Treatment of Facioscapulohumeral Muscular Dystrophy (FSHD): A Systematic Review

Facioscapulohumeral muscular dystrophy (FSHD) is the third most common type of muscular dystrophy. This disease presents as a slowly progressive asymmetric muscle weakness that involves the facial, scapular, and upper arm muscles mainly. Currently, there is no established consensus on this disease treatment in terms of medications. We assessed the response to the treatment of the drugs utilized in clinical trials by performing a systematic literature review in English using the preferred reporting items for systematic reviews (PRISMA) and meta-analyses. We only used human clinical trials in patients diagnosed with FSHD that received consistent pharmacological treatment. We included 11 clinical trials that fulfilled our criteria. We concluded that albuterol had statistically significant results in three out of four clinical trials, with improved elbow flexors muscle strength. Vitamin C, vitamin E, zinc gluconate, and selenomethionine showed significant improvement in the maximal voluntary contraction and endurance limit time of quadriceps muscle. At the same time, diltiazem and MYO-029 demonstrate no improvement in function, strength, or muscle mass. Losmapimod, currently in phase I of the ReDUX4 trial, showed promising results. Peradventure, more clinical trials are still needed to address this subject. Nevertheless, this review provides a clear and concise update on the treatment for this disease.

Anticancer Effect of Amygdalin (Vitamin B-17) on Hepatocellular Carcinoma Cell Line (HepG2) in the Presence and Absence of Zinc

BACKGROUND

Amygdalin (Vitamin B-17) is a naturally occurring vitamin found in the seeds of the fruits of Prunus Rosacea family including apricot, bitter almond, cherry, and peach.

OBJECTIVE

The purpose of this study was to examine the effect of amygdalin with and without zinc on hepatocellular carcinoma (HepG2) cell line.

METHODS

MTT assay was used to evaluate the cytotoxicity of amygdalin without zinc, amygdalin + 20μmol zinc, and amygdalin + 800μmol zinc on HepG2 cell lines. The cell cycle distribution assay was determined by flow cytometry. Apoptosis was confirmed by Annexin V-FITC/PI staining assay. Moreover, the pathway of apoptosis was determined by the percentage of change in the mean levels of P53, Bcl2, Bax, cytochrome c, and caspase-3.

RESULTS

Amygdalin without zinc showed strong anti-HepG2 activity. Furthermore, HepG2 cell lines treatment with amygdalin + 20μmol zinc and amygdalin + 800μmol zinc showed a highly significant apoptotic effect than the effect of amygdalin without zinc. Amygdalin treatment induced cell cycle arrest at G2/M and increased the levels of P53, Bax, cytochrome c, and caspase-3 significantly, while it decreased the level of anti-apoptotic Bcl2.

CONCLUSION

Amygdalin is a natural anti-cancer agent, which can be used for the treatment of hepatocellular carcinoma. It promotes apoptosis via the intrinsic cell death pathway (the mitochondria-initiated pathway) and cell cycle arrest at G/M. The potency of amygdalin in HepG2 treatment increased significantly by the addition of zinc.

Mitogen-Induced Interferon Gamma Production in Human Whole Blood: The Effect of Heat and Cations

BACKGROUND

Interferon-gamma release assays (IGRAs) are blood tests used to measure the amount of interferon-γ (IFN-γ) released by T lymphocytes after stimulation by antigens specific for the diagnosis of latent tuberculosis infection. A mitogen serves as a positive control to assess the immune function in IGRAs.

METHODS

This in vitro study was conducted to evaluate IFN-γ production by human whole blood stimulated with heat-treated and/or cation-supplemented phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM), using QuantiFERON-TB Gold Kit ELISA tests.

RESULTS

The optimal concentrations of PWM, Con A and PHA for IGRAs were 2 µg/mL, 5 µg/mL and 10 µg/mL, respectively. The results showed that IFN-γ production in response to PWM was the highest and PHA was the lowest amount. The median values of three mitogens were in the following order: PWM≥Con A≥ positive control>>PHA-P>>negative control. PWM and PHA were heat stable, while Con A was heat sensitive. The mitogen response of lymphocytes to untreated or heat-treated PWM and heat-treated Con A was increased in 1 mM Ca2+-supplemented groups, whereas the response to heat-treated PHA was decreased. Exposure to 1 mM Mg2+ had no effect on untreated or heat-treated PWM, and a concentration of 1 mM Zn2+ inhibited the stimulation of un-treated PWM. We found that calcium supplementation improved the PWM-induced production of IFN-γ.

