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2.
Pest Manag Sci ; 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39189553

ABSTRACT

BACKGROUND: Epicoccum sorghinum is a pathogenic fungus that causes leaf spot in a wide range of plants, including maize, and synthesizes the mycotoxin tenuazonic acid (TEA), which is carcinogenic. Despite the relevant economic and yield losses caused by E. sorghinum worldwide, methods for the control of this pathogen are lacking. RESULTS: In this work, the efficacy of Bacillus-produced dipicolinic acid (DPA) for control of E. sorghinum was evaluated using in vitro and in vivo assays, and compared with the efficacy of three commercial fungicides, including carbendazim, prochloraz, and thiram. DPA inhibited E. sorghinum mycelial growth, and conidia germination, and produced important alterations in E. sorghinum hyphae. Interestingly, 10 mM DPA reduced TEA biosynthesis by 86.6%. Although DPA rapidly degraded on maize leaves, 10 mM DPA showed higher preventive (67.4% lesion length inhibition) and inhibitory (89.5% lesion length inhibition) efficacies for the control of E. sorghinum on maize leaves compared to the commercial fungicides. CONCLUSIONS: Collectively, this study presents the first method for the control of E. sorghinum on maize and demonstrates that DPA application is a suitable approach to inhibit E. sorghinum symptoms in plants and TEA biosynthesis. © 2024 Society of Chemical Industry.

3.
Biomaterials ; 311: 122674, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38897028

ABSTRACT

Clinical results with photovoltaic subretinal prosthesis (PRIMA) demonstrated restoration of sight via electrical stimulation of the interneurons in degenerated retina, with resolution matching the 100 µm pixel size. Since scaling the pixels below 75 µm in the current bipolar planar geometry will significantly limit the penetration depth of the electric field and increase stimulation threshold, we explore the possibility of using smaller pixels based on a novel 3-dimensional honeycomb-shaped design. We assessed the long-term biocompatibility and stability of these arrays in rats by investigating the anatomical integration of the retina with flat and 3D implants and response to electrical stimulation over lifetime - up to 32-36 weeks post-implantation in aged rats. With both flat and 3D implants, signals elicited in the visual cortex decreased after the day of implantation by more than 3-fold, and gradually recovered over the next 12-16 weeks. With 25 µm high honeycomb walls, the majority of bipolar cells migrate into the wells, while amacrine and ganglion cells remain above the cavities, which is essential for selective network-mediated stimulation of the retina. Retinal thickness and full-field stimulation threshold with 40 µm-wide honeycomb pixels were comparable to those with planar devices - 0.05 mW/mm2 with 10 ms pulses. However, fewer cells from the inner nuclear layer migrated into the 20 µm-wide wells, and stimulation threshold increased over 12-16 weeks, before stabilizing at about 0.08 mW/mm2. Such threshold is still significantly lower than 1.8 mW/mm2 with a previous design of flat bipolar pixels, confirming the promise of the 3D honeycomb-based approach to high resolution subretinal prosthesis.


Subject(s)
Retina , Visual Prosthesis , Animals , Retina/physiology , Rats , Electric Stimulation , Rats, Long-Evans , Follow-Up Studies , Electrodes, Implanted
4.
Dev Cell ; 59(15): 1954-1971.e7, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38776924

ABSTRACT

A significant variation in chromatin accessibility is an epigenetic feature of leukemia. The cause of this variation in leukemia, however, remains elusive. Here, we identify SMARCA5, a core ATPase of the imitation switch (ISWI) chromatin remodeling complex, as being responsible for aberrant chromatin accessibility in leukemia cells. We find that SMARCA5 is required to maintain aberrant chromatin accessibility for leukemogenesis and then promotes transcriptional activation of AKR1B1, an aldo/keto reductase, by recruiting transcription co-activator DDX5 and transcription factor SP1. Higher levels of AKR1B1 are associated with a poor prognosis in leukemia patients and promote leukemogenesis by reprogramming fructose metabolism. Moreover, pharmacological inhibition of AKR1B1 has been shown to have significant therapeutic effects in leukemia mice and leukemia patient cells. Thus, our findings link the aberrant chromatin state mediated by SMARCA5 to AKR1B1-mediated endogenous fructose metabolism reprogramming and shed light on the essential role of AKR1B1 in leukemogenesis, which may provide therapeutic strategies for leukemia.


