PE-STOP: A versatile tool for installing nonsense substitutions amenable for precise reversion.

The rapid advances in genome editing technologies have revolutionized the study of gene functions in cell or animal models. The recent generation of double-stranded DNA cleavage-independent base editors has been suitably adapted for interrogation of protein-coding genes on the basis of introducing premature stop codons or disabling the start codons. However, such versions of stop/start codon-oriented genetic tools still present limitations on their versatility, base-level precision, and target specificity. Here, we exploit a newly developed prime editor (PE) that differs from base editors by its adoption of a reverse transcriptase activity, which enables incorporation of various types of precise edits templated by a specialized prime editing guide RNA. Based on such a versatile platform, we established a prime editing-empowered method (PE-STOP) for installation of nonsense substitutions, providing a complementary approach to the present gene-targeting tools. PE-STOP is bioinformatically predicted to feature substantially expanded coverage in the genome space. In practice, PE-STOP introduces stop codons with good efficiencies in human embryonic kidney 293T and N2a cells (with medians of 29% [ten sites] and 25% [four sites] editing efficiencies, respectively), while exhibiting minimal off-target effects and high on-target precision. Furthermore, given the fact that PE installs prime editing guide RNA-templated mutations, we introduce a unique strategy for precise genetic rescue of PE-STOP-dependent nonsense mutation via the same PE platform. Altogether, the present work demonstrates a versatile and specific tool for gene inactivation and for functional interrogation of nonsense mutations.

Nonenzymatic Sweat Wearable Uric Acid Sensor Based on N-Doped Reduced Graphene Oxide/Au Dual Aerogels.

Sweat wearable sensors enable noninvasive and real-time metabolite monitoring in human health management but lack accuracy and wearable applicability. The rational design of sensing electrode materials will be critical yet challenging. Herein, we report a dual aerogel-based nonenzymatic wearable sensor for the sensitive and selective detection of uric acid (UA) in human sweat. The three-dimensional porous dual-structural aerogels composed of Au nanowires and N-doped graphene nanosheets (noted as N-rGO/Au DAs) provide a large active surface, abundant access to the target, rapid electron transfer pathways, and a high intrinsic activity. Thus, a direct UA electro-oxidation is demonstrated at the N-rGO/Au DAs with a much higher activity than those at the individual gels (i.e., Au and N-rGO). Moreover, the resulting sensing chip displays high performance with a good anti-interfering ability, long-term stability, and excellent flexibility toward the UA detection. With the assistance of a wireless circuit, a wearable sensor is successfully applied in the real-time UA monitoring on human skin. The obtained result is comparable to that evaluated by high-performance liquid chromatography. This dual aerogel-based nonenzymatic biosensing platform not only holds considerable promise for the reliable sweat metabolite monitoring but also opens an avenue for metal-based aerogels as flexible electrodes in wearable sensing.

Dual Structural Design of Platinum-Nickel Hydrogels for Wearable Glucose Biosensing with Ultrahigh Stability.

Wearable glucose sensors are of great significance and highly required in mobile health monitoring and management but suffering from limited long-term stability and wearable adaptability. Here a simultaneous component and structure engineering strategy is presented, which involves Pt with abundant Ni to achieve three-dimensional, dual-structural Pt-Ni hydrogels with interconnected networks of PtNi nanowires and Ni(OH)2 nanosheets, showing prominent electrocatalytic activity and stability in glucose oxidation under neutral condition. Specifically, the PtNi(1:3) dual hydrogels shows 2.0 and 270.6 times' activity in the glucose electro-oxidation as much as the pure Pt and Ni hydrogels. Thanks to the high activity, structural stability, good flexibility, and self-healing property, the PtNi(1:3) dual gel-based non-enzymatic glucose sensing chip is endowed with high performance. It features a high sensitivity, an excellent selectivity and flexibility, and particularly an outstanding long-term stability over 2 months. Together with a pH sensor and a wireless circuit, an accurate, real-time, and remote monitoring of sweat glucose is achieved. This facile design of novel dual-structural metallic hydrogels sheds light to rationally develop new functional materials for high-performance wearable biosensors.

Correction of the pathogenic mutation in TGM1 gene by adenine base editing in mutant embryos.

