Losartan ameliorates renal fibrosis by inhibiting tumor necrosis factor signal pathway / Losartán mejora la fibrosis renal al inhibir la vía de señalización del factor de necrosis tumoral

Losartan is widely used in the treatment of chronic kidney disease (CKD) and has achieved good clinical efficacy, but its exact mechanism is not clear. We performed high-throughput sequencing (HTS) technology to screen the potential target of losartan in treating CKD. According to the HTS results, we found that the tumor necrosis factor (TNF) signal pathway was enriched. Therefore, we conducted in vivo and in vitro experiments to verify it. We found that TNF signal pathway was activated in both unilateral ureteral obstruction (UUO) rats and human proximal renal tubular epithelial cells (HK-2) treated with transforming growth factor-β1 (TGF-β1), while losartan can significantly inhibit TNF signal pathway as well as the expression of fibrosis related genes (such as COL-1, α-SMA and Vimentin). These data suggest that losartan may ameliorate renal fibrosis through modulating the TNF pathway.(AU)

El Losartán es ampliamente utilizado en el tratamiento de la enfermedad renal crónica (CKD) y ha logrado buenos resultados clínicos, pero su mecanismo exacto aún no está claro. Utilizamos la técnica de secuenciación de alto rendimiento (HTS) para detectar posibles dianas de losartán para el tratamiento de la CKD. Según los resultados de HTS, encontramos un enriquecimiento de la vía de señalización del factor de necrosis tumoral (TNF). Así, realizamos experimentos in vivo e in vitro para verificar esto. Encontramos que, tanto en ratas con obstrucción ureteral unilateral (uuo) como en células epiteliales tubulares renales proximal humanas (HK-2) tratadas con factor de crecimiento transformador β1 (TGF-β1), se activó la vía de señalización del TNF. El losartán inhibe significativamente la expresión de las vías de señalización del TNF y genes relacionados con la fibrosis, como COL-1, α-SMA y vicentin. Estos datos sugieren que el losartán puede mejorar la fibrosis renal regulando la vía del TNF.(AU)

The role of PI3K/Akt signaling pathway in chronic kidney disease.

Chronic kidney disease (CKD), including chronic glomerulonephritis, IgA nephropathy and diabetic nephropathy, are common chronic diseases characterized by structural damage and functional decline of the kidneys. The current treatment of CKD is symptom relief. Several studies have reported that the phosphatidylinositol 3 kinases (PI3K)/protein kinase B (Akt) signaling pathway is a pathway closely related to the pathological process of CKD. It can ameliorate kidney damage by inhibiting this signal pathway which is involved with inflammation, oxidative stress, cell apoptosis, epithelial mesenchymal transformation (EMT) and autophagy. This review highlights the role of activating or inhibiting the PI3K/Akt signaling pathway in CKD-induced inflammatory response, apoptosis, autophagy and EMT. We also summarize the latest evidence on treating CKD by targeting the PI3K/Akt pathway, discuss the shortcomings and deficiencies of PI3K/Akt research in the field of CKD, and identify potential challenges in developing these clinical therapeutic CKD strategies, and provide appropriate solutions.

A comparative full-length transcriptomic resource provides insight into the perennial monocarpic mass flowering.

Perennial monocarpic mass flowering represents as a key developmental innovation in flowering time diversity in several biological and economical essential families, such as the woody bamboos and the shrubby Strobilanthes. However, molecular and genetic mechanisms underlying this important biodiversity remain poorly investigated. Here, we generated a full-length transcriptome resource incorporated into the BlueOmics database (http://blueomics.iflora.cn) for two Strobilanthes species, which feature contrasting flowering time behaviors. Using about 112 and 104 Gb Iso-seq reads together with ~185 and ~75 Gb strand-specific RNA seq data, we annotated 80 971 and 79 985 non-redundant full-length transcripts for the perennial polycarpic Strobilanthes tetrasperma and the perennial monocarpic Strobilanthes biocullata, respectively. In S. tetrasperma, we identified 8794 transcripts showing spatiotemporal expression in nine tissues. In leaves and shoot apical meristems at two developmental stages, 977 and 1121 transcripts were differentially accumulated in S. tetrasperma and S. biocullata, respectively. Interestingly, among the 33 transcription factors showing differential expression in S. tetrasperma but without differential expression in S. biocullata, three were involved potentially in the photoperiod and circadian-clock pathway of flowering time regulation (FAR1 RELATED SEQUENCE 12, FRS12; NUCLEAR FACTOR Y A1, NFYA1; PSEUDO-RESPONSE REGULATOR 5, PRR5), hence provides an important clue in deciphering the flowering diversity mechanisms. Our data serve as a key resource for further dissection of molecular and genetic mechanisms underpinning key biological innovations, here, the perennial monocarpic mass flowering.