Subject(s)
Fructose , Animals , Humans , Mice , Adenosine Triphosphatases , Aldehyde Reductase/metabolism , Aldehyde Reductase/genetics , Carcinogenesis/metabolism , Carcinogenesis/pathology , Carcinogenesis/genetics , Cell Line, Tumor , Chromatin/metabolism , Chromatin Assembly and Disassembly , Chromosomal Proteins, Non-Histone/metabolism , Chromosomal Proteins, Non-Histone/genetics , Fructose/metabolism , Leukemia/metabolism , Leukemia/pathology , Leukemia/genetics , Transcription Factors/metabolism , Transcription Factors/genetics
5.
Chem Commun (Camb) ; 60(46): 5948-5951, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38764410

ABSTRACT

Structurally symmetric dyes using functionalized fluorenes and benzotriazole as the main building moieties have been synthesized and found to exhibit efficient dual-state emission (DSE) and interesting two-wavelength or dual amplified spontaneous emission (dual-ASE) behaviors in the solution phase, which may benefit the development of organic gain materials with dual-wavelength amplification.

6.
Zhongguo Zhong Yao Za Zhi ; 49(8): 2064-2075, 2024 Apr.
Article in Chinese | MEDLINE | ID: mdl-38812223

ABSTRACT

Dachaihu Decoction is a classic prescription with the function of harmonizing Shaoyang and purging away internal stasis of heat, which was specially developed by Master ZHANG Zhongjing for the concurrent disease of Shaoyang and Yangming. A large number of international studies have shown that Dachaihu Decoction has liver protection, gallbladder benefit, anti-inflammatory, and other pharmacological effects and is mostly used in modern clinical treatment of acute pancreatitis, acute cholecystitis, cholelithiasis, and other digestive diseases. This paper combined bibliography and statistics and selected the ancient book database and CNKI database to search the relevant literature on Dachaihu decoction, verify the composition and dosage, processing method, main diseases, and modern clinical application, and predict its quality markers(Q-markers) based on the "five principles" of Q-markers. The results suggest that saikosaponin a, baicalin, and 6-gingerol can be selected as potential Q-markers for Dachaihu Decoction, so as to provide a basis for the clinical research of traditional Chinese medicine and the development and application of compound preparations.


Subject(s)
Drugs, Chinese Herbal , Animals , Humans , Biomarkers/analysis , China , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/therapeutic use , History, 21st Century , History, Ancient
7.
Chem Commun (Camb) ; 60(42): 5546-5549, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38700121

ABSTRACT

Airborne nanoplastics can enter alveolar cells and trigger intracellular oxidative stress primarily. Herein, taking advantage of the high electrochemical resolution of SiC@Pt nanoelectrodes, we achieved the quantitative discrimination of the major ROS/RNS within A549 cells, disclosed the sources of their precursors, and observed that the NO (RNS precursor) level significantly increased, whereas O2˙- (ROS precursor) remained relatively stable during the nanoplastics exposure. This establishes that iNOS or mitochondrion-targeted treatment may be a preventive or therapeutic strategy for nanoplastic-induced lung injury.


Subject(s)
Electrochemical Techniques , Reactive Nitrogen Species , Reactive Oxygen Species , Humans , Reactive Oxygen Species/metabolism , A549 Cells , Reactive Nitrogen Species/metabolism , Oxidative Stress/drug effects , Electrodes
8.
One Health ; 18: 100714, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38596323