A couple diagnosed as carriers for lamellar ichthyosis, an autosomal recessive rare disease, encountered two pregnancy losses. Their blood samples showed the same heterozygous c.607C>T mutation in the TGM1 gene. However, we found that about 98.4% of the sperm had mutations, suggesting possible de novo germline mutation. To explore the probability of correcting this mutation, we used two different adenine base editors (ABEs) combined with related truncated single guide RNA (sgRNA) to repair the pathogenic mutation in mutant zygotes. Our results showed that the editing efficiency was 73.8% for ABEmax-NG combined with 20-bp-length sgRNA and 78.7% for Sc-ABEmax combined with 19-bp-length sgRNA. The whole-genome sequencing (WGS) and deep sequencing analysis demonstrated precise DNA editing. This study reveals the possibility of correcting the genetic mutation in embryos with the ABE system.

Quantitative analysis method of Panax notoginseng based on thermal perturbation terahertz two-dimensional correlation spectroscopy.

This paper proposes a Panax notoginseng (P. notoginseng) quantitative analysis based on terahertz time-domain spectroscopy and two-dimensional correlation spectroscopy (2DCOS). By imposing temperature perturbation combined with 2DCOS, the one-dimensional absorbance spectra were transformed into 2DCOS synchronous spectra, which reflected the differences in characteristic information between different P. notoginseng contents more clearly. Then, the feature information of P. notoginseng contents was extracted from the 2DCOS synchronous spectra by a competitive adaptive reweighted sampling (CARS) method and was used to build a quantitative model combined with a support vector regression machine (SVR), called 2DCOS-CARS-SVR. We obtained a more accurate analysis result than the commonly used principal component analysis (PCA)-partial least squares regression (PLSR) and PCA-SVR. The prediction set correlation coefficient and root mean square error reached 0.9915% and 0.8160%, respectively.

De novo assisted AFB1-Specific monoclonal antibody sequence assembly and comprehensive molecular characterization.

Despite their widely used and access as biological reagents in analytical methods, the detailed structural features for most of the antibodies were rarely known. Here, a new antibody for AFB1 with high specificity in constructing ELISA was studied in detail. The molecular structure and modification were elucidated mainly by nano-electrospray ionization mass spectrometry. The mass experiments, including MALDI-TOF MS, revealed complete and specific fragments, including antibody molecular weight, peptides, glycopeptide, and N-glycoform. By proteolytic treatment of pepsin and trypsin and high-resolution tandem-MS, the primary structure of the newly developed anti-AFB1 antibody was assembled by several rounds of Database search process assisted with the de novo results. The antibody CDR annotation and constraint-based multiple alignment tool were used to differentiate and align the sequences. The method uses only two proteases to generate numerous peptides for de novo sequencing. This artificial assembled AFB1-specific monoclonal antibody sequence was validated by comparison with the sequencing results of the immunoglobulin gene. The results showed that this method achieves full sequence coverage of anti-AFB1 monoclonal antibody, with an accuracy of 100% in the CDR regions of light chain and four amino acid mismatch in heavy chain. This simple and low-cost method was confirmed by treating a public dataset. The secondary structure information of intact antibody was also elucidated from the results of circular dichroism spectrum.

Clinical evidence for elevated levels of caveolin-1 in circulation of patients with diabetic foot ulcers.

Caveolin-1 directly interacts vascular endothelial growth factor receptor-2 (VEGFR2) and therefore prevents VEGF-induced angiogenesis. In addition, the production of nitric oxide (NO), which is effective in reducing ischemia in diabetic foot ulcers (DFU), is suppressed by caveolin-1 in endothelial cells. The present study was designed to investigate the change of caveolin-1 concentrations in DFU patients. A total of 150 participants were consecutively enrolled, including 40 DFU patients (DFU group), 40 diabetes patients without DFU (type 2 diabetes mellitus [T2DM] group), and 70 participants without diabetes (control group). Significant increased levels of plasma caveolin-1, accompanied with decreased concentration of plasma VEGF-A (vascular endothelial growth factor-A) and NO, were detected in DFU patients. Moreover, Pearson's correlation analysis revealed a negative correlation between plasma caveolin-1 and VEGF-A as well as NO levels in DFU patients. Furthermore, DFU patients had higher expression of caveolin-1 in the popliteal artery, compared to those in control and T2DM groups. Simultaneously, the amounts of eNOS (an enzyme responsible for the production of NO) and VEGFR2 were attenuated in the popliteal artery of DFU patients. Taken together, our study provided clinical evidence for the possible association of elevated caveolin-1 levels and the development of DFU. This may be induced by the suppressed VEGF-A/VEGFR2 and eNOS/NO signalling axis.

