Endogenous AND Logic DNA Nanomachine for Highly Specific Cancer Cell Imaging.

Intracellular cancer-related biomarker imaging strategy has been used for specific identification of cancer cells, which was of great importance to accurate cancer clinical diagnosis and prognosis studies. Localized DNA circuits with improved sensitivity showed great potential for intracellular biomarkers imaging. However, the ability of localized DNA circuits to specifically image cancer cells is limited by off-site signal leakage associated with a single-biomarker sensing strategy. Herein, we integrated the endogenous enzyme-powered strategy with logic-responsive and localized signal amplifying capability to construct a self-assembled endogenously AND logic DNA nanomachine (EDN) for highly specific cancer cell imaging. When the EDN encountered a cancer cell, the overexpressed DNA repairing enzyme apurinic/apyrimidinic endonuclease 1 (APE1) and miR-21 could synergistically activate a DNA circuit via cascaded localized toehold-mediated strand displacement (TMSD) reactions, resulting in amplified fluorescence resonance energy transfer (FRET) signal. In this strategy, both endogenous APE1 and miR-21, served as two "keys" to activate the AND logic operation in cancer cells to reduce off-tumor signal leakage. Such a multiplied molecular recognition/activation nanomachine as a powerful toolbox realized specific capture and reliable imaging of biomolecules in living cancer cells.

Long-term grazing improved soil chemical properties and benefited community traits under climatic influence in an alpine typical steppe.

Grazing and climate change both contribute to diversity loss and productivity fluctuations. Sensitive climate conditions and long-term grazing activities have a profound influence on community change, particularly in high-altitude mountain grassland ecosystems. However, knowledge about the role of long-term continuous grazing management on diversity, productivity and the regulation mechanisms in fragile grassland ecosystems is still rudimentary. We conducted a long-term grazing experiment on an alpine typical steppe in the Qilian Mountains to assess effects of grazing intensity on soil, diversity, productivity and the regulation mechanisms. Plants and soil were sampled along grazing gradients at different distances from the pasture entrance (0, 0.3, 0.6, 0.9, 1.2 and 1.5 km) under the non-growing (WP) and the growing season grazing pasture (SAP). The results revealed that community diversity and biomass did not change significantly on a time scale, while the concentration of soil organic carbon and total phosphorus increased significantly. Heavy grazing (0-0.3 km) decreased community diversity and biomass. Grazing increased soil chemical properties in heavy grazed areas of WP, while the opposite was recorded in SAP. Soil chemical properties explained the largest variances in community diversity and community biomass. The prediction model indicates that grazing in WP mainly affects community diversity through soil chemical properties, and promotes a positive correlation between community diversity and community biomass; in SAP, the direct effect of grazing gradients on community diversity and biomass is the main pathway, but not eliminating the single positive relationship between diversity and biomass, which means that diversity can still be used as a potential resource to promote productivity improvement. Therefore, we should focus on the regulation of soil chemical properties in WP, such as the health and quality of soil, strengthening its ability to store water, sequester carbon and increase nutrients; focus on the management of livestock in SAP, including providing fertilizer and sowing to increase diversity and production in heavily grazed regions and reducing grazing pressure through regional rotational grazing. Ultimately, we call for strengthening the stability and sustainability of ecosystems through targeted and active human intervention in ecologically sensitive areas to cope with future grazing pressures and climate disturbances.

S-propargyl-cysteine delays the progression of atherosclerosis and increases eNOS phosphorylation in endothelial cells.

The present study aimed to investigate the protective effect of S-propargyl-cysteine (SPRC) on atherosclerosis progression in mice. A mouse model of vulnerable atherosclerotic plaque was created in ApoE-/- mice by carotid artery tandem stenosis (TS) combined with a Western diet. Macrophotography, lipid profiles, and inflammatory markers were measured to evaluate the antiatherosclerotic effects of SPRC compared to atorvastatin as a control. Histopathological analysis was performed to assess the plaque stability. To explore the protective mechanism of SPRC, human umbilical vein endothelial cells (HUVECs) were cultured in vitro and challenged with oxidized low-density lipoprotein (ox-LDL). Cell viability was determined with a Cell Counting Kit-8 (CCK-8). Endothelial nitric oxide synthase (eNOS) phosphorylation and mRNA expression were detected by Western blot and RT-qPCR respectively. The results showed that the lesion area quantified by en face photographs of the aortic arch and carotid artery was significantly less, plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were reduced, plaque collagen content was increased and matrix metalloproteinase-9 (MMP-9) was decreased in 80 mg/kg per day SPRC-treated mice compared with model mice. These findings support the role of SPRC in plaque stabilization. In vitro studies revealed that 100 µmol/L SPRC increased the cell viability and the phosphorylation level of eNOS after ox-LDL challenge. These results suggest that SPRC delays the progression of atherosclerosis and enhances plaque stability. The protective effect may be at least partially related to the increased phosphorylation of eNOS in endothelial cells.