ABSTRACT

The global spread of highly pathogenic avian influenza (HPAI) A (H5N1) clade 2.3.4.4b virus since 2021 necessitates a re-evaluation of the role of vaccination in controlling HPAI outbreaks among poultry, which has been controversial because of the concern of silent spread with viral mutation and spillover to human. We systematically reviewed and meta-analyzed all existing data from experimental challenge trials to assess the efficacy of HPAI vaccines against mortality in specific pathogen free (SPF) chickens, with evaluation of the certainty of evidence (CoE) using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Out of 223 screened publications, 46 trials met our eligibility criteria. Inactivated vaccines showed an efficacy of 95% (risk ratio [RR] = 5% [95% CI: 1% to 17%], I2 = 0%, CoE high) against homologous strains and an efficacy of 78% (RR = 22% [95% CI: 14% to 37%], I2 = 18%, CoE high) against heterologous strains (test for subgroup difference p = 0.02). Live recombinant vaccines exhibited the highest efficacy at 97% (RR = 3% [95% CI: 1% to 13%], I2 = 0%, CoE high). Inactivated recombinant vaccines had an overall efficacy of 90% (RR = 10% [95% CI: 6% to 16%], I2 = 47%, CoE high). Commercial vaccines showed an overall efficacy of 91% (RR = 9% [95% CI: 5% to 17%], I2 = 23%, CoE high), with 96% efficacy (RR = 4% [95% CI: 1% to 21%], I2 = 0%, CoE high) against homologous strains and 90% efficacy (RR = 10% [95% CI: 5% to 20%], I2 = 31%, CoE moderate) against heterologous strains. Our systematic review offers an updated and unbiased assessment of vaccine efficacy against HPAI-related mortality, providing timely and crucial information for re-evaluating the role of vaccination in poultry avian influenza control policy amist the global HPAI outbreak post-2021.

9.
Sheng Li Xue Bao ; 76(2): 257-265, 2024 Apr 25.
Article in Chinese | MEDLINE | ID: mdl-38658375

ABSTRACT

The present study aims to observe the change in expression of heat shock protein 90 (HSP90) along with amyloid-ß (Aß) and phosphorylated Tau (p-Tau) protein levels in the hippocampus tissue of Alzheimer's disease (AD) transgenic animal model with age. APP/PS1 transgenic mice at age of 6-, 9- and 12-month and C57BL/6J mice of the same age were used. The cognitive abilities of these animals were evaluated using a Morris water maze. Western blot or immunohistochemistry was used to detect the expressions of HSP90 and Aß1-42, as well as the phosphorylation levels of Tau protein in the hippocampus. The hsp90 mRNA levels and the morphology and number of cells in the hippocampus were detected with real-time quantitative polymerase chain reaction (qRT-PCR) and Nissl staining, respectively. The results showed that compared with C57BL/6J mice of the same age, HSP90 and hsp90 mRNA expression were decreased (P < 0.05 or P < 0.01), while Aß1-42 and p-Tau protein levels were increased (P < 0.05 or P < 0.01) in the hippocampal tissue of APP/PS1 transgenic mice. Meanwhile, the decrease in HSP90 and hsp90 mRNA expression (P < 0.05 or P < 0.01), the increase in Aß1-42 and p-Tau levels (P < 0.01 or P < 0.05) in hippocampal tissue and the reduction in behavioral ability showed a progressive development with the advancing of age in the APP/PS1 transgenic mice. In conclusion, in the hippocampal tissue of APP/PS1 mice, the decrease in HSP90 expression and the increase in Aß1-42 and p-Tau levels together with the decline of their cognitive ability are age-dependent.


Subject(s)
Alzheimer Disease , Amyloid beta-Peptides , Amyloid beta-Protein Precursor , HSP90 Heat-Shock Proteins , Hippocampus , Mice, Inbred C57BL , Mice, Transgenic , tau Proteins , Animals , HSP90 Heat-Shock Proteins/metabolism , HSP90 Heat-Shock Proteins/genetics , Hippocampus/metabolism , Mice , Alzheimer Disease/metabolism , Alzheimer Disease/genetics , tau Proteins/metabolism , tau Proteins/genetics , Amyloid beta-Peptides/metabolism , Amyloid beta-Peptides/genetics , Amyloid beta-Protein Precursor/genetics , Amyloid beta-Protein Precursor/metabolism , Male , Disease Models, Animal , Phosphorylation , Age Factors , Aging/metabolism , RNA, Messenger/metabolism , RNA, Messenger/genetics , Peptide Fragments/metabolism , Peptide Fragments/genetics , Presenilin-1/genetics , Presenilin-1/metabolism
11.
Front Plant Sci ; 15: 1361959, 2024.
Article in English | MEDLINE | ID: mdl-38576787

