The effect of repetitive magnetic stimulation on neuronal apoptosis and PI3K/Akt protein expression in rats with incomplete spinal cord injury.

The pathological and physiological process of spinal cord injury is complex, and there is currently no effective treatment method. Magnetic stimulation is an emerging electromagnetic therapy method in recent years, and studies have shown its potential to reduce cell apoptosis. This study used an improved Allen's method to replicate an incomplete spinal cord injury rat model, and repetitive magnetic stimulation intervention was performed on the rats for 21 days. The research plan consists of two parts. The first part aims to observe the effects of rMS on motor function and neuronal cell apoptosis in rats. The BBB score results indicate that rMS promotes the recovery of motor function in rats; H&E staining showed that rMS improved spinal cord structural damage and inflammatory infiltration; TUNEL and NeuN staining suggest that rMS can reduce cell apoptosis and promote neuronal cell survival. The second part aims to explore the mechanism of action of rMS. Immunofluorescence staining showed that after rMS intervention, the positive counts of PI3K and Akt increased, while the positive counts of Caspase-3 decreased. Western blot showed that after rMS intervention, the expression of p-PI3K/PI3K, p-Akt/Akt, and Bcl-2 increased, while the expression of Bax and Caspase-3 decreased. In summary, rMS can significantly reduce cell apoptosis in the damaged spinal cord and promote neuronal cell survival. Its mechanism of action may be related to promoting the expression of PI3K/Akt pathway proteins, upregulating the anti apoptotic protein Bcl-2, downregulating the pro apoptotic protein Bax, and thereby inhibiting the expression of apoptotic protein Caspase-3.

PagJAZ5 regulates cambium activity through coordinately modulating cytokinin concentration and signaling in poplar.

Wood is resulted from the radial growth paced by the division and differentiation of vascular cambium cells in woody plants, and phytohormones play important roles in cambium activity. Here, we identified that PagJAZ5, a key negative regulator of jasmonate (JA) signaling, plays important roles in enhancing cambium cell division and differentiation by mediating cytokinin signaling in poplar 84K (Populus alba × Populus glandulosa). PagJAZ5 is preferentially expressed in developing phloem and cambium, weakly in developing xylem cells. Overexpression (OE) of PagJAZ5m (insensitive to JA) increased cambium activity and xylem differentiation, while jaz mutants showed opposite results. Transcriptome analyses revealed that cytokinin oxidase/dehydrogenase (CKXs) and type-A response regulators (RRs) were downregulated in PagJAZ5m OE plants. The bioactive cytokinins were significantly increased in PagJAZ5m overexpressing plants and decreased in jaz5 mutants, compared with that in 84K plants. The PagJAZ5 directly interact with PagMYC2a/b and PagWOX4b. Further, we found that the PagRR5 is regulated by PagMYC2a and PagWOX4b and involved in the regulation of xylem development. Our results showed that PagJAZ5 can increase cambium activity and promote xylem differentiation through modulating cytokinin level and type-A RR during wood formation in poplar.

PagERF81 regulates lignin biosynthesis and xylem cell differentiation in poplar.

Lignin is a major component of plant cell walls and is essential for plant growth and development. Lignin biosynthesis is controlled by a hierarchical regulatory network involving multiple transcription factors. In this study, we showed that the gene encoding an APETALA 2/ethylene-responsive element binding factor (AP2/ERF) transcription factor, PagERF81, from poplar 84 K (Populus alba × P. glandulosa) is highly expressed in expanding secondary xylem cells. Two independent homozygous Pagerf81 mutant lines created by gene editing, produced significantly more but smaller vessel cells and longer fiber cells with more lignin in cell walls, while PagERF81 overexpression lines had less lignin, compared to non-transgenic controls. Transcriptome and reverse transcription quantitative PCR data revealed that multiple lignin biosynthesis genes including Cinnamoyl CoA reductase 1 (PagCCR1), Cinnamyl alcohol dehydrogenase 6 (PagCAD6), and 4-Coumarate-CoA ligase-like 9 (Pag4CLL9) were up-regulated in Pagerf81 mutants, but down-regulated in PagERF81 overexpression lines. In addition, a transient transactivation assay revealed that PagERF81 repressed the transcription of these three genes. Furthermore, yeast one hybrid and electrophoretic mobility shift assays showed that PagERF81 directly bound to a GCC sequence in the PagCCR1 promoter. No known vessel or fiber cell differentiation related genes were differentially expressed, so the smaller vessel cells and longer fiber cells observed in the Pagerf81 lines might be caused by abnormal lignin deposition in the secondary cell walls. This study provides insight into the regulation of lignin biosynthesis, and a molecular tool to engineer wood with high lignin content, which would contribute to the lignin-related chemical industry and carbon sequestration.