Harnessing A3G for efficient and selective C-to-T conversion at C-rich sequences.

BACKGROUND: Site-specific C>T DNA base editing has been achieved by recruiting cytidine deaminases to the target C using catalytically impaired Cas proteins; the target C is typically located within 5-nt editing window specified by the guide RNAs. The prototypical cytidine base editor BE3, comprising rat APOBEC1 (rA1) fused to nCas9, can indiscriminately deaminate multiple C's within the editing window and also create substantial off-target edits on the transcriptome. A powerful countermeasure for the DNA off-target editing is to replace rA1 with APOBEC proteins which selectively edit C's in the context of specific motifs, as illustrated in eA3A-BE3 which targets TC. However, analogous editors selective for other motifs have not been described. In particular, it has been challenging to target a particular C in C-rich sequences. Here, we sought to confront this challenge and also to overcome the RNA off-target effects seen in BE3. RESULTS: By replacing rA1 with an optimized human A3G (oA3G), we developed oA3G-BE3, which selectively targets CC and CCC and is also free of global off-target effects on the transcriptome. Furthermore, we created oA3G-BE4max, an upgraded version of oA3G-BE3 with robust on-target editing. Finally, we showed that oA3G-BE4max has negligible Cas9-independent off-target effects at the genome. CONCLUSIONS: oA3G-BE4max can edit C(C)C with high efficiency and selectivity, which complements eA3A-editors to broaden the collective editing scope of motif selective editors, thus filling a void in the base editing tool box.

Integrating Highly Porous and Flexible Au Hydrogels with Soft-MEMS Technologies for High-Performance Wearable Biosensing.

Wearable biosensors for real-time and non-invasive detection of biomarkers are of importance in early diagnosis and treatment of diseases. Herein, a high-performance wearable biosensing platform was proposed by combining a three-dimensional hierarchical porous Au hydrogel-enzyme electrode with high biocompatibility, activity, and flexibility and soft-MEMS technologies with high precision and capability of mass production. Using glucose oxidase as the model enzyme, the glucose sensor exhibits a sensitivity of 10.51 µA mM-1 cm-2, a long durability over 15 days, and a good selectivity. Under the mechanical deformation (0 to 90°), it is able to maintain an almost constant performance with a low deviation of <1.84%. With the assistance of a wireless or a Bluetooth module, this wearable sensing platform achieves real-time and non-invasive glucose monitoring on human skins. Similarly, continuous lactic acid monitoring was also realized with lactate oxidase immobilized on the same sensing platform, further verifying the universality of this sensing platform. Therefore, our work holds promise to provide a universal, high-performance wearable biosensing platform for various biomarkers in sweat and reliable diagnostic information for health management.

Efficient Gene Silencing by Adenine Base Editor-Mediated Start Codon Mutation.

Traditional CRISPR/Cas9-based gene knockouts are generated by introducing DNA double-strand breaks (DSBs), but this may cause excessive DNA damage or cell death. CRISPR-based cytosine base editors (CBEs) and adenine base editors (ABEs) can facilitate C-to-T or A-to-G exchanges, respectively, without DSBs. CBEs have been employed in a gene knockout strategy: CRISPR-STOP or i-STOP changes single nucleotides to induce in-frame stop codons. However, this strategy is not applicable for some genes, and the unwanted mutations in CBE systems have recently been reported to be surprisingly significant. As a variant, the ABE systems mediate precise editing and have only rare unwanted mutations. In this study, we implemented a new strategy to induce gene silencing (i-Silence) with an ABE-mediated start codon mutation from ATG to GTG or ACG. Using both in vitro and in vivo model systems, we showed that the i-Silence approach is efficient and precise for producing a gene knockout. In addition, the i-Silence strategy can be employed to analyze ~17,804 human genes and can be used to mimic 147 kinds of pathogenic diseases caused by start codon mutations. Altogether, compared to other methods, the ABE-based i-Silence method is a safer gene knockout strategy, and it has promising application potential.