Paeoniflorin-6'-O-benzene sulfonate down-regulates CXCR4-Gßγ-PI3K/AKT mediated migration in fibroblast-like synoviocytes of rheumatoid arthritis by inhibiting GRK2 translocation.

OBJECTIVE: This study aims to explore the effect of paeoniflorin-6'-O-benzene sulfonate (CP-25) on the migration of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA) and the mechanism focused on CXCR4-Gßγ-PI3K/AKT signaling. METHODS: Human synovial tissues were collected from RA and osteoarthritis (OA) patients. Immunohistochemistry (IHC) and Western blot were used to detect the protein expression of CXCR4, GRK2, Gßγ, PI3K, p-PI3K, AKT and p-AKT. Transwell was adopted to analyse the migration of fibroblast-like synoviocytes (FLS). Co-immunoprecipitation (Co-IP) and laser scanning confocal microscopy (LSCM) were used to detect the combination of GRK2 and Gßγ, the combination of PI3K and Gßγ. RESULTS: The expression level of CXCR4, GRK2, Gßγ, p-p85 and p-AKT were increased in RA synovial tissue according to the results of IHC and Western blot. In vitro, the migration of FLS was increased after stimulation of CXCL12, inhibition of Gßγ suppressed the migration and phosphorylation of p85 and AKT induced by CXCL12 in FLS, and CP-25 had the same effect as inhibition of Gßγ. The membrane expression of GRK2, Gßγ, PI3K and the combination of GRK2 and Gßγ, the combination of PI3K and Gßγ in FLS were increased after the stimulation of CXCL12, and CP-25 had an ability in reducing the membrane expression and the combination of these proteins. CONCLUSION: Excessive migration of FLS in RA was associated with over-activation of PI3K/AKT signaling, and the activity of Gßγ was involved in the over-activation of PI3K/AKT. CP-25 down-regulated CXCR4-Gßγ-PI3K/AKT signals by inhibiting GRK2-Gßγ complex membrane translocation.

CP-25 inhibits PGE2-induced angiogenesis by down-regulating EP4/AC/cAMP/PKA-mediated GRK2 translocation.

G protein-coupled receptor kinase 2 (GRK2), a type of cytosolic enzyme, transiently translocates to the plasma membrane upon G protein-coupled receptors (GPCRs) activation, and it also binds to extracellular signal-regulated kinase (ERK) to inhibit the activation of ERK. GRK2 deficiency in endothelial cells (ECs) leads to increased pro-inflammatory signaling and promotes recruitment of leukocytes to activated ECs. However, the role of GRK2 in regulating angiogenesis remains unclear. Here, we show that GRK2 is a novel regulatory molecule on migration and tube formation of ECs, vessel sprouting ex vivo and angiogenesis in vivo. We identify that EP4/AC/cAMP/protein kinase A (PKA)-mediated GRK2 translocation to cells membrane decreases the binding of GRK2 and ERK1/2 to inhibit ERK1/2 activation, which promotes prostaglandin E2 (PGE2)-induced angiogenesis. GRK2 small interfering RNA (siRNA) inhibits the increase in PGE2-induced HUVECs migration and tube formation. In vivo, PGE2 increases ECs sprouting from normal murine aortic segments and angiogenesis in mice, but not from GRK2-deficient ones, on Matrigel. Further research found that Lys220 and Ser685 of GRK2 play an important role in angiogenesis by regulating GRK2 translocation. Paeoniflorin-6'-O-benzene sulfonate (CP-25), as a novel ester derivative of paeoniflorin (pae), has therapeutic potential for the treatment of adjuvant arthritis (AA) and collagen-induced arthritis (CIA), but the underlying mechanism of CP-25 on angiogenesis has not been elucidated. In our study, CP-25 inhibits the migration and tube formation of HUVECs, and angiogenesis in mice by down-regulating GRK2 translocation activation without affecting GRK2 total expression. Taken together, the present results revealed that CP-25 down-regulates EP4/AC/cAMP/PKA-mediated GRK2 translocation, restoring the inhibition of GRK2 for ERK1/2, thereby inhibiting PGE2-stimulated angiogenesis.