Design, synthesis and biological evaluation of novel 4-aminopiperidine derivatives as SMO/ERK dual inhibitors.

The hedgehog (Hh) pathway is tightly related with the formation, metastasis and recurrence of various cancers, which makes it a perfect anticancer target. Smoothened (SMO) is one of its key members. Three drugs targeting the Hh pathway have been successfully used in clinic, and they are all known as SMO inhibitors. However, serious drug resistant problem has limited their clinical application. The interaction of oncogenic ERK pathway with the Hh pathway in multiple ways has been proved as one of the main factors that result in drug resistance. Dual inhibition of the Hh and ERK pathways has displayed synergistic suppression to cancer cells overexpressing both pathways. Herein, we designed and synthesized a series of novel 4-aminopiperidine derivatives as SMO/ERK dual inhibitors, and evaluated their biological activities. The results showed that compounds I-13 displayed strong inhibitory activities towards both SMO and ERK, and it also exhibited significant cytotoxicity against human cholangiocarcinoma RBE cells which overexpress both the Hh and ERK pathways. All the results indicate that compound I-13 is a promising anticancer candidate as a SMO/ERK dual inhibitor.

Inhibiting Mercury Re-emission and Enhancing Magnesia Recovery by Cobalt-Loaded Carbon Nanotubes in a Novel Magnesia Desulfurization Process.

Mercury re-emission, because of the reduction of Hg2+ to form Hg0 by sulfite, has become a great concern in the desulfurization process. Lowering the concentrations of Hg2+ and sulfite in the desulfurization slurry can retard the Hg0 formation and, thus, mitigate mercury re-emission. To that end, cobalt-based carbon nanotubes (Co-CNTs) were developed for the simultaneous Hg2+ removal and sulfite oxidation in this work. Furthermore, the thermodynamics and kinetics of the Hg2+ adsorption and effect of Hg2+ adsorption on catalytic activity of Co-CNTs were investigated. Experimental results revealed that the Co-CNTs not only accelerated sulfite oxidation to enable the recovery of desulfurization by-products but also acted as an effective adsorbent of Hg2+ removal. The Hg2+ adsorption rate mainly depended on the structure of the adsorption material regardless of the cobalt loading and morphological distribution. The catalytic activity of the Co-CNTs for sulfite oxidation was not significantly affected due to the Hg2+ adsorption. Additionally, the isothermal adsorption behavior was well-fitted to the Langmuir model with an adsorption capacity of 166.7 mg/g. The mercury mass balance analysis revealed that the Hg0 re-emission was decreased by 156% by adding 2.0 g/L of Co-CNTs. These results can be used as a reference for the simultaneous removal of multiple pollutants in the wet-desulfurization process.

PagKNAT2/6b regulates tension wood formation and gravitropism by targeting cytokinin metabolism.

Tension wood is a specialized xylem tissue associated with gravitropism in angiosperm trees. However, few regulators of tension wood formation have been identified. The molecular mechanisms underpinning tension wood formation remain elusive. Here, we report that a Populus KNOTTED-like homeobox gene, PagKNAT2/6b, is involved in tension wood formation and gravity response. Transgenic poplar plants overexpressing PagKNAT2/6b displayed more sensitive gravitropism than controls, as indicated by increased stem curvature. Microscopic examination revealed greater abundance of fibre cells with a gelatinous cell wall layer (G-layer) and asymmetric growth of secondary xylem in PagKNAT2/6b overexpression lines. Conversely, PagKNAT2/6b dominant repression plants exhibited decreased tension wood formation and reduced response to gravity stimulation. Moreover, sensitivity to gravity stimulation showed a negative relationship with development stage. Expression of genes related to growth and senescence was affected in PagKNAT2/6b transgenic plants. More importantly, transcription activation and electrophoretic mobility shift assays suggested that PagKNAT2/6b promotes the expression of cytokinin metabolism genes. Consistently, cytokinin content was increased in PagKNAT2/6b overexpression plants. Therefore, PagKNAT2/6b is involved in gravitropism and tension wood formation, likely via modulation of cytokinin metabolism.

Genetic diversity and shallow genetic differentiation of the endangered scaly-sided merganser Mergus squamatus.