ABSTRACT

Artemisinin biosynthesis, unique to Artemisia annua, is suggested to have evolved from the ancestral costunolide biosynthetic pathway commonly found in the Asteraceae family. However, the evolutionary landscape of this process is not fully understood. The first oxidase in artemisinin biosynthesis, CYP71AV1, also known as amorpha-4,11-diene oxidase (AMO), has specialized from ancestral germacrene A oxidases (GAOs). Unlike GAO, which exhibits catalytic promiscuity toward amorpha-4,11-diene, the natural substrate of AMO, AMO has lost its ancestral activity on germacrene A. Previous studies have suggested that the loss of the GAO copy in A. annua is responsible for the abolishment of the costunolide pathway. In the genome of A. annua, there are two copies of AMO, each of which has been reported to be responsible for the different product profiles of high- and low-artemisinin production chemotypes. Through analysis of their tissue-specific expression and comparison of their sequences with those of other GAOs, it was discovered that one copy of AMO (AMOHAP) exhibits a different transcript compared to the reported artemisinin biosynthetic genes and shows more sequence similarity to other GAOs in the catalytic regions. Furthermore, in a subsequent in vitro enzymatic assay, the recombinant protein of AMOHAP unequivocally demonstrated GAO activity. This result clearly indicates that AMOHAP is a GAO rather than an AMO and that its promiscuous activity on amorpha-4,11-diene has led to its misidentification as an AMO in previous studies. In addition, the divergent expression pattern of AMOHAP compared to that of the upstream germacrene A synthase may have contributed to the abolishment of costunolide biosynthesis in A. annua. Our findings reveal a complex evolutionary landscape in which the emergence of a new metabolic pathway replaces an ancestral one.

12.
Regen Ther ; 25: 377-386, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38414558

ABSTRACT

Cerebral small vessel disease (CSVD), as the most common, chronic and progressive vascular disease on the brain, is a serious neurological disease, whose pathogenesis remains unclear. The disease is a leading cause of stroke and vascular cognitive impairment and dementia, and contributes to about 20% of strokes, including 25% of ischemic strokes and 45% of dementias. Undoubtedly, the high incidence and poor prognosis of CSVD have brought a heavy economic and medical burden to society. The present treatment of CSVD focuses on the management of vascular risk factors. Although vascular risk factors may be important causes or accelerators of CSVD and should always be treated in accordance with best clinical practice, controlling risk factors alone could not curb the progression of CSVD brain injury. Therefore, developing safer and more effective treatment strategies for CSVD is urgently needed. Recently, mesenchymal stem cells (MSCs) therapy has become an emerging therapeutic modality for the treatment of central nervous system disease, given their paracrine properties and immunoregulatory. Herein, we discussed the therapeutic potential of MSCs for CSVD, aiming to enable clinicians and researchers to understand of recent progress and future directions in the field.

13.
Lett Appl Microbiol ; 77(3)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38414284

ABSTRACT

The most toxic of the ochratoxins is ochratoxin A (OTA), which is primarily produced by species of Aspergillus and Penicillium that can be found in maize, wheat, coffee, red wine, and various grains. OTA induces immunotoxicity, nephrotoxicity, hepatotoxicity, teratogenicity, and carcinogenicity in both animals and humans. Thus, there is a need to identify mycotoxin detoxification agents that can effectively decontaminate OTA. Seeds of basil (Ocimum basilicum L.), chan (Hyptis suaveolens L.), and chia (Salvia hispanica L.) are functional foods capable of eliminating harmful substances. Despite this potential, the impact of these seeds on OTA detoxification remains unclear. This study reveals that milled basil, chan, and chia seeds adsorb significant levels of OTA, with chia demonstrating the highest adsorption capacity, followed by chan and basil seeds showing the least efficiency. Furthermore, milled basil, chan, and chia seeds effectively reduced OTA residues in artificial gastric and intestinal fluids, where they achieved up to 93% OTA adsorption in the former. In addition, these milled seeds were able to remove OTAs from canned, drip, and instant coffee. This study is the first to report the OTA elimination potential of basil, chan, and chia seeds.


