How Mitochondrial Metabolism Contributes to Macrophage Phenotype and Functions

Metabolic reprogramming of cells from the innate immune system is one of the most noteworthy topics in immunological research nowadays. Upon infection or tissue damage, innate immune cells, such as macrophages, mobilize various immune and metabolic signals to mount a response best suited to eradicate the threat. Current data indicate that both the immune and metabolic responses are closely interconnected. On account of its peculiar position in regulating both of these processes, the mitochondrion has emerged as a critical organelle that orchestrates the coordinated metabolic and immune adaptations in macrophages. Significant effort is now underway to understand how metabolic features of differentiated macrophages regulate their immune specificities with the eventual goal to manipulate cellular metabolism to control immunity. In this review, we highlight some of the recent work that place cellular and mitochondrial metabolism in a central position in the macrophage differentiation program.     

Optimization of callus culture and shoot multiplication ofAsparagus densiflorus

The effects of different growth regulators on induction and growth of callus ofAsparagus densiflorus cv. Sprengeri were studied. Calluses grew more rapidly on Murashige and Skoog basal medium supplemented with 5.4 μM p-chlorophenoxyacetic acid (pCPA) and 4.4 μM 6-benzylaminopurine (BA) (medium 1) as compared to the same medium with 11.3 μM 2,4-dichlorophenoxyacetic acid (2,4-d) and 4.6 μM kinetin (medium 2). Calluses on medium 1 were soft and friable, whereas, compact, hard calluses originated on medium 2. Different concentrations and combinations of BA and/or kinetin were also used to study their effects on shoot regeneration. Kinetin was found to be less effective than BA in the initiation of shoots (1.8 shoots/callus). High numbers of shoots were produced in the presence of 0.4 μM BA alone (3.3 shoots/callus). The addition of ancymidol (5 μM) in MS with 0.4 μM BA enhanced multiplication of shoots (9.8 shoots/explant) and also produced well-developed crowns.     

Factors influencing regeneration from protoplasts of Asparagus densiflorus cv. Sprengeri

This article describes conditions to optimize the yield of viable protoplasts from callus tissue of Asparagus densiflorus cv. Sprengeri and their subsequent regeneration into plantlets. Callus tissue was initiated by culturing spear sections (5–7 mm) on Murashige and Skoog (MS) medium supplemented with 0.8% (wt/vol) Bacto agar, 3% (wt/vol) sucrose, 0.5 mg/l each of nicotinic acid, pyridoxine-HCl, and thiamine-HCl, 1 mg/l p-chlorophenoxyaceticacid (pCPA) and 1 mg/l 6-benzylaminopurine (BAP). The maximum protoplast yield was obtained in a mixture of 1% (wt/vol) Cellulysin, 0.8% (wt/vol) Rhozyme HP 150 and 0.3% (wt/vol) Macerase, dissolved in cell protoplast wash salt solution with 7 mm CaCl₂ ^.2H₂O, 3 mm MES, 0.6 m glucose, and 0.1 m mannitol. First divisions were observed after 3–4 days of initial culture. The plating efficiency was highest (7.8%) in half-strength MS semisolid medium containing 1 g/l glutamine, 0.6 m glucose, 0.1 m mannitol, 0.5 mg/l folic acid, 0.05 mg/l biotin, 2 mg/l ascorbic acid, 1 mg/l α-naphthaleneacetic acid, 0.5 mg/l zeatin, and 0.1% (wt/vol) Gelrite. Protoplast-derived microcolonies and microcalli were cultured on the same medium on which the primary callus culture was initiated. After 10–12 weeks, calli were transferred to shoot regeneration medium containing MS salts, 1 mg/l BAP, 0.5 mg/l pCPA and 0.2% Gelrite. Shoots (3–4 cm) were then transferred to MS rooting medium with 2 mg/l indole-3-butyric acid, and 0.2% Gelrite. Plantlets were obtained within 4–5 weeks. Received: 9 August 1995 / Revision received: 27 June 1997 / Accepted: 17 July 1997     

Molecular and biochemical responses of perennial forage crops to oxygen deprivation at low temperature

