Construction of a Tandem Repeat Peptide Sequence with Pepsin Cutting Sites to Produce Recombinant α-Melanocyte-Stimulating Hormone.

The production of α-melanocyte-stimulating hormone (α-MSH), a peptide hormone composed of 13 amino acids, is attempted by recombinant expression using E. coli as the host. To achieve this aim, a synthetic gene containing eight tandem repeats of msh gene (8msh) was designed for ribosomal synthesis of 8 α-MSH. The merit of the strategy is to diminish the peptide toxicity against the host cell and to achieve a higher production yield. Pepsin cleavage sites are introduced between the peptides for enzymatic proteolysis to obtain the monomeric peptide of α-MSH. The constructed plasmid was transformed into different strains of E. coli hosts, and E. coli XL1-Blue with gene 8msh revealed the highest yield of 8 α-MSH. Although 8 α-MSH was fractionalized in the insoluble pellets after cell lysis, pepsin cleavage was able to produce soluble α-MSH peptide, as analyzed and confirmed by mass spectrometry and peptide activity assays. The production of α-MSH was quantified using HPLC with a yield of 42.9 mg/L of LB culture. This study demonstrates the feasibility of producing α-MSH using recombinant expression of tandem repeat gene. The production procedure involves minimal post-treatment and processing and can be scaled up for industrial application.

[Research progress and prospect of endophytes from medicinal plant Atractylodes lancea].

The endophytes of medicinal plants play an important role in promoting the quality formation of the host. Therefore, this paper made a review of endophytes of medicinal plant Atractylodes lancea. According to previous studies, A. lancea boasts endophytes, such as fungi, bacteria, and actinomycetes, among which the beneficial microorganisms help the growth and development of A. lancea. There is a close interaction between the volatile oil of A. lancea and endophytes. Different endophytes vary in regulating the composition and content of the volatile oil of A. lancea, which might contribute to the quality formation of A. lancea. However, the information of the endophytic flora of A. lancea obtained by traditional culture and isolation is not enough to reflect the real situation of the endophytes of A. lancea. Little is known about the endophytes of A. lancea from different chemical types and different habitats, which is not conducive to the study of the ecological relationship between A. lancea and endophytes and limits the development and utilization of the endophytes. Therefore, at the end of this paper, the authors put forward suggestions for future research on endophytes in A. lancea, including:(1)mining the core endophyte resources of A. lancea by combining high-throughput sequencing with traditional culture and isolation;(2)exploring the relationship between the diversity of endophytes and chemical types of A. lancea;(3)strengthening the application of endophytes in A. lancea cultivation, in order to facilitate the cultivation efficiency and quality of A. lancea.

[Research strategies for endophytes in medicinal plants based on high-throughput sequencing and traditional culture and isolation methods].

The research on endophytes of medicinal plants mainly relies on the traditional culture and isolation methods. Because of their functions such as promoting host growth, improving stress resistance, promoting the accumulation of medicinal active ingredients or directly producing medicinal active ingredients, the endophytes of medicinal plants have gradually attracted wide attention. However, it was found that the strains isolated by traditional methods were not the true dominant endophytes of medicinal plants by comparing the results of traditional culture isolation with high-throughput sequencing. The blind and random nature of traditional methods leads to the lack of standards in terms of medium selection, culture time and interaction between species. On the contrary, high-throughput sequencing technology is an emerging molecular biology technology developed in recent decades. Due to its high resolution level and indepen-dent culture, it can be used for thorough analysis of the community structure and diversity of environmental microorganisms. Therefore, we proposed the strategy of using high-throughput sequencing technology to guide the traditional culture and isolation of endophytes from medicinal plants. Firstly, the endophytic structure and diversity of medicinal plants were completely clear by high-throughput sequencing technology, and the dominant endophytes of the host were unequivocal. Then according to the characteristics of each dominant endophytes design or query suitable medium for its growth to culture and isolation. Finally, the function of the isolates was studied. This method can prevent researchers from missing out on the important functional strains of the host, expand the research scope of endophytes of medicinal plants, and facilitate the in-depth excavation and utilization of endophytes of medicinal plants.