Coal slime as a good modifier for the restoration of copper tailings with improved soil properties and microbial function.

In recent years, the solid wastes from the coal industry have been widely used as soil amendments. Nevertheless, the impact of utilizing coal slime for copper tailing restoration in terms of plant growth, physicochemical characteristics of the tailing soil, and microbial succession remains uncertain.Herein, the coal slime was employed as a modifier into copper tailings. Their effect on the growth and physiological response of Ryegrass, and the soil physicochemical properties as well as the bacterial community structure were investigated. The results indicated that after a 30-day of restoration, the addition of coal slime at a ratio of 40% enhanced plant growth, with a 21.69% rise in chlorophyll content, and a 62.44% increase in peroxidase activity. The addition of 40% coal slime also increased the content of nutrient elements in copper tailings. Following a 20-day period of restoration, the concentrations of available copper and available zinc in the modified tailings decreased by 39.6% and 48.51%, respectively, with 40% of coal slime added. In the meantime, there was an observed augmentation in the species diversity of the bacterial community in the modified tailings. The alterations in both community structure and function were primarily influenced by variations in pH value, available nitrogen, phosphorus, potassium, and available copper. The addition of 40% coal slime makes the physicochemical properties and microbial community evolution of copper tailings reach a balance point. The utilization of coal slime has the potential to enhance the physicochemical characteristics of tailings and promote the proliferation of microbial communities, hence facilitating the soil evolution of two distinct solid waste materials. Consequently, the application of coal slime in the restoration of heavy metal tailings is a viable approach, offering both cost-effectiveness and efficacy as an enhancer.

The nuclear receptor subfamily 4 group A1 in human disease.

Nuclear receptor 4A1 (NR4A1), a member of the NR4A subfamily, acts as a gene regulator in a wide range of signaling pathways and responses to human diseases. Here, we provide a brief overview of the current functions of NR4A1 in human diseases and the factors involved in its function. A deeper understanding of these mechanisms can potentially improve drug development and disease therapy.

MiR-20a-5p facilitates cartilage repair in osteoarthritis via suppressing mitogen-activated protein kinase kinase kinase 2.

Bone marrow mesenchymal stem cell (BMSC) chondrogenic differentiation contributes to the treatment of osteoarthritis (OA). Numerous studies have indicated that microRNAs (miRNAs) regulate the pathogenesis and development of multiple disorders, including OA. Nevertheless, the role of miR-20a-5p in OA remains obscure. Forty male C57BL/6 mice were divided into four groups and were surgically induced OA or underwent sham surgery in the presence or absence of miR-20a-5p. Flow cytometry was implemented to detect surface markers of BMSCs. Reverse transcription quantitative polymerase chain reaction revealed the upregulation of miR-20a-5p during BMSC chondrogenic differentiation. Western blotting displayed that miR-20a-5p inhibition decreased protein levels of cartilage matrix markers but enhanced those of catabolic and hypertrophic chondrocyte markers in BMSCs. Alcian blue staining, hematoxylin­eosin staining and micro-CT revealed that miR-20a-5p inhibition restrained chondrogenic differentiation and miR-20a-5p overexpression promoted the repair of damaged cartilage and subchondral bone, respectively. Luciferase reporter assay identified that mitogen activated protein kinase kinase kinase 2 (Map3k2) was a target of miR-20a-5p in BMSCs. Moreover, the expression of miR-20a-5p and Map3k2 was negatively correlated in murine cartilage tissues. Knocking down Map3k2 could rescue the suppressive influence of miR-20a-5p inhibition on chondrogenic differentiation of BMSCs. In conclusion, miR-20a-5p facilitates BMSC chondrogenic differentiation and contributes to cartilage repair in OA by suppressing Map3k2.

Fatigue life prediction of brake discs for high-speed trains via thermal stress.