Subject(s)
Ochratoxins , Ocimum basilicum , Humans , Animals , Ochratoxins/analysis , Coffee/chemistry , Seeds/chemistry
14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 32(1): 274-281, 2024 Feb.
Article in Chinese | MEDLINE | ID: mdl-38387934

ABSTRACT

OBJECTIVE: To construct recombinant lentivirus and adenovirus which regulate the expression of c-Cbl gene and evaluate their efficacy. METHODS: The interference lentivirus and overexpressed adenovirus targeting human c-Cbl gene were constructed by gene recombination technology. Quantitative PCR and western blotting were used to detect the expression changes in c-Cbl gene and its transcription after leukemia cells (HL60,THP1) were infected by virus. RESULTS: Three recombinant interfering lentiviral vectors targeting human c-Cbl genes to successfully constructed and were identified by DNA sequencing, and the titers of the packaged viruses were all greater than 1×108 TU/ml. Among them, shRNA-2 lentivirus had the highest interference efficiency, and the expression of c-Cbl gene and CBL protein were decreased about 95% and 60% respectively after leukemia cells were infected with shRNA-2; In addition, the recombinant overexpression adenovirus targeting human c-Cbl gene was packaged successfully with the virus titer greater than 1×109 TU/ml. When leukemia cells were infected with adenovirus, the expression of c-Cbl gene and CBL protein were up-regulated about 10 times and 1.5 times respectively. CONCLUSION: Both recombinant interfering lentivirus and overexpression adenovirus can efficiently infect leukemia cells and affect the expressions of c-Cbl gene and CBL protein. It will lay a preliminary foundation for the subsequent study on the function of c-Cbl gene in tumor cells.


Subject(s)
Genetic Vectors , Leukemia , Humans , Adenoviridae/genetics , Lentivirus/genetics , RNA, Small Interfering/genetics
15.
J Neural Eng ; 21(1)2024 02 23.
Article in English | MEDLINE | ID: mdl-38364290

ABSTRACT

Objective.Retinal prosthetics offer partial restoration of sight to patients blinded by retinal degenerative diseases through electrical stimulation of the remaining neurons. Decreasing the pixel size enables increasing prosthetic visual acuity, as demonstrated in animal models of retinal degeneration. However, scaling down the size of planar pixels is limited by the reduced penetration depth of the electric field in tissue. We investigated 3-dimensional (3d) structures on top of photovoltaic arrays for enhanced penetration of the electric field, permitting higher resolution implants.Approach.3D COMSOL models of subretinal photovoltaic arrays were developed to accurately quantify the electrodynamics during stimulation and verified through comparison to flat photovoltaic arrays. Models were applied to optimize the design of 3D electrode structures (pillars and honeycombs). Return electrodes on honeycomb walls vertically align the electric field with bipolar cells for optimal stimulation. Pillars elevate the active electrode, thus improving proximity to target neurons. The optimized 3D structures were electroplated onto existing flat subretinal prostheses.Main results.Simulations demonstrate that despite exposed conductive sidewalls, charge mostly flows via high-capacitance sputtered iridium oxide films topping the 3D structures. The 24µm height of honeycomb structures was optimized for integration with the inner nuclear layer cells in the rat retina, whilst 35µm tall pillars were optimized for penetrating the debris layer in human patients. Implantation of released 3D arrays demonstrates mechanical robustness, with histology demonstrating successful integration of 3D structures with the rat retinain-vivo.Significance. Electroplated 3D honeycomb structures produce vertically oriented electric fields, providing low stimulation thresholds, high spatial resolution, and high contrast for pixel sizes down to 20µm. Pillar electrodes offer an alternative for extending past the debris layer. Electroplating of 3D structures is compatible with the fabrication process of flat photovoltaic arrays, enabling much more efficient retinal stimulation.


Subject(s)
Artificial Limbs , Retinal Degeneration , Visual Prosthesis , Humans , Rats , Animals , Prostheses and Implants , Retina/physiology , Neurons/physiology , Electric Stimulation , Electrodes, Implanted
16.
Phytochem Anal ; 35(2): 336-349, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37787024