Rheological and microstructural characterization of wheat dough formulated with konjac glucomannan.

BACKGROUND: This work aimed to investigate the effects of different levels of konjac glucomannan (KGM) on the thermomechanical and pasting properties, water distribution, gelatinization, texture, and microstructural characteristics of wheat flour and dough. RESULTS: The thermomechanical properties assessed with a Mixolab showed that KGM could increase the water absorption and degree of softening and decrease the stability time of wheat dough. In addition, wheat flour starch with KGM underwent significant (P < 0.05) gelatinization changes according to the rapid viscosity analyzer and differential scanning calorimetry results. These results demonstrated that KGM enhanced the thermal stability and anti-aging capacity of wheat flour. All doughs with KGM exhibited viscoelastic behavior but lower hardness and gumminess. Low-field nuclear magnetic resonance showed that water, with a tight binding force, migrated to the weaker binding forces in the dough. A noticeable disruption of the gluten network was observed at the highest level of KGM. However, an intermediate level of KGM addition (10 or 15 g kg-1 flour) still rendered dough with satisfactory properties. CONCLUSION: A certain amount of KGM could enhance the thermal stability and anti-aging ability of wheat flour, improve the viscoelastic behavior, and decrease the hardness and gumminess of dough. In general, the mixing of flour and dough with KGM addition of 10 or 15 g kg-1 flour was of good quality. © 2021 Society of Chemical Industry.

Effects of sialylated lactulose on the mouse intestinal microbiome using Illumina high-throughput sequencing.

Sialylated oligosaccharides are known to have beneficial effects, such as increasing the level of bifidobacteria, reducing the levels of blood endotoxin and blood ammonia, and enhancing the body's immune system. However, it is unknown whether sialylated lactuloses have modulatory effects on the intestinal microbiota. In this study, 60 healthy mice were randomly divided into six groups, namely, a normal control group, a lactulose group, a Kdn-α2,3-lactulose group, a Kdn-α2,6-lactulose group, a Neu5Ac-α2,3-lactulose group, and a Neu5Ac-α2,6-lactulose group. After 14 days of lactulose administration, the feces of three mice from each group were collected, and the intestinal microbiota were detected by Illumina MiSeq high-throughput sequencing targeting the V3-V4 region of the 16S rDNA gene. At the phylum level, the relative abundance of Firmicutes was increased in the sialylated lactulose groups, while the abundance of Bacteroidetes was decreased. At the family level, sialylated lactulose intervention decreased the relative abundance of Bacteroidales S24-7 group and Helicobacteraceae and enhanced the abundance of Lactobacillaceae, which reflects the modulatory effect of sialylated lactulose on intestinal microbiota. Diversity analysis indicated that the index of Chao was higher in the sialylated lactulose groups than in the normal control group, and the Shannon and Simpson diversity indices were higher in the Kdnα-2,6-lactulose group and the Neu5Ac-α2,3-lactulose group than in the normal control group. The results of the intestinal microbiota sample composition indicated that there were differences between the sialylated lactulose groups and the normal control group. Thus, sialylated lactulose could be used as a functional food component with potential therapeutic applications in manipulating intestinal microbiota to exert beneficial effects on the host's health.

Correction of the Marfan Syndrome Pathogenic FBN1 Mutation by Base Editing in Human Cells and Heterozygous Embryos.

There are urgent demands for efficient treatment of heritable genetic diseases. The base editing technology has displayed its efficiency and precision in base substitution in human embryos, providing a potential early-stage treatment for genetic diseases. Taking advantage of this technology, we corrected a Marfan syndrome pathogenic mutation, FBN1T7498C. We first tested the feasibility in mutant cells, then successfully achieved genetic correction in heterozygous human embryos. The results showed that the BE3 mediated perfect correction at the efficiency of about 89%. Importantly, no off-target and indels were detected in any tested sites in samples by high-throughput deep sequencing combined with whole-genome sequencing analysis. Our study therefore suggests the efficiency and genetic safety of correcting a Marfan syndrome (MFS) pathogenic mutation in embryos by base editing.