CONCLUSION

Therefore, PWM is an appropriate mitogen for use as a positive control in IGRAs. It is a potential indicator of cytokine production in the diagnostic as well as research settings, and calcium supplementation improved stimulation.

The Status of Biochemical and Molecular Markers of Oxidative Stress in Preeclamptic Saudi Patients

PURPOSE

In the light of contradictory results and paucity of information, this comprehensive study examines the activities and levels of key antioxidants and oxidants/pro-oxidants in preeclamptic patients.

METHODS

Antioxidants including glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase, catalase, reduced glutathione, selenium, zinc, copper and manganese, as well as marker oxidants/pro-oxidants including hydrogen peroxide, superoxide anions, malondialdehyde, protein carbonyls and oxidized glutathione were determined in plasma and placental tissues of nonpregnant, healthy pregnant and preeclamptic subjects.

RESULTS

Data indicated that all plasma antioxidants underwent moderate but significant decreases (p< 0.05) in healthy pregnant women, , and much more significant ones (p< 0.0001) in preeclamptic patients, when both were compared to non-pregnant subjects. Furthermore, whereas all plasma antioxidants underwent significant decreases (p< 0.001) in preeclamptic patients compared to healthy pregnant subjects, their placental activities and levels were very significantly decreased (p< 0.0001). However, copper plasma and placental levels were unchanged in all study groups. In contrast, there were increases similar in magnitude and significance of all plasma and placental oxidants/prooxidants compared among the three study groups leading to equally significant decreases in the reduced/oxidized glutathione ratios. In addition, gene transcripts of all antioxidant enzymes underwent marked downregulation (p< 0.0001) in placental tissue of preeclamptic patients compared to healthy pregnant subjects.

CONCLUSION

Data indicated a metabolic shift in favor of oxidative stress more pronounced in placental tissue of preeclamptic patients compared to healthy pregnant/non-pregnant subjects. We postulate that selenium, zinc and manganese supplements could be beneficial for alleviation of the noted oxidative stress in preeclamptic patients.

Paralogs and mutants show that one DMA synthase functions in iron homeostasis in rice

Rice (Oryza sativa) secretes 2'-deoxymugineic acid (DMA) to acquire insoluble iron (Fe) from the rhizosphere. In rice, DMA is synthesized by DMA synthase 1 (OsDMAS1), a member of the aldo-keto reductase super family. We screened OsDMAS1 paralogs for DMA synthesis. None of these paralogs displayed in vitro DMA synthesis activity, suggesting that rice only harbors one functional DMAS. We further characterized OsDMAS1 mutant plants. We failed to screen homozygous knock-out plants (dmas-1), so we characterized DMAS knock-down plants (dmas-kd1 and dmas-kd2). Under Fe-deficient conditions, dmas-kd1 plants were more chlorotic compared to the wild-type (WT) plants, and the expression of OsNAS3, OsYSL2, OsIRT1, and OsIRO2 was significantly up-regulated in the dmas-kd1 mutant, indicating that metal homeostasis was significantly disturbed. The secretion of DMA in dmas-kd1 was not significantly reduced. The dmas-kd1 plants accumulated less Fe in their roots compared to WT plants when grown with 10 μM FeSO4. The dmas-kd1 plants accumulated more Zn in their roots compared to WT plants under Fe-deficient, Fe-EDTA, and FeSO4 conditions. In both dehusked rice seeds (brown rice) and polished rice, no differences were observed for Fe, Cu, or Mn accumulation, whereas dmas-kd1 seeds significantly accumulated more Zn in brown rice. Our data suggests that rice only harbors one functional gene for DMA synthesis. In addition, the knock-down of OsDMAS1 significantly up-regulates the genes involved in Fe uptake and homeostasis.

