Since the era of plant tissue culture bloomed, we have started approaching from a biotechnological perspective to overcome the massive challenges like inducing embryogenesis and organogenesis, ...initiating rooting, increasing the number of plantlets, establishing a callus from various organs of plants and also enhancing the metabolite content which was a mind-boggling thought once upon a time. Use of various elicitors, altering the media components, the strength of media, pH, precursor feeding etc. have all contributed tremendously in the in-vitro techniques used for culturing rare, endemic and medicinal plants for the commercial purposes. Owing to the demand for the plant products and drugs, the search for the other superior novel methods to increase its quantity and quality has not been stopped. Thus, one such method is the use of chemical compounds with many amino groups which serves as an additional source of nitrogen in the media and these organic compounds are called polyamines. Polyamines are known to play a wide role in plant physiological processes helping them in differentiation, inducing totipotency, increasing cell division and also in molecular signaling. Polyamines have a versatile application in this field ranging from establishing a callus to the elicitation of secondary metabolites. Thus, polyamines can be considered as a boon to the plant tissue culture field. In this review article, we have mainly focused on the in-depth applications of major polyamines like putrescine, spermidine and spermine in the field of plant tissue culture.
The glycolytic enzyme PKM2 (pyruvate kinase muscle 2) is upregulated in monocytes/macrophages of patients with atherosclerotic coronary artery disease. However, the role of cell type-specific PKM2 in ...the setting of atherosclerosis remains to be defined. We determined whether myeloid cell-specific PKM2 regulates efferocytosis and atherosclerosis.
We generated myeloid cell-specific PKM2
mice on Ldlr (low-density lipoprotein receptor)-deficient background (PKM2
Ldlr
). Controls were littermate PKM2
Ldlr
mice. Susceptibility to atherosclerosis was evaluated in whole aortae and cross sections of the aortic sinus in male and female mice fed a high-fat Western diet for 14 weeks, starting at 8 weeks.
PKM2 was upregulated in macrophages of Ldlr
mice fed a high-fat Western diet compared with chow diet. Myeloid cell-specific deletion of PKM2 led to a significant reduction in lesions in the whole aorta and aortic sinus despite high cholesterol and triglyceride levels. Furthermore, we found decreased macrophage content in the lesions of myeloid cell-specific PKM2
mice associated with decreased MCP-1 (monocyte chemoattractant protein 1) levels in plasma, reduced transmigration of macrophages in response to MCP-1, and impaired glycolytic rate. Macrophages isolated from myeloid-specific PKM2
mice fed the Western diet exhibited reduced expression of proinflammatory genes, including MCP-1, IL (interleukin)-1β, and IL-12. Myeloid cell-specific PKM2
mice exhibited reduced apoptosis concomitant with enhanced macrophage efferocytosis and upregulation of LRP (LDLR-related protein)-1 in macrophages in vitro and atherosclerotic lesions in vivo. Silencing LRP-1 in PKM2-deficient macrophages restored inflammatory gene expression and reduced efferocytosis. As a therapeutic intervention, inhibiting PKM2 nuclear translocation using a small molecule reduced glycolytic rate, enhanced efferocytosis, and reduced atherosclerosis in Ldlr
mice.
Genetic deletion of PKM2 in myeloid cells or limiting its nuclear translocation reduces atherosclerosis by suppressing inflammation and enhancing efferocytosis.
Abstract Integrin α9β1 is known to stabilize leukocyte adhesion to the activated endothelium. We determined the role of myeloid cell α9β1 in early atherosclerosis in two models: α9Mye-KOApoe−/− or ...the Ldlr−/− mice transplanted with bone marrow (BM) from α9Mye-KO mice fed a high-fat “Western” diet for 4 wk. α9Mye-KOApoe−/− mice exhibited reduced early lesions in the aortae and aortic sinuses (P < 0.05 vs α9WT Apoe−/− mice). Similar results were obtained in α9Mye-KO BM→Ldlr−/− mice (P < 0.05 vs α9WT BM→Ldlr−/− mice). Reduced early atherosclerosis in α9Mye-KOApoe−/− mice was associated with decreased neutrophil and neutrophil extracellular traps (NETs) content in the aortic lesions (P < 0.05 vs α9WTApoe−/−). Vascular cell adhesion molecule-1-stimulated neutrophils from α9Mye-KO mice exhibited reduced adhesion, transmigration, and NETs formation (NETosis) (P < 0.05 vs α9WT neutrophils). Reduced NETosis was associated with decreased extracellular signal-regulated kinase phosphorylation, peptidyl arginine deiminase 4, and citrullinated histone H3 expression. In summary, genetic ablation of myeloid cell-specific α9 reduces early atherosclerosis, most likely by reducing neutrophil adhesion, transmigration, and NETosis.