An endogenous DNA adduct as a prognostic biomarker for hepatocarcinogenesis and its prevention by Theaphenon E in mice.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide, mainly because of its poor prognosis. A valid mechanism-based prognostic biomarker is urgently needed. γ-hydroxy-1,N2 -propanodeoxyguanosine (γ-OHPdG) is an endogenously formed mutagenic DNA adduct derived from lipid peroxidation. We examined the relationship of γ-OHPdG with hepatocarcinogenesis in two animal models and its potential role as a prognostic biomarker for recurrence in HCC patients. Bioassays were conducted in xeroderma pigmentosum group A knockout mice and diethylnitrosamine-injected mice, both prone to HCC development. γ-OHPdG levels in the livers of these animals were determined. The effects of antioxidant treatments on γ-OHPdG and hepatocarcinogenesis were examined. Using two independent sets of HCC specimens from patients, we examined the relationship between γ-OHPdG and survival or recurrence-free survival. γ-OHPdG levels in liver DNA showed an age-dependent increase and consistently correlated with HCC development in all three animal models. Theaphenon E treatment significantly decreased γ-OHPdG levels in the liver DNA of xeroderma pigmentosum group A knockout mice and remarkably reduced HCC incidence in these mice to 14% from 100% in the controls. It also effectively inhibited HCC development in the diethylnitrosamine-injected mice. Using clinical samples from two groups of patients, our study revealed that higher levels of γ-OHPdG are strongly associated with low survival (P < 0.0001) and low recurrence-free survival (P = 0.007). CONCLUSION: These results support γ-OHPdG as a mechanism-based, biologically relevant biomarker for predicting the risk of HCC and its recurrence. (Hepatology 2018;67:159-170).

Cartilage-specific deletion of Mig-6 results in osteoarthritis-like disorder with excessive articular chondrocyte proliferation.

A deficiency of mitogen-inducible gene-6 (Mig-6) in mice leads to the development of an early-onset, osteoarthritis (OA)-like disorder in multiple synovial joints, underlying its importance in maintaining joint homeostasis. Here we determined what joint tissues Mig-6 is expressed in and what role chondrocytes play in the Mig-6-deficient OA-like disorder. A Mig-6/lacZ reporter mouse strain expressing ß-galactosidase under the control of the Mig-6 gene promoter was generated to determine Mig-6 expression in joint tissues. By ß-galactosidase staining, we demonstrated that Mig-6 was uniquely expressed in the cells across the entire surface of the synovial joint cavity, including chondrocytes in the superficial zone of articular cartilage and in the meniscus, as well as synovial lining cells. By crossing Mig-6-floxed mice to Col2a1-Cre transgenic mice, to generate cartilage-specific deletion of Mig-6, we demonstrated that deficiency of Mig-6 in the chondrocytes results in a joint phenotype that only partially recapitulates the OA-like disorder of the Mig-6-deficient mice: Ubiquitous deletion of Mig-6 led to the OA-like disorder in multiple joints, whereas cartilage-specific deletion affected the knees but rarely other joints. Furthermore, chondrocytes with Mig-6 deficiency showed excessive proliferative activities along with enhanced EGF receptor signaling in the articular cartilage and in the abnormally formed osteophytes. Our findings provide insight into the crucial requirement for Mig-6 in maintaining joint homeostasis and in regulating chondrocyte activities in the synovial joints. Our data also suggest that other cell types are required for fully developing the Mig-6-deficient OA-like disorder.

Monovalent antibody design and mechanism of action of onartuzumab, a MET antagonist with anti-tumor activity as a therapeutic agent.