Virtual Reality Rehabilitation Versus Conventional Physical Therapy for Improving Balance and Gait in Parkinson's Disease Patients: A Randomized Controlled Trial.

BACKGROUND The aim of this study was to investigate the effect of virtual reality (VR) technology on balance and gait in patients with Parkinson's disease (PD). MATERIAL AND METHODS The study design was a single-blinded, randomized, controlled study. Twenty-eight patients with PD were randomly divided into the experimental group (n=14) and the control group (n=14). The experimental group received VR training, and the control group received conventional physical therapy. Patients performed 45 minutes per session, 5 days a week, for 12 weeks. Individuals were assessed pre- and post-rehabilitation with the Berg Balance Scale (BBS), Timed Up and Go Test (TUGT), Third Part of Unified Parkinson's Disease Rating Scale (UPDRS3), and Functional Gait Assessment (FGA). RESULTS After treatment, BBS, TUGT, and FGA scores had improved significantly in both groups (P<0.05). However, there was no significant difference in the UPDRS3 between the pre- and post-rehabilitation data of the control group (P>0.05). VR training resulted in significantly better performance compared with the conventional physical therapy group (P<0.05). CONCLUSIONS The results of this study indicate that 12 weeks of VR rehabilitation resulted in a greater improvement in the balance and gait of individuals with PD when compared to conventional physical therapy.

Exendin-4 Exacerbates Burn-Induced Morbidity in Mice by Activation of the Sympathetic Nervous System.

BACKGROUND: Although glucagon-like peptide 1- (GLP-1-) based therapy of hyperglycemia in burn injury has shown great potential in clinical trials, its safety is seldom evaluated. We hypothesize that exendin-4, a GLP-1 analogue, might affect the immune response via the activation of the sympathetic nervous system in burn injury. METHODS: Male Balb/c mice were subjected to sham or thermal injury of 15% total body surface area. Exendin-4 on T cell function in vitro was examined in cultured splenocytes in the presence of ß-adrenoceptor antagonist propranolol (1 nmol/L) or GLP-1R antagonist exendin (9-39) (1 µmol/L), whereas its in vivo effect was determined by i.p. injection of exendin-4 (2.4 nmol/kg) in mice. To further elucidate the sympathetic mechanism, propranolol (30 mg/kg) or vehicle was applied 30 min prior to injury. RESULTS: Although the exacerbated burn-induced mortality by exendin-4 was worsened by propranolol pretreatment, the inhibition of T cell proliferation by exendin-4 in vitro could be restored by propranolol instead of exendin (9-39). However, a Th2 switch by exendin-4 in vitro could only be reversed by exendin (9-39). Likewise, the inhibition of splenic T cell function and NFAT activity by exendin-4 in vivo was restored by propranolol. By contrast, the increased splenic NF-κB translocation by exendin-4 in vivo was potentiated by propranolol in sham mice but suppressed in burn mice. Accordingly, propranolol abrogated the heightened inflammatory response in the lung and the accelerated organ injuries by exendin-4 in burn mice. On the contrary, a Th2 switch and higher serum levels of inflammatory mediators by exendin-4 were potentiated by propranolol in burn mice. Lastly, exendin-4 raised serum stress hormones which could be remarkably augmented by propranolol. CONCLUSIONS: Exendin-4 suppresses T cell function and promotes organ inflammation through the activation of the sympathetic nervous system, while elicits Th2 switch via GLP-1R in burn injury.

Proinflammatory switch from Gαs to Gαi signaling by Glucagon-like peptide-1 receptor in murine splenic monocyte following burn injury.

