Removal of signal peptide variants by cation exchange chromatography: A case study.

Signal peptide (SP) is required for secretion of recombinant proteins and typically cleaved by signal peptidase at its C-region to generate the mature proteins. Miscleavage of the SP is reported occasionally, resulting in a truncated- or elongated-terminal sequence. In the present work, we demonstrated that cation exchange (CEX) chromatography is an effective means for removing SP variants with a case study. With the selected resin/conditions, the chromatographic performance is comparable between runs performed at the low end and high end of load density and elution range. The procedure described in this work can be used as a general approach for resin selection and optimization of chromatographic conditions to remove byproducts that bind more strongly than the product to the selected resin.

Wearable Self-Powered Smart Sensors for Portable Nutrition Monitoring.

Self-powered sensors have attracted great attention in the field of analysis owing to the necessity of power resources for the routine use of sensor devices. However, it is still challenging to construct wearable self-powered sensors in a simple and efficient way. Herein, wearable self-powered textile smart sensors based on advanced bifunctional polyaniline/reduced graphene oxide (PANI/RGO) films have been successfully developed for remote real-time detection of vitamin C. Specifically, a pH-assisted oil/water (O/W) self-assembly strategy was proposed to boost the O/W self-assembled PANI/RGO films via proton regulation. The as-obtained PANI/RGO films could be directly loaded on the textile substrate, with good capacitive and biosensing performance due to the multifunctionality of PANI and RGO, respectively. Moreover, both wearable power supply devices and wearable biosensors based on PANI/RGO films possess good electrochemical performance, which paves the way for the actual application of self-powered nutrition monitoring. Significantly, obvious signals have been obtained in the detection of vitamin C beverages, exhibiting promising application values in daily nutrition track necessities. Prospectively, this study would provide an effective and simple strategy for integrating wearable self-powered sensors, and the developed smart sensing system is an ideal choice for the portable detection of nutrition.

Wearable healthcare smart electrochemical biosensors based on co-assembled prussian blue-graphene film for glucose sensing.

Wearable film-based smart biosensors have been developed for real-time biomolecules detection. Particularly, interfacial co-assembly of reduced graphene oxide-prussian blue (PB-RGO) film through electrostatic interaction has been systematically studied by controllable pH values, achieving optimal PB-RGO nanofilms at oil/water (O/W) phase interface driven by minimization of interfacial free energy for wearable biosensors. As a result, as-prepared wearable biosensors of PB-RGO film could be easily woven into fabrics, exhibiting excellent glucose sensing performance in amperometric detection with a sensitivity of 27.78 µA mM-1 cm-2 and a detection limit of 7.94 µM, as well as impressive mechanical robustness of continuously undergoing thousands of bending or twist. Moreover, integrated wearable smartsensing system could realize remotely real-time detection of biomarkers in actual samples of beverages or human sweat via cellphones. Prospectively, interfacial co-assembly engineering driven by pH-induced electrostatic interaction would provide a simple and efficient approach for acquiring functional graphene composites films, and further fabricate wearable smartsensing devices in health monitoring fields.

Bone morphogenetic protein-2 and -7 mediate the anabolic function of nucleus pulposus cells with discrete mechanisms.

Bone morphogenetic proteins (BMPs) play roles in promoting cell anabolism, especially in extracellular matrix production. The difference between BMP members in their capacity to modulate intervertebral disc cell activity is yet to be defined. BMP-7/OP-1 has been shown to retard disc degeneration. We compared the activity of BMP-7 with that of BMP-2 on nucleus pulposus (NP) cell phenotype and function, and investigated how they differentially affect the gene expression profiles of signaling cascade components in human NP cells under degenerative states. We found that while both BMP-2 and BMP-7 enhanced matrix production of bovine NP cells, BMP-7 is more potent than BMP-2 at various dosages (50-800 ng/ml). BMP-7 exerted a relatively stronger stimulation on sulfated glycosaminoglycan production and proliferation in human NP cells. Degenerated NP cells showed an overall weaker response to the BMPs than non-degenerated cells, and were more sensitive to BMP-7 than BMP-2 stimulation. Compared to BMP-2, BMP-7 not only induced the gene expression of canonical BMP components, but also evoked changes in MAPKs as well as CREB1 and EP300 gene expression in degenerated NP cells, suggesting potential activation of the cAMP dependent protein kinase related pathways. In contrast to BMP-2, BMP-7 concomitantly inhibited the expression of profibrotic genes. We propose that BMP-2 and BMP-7, and likely other BMPs, may operate multifaceted but discrete molecular machineries that give rise to their different capacity in regulating NP cell phenotype. Further investigations into such differential capacity may possibly derive alternative cues important for IVD repair or engineering.