Binding of hepatocyte growth factor (HGF) to the receptor tyrosine kinase MET is implicated in the malignant process of multiple cancers, making disruption of this interaction a promising therapeutic strategy. However, targeting MET with bivalent antibodies can mimic HGF agonism via receptor dimerization. To address this limitation, we have developed onartuzumab, an Escherichia coli-derived, humanized, and affinity-matured monovalent monoclonal antibody against MET, generated using the knob-into-hole technology that enables the antibody to engage the receptor in a one-to-one fashion. Onartuzumab potently inhibits HGF binding and receptor phosphorylation and signaling and has antibody-like pharmacokinetics and antitumor activity. Biochemical data and a crystal structure of a ternary complex of onartuzumab antigen-binding fragment bound to a MET extracellular domain fragment, consisting of the MET Sema domain fused to the adjacent Plexins, Semaphorins, Integrins domain (MET Sema-PSI), and the HGF ß-chain demonstrate that onartuzumab acts specifically by blocking HGF α-chain (but not ß-chain) binding to MET. These data suggest a likely binding site of the HGF α-chain on MET, which when dimerized leads to MET signaling. Onartuzumab, therefore, represents the founding member of a class of therapeutic monovalent antibodies that overcomes limitations of antibody bivalency for targets impacted by antibody crosslinking.

Current status of common cold-related knowledge, attitude, and practices among nursing students as well as relevant factors in China.

To understand the current status of cold-related knowledge, attitude, and practices (KAP) among nursing students as well as relevant factors, and provide a scientific basis for offering effective health education and promoting health care levels among nursing students. We conducted a survey of 668 nursing students using a self-designed "General Condition Questionnaire" and "Survey of common cold-related knowledge, attitude, and practices among students majoring in nursing." We used SPSS22.0 for data sorting and analysis; mean ±â€…standard deviation was used for statistical description of the questionnaire scores, and t-test and ANOVA (analysis of variance) were used for differences comparison between binary variables and polytomous variables of the relevant factors. The test level α was 0.05, and the difference was considered statistically significant when P < .05. The total KAP score of the nursing students was 128.47 ±â€…13.91 points, which is a good level. There were significant differences in the KAP scores based on gender, educational background, grade, whether relevant knowledge had been acquired, extracurricular activities, weekly exercise frequency, exercise time per session, coping method after catching a cold, and medicine purchase methods (P < .05). The KAP level for cold among nursing students is at a good level. It is recommended that the relevant departments of nursing schools strengthen the education of nursing students on the knowledge about cold and physical exercise.

Evaluation of the feeding safety of Moringa (Moringa oleifera L.) in the Sprague Dawley rat.

This study aimed to evaluate the safety of Moringa by comparing the effects of different gavage doses of Moringa. The general behavior, body weight, food intake, blood indexes, serum biochemical indexes, and histopathology of rats were used to determine the safety threshold and to provide a reference for the further development and use of Moringa as animal feed. 40 Sprague Dawley rats were selected and given transoral gavage for 28 consecutive days. The T1, T2 and T3 groups were observed for general behavior, body weight, and food intake. Blood and serum biochemical indices were quantified, and histopathology was performed to evaluate the effect and safety of Moringa. The results of the toxicological test showed that (1) Only T1 groups experienced diarrhea. (2) The body weight and food intake of rats in each group were normal compared with the control group. (3) The hematological and serum biochemical indices of rats in the T1 group were significantly different from those of CK but were in the normal range; (4) The results of microscopic examination of the heart, liver, spleen, lung, and kidney of rats in each group were normal, but inflammation occurred in stomach and jejunum of rats in the T1 group, but not in the ileum. The gastrointestinal tract of rats in the T2 and T3 groups were normal. (5) No abnormal death occurred in any of the treatment groups.The results of this study revealed that gavage of Moringa homogenate at a dose of 6 g/kg BW can cause diarrhea in rats. Although there is no pathological effect on weight, food intake, blood and serum biochemical indicators in rats, there are pathological textures in the gastrointestinal tissue caused by diarrhea. Therefore, the safety threshold of Moringa homogenate should be ≤ 3 g/kg BW.

Simulation-Assisted DNA Nanodevice Serve as a General Optical Platform for Multiplexed Analysis of Micrornas.

Small frame nucleic acids (FNAs) serve as excellent carrier materials for various functional nucleic acid molecules, showcasing extensive potential applications in biomedicine development. The carrier module and function module combination is crucial for probe design, where an improper combination can significantly impede the functionality of sensing platforms. This study explores the effect of various combinations on the sensing performance of nanodevices through simulations and experimental approaches. Variances in response velocities, sensitivities, and cell uptake efficiencies across different structures are observed. Factors such as the number of functional molecules loaded, loading positions, and intermodular distances affect the rigidity and stability of the nanostructure. The findings reveal that the structures with full loads and moderate distances between modules have the lowest potential energy. Based on these insights, a multisignal detection platform that offers optimal sensitivity and response speed is developed. This research offers valuable insights for designing FNAs-based probes and presents a streamlined method for the conceptualization and optimization of DNA nanodevices.