As one of the essential components of the braking system, the high-speed train brake disc is an integral part of ensuring the safety of the train. The main objective of this study is to conduct thermal analysis and reliable life prediction on brake discs. The research was conducted by developing a programmer spectrum of brake discs with high-speed train brake discs. According to the results of numerical analysis and the S-N curve of the material, the temperature distribution on the surface of the brake disc is determined, and the fatigue life of the brake disc is predicted. The comparison with the service life of the brake disc verifies the rationality of the calculation results. In addition, a fatigue damage probability model of brake discs is established based on the theory of fatigue cumulative damage. Through the relationship between the reliability of mechanical parts and the number of load cycles, the reliable life of the brake disc under different working conditions is predicted. This work establishes a method of reliable life analysis for brake discs of high-speed trains based on the load spectrum, which could analyze the life and reliability of brake discs more systematically.

Clinical results of a 10-year follow-up of surgical treatment for elbow stiffness in rheumatoid arthritis: A case series.

BACKGROUND: Rheumatoid arthritis commonly causes transient limitation of joint motion, but the treatment of persistent stiffness in the rheumatoid elbow has rarely been reported. The purpose of this study was to evaluate the long-term clinical results of surgical treatment of rheumatoid elbow stiffness. METHODS: Surgical treatment, including open arthrolysis with hinged external fixation, total synovectomy, and ulnar nerve release and anteriorization, was performed in 48 elbows in 43 patients with rheumatoid arthritis and early joint destruction. Mobility (flexion-extension and pronation-supination), Mayo Elbow Performance Score (MEPS), visual analog scale (VAS) score, muscle strength, nerve symptoms, postoperative complications, and recurrent synovitis were evaluated 9-11 years (average, 9.88 years) postoperatively. RESULTS: The mobility of the elbow was significantly improved over the preoperative period either in extension, flexion, protonation, supination (P < .001, P < .001, P < .001, P = .002). The mean MEPS was significantly improved from 56.25 points (range, 30-90) to 87.40 points (range, 40-100) (P < .001). The pain was relieved, and the mean VAS score was reduced from 3.56 (range, 0-8) to 1.08 (range, 0-5) points (P < .001). Preoperative ulnar nerve symptoms were observed in 17 patients and relieved in 10 (59%) patients, and the mean Amadio score was raised from 6.9 (range, 3-9) to 7.96 (range, 4-9) points (P < .001). Through surgical treatment and postoperative rehabilitation, the mean grip strength of the patients was significantly improved from an average of 9.01 (range, 3.4-18.5) to 17.56 kg (range, 3.9-40.2) (P < .001). Five elbows developed recurrent synovitis, and one underwent total elbow arthroplasty. Postoperative complications were uncommon and not severe. CONCLUSION: Surgical treatment is a reliable procedure for rheumatoid elbow stiffness and can be effective in improving elbow mobility, function, muscle strength, pain relief, and relief of nerve symptoms.

Structural definition of the discrete hotspot sites of BMP-2 conformational wrist epitope and rational design of the hotspot-derived osteogenic peptides against chondrocyte senescence.

The bone morphogenetic protein-2 (BMP-2) is an essential regulator of bone formation and remodeling, which has also been implicated in the pathogenesis of osteoarthritis and its closely related chondrocyte senescence. The BMP-2 uses a conformational wrist epitope and a linear knuckle epitope to interact with type-I (BMPR-I) and type-II (BMPR-II) receptors, respectively. Previously, the knuckle epitope has been intensely studied, but the wrist epitope still remains largely unexplored due to its discontinuous nature. In the present work, the intermolecular interaction of BMP-2 with BMPR-I was investigated systematically at structural, energetic and dynamic levels. Three discrete hotspots that represent the key BMPR-I recognition sites of BMP-2 were identified; they are spatially dispersed over the two monomers of BMP-2 dimer and totally account for 83.5 % binding potency of BMP-2 to BMPR-I (hotspot 1: residues 49-70 in monomer 1; hotspot 2: residues 24-31 in monomer 2; hotspot 3: residues 88-107 in monomer 2). Therefore, we defined the three discrete hotspot sites as the core region of wrist epitope; their contribution to the binding increases in the order: hotspot 2 < hotspot 3 < hotspot 1. We demonstrated that the primary hotspot 1 site has a native U-shaped conformation in the full-length BMP-2 protein context, but it cannot maintain in the native conformation when split from the context to obtain a free hotspot-1 peptide, thus largely impairing its binding potency to BMPR-I. We further employed disulfide-bonded cyclization and head-to-tail cyclization to constrain the peptide conformation, and found that only the former can effectively constrain the peptide into native conformation, thus considerably improving its binding affinity to BMPR-I, whereas the latter totally disorders the native conformation, thus rendering the peptide as a full nonbinder of BMPR-I.