Anaerobic conditions developing under ice cover affect winter survival and spring regrowth of economically important perennial crops. Our objective was to assess interspecific differences in the resistance to anaerobic conditions at low temperature, and to relate those differences to plant metabolism. Four perennial forage species, alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), timothy (Phleum pratense L.) and orchardgrass (Dactylis glomerata L.), were subjected to a progressively developing anoxic stress by enclosing potted plants in gas‐tight bags in late autumn and exposing them to simulated winter conditions in an unheated greenhouse. Near‐anaerobic conditions were reached after 60 d of enclosure for orchardgrass, alfalfa and red clover, and after 80 d for timothy. The sensitivity of the species to anaerobic conditions, based on plant regrowth, was: red clover and orchardgrass > alfalfa > timothy. The concentration of ethanol increased in response to oxygen deprivation, and reached the highest value in the sensitive red clover, whereas its concentration was the lowest in timothy. The expression of the alcohol dehydrogenase (ADH) gene was markedly lower in timothy than in the other three species for which the expression was equivalent. We conclude that the greater resistance of timothy to anaerobic conditions at low temperature is associated with a slower glycolytic metabolism.     

Optimization of callus culture and shoot multiplication ofAsparagus densiflorus

The effects of different growth regulators on induction and growth of callus ofAsparagus densiflorus cv. Sprengeri were studied. Calluses grew more rapidly on Murashige and Skoog basal medium supplemented with 5.4 μM p-chlorophenoxyacetic acid (pCPA) and 4.4 μM 6-benzylaminopurine (BA) (medium 1) as compared to the same medium with 11.3 μM 2,4-dichlorophenoxyacetic acid (2,4-d) and 4.6 μM kinetin (medium 2). Calluses on medium 1 were soft and friable, whereas, compact, hard calluses originated on medium 2. Different concentrations and combinations of BA and/or kinetin were also used to study their effects on shoot regeneration. Kinetin was found to be less effective than BA in the initiation of shoots (1.8 shoots/callus). High numbers of shoots were produced in the presence of 0.4 μM BA alone (3.3 shoots/callus). The addition of ancymidol (5 μM) in MS with 0.4 μM BA enhanced multiplication of shoots (9.8 shoots/explant) and also produced well-developed crowns.     

Quantitative trait loci analysis for the developmental behavior of tiller number in rice (Oryza sativa L.)

 A doubled-haploid rice population of 123 lines from Azucena/IR64 was used for analyzing the developmental behavior of tiller number by conditional and unconditional QTL mapping methods. It was indicated that the number of QTLs significantly affecting tiller number was different at different measuring stages. Many QTLs controlling tiller growth identified at the early stages were undetectable at the final stage. Only one QTL could be detected across the whole growth period. By conditional QTL mapping, more QTLs for tiller number could be detected than that by unconditional mapping. The temporal patterns of gene expression for tiller number could be different at different stages. Even an individual gene or genes at the same genomic region might have opposite genetic effects at various growth stages. Received: 7 July 1997 / Accepted: 10 February 1998     

Potato flour viscosity improvement is associated with the expression of a wheat LMW-glutenin gene

It has been previously shown that expression of a high-molecular-weight glutenin (HMW-GS) in transgenic wheat seeds resulted in the improvement of flour functional properties. In this study, potato flour viscosity was improved through a specific expression of a low-molecular-weight glutenin (LMW-GS-MB1) gene in tuber. The resulting construct was introduced into potato leaf explants (Solanum tuberosum cv Kennebec) through Agrobacterium tumefaciens-mediated gene transfer. Southern and Northern analysis of transgenic potato confirmed that the integration of LMW-GS-MB1 in genomic DNA was stable and its mRNA was abundant in transgenic line 16 tubers. Western blot analysis of line 16 extract shows a LMW-GS subunit accumulation in tuber. To demonstrate the capacity of transgenic lines to produce tubers with improved flour functional properties, transgenic lines 9 and 16 exhibiting, respectively, moderate and high expression of LMW-GS-MB1 mRNA and nontransgenic plants were transferred to field plots. The mean viscosity value of flour obtained from the field-grown tubers of transgenic line 16 exhibited a 3-fold increase in viscosity at 23 degrees C when compared to flour from nontransgenic tubers.     