Electroacupuncture modulates abnormal brain connectivity after ischemia reperfusion injury in rats: A graph theory-based approach.

BACKGROUND: Electroacupuncture (EA) has been shown to facilitate brain plasticity-related functional recovery following ischemic stroke. The functional magnetic resonance imaging technique can be used to determine the range and mode of brain activation. After stroke, EA has been shown to alter brain connectivity, whereas EA's effect on brain network topology properties remains unclear. An evaluation of EA's effects on global and nodal topological properties in rats with ischemia reperfusion was conducted in this study. METHODS AND RESULTS: There were three groups of adult male Sprague-Dawley rats: sham-operated group (sham group), middle cerebral artery occlusion/reperfusion (MCAO/R) group, and MCAO/R plus EA (MCAO/R + EA) group. The differences in global and nodal topological properties, including shortest path length, global efficiency, local efficiency, small-worldness index, betweenness centrality (BC), and degree centrality (DC) were estimated. Graphical network analyses revealed that, as compared with the sham group, the MCAO/R group demonstrated a decrease in BC value in the right ventral hippocampus and increased BC in the right substantia nigra, accompanied by increased DC in the left nucleus accumbens shell (AcbSh). The BC was increased in the right hippocampus ventral and decreased in the right substantia nigra after EA intervention, and MCAO/R + EA resulted in a decreased DC in left AcbSh compared to MCAO/R. CONCLUSION: The results of this study provide a potential basis for EA to promote cognitive and motor function recovery after ischemic stroke.

Metabolic and transcriptomic analyses elucidate a novel insight into the network for biosynthesis of carbohydrate and secondary metabolites in the stems of a medicinal orchid Dendrobium nobile.

Dendrobium nobile is an important medicinal and nutraceutical herb. Although the ingredients of D. nobile have been identified as polysaccharides, alkaloids, amino acids, flavonoids and bibenzyls, our understanding of the metabolic pathways that regulate the synthesis of these compounds is limited. Here, we used transcriptomic and metabolic analyses to elucidate the genes and metabolites involved in the biosynthesis of carbohydrate and several secondary metabolites in the stems of D. nobile. A total of 1005 metabolites and 31,745 genes were detected in the stems of D. nobile. The majority of these metabolites and genes were involved in the metabolism of carbohydrates (fructose, mannose, glucose, xylulose and starch), while some were involved in the metabolism of secondary metabolites (alkaloids, ß-tyrosine, ferulic acid, 4-hydroxybenzoate and chrysin). Our predicted regulatory network indicated that five genes (AROG, PYK, DXS, ACEE and HMGCR) might play vital roles in the transition from carbohydrate to alkaloid synthesis. Correlation analysis identified that six genes (ALDO, PMM, BGLX, EGLC, XYLB and GLGA) were involved in carbohydrate metabolism, and two genes (ADT and CYP73A) were involved in secondary metabolite biosynthesis. Our analyses also indicated that phosphoenol-pyruvate (PEP) was a crucial bridge that connected carbohydrate to alkaloid biosynthesis. The regulatory network between carbohydrate and secondary metabolite biosynthesis established will provide important insights into the regulation of metabolites and biological systems in Dendrobium species.

Intracellular activated logic nanomachines based on framework nucleic acids for low background detection of microRNAs in living cells.

DNA molecular machines based on DNA logic circuits show unparalleled potential in precision medicine. However, delivering DNA nanomachines into real biological systems and ensuring that they perform functions specifically, quickly and logically remain a challenge. Here, we developed an efficient DNA molecular machine integrating transfer-sensor-computation-output functions to achieve high fidelity detection of intracellular biomolecules. The introduction of pH nanoswitches enabled the nanomachines to be activated after entering the cell, and the spatial-confinement effect of the DNA triangular prism (TP) enables the molecular machine to process complex information at the nanoscale, with higher sensitivity and shorter response time than diffuse-dominated logic circuits. Such cascaded activation molecular machines follow the logic of AND to achieve specific capture and detection of biomolecules in living cells through a multi-hierarchical response, providing a new insight into the construction of efficient DNA molecular machines.

Age-related differences in physiological and metabolic responses of Pleione aurita (Orchidaceae) pseudobulbs to drought stress and recovery.

