstruction directly revealed changes in the fusion of different nerve functional fascicular groups. In conclusion. The technique is fast with satisfactory visual reconstruction.

Malignant atrophic papulosis:Two case reports

BACKGROUND Malignant atrophic papulosis is a rare and potentially lethal thrombo-occlusive microvasculopathy characterized by cutaneous papules and gastrointestinal perforation.The precise pathogenesis of this disease remains obscure.CASE SUMMARY We describe the case of a 67-year-old male patient who initially presented with cutaneous aubergine papules and dull pain in the epigastrium.One week after symptom onset,he was admitted to the hospital for worsening abdominal pain.Exploratory laparotomy showed patchy necrosis and subserosal white plaque lesions on the small intestinal wall,along with multiple perforations.Histological examination of the small intestine showed extensive hyperemia,edema,necrosis with varying degrees of inflammatory reactions in the small bowel wall,small vasculitis with fibrinoid necrosis and intraluminal thrombosis in the mesothelium.Based on the mentioned evidence,a diagnosis of malignant atrophic papulosis was made.We also present the case of a 46-year-old man with known cutaneous manifestations,abdominal pain,nausea and vomiting.His physical examination showed positive rebound tenderness.A computed tomography scan revealed free intraperitoneal air.He required surgical intervention on admission and then developed an esophageal perforation.He ultimately died of a massive hemorrhage.CONCLUSION In previously published cases of this disease,the cutaneous lesions initially appeared as small erythematous papules.Subsequently,the papules became porcelain-white atrophic depression lesions with a pink,telangiectatic peripheral rim.In one of the patients,the cutaneous lesions appeared as aubergine papules.The other patient developed multiple perforations in the gastrointestinal tract.Due to malignant atrophic papulosis affecting multiple organs,many authors speculated that it is not a specific entity.This case series serves as additional evidence for our hypothesis.

神经损伤是轮胎橡胶衍生污染物6PPDQ引起虹鳟急性毒性的重要原因

N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine quinone(6PPDQ)has attracted significant attention due to its highly acute lethality to sensitive salmonids.However,studies investigating the mechanisms underlying its acute toxicity have been lacking.In this work,we demonstrated the sensitivity of rainbow trout to 6PPDQ-induced mortality.Moribund trout exhibited significantly higher brain concentrations of 6PPDQ compared to surviving trout.In an in vitro model using human brain microvascular endothelial cells,6PPDQ can penetrate the blood–brain barrier and enhance blood–brain barrier permeability without compromising cell viability.The time spent in the top of the tank increased with rising6PPDQ concentrations,as indicated by locomotion behavior tests.Furthermore,6PPDQ influenced neurotransmitter levels and m RNA expression of neurotransmission-related genes in the brain and exhibited strong binding affinity to target neurotransmission-related proteins using computational simulations.The integrated biomarker response value associated with neurotoxicity showed a positive linear correlation with trout mortality.These findings significantly contribute to filling the knowledge gap between neurological impairments and apical outcomes,including behavioral effects and mortality,induced by6PPDQ.

Early use of dexamethasone increases Nr4a1 in Kupffer cells ameliorating acute liver failure in mice in a glucocorticoid receptor-dependent manner

Background and objective:Acute liver failure(ALF)is a type of disease with high mortality and rapid progression with no specific treatment methods currently available.Glucocorticoids exert beneficial clinical effects on therapy for ALF.However,the mechanism of this effect remains unclear and when to use glucocorticoids in patients with ALF is difficult to determine.The purpose of this study was to investigate the specific immunological mechanism of dexamethasone(Dex)on treatment of ALF induced by lipopolysaccharide(LPS)/D-galactosamine(D-Ga IN)in mice.Methods:Male C57 BL/6 mice were given LPS and D-Ga IN by intraperitoneal injection to establish an animal model of ALF.Dex was administrated to these mice and its therapeutic effect was observed.Hematoxylin and eosin(H&E)staining was used to determine liver pathology.Multicolor flow cytometry,cytometric bead array(CBA)method,and next-generation sequencing were performed to detect changes of messenger RNA(m RNA)in immune cells,cytokines,and Kupffer cells,respectively.Results:A mouse model of ALF can be constructed successfully using LPS/D-Ga IN,which causes a cytokine storm in early disease progression.Innate immune cells change markedly with progression of liver failure.Earlier use of Dex,at 0 h rather than 1 h,could significantly improve the progression of ALF induced by LPS/D-Ga IN in mice.Numbers of innate immune cells,especially Kupffer cells and neutrophils,increased significantly in the Dex-treated group.In vivo experiments indicated that the therapeutic effect of Dex is exerted mainly via the glucocorticoid receptor(Gr).Sequencing of Kupffer cells revealed that Dex could increase m RNA transcription level of nuclear receptor subfamily 4 group A member 1(Nr4 a1),and that this effect disappeared after Gr inhibition.Conclusions:In LPS/D-Ga IN-induced ALF mice,early administration of Dex improved ALF by increasing the numbers of innate immune cells,especially Kupffer cells and neutrophils.Gr-dependent Nr4 a1 upregulation in Kupffer cells may be an important ALF effect regulated by Dex in this process.