ABSTRACT

INTRODUCTION: The root of Bupleurum scorzonerifolium Willd. (BS) is officially recognized in the Chinese Pharmacopoeia. In contrast, the aerial part of BS (ABS), accounting for 80% of BS, is typically discarded, causing potential waste of medicinal resources. ABS has shown benefits in the treatment of inflammation-related diseases in China and Spain, and the material basis underlying its anti-inflammatory effects must be systematically elucidated for the rational use of ABS. OBJECTIVE: We aimed to screen and validate the anti-inflammatory quality markers (Q-markers) of ABS and to confirm the ideal time for ABS harvesting. METHODS: The chemical components and anti-inflammatory effects of ABS from 10 extracted parts were analyzed by UPLC-Q-TOF-MS/MS and in a lipopolysaccharide (LPS)-induced cell model. Anti-inflammatory substances were screened by Pearson bivariate analysis and gray correlation analysis, and the anti-inflammatory effects were verified in a zebrafish tail-cutting inflammation model. HPLC was applied to measure the Q-marker contents of ABS in different harvesting periods. RESULTS: Ten ABS extracts effectively alleviated the increase in LPS-induced proinflammatory cytokines in RAW 264.7 cells. Forty components were identified from them, among which 27 were common components. Eight components were correlated with anti-inflammatory effects, which were confirmed to reverse the expression of proinflammatory and anti-inflammatory factors in a zebrafish model. Chlorogenic acid, hypericin, rutin, quercetin, and isorhamnetin can be detected by HPLC, and the maximum contents of these five Q-markers were obtained in the sample harvested in August. CONCLUSION: The anti-inflammatory Q-markers of ABS were elucidated by chromatographic-pharmacodynamic-stoichiometric analysis, which served as a crucial basis for ABS quality control.


Subject(s)
Bupleurum , Tandem Mass Spectrometry , Mice , Animals , Zebrafish , Chromatography, High Pressure Liquid , Bupleurum/chemistry , RAW 264.7 Cells , Lipopolysaccharides/pharmacology , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/analysis , Inflammation/drug therapy , Plant Components, Aerial/chemistry
17.
bioRxiv ; 2023 Nov 13.
Article in English | MEDLINE | ID: mdl-38014082

ABSTRACT

Objective: High-resolution retinal prosthetics offer partial restoration of sight to patients blinded by retinal degenerative diseases through electrical stimulation of the remaining neurons. Decreasing the pixel size enables an increase in prosthetic visual acuity, as demonstrated in animal models of retinal degeneration. However, scaling down the size of planar pixels is limited by the reduced penetration depth of the electric field in tissue. We investigate 3-dimensional structures on top of the photovoltaic arrays for enhanced penetration of electric field to permit higher-resolution implants. Approach: We developed 3D COMSOL models of subretinal photovoltaic arrays that accurately quantify the device electrodynamics during stimulation and verified it experimentally through comparison with the standard (flat) photovoltaic arrays. The models were then applied to optimise the design of 3D electrode structures (pillars and honeycombs) to efficiently stimulate the inner retinal neurons. The return electrodes elevated on top of the honeycomb walls surrounding each pixel orient the electric field inside the cavities vertically, aligning it with bipolar cells for optimal stimulation. Alternatively, pillars elevate the active electrode into the inner nuclear layer, improving proximity to the target neurons. Modelling results informed a microfabrication process of electroplating the 3D electrode structures on top of the existing flat subretinal prosthesis. Main results: Simulations demonstrate that despite the conductive sidewalls of the 3D electrodes being exposed to electrolyte, most of the charge flows via the high-capacitance sputtered Iridium Oxide film that caps the top of the 3D structures. The 24 µm height of the electroplated honeycomb structures was optimised for integration with the inner nuclear layer cells in rat retina, while 35 µm height of the pillars was optimized for penetrating the debris layer in human patients. Release from the wafer and implantation of the 3D arrays demonstrated that they are mechanically robust to withstand the associated forces. Histology demonstrated successful integration of the 3D structures with the rat retina in-vivo. Significance: Electroplated 3D honeycomb structures produce a vertically oriented electric field that offers low stimulation threshold, high spatial resolution and high contrast for the retinal implants with pixel sizes down to 20µm in width. Pillar electrodes offer an alternative configuration for extending the stimulation past the debris layers. Electroplating of the 3D structures is compatible with the fabrication process of the flat photovoltaic arrays, thereby enabling much more efficient stimulation than in their original flat configuration.