[Core position of secondary metabolism of medicinal plants in ecological planting of Chinese materia medica and its utilization].

This paper summarized the effects of ecological planting on secondary metabolism firstly and pointed out that ecological planting can increase the content of secondary metabolites in plants, especially the content of defensive secondary metabolites. The possible mechanism was analyzed subsequently. Then, we reviewed the induction and utilization of secondary metabolism in the ecological planting of Chinese materia medica from the perspectives of biological control of pests and diseases, promotion of beneficial microorganism accumulation, optimization of mixed planting, regulation of no-tillage and straw cover. In this article, we pointed out that paying close attention to secondary metabolism is the most important feature of ecological planting of Chinese materia medica. Ecological planting can promote the accumulation of secondary metabolites of Chinese materia medica which means can improve the quality of Chinese materia medica, beneficial to the prevention and control of diseases, insects and weeds. Furthermore, lacking of systemic researches,the extensive verifications and systematic in-depth researches on the ecological planting of Chinese materia medica should be carry out urgently.

[Influence and mechanism of stress combination on medicinal plants secondary metabolism].

Numerous studies showed that the growth of medicinal plants in their native areas was simultaneously affected by abiotic stress combinations. Compared with single stress, plants have unique responses to a combination of different abiotic stresses and cannot be inferred directly from plants' responses to each individual stress. The effect of combined stresses on plants usually has three types of synergistic antagonism or independence. The secondary metabolism in the process of medicinal plant stress combination response also played a vital role, and environmental stresses can spur the accumulation of secondary metabolites, but under the stress combination, plants induce specific gene expression of key enzymes on secondary metabolic pathways, in turn, the accumulation of secondary metabolites against stress is formed. When plants are subjected to stress combination, the interaction of multiple signaling pathways makes it highly complex for plants to respond to stress combination. This paper summarized the effects of stress combination on physiological and secondary metabolism of medicinal plants, and discussed the related physiological, biochemical and molecular mechanisms. It provides theoretical basis for improving the adaptability of medicinal plants to adversity, improving the quality of Chinese medicinal materials, and further optimizing the cultivation of medicinal plants.

[Research progress in effects of interspecific interaction on medicinal plants in intercropping system].

Intercropping farming system is one of the essence of traditional agriculture in China and one of the most common and basic patterns of modern ecological planting. Intercropping system uses the principle of species diversity to create reasonable interspecific interaction conditions with obvious productivity advantages. In this paper, the interspecies interaction is divided into aboveground and underground parts from the space view, and its influence and mechanism on the yield and secondary metabolites of medicinal plants are elaborated.The interspecific interaction in the aboveground part mainly introduces the distribution and utilization of space resources among plants. The interspecific interaction in the underground part mainly introduces the soil rhizosphere effect and related mediating factors, root exudates, soil microorganisms, root space structure and soil environmental factors. On the basis of understanding the mechanism of interspecific interaction, this paper further discusses the application of intercropping in traditional Chinese medicine ecological agriculture, taking the effective control of diseases and insect pests, the increase of medicinal material yield and the improvement of medicinal material quality as the benefit index, so as to seek better advantages of intercropping and provide ideas for the utilization of intercropping production mode in traditional Chinese medicine ecological agriculture.

[Community structure and diversity of soil bacteria in rhizosphere of Salvia miltiorrhiza and Salvia miltiorrhiza f. alba based on pyrosequencing].

