Waleed H. Albuali

Lack of MERS Coronavirus Neutralizing Antibodies in Humans, Eastern Province, Saudi Arabia

We used a lentiviral vector bearing the viral spike protein to detect neutralizing antibodies against Middle East respiratory syndrome coronavirus (MERS-CoV) in persons from the Eastern Province of Saudi Arabia. None of the 268 samples tested displayed neutralizing activity, which suggests that MERS-CoV infections in humans are infrequent in this province.

Sickle cell disease in Saudi Arabia: the phenotype in adults with the Arab-Indian haplotype is not benign.

Sickle cell disease (SCD) in Saudi patients from the Eastern Province is associated with the Arab‐Indian (AI) HBB (β‐globin gene) haplotype. The phenotype of AI SCD in children was described as benign and was attributed to their high fetal haemoglobin (HbF). We conducted a hospital‐based study to assess the pattern of SCD complications in adults. A total of 104 patients with average age of 27 years were enrolled. Ninety‐six per cent of these patients reported history of painful crisis; 47% had at least one episode of acute chest syndrome, however, only 15% had two or more episodes; symptomatic osteonecrosis was reported in 18%; priapism in 17%; overt stroke in 6%; none had leg ulcers. The majority of patients had persistent splenomegaly and 66% had gallstones. Half of the patients co‐inherited α‐thalassaemia and about one‐third had glucose‐6‐phosphate dehydrogenase deficiency. Higher HbF correlated with higher rate of splenic sequestration but not with other phenotypes. The phenotype of adult patients with AI SCD is not benign despite their relatively high HbF level. This is probably due to the continued decline in HbF level in adults and the heterocellular and variable distribution of HbF amongst F‐cells.

Cardioprotective effect of cannabidiol in rats exposed to doxorubicin toxicity.

The potential protective effect of cannabidiol, the major non-psychotropic Cannabis constituent, was investigated against doxorubicin cardiotoxicity in rats. Cardiotoxicity was induced by six equal doses of doxorubicin (2.5mgkg(-1) i.p., each) given at 48h intervals over two weeks to achieve a total dose of 15mgkg(-1). Cannabidiol treatment (5mgkg(-1)/day, i.p.) was started on the same day of doxorubicin administration and continued for four weeks. Cannabidiol significantly reduced the elevations of serum creatine kinase-MB and troponin T, and cardiac malondialdehyde, tumor necrosis factor-α, nitric oxide and calcium ion levels, and attenuated the decreases in cardiac reduced glutathione, selenium and zinc ions. Histopathological examination showed that cannabidiol ameliorated doxorubicin-induced cardiac injury. Immunohistochemical analysis revealed that cannabidiol significantly reduced the expression of inducible nitric oxide synthase, nuclear factor-κB, Fas ligand and caspase-3, and increased the expression of survivin in cardiac tissue of doxorubicin-treated rats. These results indicate that cannabidiol represents a potential protective agent against doxorubicin cardiac injury.

Fetal hemoglobin in sickle cell anemia: genetic studies of the Arab-Indian haplotype.

Sickle cell anemia is common in the Middle East and India where the HbS gene is sometimes associated with the Arab-Indian (AI) β-globin gene (HBB) cluster haplotype. In this haplotype of sickle cell anemia, fetal hemoglobin (HbF) levels are 3-4 fold higher than those found in patients with HbS haplotypes of African origin. Little is known about the genetic elements that modulate HbF in AI haplotype patients. We therefore studied Saudi HbS homozygotes with the AI haplotype (mean HbF 19.2±7.0%, range 3.6 to 39.6%) and employed targeted genotyping of polymorphic sites to explore cis- and trans- acting elements associated with high HbF expression. We also described sequences which appear to be unique to the AI haplotype for which future functional studies are needed to further define their role in HbF modulation. All cases, regardless of HbF concentration, were homozygous for AI haplotype-specific elements cis to HBB. SNPs in BCL11A and HBS1L-MYB that were associated with HbF in other populations explained only 8.8% of the variation in HbF. KLF1 polymorphisms associated previously with high HbF were not present in the 44 patients tested. More than 90% of the HbF variance in sickle cell patients with the AI haplotype remains unexplained by the genetic loci that we studied. The dispersion of HbF levels among AI haplotype patients suggests that other genetic elements modulate the effects of the known cis- and trans-acting regulators. These regulatory elements, which remain to be discovered, might be specific in the Saudi and some other populations where HbF levels are especially high.