Symptomatic versus Asymptomatic Intervertebral Disc Degeneration: Is Inflammation the Key?

Degenerated intervertebral discs (d-IVDs) contribute to low back pain (LBP) and are highly common. While some d-IVDs cause discogenic LBP, others are pain-free. Understanding the differences in pathophysiology between painful and pain-free intervertebral disc degeneration (IDD), especially the pathogenic signaling involved in the regulation of painful d-IVDs, is vital for achieving satisfactory effects in clinical treatment. In this review, we revisit recent findings on the detection of inflammatory factors in d-IVDs and summarize the differences between d-IVDs that are painful and those that are pain-free. We postulate that persistent inflammation and innervation are the key factors distinguishing those that are symptomatic and those that are not. This highlights the necessity to use painful, rather than pain-free, degenerated discs in the mechanistic study of disc degeneration and in the development of regenerative approaches, to avoid false positive/negative outcomes. Based on previous molecular d-IVD studies, we also postulate the signaling events from disc overload/ injury to discogenic pain. Although these proposed events are supported by experimental findings, many details about how they are interconnected are not addressed and therefore require experimental investigation.

Concise review: the surface markers and identity of human mesenchymal stem cells.

The concept of mesenchymal stem cells (MSCs) is becoming increasingly obscure due to the recent findings of heterogeneous populations with different levels of stemness within MSCs isolated by traditional plastic adherence. MSCs were originally identified in bone marrow and later detected in many other tissues. Currently, no cloning based on single surface marker is capable of isolating cells that satisfy the minimal criteria of MSCs from various tissue environments. Markers that associate with the stemness of MSCs await to be elucidated. A number of candidate MSC surface markers or markers possibly related to their stemness have been brought forward so far, including Stro-1, SSEA-4, CD271, and CD146, yet there is a large difference in their expression in various sources of MSCs. The exact identity of MSCs in vivo is not yet clear, although reports have suggested they may have a fibroblastic or pericytic origin. In this review, we revisit the reported expression of surface molecules in MSCs from various sources, aiming to assess their potential as MSC markers and define the critical panel for future investigation. We also discuss the relationship of MSCs to fibroblasts and pericytes in an attempt to shed light on their identity in vivo.

Mesenchymal stem cells reduce intervertebral disc fibrosis and facilitate repair.

Intervertebral disc degeneration is associated with back pain and radiculopathy which, being a leading cause of disability, seriously affects the quality of life and presents a hefty burden to society. There is no effective intervention for the disease and the etiology remains unclear. Here, we show that disc degeneration exhibits features of fibrosis in humans and confirmed this in a puncture-induced disc degeneration (PDD) model in rabbit. Implantation of bone marrow-derived mesenchymal stem cells (MSCs) to PDD discs can inhibit fibrosis in the nucleus pulposus with effective preservation of mechanical properties and overall spinal function. We showed that the presence of MSCs can suppress abnormal deposition of collagen I in the nucleus pulposus, modulating profibrotic mediators MMP12 and HSP47, thus reducing collagen aggregation and maintaining proper fibrillar properties and function. As collagen fibrils can regulate progenitor cell activities, our finding provides new insight to the limited self-repair capability of the intervertebral disc and importantly the mechanism by which MSCs may potentiate tissue regeneration through regulating collagen fibrillogenesis in the context of fibrotic diseases.