Synthetic Homogeneous Glycoforms of the SARS-CoV-2 Spike Receptor-Binding Domain Reveals Different Binding Profiles of Monoclonal Antibodies.

SARS-CoV-2 attaches to its host receptor, angiotensin-converting enzyme 2 (ACE2), via the receptor-binding domain (RBD) of the spike protein. The RBD glycoprotein is a critical target for the development of neutralizing antibodies and vaccines against SARS-CoV-2. However, the high heterogeneity of RBD glycoforms may lead to an incomplete neutralization effect and impact the immunogenic integrity of RBD-based vaccines. Investigating the role of different carbohydrate domains is of paramount importance. Unfortunately, there is no viable method for preparing RBD glycoproteins with structurally defined glycans. Herein we describe a highly efficient and scalable strategy for the preparation of six glycosylated RBDs bearing defined structure glycoforms at T323, N331, and N343. A combination of modern oligosaccharide, peptide synthesis and recombinant protein engineering provides a robust route to decipher carbohydrate structure-function relationships.

Oriented inner fabrication of bi-layer biomimetic tendon sheath for anti-adhesion and tendon healing.

INTRODUCTION: Synthetic fibrous membranes unveil a promising field in anti-adhesion of tendons. Meanwhile, oriented nanofiber structures have been widely studied and used in the application of biomedical engineering, particularly in repairing and strengthening effects. METHODS: In this study, a bi-layer poly(L-lactic acid) (PLLA) electrospun membrane was fabricated, in which the inner oriented fibrous layer was designed to promote tendon healing while outer random aligned layer was designed to prevent peritendinous adhesion. RESULTS: It was found that fibroblasts were aligned along the oriented fiber of membranes in vitro and in a Leghorn chicken model. In biomechanical tests of repaired tendons, no significant difference was found between oriented fibrous membrane and blank control in maximum tensile strength; both oriented fibrous membranes and random fibrous membranes showed lower work of flexion than blank control, which was consistent with gross assessment. CONCLUSION: It was practicable to promote tendon healing while preventing adhesion via bi-layer PLLA membranes with an inner-oriented-fiber fabricated structure.

Machine learning-guided evolution of BMP-2 knuckle Epitope-Derived osteogenic peptides to target BMP receptor II.

Bone morphogenetic protein-2 (BMP-2) is a key regulator of bone formation, growth and regeneration, which contains a conformational wrist epitope and a linear knuckle epitope that are functionally responsible for the protein by mediating its interaction with type-I and type-II receptors, respectively. Previously, a long (19-mer) knuckle peptide derived from the knuckle epitope region (residues 73-92) has been found to promote osteogenesis and bone repair. Here, we attempt to rationally redesign the knuckle peptide by using bioinformatics and machine learning-guided evolution to obtain structurally simplified, potent osteogenic peptides that are capable of targeting type-II receptor. Complex analysis reveals that only a fraction of the epitope region can directly interact with type-II receptor, which represents a small (12-mer) knuckle-derived peptide (KDP0 peptide). Glycine scanning further identifies three KDP0 anchor residues Ser88, Leu90 and Tyr91 that are fundamentally important in the peptide-receptor binding. Systematic mutation, amino acid combination and uniform design of other nine KDP0 non-anchor residues generate 32 new knuckle-derived peptides (KDP1-KDP32); their binding affinities to recombinant protein of human type-II receptor are determined using fluorescence spectroscopy assay. The resulting affinity values (Kd) are used to train six regression models developed by combination of two machine learning methods and three amino acids descriptors. The best SVM/VHSE predictor is then utilised to guide the genetic evolution of a knuckle-derived peptide population. Eight peptides (KDP33-KDP40) with high affinity scores are selected from the improved population, and their osteogenic activities on bone marrow stromal cells are measured using alkaline phosphatase assay. Consequently, six out of the 8 tested peptides exhibit increased activity relative to KDP0 peptide. The KDP34 (DFQTWSFLYVEN) is found as the most potent peptide with APL activities of 195% and 279% at 0.01 and 0.1 µg/ml, respectively, which shares a similar binding mode with the native knuckle epitope and can form diverse nonbonded interactions of hydrogen bond, hydrophobic contact, cation-π/π-π stacking and salt bridge with type-II receptor.