Protective effect of naringenin against gentamicin-induced nephrotoxicity in rats.

The protective effect of naringenin, a flavonoid compound isolated from citrus fruits, was investigated against nephrotoxicity induced by gentamicin (80mgkg(-1)/day, i.p., for eight days) in rats. Naringenin treatment (50mgkg(-1)/day, p.o.) was administered for eight days, starting on the same day of gentamicin administration. Gentamicin caused significant elevations of serum creatinine, and kidney tissue levels of malondialdehyde, nitric oxide, and interleukin-8, and a significant decrease in renal glutathione peroxidase activity. Naringenin treatment significantly ameliorated the changes in the measured biochemical parameters resulted from gentamicin administration. Also, naringenin markedly attenuated the histopathological renal tissue injury observed with gentamicin. Immunohistochemical examinations showed that naringenin significantly reduced the gentamicin-induced expression of kidney injury molecule-1, vascular endothelial growth factor, inducible nitric oxide synthase, and caspase-9, and increased survivin expression in the kidney tissue. It was concluded that naringenin, through its antioxidant and anti-inflammatory effects, may represent a therapeutic option to protect against gentamicin nephrotoxicity.

Spectrum of α-Thalassemia Mutations in Transfusion-Dependent β-Thalassemia Patients from the Eastern Province of Saudi Arabia

Both α- and β-thalassemia (α- and β-thal) are highly prevalent in the population of the Al-Qatif and Al-Ahsa regions in the Eastern Province of Saudi Arabia. This study provides a more precise picture of the α-thal mutations prevalent in 104 transfusion-dependent β-thal patients in the Eastern Province. Detection of α-thal mutations was carried out using the α-globin StripAssay kit. A total of 12 α-thal mutations (21 genotypes) were identified in 33.7% of the chromosomes (46 patients). The heterozygous and homozygous –α3.7 (α+) deletion mutations were the most prevalent in the β-thal patients (21.7%). We identified three α0 deletions [– –MED, – –FIL and –(α)20.5] that have not been previously reported for the population of Saudi Arabia. The seven point mutations identified in the β-thal patients were: codon 14 [TGG>TAG (α1)], codon 59 [GGC>GAC (α1)] (Hb Adana), polyadenylation signal site (polyA1) [AATAAA>AATAAG (α2)], codon 142 [TAA>TCA (α2)] (Hb Koya Dora), codon 59 [GGC>GAC (α2)] (Hb Adana), initiation codon [ATG>ACG (α2)] and the αααanti 3.7 gene triplication. The Hb Koya Dora mutation occurred at the highest frequency (15.38%). Comparison of the clinical phenotype of β-thal patients, with and without an α-thal mutation, showed that patients with β-thal alone had a significantly elevated level of alanine transaminase (ALT) (mean 72.5 IU/L) and aspartate transaminase (AST) (mean 71.8 IU/L) (p <0.005). In addition, the β-thal patients without an α-thal mutation had a higher percentage of osteoporosis (16.6%), fractures (12.5%), and splenectomies (58.3%). This confirms previous data that the co-inheritance of α-thal in β-thal patients results in the amelioration of the clinical phenotype of β-thal patients. Moreover, the high frequency of α- and β-thal in the Eastern Province of Saudi Arabia and their coinheritance, necessitates the inclusion of α-thal testing in the current pre marital testing program to highlight the risk to the offspring of affected individuals.

A functional promoter polymorphism of the δ‐globin gene is a specific marker of the Arab‐Indian haplotype