In search of nucleus pulposus-specific molecular markers.

Intervertebral disc degeneration usually starts from the inner nucleus pulposus (NP). The majority of previous NP-related studies assessed the outcome by the expression of chondrogenic markers since NP cells are chondrocyte like. However, NP cells are unique from chondrocytes and such assessments may be inappropriate. Very recently, several investigators published their findings about the transcriptional differences between NP cells and other related cell types on a genomic scale. In this review we discuss these recent findings and summarize the molecules that may be utilized as NP-specific markers to distinguish normal NP cells from several cell types and as markers that indicate its degeneration. We will revisit markers that distinguish NP cells from the outer surrounding annulus fibrosus (AF) cells and articular chondrocytes so as to facilitate authentic NP cell engineering from stem cells. Our review indicated that N-cadherin and keratin 19 have the potential to serve as common NP markers, as they distinguish healthy NP cells from AF cells, articular cartilage cells and degenerated NP cells.

Sesame bacterial wilt significantly alters rhizosphere soil bacterial community structure, function, and metabolites in continuous cropping systems.

Bacterial wilt is the leading disease of sesame and alters the bacterial community composition, function, and metabolism of sesame rhizosphere soil. However, its pattern of change is unclear. Here, the purpose of this study was to investigate how these communities respond to three differing severities of bacterial wilt in mature continuously cropped sesame plants by metagenomic and metabolomic techniques, namely, absence (WH), moderate (WD5), and severe (WD9) wilt. The results indicated that bacterial wilt could significantly change the bacterial community structure in the rhizosphere soil of continuously cropped sesame plants. The biomarker species with significant differences will also change with increasing disease severity. In particular, the gene expression levels of Ralstonia solanacearum in the WD9 and WD5 treatments increased by 25.29% and 33.61%, respectively, compared to those in the WH treatment (4.35 log10 copies g-1). The occurrence of bacterial wilt significantly altered the functions of the bacterial community in rhizosphere soil. KEEG and CAZy functional annotations revealed that the number of significantly different functions in WH was greater than that in WD5 and WD9. Bacterial wilt significantly affected the relative content of metabolites, especially acids, in the rhizosphere soil, and compared with those in the rhizosphere soil from WH, 10 acids (including S-adenosylmethionine, N-acetylleucine, and desaminotyrosine, etc.) in the rhizosphere soil from WD5 or WD9 significantly increased. In comparison, the changes in the other 10 acids (including hypotaurine, erucic acid, and 6-hydroxynicotinic acid, etc.) were reversed. The occurrence of bacterial wilt also significantly inhibited metabolic pathways such as ABC transporter and amino acid biosynthesis pathways in rhizosphere soil and had a significant impact on two key enzymes (1.1.1.11 and 2.6.1.44). In conclusion, sesame bacterial wilt significantly alters the rhizosphere soil bacterial community structure, function, and metabolites. This study enhances the understanding of sesame bacterial wilt mechanisms and lays the groundwork for future prevention and control strategies against this disease.

Species variation in the spontaneous calcification of bone marrow-derived mesenchymal stem cells.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) hold great promise for tissue regeneration. With increasing numbers of clinical trials, the safety of BM-MSCs attracts great interest. Previously, we determined that rat BM-MSCs possessed spontaneous calcification without osteogenic induction after continuous culture. However, it is unclear whether BM-MSCs from other species share this characteristic. In this study, spontaneous calcification of BM-MSCs from rat, goat, and human specimens was investigated in vitro. BM-MSCs were cultured in complete medium, and calcification was determined by morphologic observation and alizarin red staining. It was demonstrated that rat BM-MSCs possessed a typically spontaneous calcification, whereas goat and human BM-MSCs under the same system proliferated significantly but did not calcify spontaneously. The significant species variation in spontaneous calcification of BM-MSCs described in this study provides useful information regarding evaluation of numerous BM-MSC-based approaches for bone regeneration and the safety of BM-MSCs.

Highly Selective Wearable Alcohol Homologue Sensors Derived from Pt-Coated Truncated Octahedron Au.

