Flagellar brake protein YcgR interacts with motor proteins MotA and FliG to regulate the flagellar rotation speed and direction.

In E. coli and related species, flagellar brake protein YcgR responds to the elevated intracellular c-di-GMP, decreases the flagellar rotation speed, causes a CCW rotation bias, and regulates bacterial swimming. Boehm et al. suggested that c-di-GMP-activated YcgR directly interacted with the motor protein MotA to curb flagellar motor output. Paul et al. proposed that YcgR disrupted the organization of the FliG C-terminal domain to bias the flagellar rotation. The target proteins are controversial, and the role of motor proteins remains unclear in flagellar rotation speed and direction regulation by YcgR. Here we assayed the motor proteins' affinity via a modified FRET biosensor and accessed the role of those key residue via bead assays. We found that YcgR could interact with both MotA and FliG, and the affinities could be enhanced upon c-di-GMP binding. Furthermore, residue D54 of YcgR-N was needed for FliG binding. The mutation of the FliG binding residue D54 or the MotA binding ones, F117 and E232, restored flagellar rotation speed in wild-type cells and cells lacking chemotaxis response regulator CheY that switched the flagellar rotation direction and decreased the CCW ratio in wild-type cells. We propose that c-di-GMP-activated YcgR regulated the flagellar rotation speed and direction via its interaction with motor proteins MotA and FliG. Our work suggest the role of YcgR-motor proteins interaction in bacterial swimming regulation.

Determination of the affinity constants for phage display albumin-binding peptides.

Background: Phage display technology has been established as a powerful screening approach to select ligands or peptides for binding to proteins. Despite rapid growth in the field, there has been a relative dearth of quantitative criteria to measure the effectiveness of the process of phage display screening. Since human serum albumin (HSA) has been extensively studied as a drug carrier to extend the plasma half-life of protein therapeutics, the use of phage display technology is required for identifying albumin-binding peptides as the very promising strategy of albumin-binding against albumin fusion. The construction of albumin-binding drug requires the assessment of a large quantity of HSA-binding peptide (HSA binder) candidates for conjugation with therapeutic proteins. The use of the linear epitope mapping method has allowed researchers to discover many HSA-binding peptides. However, it may be inefficient to select these peptides based on sequence identity via randomly sequencing individual phage clones from enrichment pools. Method: Here, a simple assessment method to facilitate phage display selection of HSA-binding peptides was recommended. With experimentally determined phage titer, one can calculate the specificity ratios, the recovery yields and the relative dissociation constants, which are defined as quantitative criteria for panning and characterization of the binding phage fused peptides. Results: Consequently, this approach may not only enable more rapid and low-cost phage display screening, but also efficiently reduce pseudo-positive phages selected as HSA binders for conjugation with therapeutic proteins.

All-Natural Immunomodulatory Bioadhesive Hydrogel Promotes Angiogenesis and Diabetic Wound Healing by Regulating Macrophage Heterogeneity.

Macrophages are highly heterogeneous and exhibit a diversity of functions and phenotypes. They can be divided into pro-inflammatory macrophages (M1) and anti-inflammatory macrophages (M2). Diabetic wounds are characterized by a prolonged inflammatory phase and difficulty in healing due to the accumulation of pro-inflammatory (M1) macrophages in the wound. Therefore, hydrogel dressings with macrophage heterogeneity regulation function hold great promise in promoting diabetic wound healing in clinical applications. However, the precise conversion of pro-inflammatory M1 to anti-inflammatory M2 macrophages by simple and biosafe approaches is still a great challenge. Here, an all-natural hydrogel with the ability to regulate macrophage heterogeneity is developed to promote angiogenesis and diabetic wound healing. The protocatechuic aldehyde hybridized collagen-based all-natural hydrogel exhibits good bioadhesive and antibacterial properties as well as reactive oxygen species scavenging ability. More importantly, the hydrogel is able to convert M1 macrophages into M2 macrophages without the need for any additional ingredients or external intervention. This simple and safe immunomodulatory approach shows great application potential for shortening the inflammatory phase of diabetic wound repair and accelerating wound healing.