Home-made multiwall carbon nanotubes (MWCNTs) were used as a reinforcing conducting filler for a thermoplastic polymer, polycarbonate (PC) and the mechanical and electrical properties of the ...composites were investigated for electrostatic discharge (ESD) and electromagnetic interference (EMI) shielding applications. A uniformly dispersed MWCNT/PC composite system was fabricated using solvent casting and a combination of solvent casting and compression molding techniques. The effect of MWCNTs on the failure mechanism of the polymer under tensile loading showed a ductile to brittle transition with increasing amount of carbon nanotubes. ESD studies showed that the composite films of 2 and 5 wt% functionalized-MWCNT/PC with respective charge decay times of 1 and 0.6 s show promise as electrostatic dissipative materials. EMI shielding effectiveness of a five-layered system ( similar to 2 mm thickness) of as-synthesized-MWCNT/PC composite films at 20 wt% loading reached 43 dB in the X-band (8.2-12.4 GHz). The primary mechanism of shielding was absorption, suggesting possible use as an EMI absorbing material. By using low pressure (contact pressure) compression molding the EMI shielding properties of bulk composites ( similar to 2 mm thickness) improved by about 14 dB at 10 wt% MWCNT loading.
Cellulose obtained from plants is a bio‐polysaccharide and the most abundant organic polymer on earth that has immense household and industrial applications. Hence, the characterization of cellulose ...is important for determining its appropriate applications. In this article, we review the characterization of cellulose morphology, surface topography using microscopic techniques including optical microscopy, transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. Other physicochemical characteristics like crystallinity, chemical composition, and thermal properties are studied using techniques including X‐ray diffraction, Fourier transform infrared, Raman spectroscopy, nuclear magnetic resonance, differential scanning calorimetry, and thermogravimetric analysis. This review may contribute to the development of using cellulose as a low‐cost raw material with anticipated physicochemical properties.
Highlights
Morphology and surface topography of cellulose structure is characterized using microscopy techniques including optical microscopy, transmission electron microscopy, scanning electron microscopy, and atomic force microscopy.
Analytical techniques used for physicochemical characterization of cellulose include X‐ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and thermogravimetric analysis.
Schematics of ultrastructure of cellulose fibers from plant sources.
Chronic diabetes mellitus is reported to be associated with acute kidney injury. The enzyme histone deacetylase-2 (HDAC-2) was found to be upregulated in diabetes-related kidney damage. ...Alpha-cyperone (α-CYP) is one of the active ingredients of Cyperus rotundus that possesses antioxidant and anti-inflammatory effects. We evaluated the effect of α-CYP on improving oxidative stress and tissue inflammation following renal ischemia/reperfusion (I/R) injury in diabetic rats. The effect of α-CYP on HDAC-2 expression in renal homogenates and in the NRK-52 E cell line was evaluated following renal I/R injury and high glucose conditions, respectively. Molecular docking was used to investigate the binding of α-CYP with the HDAC-2 active site. Both renal function and oxidative stress were shown to be impaired in diabetic rats due to renal I/R injury. Significant improvements in kidney/body weight ratio, creatinine clearance, serum creatinine, blood urea nitrogen (BUN), and uric acid were observed in diabetic rats treated with α-CYP (50 mg/kg) two weeks prior to renal I/R injury. α-CYP treatment also improved histological alterations in renal tissue and lowered levels of malondialdehyde, myeloperoxidase, and hydroxyproline. Treatment with α-CYP suppressed the increased HDAC-2 expression in the renal tissue of diabetic rats and in the NRK-52 E cell line. The molecular docking reveals that α-CYP binds to HDAC-2 with good affinity, ascertained by molecular dynamics simulations and binding free energy analysis. Overall, our data suggest that α-CYP can effectively prevent renal injury in diabetic rats by regulating oxidative stress, tissue inflammation, fibrosis and inhibiting HDAC-2 activity.