Unhealthy alcohol inhalation is among the top 10 causes of preventable death. However, the present alcohol sensors show poor selectivity among alcohol homologues. Herein, Pt-coated truncated octahedron Au (Ptm@Auto) as the electrocatalyst for a highly selective electrochemical sensor toward alcohol homologues has been designed. The alcohol sensor is realized by distinguishing the electro-oxidation behavior of methanol (MeOH), ethanol (EtOH), or isopropanol (2-propanol). Intermediates from alcohols are further oxidized to CO2 by Ptm@Auto, resulting in different oxidation peaks in cyclic voltammograms and successful distinction of alcohols. Ptm@Auto is then modified on wearable glove-based sensors for monitoring actual alcohol samples (MeOH fuel, vodka, and 2-propanol hand sanitizer), with good mechanical performance and repeatability. The exploration of the Ptm@Auto-based wearable alcohol sensor is expected to be suitable for environmental measurement with high selectivity for alcohol homologues or volatile organic compounds.

Customizable assembly of free-standing integrated electronics for wearables by phase separation.

The non-solvent induced phase separation method is utilized to produce a free-standing electrode with good conductivity retention during 1000 bending/stretching cycles. The as-prepared electrode has been fabricated for an integrated device consisting of an ethanol fuel cell, a supercapacitor and a motion sensor. This method for fabricating free-standing electronics reveals a cost-effective approach towards wearable devices.

Wearable Motion Smartsensors Self-Powered by Core-Shell Au@Pt Methanol Fuel Cells.

A wearable self-powered sensor is a promising frontier in recent flexible electronic devices. In this work, a wearable fuel cell (FC)-type self-powering motion smartsensor has been fabricated, particularly in choosing methanol vapor as a target fuel for the first time. The core-shell structure of Pt@Au/N-rGO and the porous carbon network act as methanol oxidation and oxygen reduction reaction catalysts, with a highly conductive alkaline hydrogel as a solid-state electrolyte. As a result, a wearable FC for a self-powered sensing system demonstrates excellent sensing performance toward 2-20% (v/v) methanol vapor with a maximum power density of 2.26 µW cm-1 and good mechanical behaviors during the bending or twisting process. Significantly, this wearable FC device could power strain sensors of human motion, and real-time signals can be easily remotely detected via a cellphone. With attractive biocompatibility and self-powering performance, wearable FCs for a self-powering system would provide new opportunities for next-generation flexible smartsensing electronics and initiate a developed self-powering platform in future practical application of wearable smart monitoring.

Wearable Helical Molybdenum Nitride Supercapacitors for Self-Powered Healthcare Smartsensors.

To meet the increasing demand for wearable sensing devices, flexible supercapacitors (SCs) as energy storage devices play significant roles in powering sensors/biosensors for healthcare monitoring. Because of its high conductivity and remarkable specific capacitance in SCs, molybdenum nitride (MoN) has been widely used. Herein, a flexible helical structure of MoN modified on nitrogen-doped carbon cloth (CC@CN@MoN) has been prepared by a simple nitride process, delivering an ultralong cycle life of 10,000 cycles and high areal capacitance of 467.6 mF cm-2 as SCs. Moreover, the as-fabricated flexible all-solid-state asymmetrical SCs (ASCs) of CC@CN@MoN//CC@NiCo2O4 demonstrated outstanding electrochemical behavior after 10,000 cycles and over 90% retention, and the value of areal capacitance could reach 90.8 mF cm-2 at 10 mA cm-2. Integrated with solar energy, ASCs could be used as a self-powered energy system for strain sensors in detecting human movement, and finger movements could be further real-time monitored remotely via a smartphone. Prospectively, wearable helical MoN solid-state SCs for self-powered strain smartsensors would inspire the development of structured materials in the application of energy storage, portable self-powering, and strain or chemical/biochemical smartsensors.

Wearable Textile Supercapacitors for Self-Powered Enzyme-Free Smartsensors.