18.
J Agric Food Chem ; 71(49): 19672-19681, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38016669

ABSTRACT

Enzymatic synthesis of ursodeoxycholic acid (UDCA) catalyzed by an NADH-dependent 7ß-hydroxysteroid dehydrogenase (7ß-HSDH) is more economic compared with an NADPH-dependent 7ß-HSDH when considering the much higher cost of NADP+/NADPH than that of NAD+/NADH. However, the poor catalytic performance of NADH-dependent 7ß-HSDH significantly limits its practical applications. Herein, machine-learning-guided protein engineering was performed on an NADH-dependent Rt7ß-HSDHM0 from Ruminococcus torques. We combined random forest, Gaussian Naïve Bayes classifier, and Gaussian process regression with limited experimental data, resulting in the best variant Rt7ß-HSDHM3 (R40I/R41K/F94Y/S196A/Y253F) with improvements in specific activity and half-life (40 °C) by 4.1-fold and 8.3-fold, respectively. The preparative biotransformation using a "two stage in one pot" sequential process coupled with Rt7ß-HSDHM3 exhibited a space-time yield (STY) of 192 g L-1 d-1, which is so far the highest productivity for the biosynthesis of UDCA from chenodeoxycholic acid (CDCA) with NAD+ as a cofactor. More importantly, the cost of raw materials for the enzymatic production of UDCA employing Rt7ß-HSDHM3 decreased by 22% in contrast to that of Rt7ß-HSDHM0, indicating the tremendous potential of the variant Rt7ß-HSDHM3 for more efficient and economic production of UDCA.


Subject(s)
NAD , Ursodeoxycholic Acid , Ursodeoxycholic Acid/metabolism , NADP/metabolism , Bayes Theorem , Hydroxysteroid Dehydrogenases/genetics , Hydroxysteroid Dehydrogenases/metabolism
19.
Sci Adv ; 9(48): eadi7375, 2023 12.
Article in English | MEDLINE | ID: mdl-38019913

ABSTRACT

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic neoplasms originating from hematopoietic stem progenitor cells (HSPCs). We previously identified frequent roundabout guidance receptor 1 (ROBO1) mutations in patients with MDS, while the exact role of ROBO1 in hematopoiesis remains poorly delineated. Here, we report that ROBO1 deficiency confers MDS-like disease with anemia and multilineage dysplasia in mice and predicts poor prognosis in patients with MDS. More specifically, Robo1 deficiency impairs HSPC homeostasis and disrupts HSPC pool, especially the reduction of megakaryocyte erythroid progenitors, which causes a blockage in the early stages of erythropoiesis in mice. Mechanistically, transcriptional profiling indicates that Cdc42, a member of the Rho-guanosine triphosphatase family, acts as a downstream target gene for Robo1 in HSPCs. Overexpression of Cdc42 partially restores the self-renewal and erythropoiesis of HSPCs in Robo1-deficient mice. Collectively, our result implicates the essential role of ROBO1 in maintaining HSPC homeostasis and erythropoiesis via CDC42.


Subject(s)
Erythropoiesis , Myelodysplastic Syndromes , Animals , Humans , Mice , Erythropoiesis/genetics , Myelodysplastic Syndromes/genetics , Nerve Tissue Proteins/genetics , Prognosis , Receptors, Immunologic/genetics , Roundabout Proteins
20.
Proc Natl Acad Sci U S A ; 120(42): e2307380120, 2023 10 17.
Article in English | MEDLINE | ID: mdl-37831740

ABSTRACT

In patients blinded by geographic atrophy, a subretinal photovoltaic implant with 100 µm pixels provided visual acuity closely matching the pixel pitch. However, such flat bipolar pixels cannot be scaled below 75 µm, limiting the attainable visual acuity. This limitation can be overcome by shaping the electric field with 3-dimensional (3-D) electrodes. In particular, elevating the return electrode on top of the honeycomb-shaped vertical walls surrounding each pixel extends the electric field vertically and decouples its penetration into tissue from the pixel width. This approach relies on migration of the retinal cells into the honeycomb wells. Here, we demonstrate that majority of the inner retinal neurons migrate into the 25 µm deep wells, leaving the third-order neurons, such as amacrine and ganglion cells, outside. This enables selective stimulation of the second-order neurons inside the wells, thus preserving the intraretinal signal processing in prosthetic vision. Comparable glial response to that with flat implants suggests that migration and separation of the retinal cells by the walls does not cause additional stress. Furthermore, retinal migration into the honeycombs does not negatively affect its electrical excitability, while grating acuity matches the pixel pitch down to 40 µm and reaches the 27 µm limit of natural resolution in rats with 20 µm pixels. These findings pave the way for 3-D subretinal prostheses with pixel sizes of cellular dimensions.


Subject(s)
Porifera , Retinal Neurons , Visual Prosthesis , Humans , Rats , Animals , Prosthesis Implantation , Retina/physiology , Vision, Ocular , Electric Stimulation
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