Stereotactic neurosurgery as a symptomatic treatment for autism spectrum disorders: A systematic review.

Stereotactic neurosurgery has been employed in autism spectrum disorders (ASD). However, its safety and effectiveness remain unclear owing to limited sample size and other methodological limitations. We aimed to systematically investigate the safety and efficacy of stereotactic neurosurgery for ASD. Eleven studies with 36 patients were included. Stereotactic neurosurgery alleviated the obsessive-compulsive disorder and aggressive behavior symptoms in ASD, with a mean improvement of 42.74% and 59.59% in the Yale-Brown Obsessive Compulsive Scale and Overt Aggression Scale scores, respectively. Systematic studies are necessary to explore the role of deep brain stimulation for social and communication difficulties in ASD.

TBK1-medicated DRP1 phosphorylation orchestrates mitochondrial dynamics and autophagy activation in osteoarthritis.

Mitochondrial dynamics, including mitochondrial fission and fusion, are critical for maintaining mitochondrial functions. Evidence shows that TANK-binding kinase 1 (TBK1) regulates mitochondrial fusion and fission and then mitophagy. Since a previous study demonstrates a strong correlation between mitophagy and osteoarthritis (OA), we herein investigated the potential role of TBK1 in OA process and mitochondrial functions. We demonstrated a strong correlation between TBK1 and OA, evidenced by significantly downregulated expression of TBK1 in cartilage tissue samples of OA patients and in the chondrocytes of aged mice, as well as TNF-α-stimulated phosphorylation of TBK1 in primary mouse chondrocytes. TBK1 overexpression significantly attenuated TNF-α-induced apoptosis and abnormal mitochondrial function in primary mouse chondrocytes. Furthermore, TBK1 overexpression induced remodeling of mitochondrial morphology by directly phosphorylating dynamin-related protein 1 (DRP1) at Ser637, abolishing the fission of DRP1 and preventing its fragmentation function. Moreover, TBK1 recruitment and DRP1 phosphorylation at Ser637 was necessary for engulfing damaged mitochondria by autophagosomal membranes during mitophagy. Moreover, we demonstrated that APMK/ULK1 signaling contributed to TBK1 activation. In OA mouse models established by surgical destabilization of the medial meniscus, intraarticular injection of lentivirus-TBK1 significantly ameliorated cartilage degradation via regulation of autophagy and alleviation of cell apoptosis. In conclusion, our results suggest that the TBK1/DRP1 pathway is involved in OA and pharmacological targeting of the TBK1-DRP1 cascade provides prospective therapeutic benefits for the treatment of OA.

[A Clinical Study of Patients with Primary Parkinson's Disease Undergoing Bilateral Deep Brain Stimulation (STN-DBS) Surgery in the Subthalamic Nucleus under General Anesthesia].

Objective: To assess the efficacy and safety of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) under general anesthesia and to provide the basis for clinical research related to DBS surgeries under general anesthesia. Methods: A total of 60 patients with primary Parkinson's disease who underwent DBS surgery between January 2019 and December 2021at West China Hospital were enrolled for the study. Among them, 30 had the surgery while they were asleep, i.e., under general anesthesia, and 30, while they were awake, i.e., under local anesthesia. All the patients underwent bilateral STN-DBS surgery. Bispectral index (BIS) was used to monitor and control the depth of anesthesia. Microelectrode recording (MER) technology was used to record the characteristic signals of the bilateral subthalamic nuclei and verify their location during the operation. All patients completed the implantation of deep electrodes, connecting wires, and implantable stimulation generator (IPG) at one time. Postoperative thin-slice CT scans were done to reconstruct electrode images and to verify the accuracy of electrode implantation. The Unified Parkinson's Disease Rating Scale-Ⅲ (UPDRS-Ⅲ) was used to evaluate the preoperative vs. postoperative improvement in motor symptoms, and the results of intraoperative MER and the occurrence of surgery-related complications were documented and analyzed. Results: All patients successfully completed the implantation surgery. The electrodes were accurately implanted at the right position and there was no significant difference between the general anesthesia group and the local anesthesia group in UPDRS-Ⅲ scores and medication dosage differences before and after the operation. No intracranial hemorrhage, cerebral infarction, or infection occurred after the operation, and 5 patients had temporary mental and behavioral abnormalities, which disappeared within 48 hours after the operation. Conclusion: The postoperative therapeutic effect of STN-DBS surgery for primary Parkinson's disease under general anesthesia is comparable to that of the traditional STN-DBS surgery under local anesthesia. When the operation is performed under general anesthesia, the incidence of surgery and anesthesia-related complications is low if patients are managed strictly, and patients would also experience improved surgical comfort.