Wearable energy storage and flexible body biomolecule detection are two key factors for real-time monitoring of human health in a practical environment. It would be rather exciting if one wearable system could be used for carrying out both energy storage and biomolecule detection. Herein, carbon fiber-based NiCoO2 nanosheets coated with nitrogen-doped carbon (CF@NiCoO2@N-C) have been prepared via a simple electrochemical deposition method. Interestingly, being a dual-functional active material, CF@NiCoO2@N-C exhibits excellent behaviors as a supercapacitor and prominent electrocatalytic properties, which can be applied for enzyme-free biosensor. It exhibits outstanding energy storage, high capacitive stability (94% capacitive retention after 10,000 cycles), and pre-eminent flexible ability (95% capacitive retention after 10,000 bending cycles), as well as high sensitivity for enzyme-free glucose detection (592  µA mM-1). Moreover, the CF@NiCoO2@N-C-based wearable supercapacitors would be used as self-powered energy systems for enzyme-free biosensors. Integrating with bluetooth, we have successfully developed a wearable self-powered enzyme-free smartsensor, remotely controlled using a smartphone for health monitoring in a practical environment. From this prospective study, it was found that the design of wearable self-powered smartsensors, demonstrating energy storage and enzyme-free biosensing in one system, provides a promising device for detecting body biomolecules, which has the potential to be implemented in the artificial intelligent fields.

Wearable biomolecule smartsensors based on one-step fabricated berlin green printed arrays.

The wearable smart detection of body biomolecules and biomarkers is being of significance in the practical fields. Hydrogen peroxide (H2O2) is a product of some enzyme-catalyzed biomolecular reactions. The detection of H2O2 could reflect the concentration information of the enzyme reaction biomolecule substrate such as glucose. A high-performance berlin green (BG) carbon ink for monitoring H2O2 was prepared in this work. And we have successfully developed the wearable smartsensors for detecting H2O2 and glucose based on one-step fabricated BG arrays by screen-printing technology. Comparing with other detection methods, these sensors are wearable, movable, flexible and biocompatible for monitoring biomolecules. As a result, the sensors exhibited good sensitivity, specificity, stability and reproductivity towards H2O2 and glucose. Additionally, there also received stable response after near one hundred times stretching and thousands of bending. Moreover, the wearable sensors could be easily remotely controlled by a smart phone, when integrated with wireless into the device. In prospective studies, the one-step fabricated wearable smartsensors is of great significance in developing a straightforward, highly-efficient and low-cost method for actual detection of biomolecules reflecting body health status, and would potentially be applied in the artificial intelligence (AI) fields.

HLA class II polymorphisms associated with the physiologic characteristics defined by Traditional Chinese Medicine: linking modern genetics with an ancient medicine.

OBJECTIVES: The aim of this study was to test whether human leukocyte antigen (HLA) polymorphism contributes to the physical constitutions classified in Traditional Chinese Medicine (TCM). DESIGN: Seven hundred six (706) individuals of the Han ethnic group inhabiting South China were classified into 7 TCM constitution groups, according to the criteria described in Theories of Physical Constitutions of Traditional Chinese Medicine, and the distributions of HLA-DRB1, DPB1, and DQB1 were investigated using the polymerase chain reaction-sequencing-based typing method. RESULTS: The allele frequencies of DPB1*0501 in the Yin-deficiency group, DRB1*09012 in the Phlegm-wetness group, and DQB1*03032 in the Qi-deficiency and Phlegm-wetness groups were significantly different from that of the corresponding alleles in the Normality constitution, suggesting those alleles might be group-specific alleles and thus related to a particular constitution. Based on our analysis of serological groups of HLA, the associations of DR*04 with the Blood-stasis group and DQ*09 with the Qi-deficiency and Phlegm-wetness groups were observed. CONCLUSIONS: This was the first study to systematically investigate the relationship between HLA and TCM constitution using a high-resolution typing technique. The results suggested a genetic basis for the classification of physical constitution in TCM. This study laid the foundation, for the first time ever, toward gaining insight into the theory of traditional medicine using modern biological approaches.