Photo-cleavable purification/protection handle assisted synthesis of giant modified proteins with tandem repeats.

Proteins with tandem repeats have essential physical or biological roles in cells and have been widely investigated as biomaterials or vaccines. Chemically derived proteins with tandem repeats would be beneficial for research, owing to their accurate structures, possibly with precise modifications, produced by chemical synthesis. Traditional protein synthesis often leads to severe handling loss due to multiple ligations and HPLC purifications. To improve the protein synthesis efficiency, we developed a purification/protection handle consisting of a His6 tag and a photo-labile linker. This handle has great potential to facilitate purification with immobilized metal affinity chromatography techniques and also provides orthogonal protection for N-terminal Cys. The synthesis of the model proteins Muc1 and antifreeze glycoprotein mimics shows that the handle decreases the requirement for HPLC and enables both convergent and sequential assembly of peptide segments.

Two new species of Primulina (Gesneriaceae) from limestone karsts of China.

The limestone karst area of South China is a major biodiversity hotspot of global terrestrial biomes. During extensive field work on the Guangxi limestone formations, two unknown species of Gesneriaceae were collected. After conducting a comprehensive study of the literature and herbarium specimens, Primulina davidioides and P. hiemalis are recognized as two species new to science, and described and illustrated here. P. davidioides is morphologically close to P. lunglinensis based on the shape of the leaf and flower, but it can be easily distinguished by the shape of the bracts, corolla and stigma, indumentum of peduncles, pedicels and pistil and number of staminodes. P. hiemalis is closely relate to P. luzhaiensis in vegetative appearance, but differs in the shape of the calyx and stigma, number of bracts and staminodes, indumentum of the leaf blade and peduncle, and position of stamens in the corolla tube. Considering that not enough is known about their populations, it is proposed that their conservation statuses should currently be classed as data deficient (DD) according to the IUCN Red List Category and Criteria.

[Treatment of elbow joint stiffness by open release combined with distal radius fixation hinged external fixation].

Objective: To observe the effectiveness of open release combined with distal radius fixation hinged external fixation for the treatment of elbow stiffness. Methods: A total of 77 patients with elbow stiffness caused by trauma were enrolled in this study between October 2014 and October 2015. The patients were divided into control group (39 cases) and observation group (38 cases) by random number table method. The patients in the observation group were treated with elbow joint opening and release combined with distal radial fixation hinged external fixation, while the control group was treated with traditional release. There was no significant difference in gender, age, disease causes, original damage diagnosis, the time from injury to operation, preoperative flexion and extension activity of elbow joint, and preoperative Mayo elbow joint function score between 2 groups ( P>0.05). After operation, the function of elbow joint was evaluated by the flexion and extension activity of the elbow joint and the Mayo elbow joint function evaluation standard. Results: The incisions healed by first intention in 2 groups. In observation group, there were 1 case infection of nail tract, 2 cases ulnar nerve symptoms, 1 case elbow ossification, and 1 case moderate pain in the elbow; while in control group, there were 2 cases of infection of nail tract, 2 cases of ulnar nerve symptoms, and 3 cases moderate pain in the elbow. The patients in 2 groups were followed up 6 weeks to 12 months, with an average of 6 months. The flexion and extension activity of elbow joint and Mayo elbow joint function score at last follow-up were significantly improved when compared with preoperative ones ( P<0.05); at last follow-up, the flexion and extension activity of elbow joint and Mayo elbow joint function score in observation group patients were significantly better than those in control group ( P<0.05). According to the Mayo elbow function evaluation standard, the results were excellent in 27 cases, good in 10 cases, and fair in 1 case, with an excellent and good rate of 97.4% in observation group; and the results were excellent in 12 cases, good in 21 cases, fair in 4 cases, and poor in 2 cases, with an excellent and good rate of 84.6% in control group; showing no significant difference between 2 groups ( P=0.108). Conclusion: Open release combined with distal radius fixation hinged external fixation can significantly improve the elbow function of patients with traumatic elbow stiffness, its recovery of elbow function was superior to the traditional release.