Rhizosphere bacteria play a vital role in plant nutrition absorption,growth and disease resistance. In this study,high-throughput sequencing technology was used to analyze the rhizosphere bacterial communities of Salvia miltiorrhiza and S. miltiorrhiza f. alba. Moreover,the function of dominant rhizosphere bacterial communities was analyzed. We found that Sphingobacteriales,Sphingomonadales and Nitrosomonadaceae were both dominant and specific bacteria in the rhizosphere of S. miltiorrhiza. The main functions of dominant rhizosphere bacteria communities in both species include promoting transformation of soil nutrients,improving plant immunity and ability of stress tolerance. This study was the first to compare rhizobacterial communities structure and function of S. miltiorrhiza and S. miltiorrhiza f. alba,which provided a new theoretical reference for studing the rhizosphere mechanism of healthy S. miltiorrhiza planting in the future.

Active Neural Interface Circuits and Systems for Selective Control of Peripheral Nerves: A Review.

Interfaces with peripheral nerves have been widely developed to enable bioelectronic control of neural activity. Peripheral nerve neuromodulation shows great potential in addressing motor dysfunctions, neurological disorders, and psychiatric conditions. The integration of high-density neural electrodes with stimulation and recording circuits poses a challenge in the design of neural interfaces. Recent advances in active electrode strategies have achieved improved reliability and performance by implementing in-situ control, stimulation, and recording of neural fibers. This paper presents an overview of state-of-the-art neural interface systems that comprise a range of neural electrodes, neurostimulators, and bio-amplifier circuits, with a special focus on interfaces for the peripheral nerves. A discussion on the efficacy of active electrode systems and recommendations for future directions conclude this paper.

A modified adventitial inversion with graft insertion technique in acute Type A aortic dissection.

Acute type A aortic dissection may originate from a primary intimal tear located in the ascending aorta and often extends retrogradely into the aortic root. How to prevent bleeding in the aortic root and eliminate false lumen is very important in aortic dissection. We have developed a modified anastomotic technique that involves inverting adventitial and graft into aorta and reinforcing with a felt strip on the external border of the aortic wall. Since 2020, 45 consecutive patients with type A aortic coarctation have undergone this aortic root reconstruction procedure, to date, none have been reopened for bleeding or remnant dissection.

An optogenetic cell therapy to restore control of target muscles in an aggressive mouse model of amyotrophic lateral sclerosis.

Breakdown of neuromuscular junctions (NMJs) is an early pathological hallmark of amyotrophic lateral sclerosis (ALS) that blocks neuromuscular transmission, leading to muscle weakness, paralysis and, ultimately, premature death. Currently, no therapies exist that can prevent progressive motor neuron degeneration, muscle denervation, or paralysis in ALS. Here, we report important advances in the development of an optogenetic, neural replacement strategy that can effectively restore innervation of severely affected skeletal muscles in the aggressive SOD1G93A mouse model of ALS, thus providing an interface to selectively control the function of targeted muscles using optical stimulation. We also identify a specific approach to confer complete survival of allogeneic replacement motor neurons. Furthermore, we demonstrate that an optical stimulation training paradigm can prevent atrophy of reinnervated muscle fibers and results in a tenfold increase in optically evoked contractile force. Together, these advances pave the way for an assistive therapy that could benefit all ALS patients.

A real-world study of tyrosine kinase inhibitors plus anti-PD-1 immunotherapy with or without chemoembolization for hepatocellular carcinoma patients with main portal vein invasion.

BACKGROUND: Although systemic therapies are recommended for hepatocellular carcinoma (HCC) patients with main portal vein (MPV) invasion and preserved liver function, the outcome is limited. In the real-world, chemoembolization is a commonly used local treatment for advanced HCC. PURPOSE: To evaluate whether the additional chemoembolization treatment yields survival benefits compared to systemic therapy for HCC patients with MPV invasion and preserved liver function (Child-Pugh score ≤ B7) in a real-world study from multiple centers. PATIENTS AND METHODS: Between January 2020 and December 2022, 91 consecutive HCC patients with MPV invasion who received either systemic medical therapy (i.e., tyrosine kinase inhibitors (TKIs) plus anti-PD-1 immunotherapy, S group, n = 43) or in combination with chemoembolization treatment (S-T group, n = 48) from five centers were enrolled in the study. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS) and treatment response. Adverse events (AEs) related to treatment were also recorded. Survival curves were constructed with the Kaplan-Meier method and compared using the log-rank test. RESULTS: The baseline characteristics were comparable between the two groups. The mean number of chemoembolization sessions per patient was 2.1 (range 1-3). The median OS was 10.0 months and 8.0 months in the S-T group and S group, respectively (P = 0.254). The median PFS between the two groups was similar (4.0 months vs. 4.0 months, P = 0.404). The disease control rate between the S-T and S groups were comparable (60.4% vs. 62.8%, P = 0.816). Although no chemoembolization-related deaths occurred, 13 grade 3-4 AEs occurred in the S-T group. CONCLUSIONS: The results of the real-world study demonstrated that additional chemoembolization treatment did not yield survival benefits compared to TKIs plus anti-PD-1 immunotherapy for the overall patients with advanced HCC and MPV invasion.