Structural basis for Sfm1 functioning as a protein arginine methyltransferase.

SPOUT proteins constitute one class of methyltransferases, which so far are found to exert activity mainly towards RNAs. Previously, yeast Sfm1 was predicted to contain a SPOUT domain but can methylate ribosomal protein S3. Here we report the crystal structure of Sfm1, which comprises of a typical SPOUT domain and a small C-terminal domain. The active site is similar to that of protein arginine methyltransferases but different from that of RNA methyltransferases. In addition, Sfm1 exhibits a negatively charged surface surrounding the active site unsuitable for RNA binding. Our biochemical data show that Sfm1 exists as a monomer and has high activity towards ribosomal protein S3 but no activity towards RNA. It can specifically catalyze the methylation of Arg146 of S3 and the C-terminal domain is critical for substrate binding and activity. These results together provide the structural basis for Sfm1 functioning as a PRMT for ribosomal protein S3.

Photosynthetic characteristics of the subtending leaf of cotton boll at different fruiting branch nodes and their relationships with lint yield and fiber quality.

To investigate photosynthetic characteristics of the subtending leaf at the 2-3rd and 10-11th fruiting branch (FBN, FB2-3, and FB10-11), and their relationship with cotton yield and quality, field experiments were conducted using two cotton cultivars, Kemian 1 and Sumian 15. The results showed that with FBN increasing, chlorophyll (Chl) components, Pn and non-photochemical quenching (NPQ) in the subtending leaf significantly declined, while soluble sugar, amino acid and their ratio (C SS/C AA) as well as F v/F m increased. These results indicated that (1) non-radiative dissipation of excess light energy at FB2-3 was reduced to improve solar energy utilization efficiency to compensate for lower Pn, (2) higher NPQ at FB10-11 played a role in leaf photo-damage avoidance, (3) boll weight was related to the C SS/C AA ratio rather than carbohydrates content alone, (4) with FBN increasing, lint biomass and lint/seed ratio increased significantly, but lint yield decreased due to lower relative amount of bolls, and (5) the decreases in Pn, sucrose content and C SS /C AA in the subtending leaf at FB2-3 resulted in lower boll weight and fiber strength.

Molecular analyses of HLA-DRB1, -DPB1, and -DQB1 in Jing ethnic minority of Southwest China.

In the present study, DNA typing for HLA-DRB1, DQB1 and DPB1 was performed using polymerase chain reaction-sequencing based typing (PCR-SBT) method in 144 random selected Jing ethnic individuals inhabiting in South China. Allele frequencies and two-locus haplotypes (DRB1-DQB1) were statistically analyzed and 20 DPB1 alleles, 27 DRB1 and 20 DQB1 were detected. The most frequent DPB1 allele was DPB1*0501 with the percentage of 36.9% followed by DPB1*1301 (15.7%), DPB1*0401 (11.0%) and DPB1*020102 (9.8%). Among the 27 detected DRB1 alleles, DRB1*120201 (13.8%) was most commonly observed followed by DRB1*150201, *030101 and *090102 alleles with the frequencies of 9.4%, 9.1% and 8.3%, respectively. Among the 20 detected DQB1 alleles the most predominant one was DQB1*030101/0309 (19.9%). DQB1*050201 (19.1%), DQB1*0201/0202 (16.1%) and DQB1*050101 (12.3%) were also frequently observed in Jing population. Statistical analysis of two-locus haplotypes showed that DRB1*120201-DQB1*030101/DRB1*120201-DQB1*0309 (HF = 9.4%, D = 6.65x10(-2)) was most predominant followed by DRB1*030101-DQB1*0201/DRB1*030101-DQB1*0202 (HF = 8.1%, D = 6.66 x 10(-2)). The comparison of HLA class II allele and haplotype frequencies in Jing with those in other populations all over the world and a dendrogram based on the DRB1, DQB1 and DPB1 genes suggested that Jing ethnic population has an origin of Southeast Asia and is belonged to the southern group of Chinese populations.