Patterns of stress response and tolerance based on transcriptome profiling of rice crown tissue under zinc deficiency

Zinc (Zn) deficiency is the most prevalent micronutrient disorder in rice and leads to delayed development and decreased yield. Several studies have investigated how rice plants respond to Zn deficiency and examined the differences between Zn-efficient (ZE) and Zn-inefficient (ZI) genotypes. ZE genotypes reallocate more Zn to roots and are better at maintaining crown root development than ZI genotypes in response to Zn deficiency. However, little is known about the molecular mechanisms controlling these differences. Moreover, the role of the crown, the part of the stem from which crown roots emerge, has yet to be examined. In this study we highlight the molecular mechanisms triggered by early Zn deficiency in crown tissue through RNA sequencing of two contrasting groups of several ZE and ZI genotypes. This method allowed us to (i) identify several novel and well-known Zn transporters involved in Zn retranslocation from the crown to the shoot and roots in response to Zn deficiency; (ii) determine that Zn deficiency triggers the conversion of soluble sugars into starch; and (iii) detect several candidate genes possibly conferring Zn efficiency, including a monosaccharide transporter, a Zn finger domain-containing protein, a gibberellin-stimulated family protein and a plasma membrane polypeptide family protein.

The ratio of Zn to Cd supply as a determinant of metal-homeostasis gene expression in tobacco and its modulation by overexpressing the metal exporter AtHMA4

This study links changes in the tobacco endogenous metal-homeostasis network caused by transgene expression with engineering of novel features. It also provides insight into the concentration-dependent mutual interactions between Zn and Cd, leading to differences in the metal partitioning between wild-type and transgenic plants. In tobacco, expression of the export protein AtHMA4 modified Zn/Cd root/shoot distribution, but the pattern depended on their concentrations in the medium. To address this phenomenon, the expression of genes identified by suppression subtractive hybridization and the Zn/Cd accumulation pattern were examined upon exposure to six variants of low/high Zn and Cd concentrations. Five tobacco metal-homeostasis genes were identified: NtZIP2, NtZIP4, NtIRT1-like, NtNAS, and NtVTL. In the wild type, their expression depended on combinations of low/high Zn and Cd concentrations; co-ordinated responses of NtZIP1, NtZIP2, and NtVTL were shown in medium containing 4 µM Cd, and at 0.5 µM versus 10 µM Zn. In transgenics, qualitative changes detected for NtZIP1, NtZIP4, NtIRT1-like, and NtVTL are considered crucial for modification of Zn/Cd supply-dependent Zn/Cd root/shoot distribution. Notwithstanding, NtVTL was the most responsive gene in wild-type and transgenic plants under all concentrations of Zn and Cd tested; thus it is a candidate gene for the regulation of metal cross-homeostasis processes involved in engineering new metal-related traits.

Heterogeneity in the genetic alterations and in the clinical presentation of acrodermatitis enteropathic: Case report and review of the literature

Acrodermatitis enteropathic (AE) is a rare autosomal recessive disorder due to a zinc deficiency and characterized by a classical triad of symptoms: dermatitis, alopecia, and diarrhea. The defective gene is SLC39A4, which encodes a zinc transporter. Nevertheless many abnormalities in SLC39A4 have been relieved, only 50% of patients show alterations. Here is reported the case of an infant with mild and incomplete manifestations of AE, for whom the SLC39A4 genetic test was performed. A novel mutation in SLC39A4 was identified. Zinc replacement improved rapidly the skin lesions. Our case highlights the importance of suspecting this rare condition and to perform the genetic test even in those patients who do not fulfil the classical triad of symptoms. Further efforts should be addressed to identify a more strength correlation between genotype and phenotype of this disorder.

Zinc coordination is essential for the function and activity of the type II secretion ATPase EpsE

The type II secretion system Eps in Vibrio cholerae promotes the extracellular transport of cholera toxin and several hydrolytic enzymes and is a major virulence system in many Gram‐negative pathogens which is structurally related to the type IV pilus system. The cytoplasmic ATPase EpsE provides the energy for exoprotein secretion through ATP hydrolysis. EpsE contains a unique metal‐binding domain that coordinates zinc through a tetracysteine motif (CXXCX₂₉CXXC), which is also present in type IV pilus assembly but not retraction ATPases. Deletion of the entire domain or substitution of any of the cysteine residues that coordinate zinc completely abrogates secretion in an EpsE‐deficient strain and has a dominant negative effect on secretion in the presence of wild‐type EpsE. Consistent with the in vivo data, chemical depletion of zinc from purified EpsE hexamers results in loss of in vitro ATPase activity. In contrast, exchanging the residues between the two dicysteines with those from the homologous ATPase XcpR from Pseudomonas aeruginosa does not have a significant impact on EpsE. These results indicate that, although the individual residues in the metal‐binding domain are generally interchangeable, zinc coordination is essential for the activity and function of EpsE.