OBJECTIVE: Glucagon-like peptide-1 (GLP-1)-based therapy via G protein-coupled receptor (GPCR) GLP-1R, to attenuate hyperglycemia in critical care has attracted great attention. However, the exaggerated inflammation by GLP-1R agonist, Exendin-4, in a mouse model of burn injury was quite unexpected. Recent studies found that GPCR might elicit proinflammatory effects by switching from Gαs to Gαi signaling in the immune system. Thus, we aimed to investigate the possible Gαs to Gαi switch in GLP-1R signaling in monocyte following burn injury. MATERIALS AND METHODS: Splenic monocytes from sham and burn mice 24 h following burn injury were treated with consecutive doses of Exendin-4 alone or in combination with an inhibitor of Gαi signaling (pertussis toxin, PTX), or a blocker of protein kinase A (H89). Cell viability was assessed by CCK-8, and the supernatant was collected for cytokine measurement by ELISA. Intracellular cAMP level, phosphorylated PKA activity, and nuclear NF-κB p65 were determined by ELISA, ERK1/2 activation was analyzed by Western blot. The expression of GLP-1R downstream molecules, Gαs, Gαi and G-protein coupled receptor kinase 2 (GRK2) were examined by immunofluorescence staining and Western blot. RESULTS: Exendin-4 could inhibit the viability of monocyte from sham rather than burn mice. Unexpectedly, it could also reduce TNF-α secretion from sham monocyte while increase it from burn monocyte. The increased secretion of TNF-α by Exendin-4 from burn monocyte could be reversed by pretreatment of PTX or H89. Accordingly, Exendin-4 could stimulates cAMP production dose dependently from sham instead of burn monocyte. However, the blunt cAMP production from burn monocyte was further suppressed by pretreatment of PTX or H89 after 6-h incubation. Nevertheless, phosphorylated PKA activity was significantly increased by low dose of Exendin-4 in sham monocyte, by contrast, it was enhanced by high dose of Exendin-4 in burn monocyte after 1-h incubation. Following Exendin-4 treatment for 2 h ex vivo, total nuclear NF-κB and phosphorylated NF-κB activity, as well as cytoplasmic pERK1/2 expressions were reduced in sham monocyte, however, only pERK1/2 was increased by Exendin-4 in burn monocytes. Moreover, reduced expressions of GLP-1R, GRK-2 and Gαs in contrast with increased expression of Gαi were identified in burn monocyte relative to sham monocyte. CONCLUSIONS: This study presents an unexpected proinflammatory switch from Gαs to Gαi signaling in burn monocyte, which promotes ERK1/2 and NF-κB activation and the downstream TNF-α secretion. This phenomenon is most probably responsible for proinflammatory response evoked by Gαs agonist Exendin-4 following burn injury.

A Monolithic Electrochemical Micro Seismic Sensor Capable of Monitoring Three-Dimensional Vibrations.

A monolithic electrochemical micro seismic sensor capable of monitoring three-axial vibrations was proposed in this paper. The proposed micro sensor mainly consisted of four sensing units interconnected within flow channels and by interpreting the voltage outputs of the sensing units, vibrations with arbitrary directions can be quantified. The proposed seismic sensors are fabricated based on MEMS technologies and characterized, which produced sensitivities along x, y, and z axes as 2473.2 ± 184.5 V/(m/s), 2261.7 ± 119.6 V/(m/s), and 3480.7 ± 417.2 V/(m/s) at 30 Hz. In addition, the vibrations in x-y, x-z, and y-z planes were applied to the developed seismic sensors, leading to comparable monitoring results after decoupling calculations with the input velocities. Furthermore, the results have shown its feasibilities for seismic data recording.

A Flexible Sensing Unit Manufacturing Method of Electrochemical Seismic Sensor.

This paper presents an electrochemical seismic sensor in which paraylene was used as a substrate and insulating layer of micro-fabricated electrodes, enabling the detection of seismic signals with enhanced sensitivities in comparison to silicon-based counterparts. Based on microfabrication, paralene-based electrochemical seismic sensors were fabricated in which the thickness of the insulating spacer was 6.7 µm. Compared to silicon-based counterparts with ~100 µm insulating layers, the parylene-based devices produced higher sensitivities of 490.3 ± 6.1 V/(m/s) vs. 192.2 ± 1.9 V/(m/s) at 0.1 Hz, 4764.4 ± 18 V/(m/s) vs. 318.9 ± 6.5 V/(m/s) at 1 Hz, and 4128.1 ± 38.3 V/(m/s) vs. 254.5 ± 4.2 V/(m/s) at 10 Hz. In addition, the outputs of the parylene vs. silicon devices in response to two transit inputs were compared, producing peak responses of 2.97 V vs. 0.22 V and 2.41 V vs. 0.19 V, respectively. Furthermore, the self-noises of parylene vs. silicon-based devices were compared as follows: -82.3 ± 3.9 dB vs. -90.4 ± 9.4 dB at 0.1 Hz, -75.7 ± 7.3 dB vs. -98.2 ± 9.9 dB at 1 Hz, and -62.4 ± 7.7 dB vs. -91.1 ± 8.1 dB at 10 Hz. The developed parylene-based electrochemical seismic sensors may function as an enabling technique for further detection of seismic motions in various applications.