An atypical primary malignant melanoma arising from the cervical nerve root: A case report and review of literture.

BACKGROUND: Primary melanomas affecting the central nervous system are very rare, and melanomas originating in the spinal canal or origin of the spinal nerve root are even rarer. As a consequence, not much is known about this. CASE SUMMARY: Here we report a case of primary malignant melanoma originating in the cervical spinal cord nerve root. A 64-year-old woman presented with symptoms of numbness in the right side of the neck, pain, and hypoesthesia in the right upper limb which persisted for 1 year. Neurological examination showed that the superficial sensation in the right upper limb had decreased with muscle strength of grade 4. Magnetic resonance imaging examination revealed a mass (approximately 2.5 cm × 1.4 cm × 1 cm) in the right side of the spinal canal in the C-2 plane. Based on findings obtained during operation, perioperative examination, pathological diagnosis, and the diagnostic criteria of primary central melanoma proposed by Hayward, the mass was confirmed to be a melanoma of intraspinal nerve root origin. CONCLUSION: This is the first case of primary malignant melanoma originating from cervical spinal cord nerve roots and spread along the inside and outside of the spinal canal. The clinical relevance of this case is discussed to provide new insights into the differential diagnosis of intraspinal tumours. Further studies are needed to better understand the mechanisms driving the growth pattern and development of this type of tumour.

Prevalence of the thoracic scoliosis in children and adolescents candidates for strabismus surgery: results from a 1935-patient cross-sectional study in China.

PURPOSE: No study so far has paid attention to strabismus-related spinal imbalance. This study aimed to determine the epidemiology of thoracic scoliosis in children and adolescents with strabismus and investigate the association of two diseases. METHODS AND DESIGN: A cross-sectional study. Study group consists of 1935 consecutive candidates for strabismus surgery (4-18 years); Control group consists of the age- and sex-matched patients with respiratory diseases. All subjects underwent a screening program based on chest plain radiographs using the Cobb method. Their demographic information, clinical variables and results of Cobb angle were recorded and analyzed. RESULTS: A significantly higher prevalence of thoracic scoliosis (289/1935, 14.94% versus 58/1935, 3.00%) was found in study group compared with control group. Among strabismic patients, the coronal thoracic scoliosis curve mainly distributed in right and in main thoracic (198/289) and in the curves 10°-19° (224/289); Age range 7-9 years (103/1935), female (179/1935) and concomitant exotropia patients (159/851) were more likely to have thoracic scoliosis. According to the logistic regression, thoracic scoliosis had no significant association with age, BMI, duration of illness and onset age (p > 0.05). However, gender, BCVA, type of strabismus and degree of strabismus showed a significant relationship with the prevalence of thoracic scoliosis (p < 0.05). CONCLUSIONS: With a pooled prevalence of 14.94%, strabismus patients showed a great higher risk of developing thoracic scoliosis. Screening for scoliosis in strabismus patients can be helpful to discover a high prevalence of potential coronal scoliosis. More attention should be paid to ophthalmological problems in patients with scoliosis. These slides can be retrieved under Electronic Supplementary Material.

Downregulating Akt/NF-κB signaling and its antioxidant activity with Loureirin A for alleviating the progression of osteoarthritis: In vitro and vivo studies.