A multi-channel stimulator with an active electrode array implant for vagal-cardiac neuromodulation studies.

BACKGROUND: Implantable vagus nerve stimulation is a promising approach for restoring autonomic cardiovascular functions after heart transplantation. For successful treatment a system should have multiple electrodes to deliver precise stimulation and complex neuromodulation patterns. METHODS: This paper presents an implantable multi-channel stimulation system for vagal-cardiac neuromodulation studies in swine species. The system comprises an active electrode array implant percutaneously connected to an external wearable controller. The active electrode array implant has an integrated stimulator ASIC mounted on a ceramic substrate connected to an intraneural electrode array via micro-rivet bonding. The implant is silicone encapsulated for biocompatibility and implanted lifetime. The stimulation parameters are remotely transmitted via a Bluetooth telemetry link. RESULTS: The size of the encapsulated active electrode array implant is 8 mm × 10 mm × 3 mm. The stimulator ASIC has 10-bit current amplitude resolution and 16 independent output channels, each capable of delivering up to 550 µA stimulus current and a maximum voltage of 20 V. The active electrode array implant was subjected to in vitro accelerated lifetime testing at 70 °C for 7 days with no degradation in performance. After over 2 h continuous stimulation, the surface temperature change of the implant was less than 0.5 °C. In addition, in vivo testing on the sciatic nerve of a male Göttingen minipig demonstrated that the implant could effectively elicit an EMG response that grew progressively stronger on increasing the amplitude of the stimulation. CONCLUSIONS: The multi-channel stimulator is suitable for long term implantation. It shows potential as a useful tool in vagal-cardiac neuromodulation studies in animal models for restoring autonomic cardiovascular functions after heart transplantation.

Corrigendum: Identification of ACKR4 as an immune checkpoint in pulmonary arterial hypertension.

[This corrects the article DOI: 10.3389/fimmu.2023.1153573.].

[Reliving refractory pain of spinal metastasis patients with radiofrequency ablation through transforaminal endoscopy].

OBJECTIVE: To explore the short-term outcomes of radiofrequency ablation treatment of bone metastasis. METHODS: Between November 2011 and November 2012, a total of 18 cases were retrospectively reviewed. They underwent resection of bone metastasis with radiofrequency ablation through transforaminal endoscopic spine system. According to the Tomita classification system, the classifications were type 5 (n = 8), type 6 (n = 4) and type 7 (n = 6). There were 8 males and 10 females with a median age of 52.1 (32-76) years. The primary lesions were breast cancer (n = 5), carcinoma of prostate (n = 3), digestive cancer (n = 4), thyroid carcinoma (n = 2)and lung cancer (n = 4). And two cases had pathologic fracture. RESULTS: The operative duration was 118 (90-180) min and blood loss volume 30.6 (10-60) ml. All incisions achieved excellent healing.One case of pneumonia recovered with antibiotic. The postoperative visual analogue scale (VAS) scores were 2.4 ± 0.4, 2.6 ± 0.6, 3.0 ± 0.3 and 2.8 ± 0.7. CONCLUSION: Radiofrequency ablation through transforaminal endoscopy may be a safe and efficacious option for refractory pain with bone metastasis, especially for those with uncontrolled pain. This procedure is mini-invasive and causes less bleeding.