Examining patterns of genetic diversity are crucial for conservation planning on endangered species, while inferring the underlying process of recent anthropogenic habitat modifications in the context potential long-term demographic changes remains challenging. The globally endangered scaly-sided merganser (SSME), Mergus squamatus, is endemic to a narrow range in Northeast Asia, and its population has recently been contracted into two main breeding areas. Although low genetic diversity has been suggested in the Russian population, the genetic status and demographic history of these individuals have not been fully elucidated. We therefore examined the genetic diversity and structure of the breeding populations of the SSME and investigated the relative importance of historical and recent demographic changes to the present-day pattern of genetic diversity. Using 10 nuclear microsatellite (SSR) markers and mitochondrial DNA (mtDNA) control region sequences, we found limited female-inherited genetic diversity and a high level of nuclear genetic diversity. In addition, analysis of both markers consistently revealed significant but weak divergence between the breeding populations. Inconsistent demographic history parameters calculated from mtDNA and bottleneck analysis results based on SSR suggested a stable historical effective population size. By applying approximate Bayesian computation, it was estimated that populations started to genetically diverge from each other due to recent fragmentation events caused by anthropogenic effects rather than isolation during Last Glacial Maximum (LGM) and post-LGM recolonization. These results suggest that limited historical population size and shallow evolutionary history may be potential factors contributing to the contemporary genetic diversity pattern of breeding SSME populations. Conservation efforts should focus on protecting the current breeding habitats from further destruction, with priority given to both the Russian and Chinese population, as well as restoring the connected suitable breeding grounds.

The Application Progress of Nonthermal Plasma Technology in the Modification of Bone Implant Materials.

With the accelerating trend of global aging, bone damage caused by orthopedic diseases, such as osteoporosis and fractures, has become a shared international event. Traffic accidents, high-altitude falls, and other incidents are increasing daily, and the demand for bone implant treatment is also growing. Although extensive research has been conducted in the past decade to develop medical implants for bone regeneration and healing of body tissues, due to their low biocompatibility, weak bone integration ability, and high postoperative infection rates, pure titanium alloys, such as Ti-6A1-4V and Ti-6A1-7Nb, although widely used in clinical practice, have poor induction of phosphate deposition and wear resistance, and Ti-Zr alloy exhibits a lack of mechanical stability and processing complexity. In contrast, the Ti-Ni alloy exhibits toxicity and low thermal conductivity. Nonthermal plasma (NTP) has aroused widespread interest in synthesizing and modifying implanted materials. More and more researchers are using plasma to modify target catalysts such as changing the dispersion of active sites, adjusting electronic properties, enhancing metal carrier interactions, and changing their morphology. NTP provides an alternative option for catalysts in the modification processes of oxidation, reduction, etching, coating, and doping, especially for materials that cannot tolerate thermodynamic or thermosensitive reactions. This review will focus on applying NTP technology in bone implant material modification and analyze the overall performance of three common types of bone implant materials, including metals, ceramics, and polymers. The challenges faced by NTP material modification are also discussed.

Effects of transcranial magnetic stimulation on axonal regeneration in the corticospinal tract of female rats with spinal cord injury.

BACKGROUND: This study investigates the potential of transcranial magnetic stimulation (TMS) to enhance spinal cord axon regeneration by modulating corticospinal pathways and improving motor nerve function recovery in rats with spinal cord injury (SCI). NEW METHOD: TMS is a non-invasive neuromodulation technique that generates a magnetic field to activate neurons in the brain, leading to depolarization and modulation of cortical activity. Initially utilized for brain physiology research, TMS has evolved into a diagnostic and prognostic tool in clinical settings, with increasing interest in its therapeutic applications. However, its potential for treating motor dysfunction in SCI has been underexplored. RESULTS: The TMS intervention group exhibited significant improvements compared to the control group across behavioral assessments, neurophysiological measurements, pathological analysis, and immunological markers. COMPARISON WITH EXISTING METHODS: Unlike most studies that focus on localized spinal cord injury or muscle treatments, this study leverages the non-invasive, painless, and highly penetrating nature of TMS to focus on the corticospinal tracts, exploring its therapeutic potential for SCI. CONCLUSIONS: TMS enhances motor function recovery in rats with SCI by restoring corticospinal pathway integrity and promoting axonal regeneration. These findings highlight TMS as a promising therapeutic option for SCI patients with currently limited treatment alternatives.

Rational Design of PARP1/c-Met Dual Inhibitors for Overcoming PARP1 Inhibitor Resistance Induced by c-Met Overexpression.

The emergence of resistance to PARP1 inhibitors poses a current therapeutic challenge, necessitating the development of novel strategies to overcome this obstacle. The present study describes the design and synthesis of a series of small molecules that target both PARP1 and c-Met. Among them, compound 16 is identified as a highly potent dual inhibitor, exhibiting excellent inhibitory activities against PARP1 (IC50 = 3.3 nM) and c-Met (IC50 = 32.2 nM), as well as demonstrating good antiproliferative effects on HR-proficient cancer cell lines and those resistant to PARP1 inhibitors. Importantly, compound 16 demonstrates superior antitumor potency compared to the PARP1 inhibitor Olaparib and the c-Met inhibitor Crizotinib, either alone or in combination, in MDA-MB-231 and HCT116OR xenograft models. These findings highlight the potential of PARP1/c-Met dual inhibitors for expanding the indications of PARP1 inhibitors and overcoming tumor cells' resistance to them.