The pseudobulb is a storage organ for water and nutrients that plays a crucial role in the growth and survival of epiphytic orchids. However, the role of water and metabolites in pseudobulb during adaptation to environmental stress are rarely detected through control experiments. In the present study, water-related physiological traits and metabolite changes in the pseudobulbs at the flowering stage and full leaf expansion stage for Pleione aurita were investigated after drought stress and recovery treatments. We found that the composition of non-structural carbohydrates (starch vs. soluble sugar) varied over the lifetime of pseudobulbs, and older pseudobulbs stored more water, whereas younger pseudobulbs stored more dry matter. When plants were subjected to drought stress and subsequent recovery, multiple metabolites in the pseudobulbs including non-structural carbohydrates, flavonoids, phenolic acids, as well as amino acids and their derivatives responded positively to these water level fluctuations. For those metabolites that differently accumulated in both stress and recovery processes, old pseudobulbs contained a higher number of these key metabolites than did the connected younger pseudobulbs. In addition, young and old pseudobulbs use different metabolic pathways to both respond and recover to drought. These results indicate that orchid pseudobulbs cope with water level fluctuations by mobilizing metabolite reserves and that pseudobulbs of different ages exhibit different physiological and metabolic responses to drought stress. These findings broadens our understanding of the role pseudobulbs play in the survival of orchids growing in epiphytic habitats.

An intelligent DNA nanomachine for amplified MicroRNA imaging and MicroRNA-Guided efficient gene silencing.

The DNA nanomachines as excellent synthetic biological tools have been widely used for the sensitive detection of intracellular microRNA (miRNA) and DNAzyme-involved gene silencing. However, intelligent DNA nanomachines which have the ability to sense intracellular specific biomolecules and respond to external information in complex environments still remain challenging. Herein, we develop a miRNA-responsive DNAzyme cascaded catalytic (MDCC) nanomachine to perform multilayer cascade reactions, enabling the amplified intracellular miRNA imaging and miRNA-guided efficient gene silencing. The intelligent MDCC nanomachine is designed based on multiple DNAzyme subunit-encoded catalyzed hairpin assembly (CHA) reactants sustained by the pH-responsive Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles. After cellular uptake, the MDCC nanomachine degrades in acidic endosome and releases three hairpin DNA reactants and Zn2+, and the latter can act as an effective cofactor for DNAzyme. In the presence of miRNA-21, a catalytic hairpin assembly (CHA) reaction is triggered, which produces a large number of Y-shaped fluorescent DNA constructs containing three DNAzyme modules for gene silencing. The construction of Y-shaped DNA modified with multisite fluorescence and the circular reaction realizes ultrasensitive miRNA-21 imaging of cancer cells. Moreover, miRNA-guided gene silencing inhibits the cancer cell proliferation through the DNAzyme-specific recognition and cleavage of target EGR-1 (Early Growth Response-1) mRNA, which is one key tumor-involved mRNA. The strategy may provide a promising platform for highly sensitive determination of biomolecules and accurate gene therapy of cancer cells.

Altered Neural Pathways and Related Brain Remodeling: A Rat Study Using Different Nerve Reconstructions.

BACKGROUND: Function recovery is related to cortical plasticity. The brain remodeling patterns induced by alterations in peripheral nerve pathways with different nerve reconstructions are unknown. OBJECTIVE: To explore brain remodeling patterns related to alterations in peripheral neural pathways after different nerve reconstruction surgeries. METHODS: Twenty-four female Sprague-Dawley rats underwent complete left brachial plexus nerve transection, together with the following interventions: no nerve repair (n = 8), grafted nerve repair (n = 8), and phrenic nerve transfer (n = 8). Resting-state functional MR images of brain were acquired at the end of seventh month postsurgery. Amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) were compared among 3 groups. Behavioral observation and electromyography assessed nerve regeneration. RESULTS: Compared with brachial plexus injury group, ALFF and ReHo of left entorhinal cortex decreased in nerve repair and nerve transfer groups. The nerve transfer group showed increased ALFF and ReHo than nerve repair group in left caudate putamen, right accumbens nucleus shell (AcbSh), and right somatosensory cortex. The FC between right somatosensory cortex and bilateral piriform cortices and bilateral somatosensory cortices increased in nerve repair group than brachial plexus injury and nerve transfer groups. The nerve transfer group showed increased FC between right somatosensory cortex and areas including left corpus callosum, left retrosplenial cortex, right parietal association cortex, and right dorsolateral thalamus than nerve repair group. CONCLUSION: Entorhinal cortex is a key brain area in recovery of limb function after nerve reconstruction. Nerve transfer related brain remodeling mainly involved contralateral sensorimotor areas, facilitating directional "shifting" of motor representation.