Identification of ACKR4 as an immune checkpoint in pulmonary arterial hypertension.

Objective: Inflammation is recognized as a contributor in the development of pulmonary arterial hypertension (PAH), and the recruitment and functional capacity of immune cells are well-orchestrated by chemokines and their receptors. This study is aimed at identification of critical chemokines in the progression of PAH via transcriptomic analysis. Methods: Differentially expressed genes (DEGs) from lungs of PAH patients were achieved compared to controls based on Gene Expression Omnibus (GEO) database. Gene set enrichment analysis (GSEA) was applied for functional annotation and pathway enrichement. The abundance of immune cells was estimated by the xCell algorithm. Weighted correlation network analysis (WGCNA) was used to construct a gene expression network, based on which a diagnostic model was generated to determine its accuracy to distinguish PAH from control subjects. Target genes were then validated in lung of hypoxia-induce pulmonary hypertension (PH) mouse model. Results: ACKR4 (atypical chemokine receptor 4) was downregulated in PAH lung tissues in multiple datasets. PAH relevant biological functions and pathways were enriched in patients with low-ACKR4 level according to GSEA enrichment analysis. Immuno-infiltration analysis revealed a negative correlation of activated dendritic cells, Th1 and macrophage infiltration with ACKR4 expression. Three gene modules were associated with PAH via WGCNA analysis, and a model for PAH diagnosis was generated using CXCL12, COL18A1 and TSHZ2, all of which correlated with ACKR4. The ACKR4 expression was also downregulated in lung tissues of our experimental PH mice compared to that of controls. Conclusions: The reduction of ACKR4 in lung tissues of human PAH based on transcriptomic data is consistent with the alteration observed in our rodent PH. The correlation with immune cell infiltration and functional annotation indicated that ACKR4 might serve as a protective immune checkpoint for PAH.

Prolyl endopeptidase remodels macrophage function as a novel transcriptional coregulator and inhibits fibrosis.

Macrophages are immune cells crucial for host defense and homeostasis maintenance, and their dysregulation is involved in multiple pathological conditions, such as liver fibrosis. The transcriptional regulation in macrophage is indispensable for fine-tuning of macrophage functions, but the details have not been fully elucidated. Prolyl endopeptidase (PREP) is a dipeptidyl peptidase with both proteolytic and non-proteolytic functions. In this study, we found that Prep knockout significantly contributed to transcriptomic alterations in quiescent and M1/M2-polarized bone marrow-derived macrophages (BMDMs), as well as aggravated fibrosis in an experimental nonalcoholic steatohepatitis (NASH) model. Mechanistically, PREP predominantly localized to the macrophage nuclei and functioned as a transcriptional coregulator. Using CUT&Tag and co-immunoprecipitation, we found that PREP was mainly distributed in active cis-regulatory genomic regions and physically interacted with the transcription factor PU.1. Among PREP-regulated downstream genes, genes encoding profibrotic cathepsin B and D were overexpressed in BMDMs and fibrotic liver tissue. Our results indicate that PREP in macrophages functions as a transcriptional coregulator that finely tunes macrophage functions, and plays a protective role against liver fibrosis pathogenesis.

Insertion Guidance Based on Impedance Measurements of a Cochlear Electrode Array.