Heterogeneity of glucose-6-phosphate dehydrogenase deficiency in Algeria

Summary Glucose-6-phosphate dehydrogenase (G6PD) deficiency was found in 3.2% of the male population living in the urban area of Algiers. The deficient subjects originated from multiple geographic regions of Northern Algeria, with prevalence of individuals of Berber-Kabyle origin. Red blood cell G6PD was partially purified and characterized in deficient males from 17 families, and six different variants were found. Among them, only one, the Gd(-) Kabyle variant, had been previously described. It was detected in nine families. The other five variants were new: Gd(-) Laghouat (four cases), Gd(-) Blida (one case), Gd(-) Thenia (one case), Gd(-) Titteri (one case), and Gd(-) Alger (two brothers), Strikingly, the common Mediterranean variant was not found. G6PD deficiency is heterogeneous in northern Algeria where autochtonous variants seem to prevail. The Kabyle variant may be common in this country.     

Phenolic Profiling,Antioxidant, and Antibacterial Activities of Selected Medicinal Plants from Tunisia

Phytochemical screening of aqueous extract from six medicinal wild plants grown in South-eastern of Tunisia: Atriplex halimus, Teucrium polium, Moricandia arvensis, Deverra tortuoa, Haplophyllum tuberculatum and Polygonum equisetiforme were evaluated. Both decoction and ultrasound assisted extraction were used. Antioxidant, antibacterial proprieties, and phenolic profiling, using LC-ESI-MS method, were assessed. Total polyphenols, flavonoids, and condensed tannins contents ranged from 7.47±0.19 to 22.25±0.49 mg GAE/g Dw, 5.47±0.06 to 7.55±0.07 mg RE/g Dw, and 0.33±0.02 to 19.43±0.64 mg TAE/g Dw, respectively. Moreover, the reducing power and DPPH tests showed that P. equisetiforme (EC₅₀: 12.50±0.50 μg/ml; DPPH⋅⁺: 213.49±4.24 mg TEAC/g DW), T. polium (EC₅₀: 25.00±1.00 μg/ml; DPPH⋅⁺: 181.39±9.47 mg TEAC/g DW) as well as H. tuberculatum (EC₅₀: 56.25±0.25 μg/ml; DPPH⋅⁺: 177.83±5.85 mg TEAC/g DW) extracts were the most effective natural antioxidants. For anti-bacterial activity, the ultrasonic extract of H. tuberculatum showed the highest activity against both P. aeruginosa (13.50±0.71 mm) and S. aureus (13.00±0.00 mm) at 10 mg/ml. Furthermore 24 phenolic compounds were identified, with predominance of quinic acid, gallic acid, protocatechuic acid, syringic acid, p-coumaric acid, trans-ferulic acid, catechin (+), trans-cinnamic and silymarin. These results were further consolidated by to heatmap clustering with P. equisetiforme, H. tuberculatum, T. polium as the main antioxidant and antibacterial sources which supports their domestication and industrial use.     

Genetic polymorphism in low-molecular-weight glutenin genes from Triticum aestivum, variety Chinese Spring

Low-molecular-weight (LMW) glutenin subunits consist mainly of two domains, one at the N- terminus which contains repeats of short amino-acid motifs, and a non-repetitive one rich in cysteine, at the C- terminal region. In previous reports, polyacrylamide-gel electrophoresis has been used to show that large size variation exists among LMW and HMW glutenin subunits, and it has been suggested that deletions and insertions within the repetitive region are responsible for these variations in length. In this study, PCR-amplification of genomic DNA (Triticum aestivum variety Chinese Spring) was used to isolate three full-length LMW glutenin genes: LMWG-MB1, LMWG-MB2 and LMWG-MB3. The deduced amino-acid sequences show a high similarity between these ORFs, and with those of other LMW glutenin genes. Comparisons indicate that LMWG-MB1 has probably lost a 12-bp fragment through deletion and that LMWG-MB1 and LMWG-MB2 have an insertion of 81 bp within the repetitive domain. The current study has shown direct evidence that insertions and/or deletions provide a mechanistic explanation for the allelic variation, and the resultant evolution, of prolamin genes. Single-base substitutions at identical sites generate stop codons in both LMWG-MB2 and LMWG-MB3 indicating that these clones are pseudogenes. Received: 7 May 1999 / Accepted: 17 June 1999