Osteoarthritis(OA) is one of the most common diseases in orthopedics. It is characterized by degeneration of articular cartilage and chronic inflammation. In this study, we aim to elucidate the mechanism of Loureirin A's therapeutic effect in OA progression. In vitro, Loureirin A pretreatment can significantly inhibit production of NO, PGE2, COX-2, TNF-α, iNOS andIL-6 induced by IL-1ß in mouse articular chondrocytes. Moreover, Loureirin A suppressed the expression of matrix metalloproteinase-9(MMP-9), which leads to degradation of the extracellular matrix. The degradation of aggrecan and type II collagen protein in the extracellular matrix (ECM) stimulated by IL-1ß was reversed. For signal pathway research, Loureirin A dramatically inhibited the phosphorylation of AKT and subsequent NF-κB entering into the nucleus caused by IL-1ß in chondrocytes. Besides, a number of related indicators suggested that Loureirin A has a strong antioxidant activity in the treatment of osteoarthritis via increasing content of SOD2 and suppressing MDA and ROS. In addition, in vivo study demonstrated that Loureirin A could ameliorated the progression of OA in mice DMM model In conclusion, all results showed that Loureirin A may be a potential therapeutic candidate for the OA.

Survival and prognosis in malignant giant cell tumor of bone: A population-based analysis from 1984 to 2013.

BACKGROUND: Malignant giant cell tumor of bone (MGCTB) is extremely rare. Currently, population-based prognosis studies are lacking. This study aimed to determine the impact of demographics, tumor characteristics, and treatment on prognosis among patients with MGCTB. METHODS: The Surveillance, Epidemiology, and End Results database was used to identify patients with MGCTB from 1984 to 2013. Kaplan-Meier analyses were performed to determine the overall survival (OS). Univariable and multivariable Cox analyses were conducted to identify prognostic factors. RESULTS: There were 250 patients with MGCTB included in our study. The multivariate Cox analysis revealed that age at diagnosis (hazard ratio [HR]: 1.09; 95% confidence interval [CI]: 1.07-1.11; P < 0.001), tumor size (HR: 7.04; 95% CI: 2.38-20.77; P < 0.001), tumor extension (regional vs. localized, HR: 2.64; 95% CI: 1.10-6.34; P = 0.030; distant vs. localized, HR: 6.12; 95% CI: 2.27-16.49; P < 0.001), and radiotherapy (HR: 0.41; 95% CI: 0.18-0.89; P = 0.025) were independent risk factors of OS in patients with MGCTB. Notably, tumor site (HR: 1.98; 95% CI: 0.99-4.00; P = 0.055) exhibited borderline significance. Additionally, we found that patients with tumors measuring >70 mm (P = 0.015), located in the axial skeleton (P < 0.001) and presented with distant metastasis (P < 0.001) tended to receive radiotherapy. Moreover, a nomogram model integrating independent predictors was established to estimate the OS of patients with MGCTB. CONCLUSION: This study provides a population-based assessment of the largest number of patients with MGCTB. We found that older age, larger tumor size, regional or distant metastasis, and lack of radiotherapy was associated with poor OS. Surgical methods were not significantly associated with OS. Furthermore, we built a high-quality nomogram to predict 1-, 3-, and 5-year OS for patients with MGCTB. These findings may assist in the clinical diagnosis and treatment of MGCTB.

Effects of catalytic site mutations on active expression of phage fused penicillin acylase.

Penicillin G acylase (EC 3.5.1.11) is 86-kDa large heterodimeric protein comprising two peptide A 23-kDa and peptide B 62-kDa, produced by intein-mediated auto-splicing of a 92-kDa precursor. Since penicillin G acylase was potentially employed in the preparation of a wide range of semi-synthetic beta-lactam antibiotics from acyl side-chain precursors and beta-lactam nucleus, directed evolution of penicillin acylase using phage display technology for extending its novel specificity is an interesting topic both of industry and academic. We fused the penicillin acylase to fd phage coat protein III and used pIII secretion signal sequence instead of penicillin acylase, which coupled gene and enzyme on phage particle and will be useful for directed evolution of penicillin acylase. Western blotting and enzyme activity assay were performed to demonstrate penicillin acylase has been functionally displayed on phage surface. Owing to the intimate association of enzyme activity and precursor processing in penicillin acylase, alterations of protein residues to make a phage library should be careful not to lead to processing defects. By site-directed mutagenesis, we have then identified effect of Ser B1 and Asn B241 variants on post-translational maturation of phage fused penicillin acylase.