Current Drug Managements of Wilson's Disease: From West to East

Wilson's disease (WD), also called hepatolenticular degeneration, is an autosomal recessive inheritance disorder of copper metabolism characterized by the multiple mutations in the ATP-ase 7B gene of chromosome 13q. About half of the WD patients have neurological or psychiatric symptoms. As WD is a kind of medicable or nearly curable neurodegenerative disease in the field of medicine, early consideration/examination and without delay/ life-long treatment usually lead to better prognoses. The drugs, also named as anticopper agents, are commonly used in clinics including D-penicillamine, trientine, sodium dimercaptosuccinate, dimercaptosuccinic acid, zinc and tetrathiomolybdate. This provides detailed reviews about these medicines.

Functional analysis of the three HMA4 copies of the metal hyperaccumulator Arabidopsis halleri

In Arabidopsis halleri, the HMA4 gene has an essential function in Zn/Cd hypertolerance and hyperaccumulation by mediating root-to-shoot translocation of metals. Constitutive high expression of AhHMA4 results from a tandem triplication and cis-activation of the promoter of all three copies. The three AhHMA4 copies possess divergent promoter sequences, but highly conserved coding sequences, and display identical expression profiles in the root and shoot vascular system. Here, an AhHMA4::GFP fusion was expressed under the control of each of the three A. halleri HMA4 promoters in a hma2hma4 double mutant of A. thaliana to individually examine the function of each AhHMA4 copy. The protein showed non-polar localization at the plasma membrane of the root pericycle cells of both A. thaliana and A. halleri. The expression of each AhHMA4::GFP copy complemented the severe Zn-deficiency phenotype of the hma2hma4 mutant by restoring root-to-shoot translocation of Zn. However, each copy had a different impact on metal homeostasis in the A. thaliana genetic background: AhHMA4 copies 2 and 3 were more highly expressed and provided higher Zn tolerance in roots and accumulation in shoots than copy 1, and AhHMA4 copy 3 also increased Cd tolerance in roots. These data suggest a certain extent of functional differentiation among the three A. halleri HMA4 copies, stemming from differences in expression levels rather than in expression profile. HMA4 is a key node of the Zn homeostasis network and small changes in expression level can have a major impact on Zn allocation to root or shoot tissues.

Phosphate and zinc transport and signalling in plants: toward a better understanding of their homeostasis interaction

Inorganic phosphate (Pi) and zinc (Zn) are two essential nutrients for plant growth. In soils, these two minerals are either present in low amounts or are poorly available to plants. Consequently, worldwide agriculture has become dependent on external sources of Pi and Zn fertilizers to increase crop yields. However, this strategy is neither economically nor ecologically sustainable in the long term, particularly for Pi, which is a non-renewable resource. To date, research has emphasized the analysis of mineral nutrition considering each nutrient individually, and showed that Pi and Zn homeostasis is highly regulated in a complex process. Interestingly, numerous observations point to an unexpected interconnection between the homeostasis of the two nutrients. Nevertheless, despite their fundamental importance, the molecular bases and biological significance of these interactions remain largely unknown. Such interconnections can account for shortcomings of current agronomic models that typically focus on improving the assimilation of individual elements. Here, current knowledge on the regulation of the transport and signalling of Pi and Zn individually is reviewed, and then insights are provided on the recent progress made towards a better understanding of the Zn-Pi homeostasis interaction in plants.

Speedy small stomata?

Recent work has made progress in relating the size of stomata to stomatal functioning and, in particular, the speed of opening and closing and its implications. Calculations of the influence of stomatal size on the potential rate of osmolarity increase, assuming size-independent ion influx rate per unit area of guard cell plasmalemma set at the value found in large (60 μm long) stomata, show that 10 μm long stomata could have at least a 6-fold higher rate of osmolarity increase. There could be a corresponding decrease in the time taken in going from the closed to the fully open state from about 1h to about 10 min; this is approximately the range found for stomata.. However, there are no data on the rate of stomatal movement over a sufficient size range to test this suggestion. Faster opening requires, assuming optimal allocation, a higher activity of the required enzymes per unit volume of guard cells. This is explored for cytosolic carbonic anhydrase which is needed in guard cells, at least in the light, for malic acid synthesis which is involved in stomatal opening in most stomata. Faster opening and closing of smaller than of larger stomata could allow closer tracking of environmental (mainly light) variations, although the available data are not adequate to determine if such a greater tracking occurs. The range of speeds of stomatal movement is similar to that for photoinhibition-related phenomena, despite the very different mechanisms involved.