Effect of disease duration on functional outcomes and complications after arthrolysis in patients with elbow stiffness.

HYPOTHESIS: The purpose of this study was to determine the effect of a long duration of elbow stiffness on functional outcomes and complications after arthrolysis. METHODS: Participants included consecutive patients with a long duration of elbow stiffness (≥5 years, n = 23) and control patients matched for age, sex, and initial injury type (n = 46). All patients underwent elbow arthrolysis combined with hinged external fixation between March 2014 and March 2016. At baseline and follow-up, we evaluated elbow motion (flexion, extension, supination, pronation, and range of motion) and patient-reported outcomes, including the Mayo Elbow Performance Score (MEPS) and visual analog scale for pain. Postoperative complications including infection, nerve dysfunction, and instability were recorded. RESULTS: There were no significant differences in preoperative elbow pain, range of motion, or MEPS between groups. Postoperatively, pronation and the MEPS in patients with a long disease duration were inferior to those in control patients (P = .041 and P = .016, respectively). Patients with a long disease duration also had a significantly higher incidence of complications than control patients (P = .002). At final follow-up, 7 patients (30%) in the long disease duration group and 3 patients (7%) in the control group presented with nerve symptoms (P = .022). CONCLUSIONS: A long duration of elbow stiffness may negatively influence functional outcomes and increase the risk of complications after arthrolysis.

Management of elbow stiffness after postoperative treatment of terrible triad elbow injury: maintaining mobility and stability using a combined protocol.

PURPOSES: The purpose of this study was to evaluate the results of our protocol that include the restoration of mobility using open release combined with external fixation and stability using ligament repair, to determine the optimal timing of surgery, and to investigate whether resection and replacement of the radial head are associated with different outcomes. METHODS: Twenty-six patients with elbow stiffness after operation of terrible triad injury of the elbow were treated with our protocol. We assessed the optimal timing of the operation by comparing outcomes between the early treatment group and the delayed treatment group. The comparison was performed to investigate whether the results differed between resection and replacement of the radial head. Stability of the elbow, range of motion (ROM), Mayo Elbow Performance Score (MEPS), and complications were assessed for each patient. RESULTS: The mean interval from the initial surgery to the index procedure was 13 months, and the mean follow-up period was 29 months. The MEPS increased from a mean of 65 points to 94 points. Twenty-five of 26 patients achieved stability of the elbow, and all patients achieved functional ROM. There were no significant differences between the two subgroups with respect to ROM and stability of the elbow. CONCLUSION: Our protocol can restore mobility and stability. Resection and replacement of the radial head are both feasible using this protocol. Lastly, the timing of the surgery was not very rigorous, and the surgical delay may be insignificant. LEVEL OF EVIDENCE: Level IV; Case Series; Treatment Study.

Risk factors for development of severe post-traumatic elbow stiffness.

PURPOSE: The purpose of this study was to compare different grades of elbow stiffness and investigate demographic, injury, and treatment factors potentially associated with the development of severe elbow stiffness. METHODS: We performed a retrospective study involving 169 patients with post-traumatic elbow stiffness between June 2014 and June 2016. Patient demographics, injury, and treatment details were reviewed. Patients were classified into three groups according to the elbow motion. Ordinal regression analyses were performed to examine the independent factors. RESULTS: Patients were classified into: mild (49 patients), moderate (59 patients), and severe (61 patients) groups. Patients with severe stiffness had a significantly worse elbow functional performance. Univariate ordinal regression revealed that severe elbow stiffness was associated with high-energy injury (odds ratio [OR] 4.73), olecranon fracture (OR 1.92), fracture-dislocation (OR 2.28), and open fracture (OR 3.24). Multivariate regression showed that higher-energy injuries were associated with severe stiffness (OR 4.45, p = 0.003). CONCLUSIONS: Elbow stiffness after fracture surgery often results in joint stiffness. Severe stiffness often resulted in more significant functional impairment. Our study suggested that high-energy injuries were associated with the development of severe elbow stiffness.