Role of Mitogen-Activated Protein Kinases in the Formation of Hypertrophic Scar with Model of Lipopolysaccharide Stimulated Skin Fibroblast Cells.

OBJECTIVE: Hypertrophic scar is common in burn patients, but treating result could not meet the expectation of the patients and doctors. We have found that certain concentration level of lipopolysaccharide (LPS) stimulated normal fibroblast cells have statistically similar with fibroblast cells from hypertrophic scar on the phenotype level, and with this work we are trying to figure out which Mitogen-Activated Protein Kinase (MAPK) is affected and how it is affected. METHODS: Experiments were conducted in May, 2017 at the first affiliated hospital of the Chinese PLA General Hospital, Beijing, China. We have cultured the cell line of human skin fibroblast cells and randomly divided cells into four groups: control group and three stimulation groups. We have rebuilt the LPS stimulated model of skin fibroblast cells in hypertrophic scar based on our previous work. Experimental groups were stimulated with 0.1ug/mL LPS concentration for 24 hours, 48 hours, and 72 hours, respectively. Then we performed western blot analysis of Erk, p-Erk, JNK, p-JNK, p38 and p-p38. We performed statistical analysis with SPSS 15.0. RESULTS: LPS can up regulate the MAPK/p38 pathway (p<0.05) and down regulate the MAPK/Erk and MAPK/JNK pathways (p<0.05). The changes of phosphorylated protein are time-related, with longer stimulation duration, significant difference is increased (p<0.05). CONCLUSION: MAPKs can play an important role in the formation of hypertrophic scar in the skin. Early intervention through the MAPKs could be a promising target in the prevention of the formation of hypertrophic scar.

An Electrochemical, Low-Frequency Seismic Micro-Sensor Based on MEMS with a Force-Balanced Feedback System.

Electrochemical seismic sensors are key components in monitoring ground vibration, which are featured with high performances in the low-frequency domain. However, conventional electrochemical seismic sensors suffer from low repeatability due to limitations in fabrication and limited bandwidth. This paper presents a micro-fabricated electrochemical seismic sensor with a force-balanced negative feedback system, mainly composed of a sensing unit including porous sensing micro electrodes immersed in an electrolyte solution and a feedback unit including a feedback circuit and a feedback magnet. In this study, devices were designed, fabricated, and characterized, producing comparable performances among individual devices. In addition, bandwidths and total harmonic distortions of the proposed devices with and without a negative feedback system were quantified and compared as 0.005-20 (feedback) Hz vs. 0.3-7 Hz (without feedback), 4.34 ± 0.38% (without feedback) vs. 1.81 ± 0.31% (feedback)@1 Hz@1 mm/s and 3.21 ± 0.25% (without feedback) vs. 1.13 ± 0.19% (feedback)@5 Hz@1 mm/s (ndevice = 6, n represents the number of the tested devices), respectively. In addition, the performances of the proposed MEMS electrochemical seismometers with feedback were compared to a commercial electrochemical seismic sensor (CME 6011), producing higher bandwidth (0.005-20 Hz vs. 0.016-30 Hz) and lower self-noise levels (-165.1 ± 6.1 dB vs. -137.7 dB at 0.1 Hz, -151.9 ± 7.5 dB vs. -117.8 dB at 0.02 Hz (ndevice = 6)) in the low-frequency domain. Thus, the proposed device may function as an enabling electrochemical seismometer in the fields requesting seismic monitoring at the ultra-low frequency domain.