A method for analyzing programmed cell death in xylem development by flow cytometry.

Programmed cell death (PCD) is a genetically regulated developmental process leading to the death of specific types of plant cells, which plays important roles in plant development and growth such as wood formation. However, an efficient method needs to be established to study PCD in woody plants. Flow cytometry is widely utilized to evaluate apoptosis in mammalian cells, while it is rarely used to detect PCD in plants, especially in woody plants. Here, we reported that the xylem cell protoplasts from poplar stem were stained with a combination of fluorescein annexin V-FITC and propidium iodide (PI) and then sorted by flow cytometry. As expected, living cells (annexin V-FITC negative/PI negative), early PCD cells (annexin V-FITC positive/PI negative), and late PCD cells (annexin V-FITC positive/PI positive) could be finely distinguished through this method and then subjected for quantitative analysis. The expression of cell-type- and developmental stages-specific marker genes was consistent with the cell morphological observation. Therefore, the newly developed fluorescence-activated cell sorting (FACS) method can be used to study PCD in woody plants, which will be beneficial for studying the molecular mechanisms of wood formation.

Body Weight Support Treadmill Training Combined With Sciatic Nerve Electrical Stimulation Ameliorating Motor Function by Enhancing PI3K/Akt Proteins Expression via BDNF/TrkB Signaling Pathway in Rats with Spinal Cord Injury.

OBJECTIVE: To investigate the effects of body weight support treadmill training (BWSTT) and sciatic nerve electrical stimulation (SNES) on motor function recovery in spinal cord injury (SCI) rats and its possible mechanism. METHODS: Modified Allen's method was utilized for T10 incomplete SCI. The Basso-Beattie-Bresnahan (BBB) score and modified Tarlov score were applied to assess motor function. Pathologic alterations of the spinal cord and muscles were observed by hematoxylin and eosin (HE) staining. The positive staining region of collagen fibers was assessed with Masson staining. Immunofluorescence was applied to count the positive cells of brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB). BDNF, TrkB, phosphatidylinositol-3-kinase (PI3K), and protein kinase B (Akt) relative mRNA and protein expressions were evaluated by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting. RESULTS: On the 21st day of the intervention, the motor scores in SNES and BWSTT + SNES groups were higher than that in SCI group (P < 0.05). Compared with SCI group, mRNA and protein expressions of BDNF/TrkB and PI3K/Akt were more significant on the 21st day of the intervention in SNES and BWSTT + SNES groups (P < 0.05), but there was no difference in BWSTT group (P > 0.05). CONCLUSIONS: This experiment demonstrated that BWSTT combined with SNES contributed to alleviating spinal cord tissue injury, delaying muscle atrophy and improving locomotion. One of the possible mechanisms may be related to the regulation of the BDNF/TrkB signaling pathway, which changes the expression of PI3K/Akt protein. Furthermore, it was discovered that the ultra-early BWSTT may not be conducive to recovery.

[Adsorption of methylene blue from aqueous solution onto magnetic Fe3O4/ graphene oxide nanoparticles].

A simple ultrasound-assisted co-precipitation method was developed to prepare magnetic Fe3O4/graphene oxide (Fe3O4/ GO) nanoparticles. The characterization with transmission electron microscope (TEM) indicated that the products possessed small particle size. The hysteresis loop of the dried Fe3O4/GO nanoparticles demonstrated that the sample had typical features of superparamagnetic material. Batch adsorption studies were carried out to investigate the effects of the initial pH of the solution, the dosage of adsorbent, the contact time and temperature on the adsorption of methylene blue. The results indicated that the composites prepared could be used over a broad pH range (pH 6-9). The adsorption process was very fast within the first 25 min and the equilibrium was reached at 180 min. The adsorption equilibrium and kinetics data fitted well with the Langmuir isotherm model and the pseudo-second-order kinetic model. The adsorption process was a spontaneous and endothermic process in nature. The composite exhibited fairly high adsorption capacity (196.5 mg.g-1) of methylene blue at 313 K. In addition, the magnetic composite could be effectively and simply separated by using an external magnetic field, and then regenerated by hydrogen peroxide and recycled for further use. The results indicated that the adsorbent had a potential in the application of the dye wastewater treatment.