There is a critical need for cerebro-protective interventions to improve the suboptimal outcomes of patients with ischemic stroke who have been treated with reperfusion strategies. We found that ...nuclear pyruvate kinase muscle 2 (PKM2), a modulator of systemic inflammation, was upregulated in neutrophils after the onset of ischemic stroke in both humans and mice. Therefore, we determined the role of PKM2 in stroke pathogenesis by using murine models with preexisting comorbidities. We generated novel myeloid cell–specific PKM2−/− mice on wild-type (PKM2fl/flLysMCre+) and hyperlipidemic background (PKM2fl/flLysMCre+Apoe−/−). Controls were littermate PKM2fl/flLysMCre– or PKM2fl/flLysMCre–Apoe−/− mice. Genetic deletion of PKM2 in myeloid cells limited inflammatory response in peripheral neutrophils and reduced neutrophil extracellular traps after cerebral ischemia and reperfusion, suggesting that PKM2 promotes neutrophil hyperactivation in the setting of stroke. In the filament and autologous clot and recombinant tissue plasminogen activator stroke models, irrespective of sex, deletion of PKM2 in myeloid cells in either wild-type or hyperlipidemic mice reduced infarcts and enhanced long-term sensorimotor recovery. Laser speckle imaging revealed improved regional cerebral blood flow in myeloid cell–specific PKM2-deficient mice that was concomitant with reduced post-ischemic cerebral thrombo-inflammation (intracerebral fibrinogen, platelet CD41+ deposition, neutrophil infiltration, and inflammatory cytokines). Mechanistically, PKM2 regulates post-ischemic inflammation in peripheral neutrophils by promoting STAT3 phosphorylation. To enhance the translational significance, we inhibited PKM2 nuclear translocation using a small molecule and found significantly reduced neutrophil hyperactivation and improved short-term and long-term functional outcomes after stroke. Collectively, these findings identify PKM2 as a novel therapeutic target to improve brain salvage and recovery after reperfusion.
•Nuclear PKM2 is upregulated in neutrophils after the onset of ischemic stroke and promotes neutrophil hyperactivation.•PKM2 deficiency in myeloid cells improves short- and long-term stroke outcome by limiting postischemic cerebral thrombo-inflammation.
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Generators are critical components of electrical grids and have to operate synchronously. Unfortunately, faults in power grids can cause significant electro-mechanical oscillations. A number of ...methods to estimate these electro-mechanical oscillation modes have been proposed in the literature. With the advent of synchrophasors which enable real-time measurements over a wide-area, and in keeping with a trend towards more distributed monitoring and control applications (e.g., WAMPAC), measurement-based methods to estimate oscillation modes in a distributed manner have been proposed. Like other power system applications these distributed mode estimation approaches also face the prospect of false data injection attacks. In this paper, we introduce a mechanism, inspired by byzantine fault tolerance, for making distributed alternating direction of multipliers method of mode estimation resilient against data manipulation attacks. We evaluate our approach using IEEE 68-bus and 145-bus test systems under different attack scenarios and show that in all the scenarios considered our approach allows distributed mode estimation to converge well.
With the emerging rise in the need for drugs extracted from various plant sources, there also arises the need for the optimum production of the drugs on a larger scale and conservation of those ...medicinal plants using different
in vitro
techniques and biotechnological approaches. Plant tissue culture techniques play a prominent role in mass multiplication of the plant. Whereas, strategies such as precursor feeding, elicitation, increases the metabolite content several-fold. Thus, an attempt of using the biotic elicitors for enhancing L-DOPA production, the anti-Parkinson’s drug from
Mucuna pruriens
(L.) DC. cell cultures, has been reported in the present study. Aqueous extracts of algae
Amphiroa anceps
(AA),
Gracillaria ferogusonii
(GF),
Kappaphycus striatum
(KS), and
Sargassum lanceolatum
(SL), fungus
Aspergillus
sps. (AS),
Penicillium
sps. (PE), and
Cordyceps
sps (CO), and polysaccharide Chitosan (CH) solution were exposed to the cell cultures for 3, 6, and 9 d, respectively, and their effect on biomass and L-DOPA production was noted. This is the first report demonstrating the enhancement of biomass and L-DOPA from
M. pruriens
cell cultures with the use of various algal and fungal elicitors. Based on productivity (L-DOPA concentration × biomass × volume), it was observed that
Cordyceps
showed the best result and enhanced both biomass and metabolite to a greater scale. The elicitors, which showed a significant increase, are as follows: CO > AS > PE > CH > AA > KS > GF > SL. On the whole, it was noted that fungal extracts showed better results than algae.
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