Modified constraint-induced movement therapy enhances cortical plasticity in a rat model of traumatic brain injury: a resting-state functional MRI study.

Modified constraint-induced movement therapy (mCIMT) has shown beneficial effects on motor function improvement after brain injury, but the exact mechanism remains unclear. In this study, amplitude of low frequency fluctuation (ALFF) metrics measured by resting-state functional magnetic resonance imaging was obtained to investigate the efficacy and mechanism of mCIMT in a control cortical impact (CCI) rat model simulating traumatic brain injury. At 3 days after control cortical impact model establishment, we found that the mean ALFF (mALFF) signals were decreased in the left motor cortex, somatosensory cortex, insula cortex and the right motor cortex, and were increased in the right corpus callosum. After 3 weeks of an 8-hour daily mCIMT treatment, the mALFF values were significantly increased in the bilateral hemispheres compared with those at 3 days postoperatively. The mALFF signal values of left corpus callosum, left somatosensory cortex, right medial prefrontal cortex, right motor cortex, left postero dorsal hippocampus, left motor cortex, right corpus callosum, and right somatosensory cortex were increased in the mCIMT group compared with the control cortical impact group. Finally, we identified brain regions with significantly decreased mALFF values at 3 days postoperatively. Pearson correlation coefficients with the right forelimb sliding score indicated that the improvement in motor function of the affected upper limb was associated with an increase in mALFF values in these brain regions. Our findings suggest that functional cortical plasticity changes after brain injury, and that mCIMT is an effective method to improve affected upper limb motor function by promoting bilateral hemispheric cortical remodeling. mALFF values correlate with behavioral changes and can potentially be used as biomarkers to assess dynamic cortical plasticity after traumatic brain injury.

Alteration of neural activity and neuroinflammatory factors in the insular cortex of mice with corneal neuropathic pain.

Dry eye disease (DED) affects nearly 55% of people worldwide; several studies have proposed that central sensitization and neuroinflammation may contribute to the developing corneal neuropathic pain of DED, while the underlying mechanisms of this contribution remain to be investigated. Excision of extra orbital lacrimal glands established the dry eye model. Corneal hypersensitivity was examined through chemical and mechanical stimulation, and open field test measured the anxiety levels. Restingstate fMRI is a method of functional magnetic resonance imaging (rs-fMRI) was performed for anatomical involvement of the brain regions. The amplitude of low-frequency fluctuation (ALFF) determined brain activity. Immunofluorescence testing and Quantitative real-time polymerase chain reaction were also performed to further validate the findings. Compared with the Sham group, ALFF signals in the supplemental somatosensory area, secondary auditory cortex, agranular insular cortex, temporal association areas, and ectorhinal cortex brain areas were increased in the dry eye group. This change of ALFF in the insular cortex was linked with the increment in corneal hypersensitivity (p < 0.01), c-Fos (p < 0.001), brain-derived neurotrophic factor (p < 0.01), TNF-α, IL-6, and IL-1ß (p < 0.05). In contrast, IL-10 levels (p < 0.05) decreased in the dry eye group. DED-induced corneal hypersensitivity and upregulation of inflammatory cytokines could be blocked by insular cortex injection of Tyrosine Kinase receptor B agonist cyclotraxin-B (p < 0.01) without affecting anxiety levels. Our study reveals that the functional activity of the brain associated with corneal neuropathic pain and neuroinflammation in the insular cortex might contribute to dry eye-related corneal neuropathic pain.

Met decoys: will cancer take the bait?

Inappropriate Met receptor tyrosine kinase signaling can produce proliferative, invasive, angiogenic, and antiapoptotic activities that contribute to malignant growth. Met can be activated by paracrine or autocrine mechanisms in a ligand-dependent fashion, or be constitutively activated by mutation and by other ligand-independent mechanisms. Because Met is inappropriately expressed in almost all types of human cancer, the HGF/SF-Met signaling pathway should be an exceptional target for cancer intervention strategies and therapies. In this issue of Cancer Cell, two reports show that the extracellular domain of Met is an important target for developing anticancer therapies.