The cochlear implantable neuromodulator provides substantial auditory perception to those with severe or profound impaired hearing. Correct electrode array positioning in the cochlea is one of the important factors for quality hearing, and misplacement may lead to additional injury to the cochlea. Visual inspection of the progress of electrode insertion is limited and mainly relies on the surgeon's tactile skills, and there is a need to detect in real-time the electrode array position in the cochlea during insertion. The available clinical measurement presently provides very limited information. Impedance measurement may be used to assist with the insertion of the electrode array. Using computational modeling of the cochlea, and its local tissue layers merging with the associated neuromodulator electrode array parameters, the impedance variations at different insertion depths and the proximities to the cochlea walls have been analyzed. In this study, an anatomical computational model of the temporal region of a patient is used to derive the relationship between impedance variations and the electrode proximity to the cochlea wall and electrode insertion depth. The aim was to examine whether the use of electrode impedance variations can be an effective marker of electrode proximity and electrode insertion depth. The proposed anatomical model simulates the quasi-static electrode impedance variations at different selected points but at considerable computation cost. A much less computationally intensive geometric model (~1/30) provided comparative impedance measurements with differences of <2%. Both use finite element analysis over the entire cross-section area of the scala tympani. It is shown that the magnitude of the impedance varies with both electrode insertion depth and electrode proximity to the adjacent anatomical layers (e.g., cochlea wall). In particular, there is a 1,400% increase when the electrode array is moved very close to the cochlea wall. This may help the surgeon to find the optimal electrode position within the scala tympani by observation of such impedance characteristics. The misplacement of the electrode array within the scala tympani may be eliminated by using the impedance variation metric during electrode array insertion if the results are validated with an experimental study.

A Fully Implantable Opto-Electro Closed-Loop Neural Interface for Motor Neuron Disease Studies.

This paper presents a fully implantable closed-loop device for use in freely moving rodents to investigate new treatments for motor neuron disease. The 0.18 µm CMOS integrated circuit comprises 4 stimulators, each featuring 16 channels for optical and electrical stimulation using arbitrary current waveforms at frequencies from 1.5 Hz to 50 kHz, and a bandwidth programmable front-end for neural recording. The implant uses a Qi wireless inductive link which can deliver >100 mW power at a maximum distance of 2 cm for a freely moving rodent. A backup rechargeable battery can support 10 mA continuous stimulation currents for 2.5 hours in the absence of an inductive power link. The implant is controlled by a graphic user interface with broad programmable parameters via a Bluetooth low energy bidirectional data telemetry link. The encapsulated implant is 40 mm × 20 mm × 10 mm. Measured results are presented showing the electrical performance of the electronics and the packaging method.

A Multi-Channel Stimulator With High-Resolution Time-to-Current Conversion for Vagal-Cardiac Neuromodulation.

This paper presents a low power integrated multi-channel stimulator for a cardiac neuroprosthesis designed to restore the parasympathetic control after heart transplantation. The proposed stimulator is based on time-to-current conversion. It replaces the conventional current mode digital-to-analog converter (DAC) that uses tens of microamps for biasing, with a novel capacitor time-based DAC (CT-DAC) offering about 10-bit current amplitude resolution with a bias current of only 250 nA. A stimulator chip was designed in a 0.18 µm CMOS high-voltage (HV) technology. It consists of 16 independent channels, each capable of delivering up to 550 µA stimulus current with a HV output stage that can be operated up to 20 V. The stimulator chip performance was evaluated using both RC equivalent load and a microelectrode array in saline solution. It is power efficient, provides high-resolution current amplitude stimulation, and has good charge balance. The design is suitable for multi-channel neural stimulation applications.

An Imaged Based Method for Universal Performance Evaluation of Electrical Impedance Tomography Systems.

This paper describes a simple and reproducible method for universal evaluation of the performance of electrical impedance tomography (EIT) systems using reconstructed images. To address the issues where common electrical parameters are not directly related to the quality of EIT images, based on objective full reference (FR) image quality assessment, the method provides a visually distinguishable hot colormap and two new FR metrics, the global and the more specific 'region of interest'. A passive 16 electrode EIT system using an application specific integrated circuit front-end was used to evaluate the proposed method. The measured results show, both visually and in terms of the proposed FR metrics, the impact on recorded EIT images with different design parameters and non-idealities. The paper also compares the image results of a passive electrode system with a matched 'single variable' active electrode system and demonstrates the merit of an active electrode system for noise interference. A figure of merit based on the FR metrics is proposed.