Spatial imaging of Zn and other elements in Huanglongbing-affected grapefruit by synchrotron-based micro X-ray fluorescence investigation

Huanglongbing (HLB) is a highly destructive, fast-spreading disease of citrus, causing substantial economic losses to the citrus industry worldwide. Nutrient levels and their cellular distribution patterns in stems and leaves of grapefruit were analysed after graft-inoculation with lemon scions containing 'Candidatus Liberibacter asiaticus' (Las), the heat-tolerant Asian type of the HLB bacterium. After 12 months, affected plants showed typical HLB symptoms and significantly reduced Zn concentrations in leaves. Micro-XRF imaging of Zn and other nutrients showed that preferential localization of Zn to phloem tissues was observed in the stems and leaves collected from healthy grapefruit plants, but was absent from HLB-affected samples. Quantitative analysis by using standard references revealed that Zn concentration in the phloem of veins in healthy leaves was more than 10 times higher than that in HLB-affected leaves. No significant variation was observed in the distribution patterns of other elements such as Ca in stems and leaves of grapefruit plants with or without graft-inoculation of infected lemon scions. These results suggest that reduced phloem transport of Zn is an important factor contributing to HLB-induced Zn deficiency in grapefruit. Our report provides the first in situ, cellular level visualization of elemental variations within the tissues of HLB-affected citrus.

Coordination between zinc and phosphate homeostasis involves the transcription factor PHR1, the phosphate exporter PHO1, and its homologue PHO1;H3 in Arabidopsis

Interactions between zinc (Zn) and phosphate (Pi) nutrition in plants have long been recognized, but little information is available on their molecular bases and biological significance. This work aimed at examining the effects of Zn deficiency on Pi accumulation in Arabidopsis thaliana and uncovering genes involved in the Zn-Pi synergy. Wild-type plants as well as mutants affected in Pi signalling and transport genes, namely the transcription factor PHR1, the E2-conjugase PHO2, and the Pi exporter PHO1, were examined. Zn deficiency caused an increase in shoot Pi content in the wild type as well as in the pho2 mutant, but not in the phr1 or pho1 mutants. This indicated that PHR1 and PHO1 participate in the coregulation of Zn and Pi homeostasis. Zn deprivation had a very limited effect on transcript levels of Pi-starvation-responsive genes such as AT4, IPS1, and microRNA399, or on of members of the high-affinity Pi transporter family PHT1. Interestingly, one of the PHO1 homologues, PHO1;H3, was upregulated in response to Zn deficiency. The expression pattern of PHO1 and PHO1;H3 were similar, both being expressed in cells of the root vascular cylinder and both localized to the Golgi when expressed transiently in tobacco cells. When grown in Zn-free medium, pho1;h3 mutant plants displayed higher Pi contents in the shoots than wild-type plants. This was, however, not observed in a pho1 pho1;h3 double mutant, suggesting that PHO1;H3 restricts root-to-shoot Pi transfer requiring PHO1 function for Pi homeostasis in response to Zn deficiency.

Zinc lozenges may shorten the duration of colds: a systematic review

BACKGROUND

A number of controlled trials have examined the effect of zinc lozenges on the common cold but the findings have diverged. The purpose of this study was to examine whether the total daily dose of zinc might explain part of the variation in the results.

METHODS

The Medline, Scopus and Cochrane Central Register of Controlled Trials data bases were searched for placebocontrolled trials examining the effect of zinc lozenges on common cold duration. Two methods were used for analysis: the P-values of the trials were combined by using the Fisher method and the results of the trials were pooled by using the inverse-variance method. Both approaches were used for all the identified trials and separately for the low zinc dose and the high zinc dose trials.

RESULTS

Thirteen placebo-controlled comparisons have examined the therapeutic effect of zinc lozenges on common cold episodes of natural origin. Five of the trials used a total daily zinc dose of less than 75 mg and uniformly found no effect. Three trials used zinc acetate in daily doses of over 75 mg, the pooled result indicating a 42% reduction in the duration of colds (95% CI: 35% to 48%). Five trials used zinc salts other than acetate in daily doses of over 75 mg, the pooled result indicating a 20% reduction in the duration of colds (95% CI: 12% to 28%).

CONCLUSIONS

This study shows strong evidence that the zinc lozenge effect on common cold duration is heterogeneous so that benefit is observed with high doses of zinc but not with low doses. The effects of zinc lozenges should be further studied to determine the optimal lozenge compositions and treatment strategies.