Most sickle cell anemia (SCA) patients indigenous to the Eastern Province of Saudi Arabia have their HbS gene on the Arab-Indian (AI) HBB gene cluster haplotype. Their fetal hemoglobin (HbF) levels are near 20% and they have milder disease compared with SCA where the HbS gene is on African origin HBB haplotypes [1–9]. The AI haplotype is characterized by an Xmn1 restriction site at position 2158 50 to HBG2 (rs7482144), a Hinc2 site 50 to HBE (rs3834466) and other polymorphisms [10]. The causal elements that modify HbF might be in linkage disequilibrium with the b globin gene in this Saudi population. We first performed homozygosity mapping using genome-wide single nucleotide polymorphisms (SNPs) in AI HbS homozygotes [11,12] and identified a single large autozygous region including the HBB cluster and surrounding genes. By next generation sequencing, we examined this region in these same individuals and identified several variants that included a SNP in the HBD promoter region at position 268 bp 50 to HBD (CCAAC > TCAAC). We found this SNP only when the HbS gene was on an AI haplotype and not in SCA with other haplotypes. This SNP was functional in reporter assays in K562 cells and is an AI haplotype-specific marker. Table I summarizes the patient characteristics. Using genome-wide SNP data from a limited number of cases, a region of autozygosity was found only in AI HbS homozygotes on chromosome 11 (coordinates 5,196,450– 5,323,071). The region contains HBD, HBG1, HBG2, HBE1, and the Xmn1 50 HBG2 restriction site (rs7482144). By targeted deep sequencing of 400 kb of chromosome 11 (coordinates 5,143,424–5,543,424; average coverage 42x) in 4 AI patients 1,195 variants were found. A homozygous C-T variant 268 bp 50 HBD with high genotyping and mapping quality that was not in dbSNP build 135 or 1,000 Genomes, was present. Resequencing of 15.9 kb of chr11 (coordinates 5,253,531–5,269,435) by Sanger sequencing detected three new SNPs of which one was the 268 C > T SNP. We focused on this SNP because of its location within the Corfu deletion region and its location in the HBD promoter. The C > T SNP in the HBD promoter was found only in individuals with the AI haplotype. Saudi sickle cell trait carriers with the AI haplotype were heterozygous for this SNP; while siblings without HbS did not carry this mutation. Among 25 AI HbS-b thalassemia patients, 16 were heterozygous at this site (C/T) and 9 were homozygous (T/T). All AI HbS-b thalassemia patients who were homozygous T/T were also homozygous for the AI haplotype (Table I). Fifteen African American SCA patients with unusually high HbF, 54 Saudi SCA patients from the Southwestern Province (SW)—mainly Benin but including subjects with the Senegal haplotype—19 SW HbS-b thalassemia patients, 16 SW sickle cell trait cases, and 25 normal Saudi controls did not carry the 268 HBD SNP. This SNP was not found in 1,094 individuals in 1,000 Genomes May 2011 release. It is important to note that hemoglobin electrophoresis results in Table I were performed using different methods, so direct comparison of HbF and HbA2 between different groups will not be accurate. In addition, the effect of coinheritance of a-thalassemia, or presence of iron deficiency anemia on Hb A2 level was not assessed. Finally, HbA2 levels are artifactually high when HbS is present because of the co-elution of minor HbS species. For these reasons, it is not possible to estimate the effects of the 268 C-T SNP on these subjects HbA2 levels. Reduced expression of HBD relative to HBB in normal individuals is partly a result of a degenerate CCAAT box in the HBD promoter (CCAAC). The CCAAC motif is the site of the 268 C > T SNP (TCAAC) [13–15]. When we compared the activity of the wild-type HBD promoter with the promoter containing the 268 C > T SNP the variant promoter was associated with a significant decrease in the expression of a reporter construct suggesting that it could further impair already enfeebled HBD expression (Fig. 1). Although HBG is expressed at high levels in K562 cells, endogenous HBD is also expressed [16]. The expression studies were designed solely to test the hypothesis that the 268 C > T SNP downregulates the expression of the HBD promoter. The literature provides further evidence for a functional role of the 268 C > T SNP. Its presence was associated with d thalassemia in one individual with reduced HbA2 of 2% and a slightly increased HbF of 1.3% [13]. Moreover, mutations at positions 230, 231, 236, 255, 265, 276, and 277 in the HBD promoter were reported in HbVar database (http://globin.cse.psu.edu/) to cause d thalassemia [14,17–19], and HbF levels of 3.3–4.7% have been noted in some hematologically normal individuals with homozygous d thalassemia [19,20]. A mechanism for increased HbF in the presence of less common HBD promoter mutations is unknown. Any role for the 268 C-T SNP as a modifier of HbF in AI haplotype HbS sickle cell disease is unknown. Perhaps HBD promoter SNPs reduce the interaction of the locus control region and the transcription apparatus with this promoter permitting enhanced interactions with HBG promoters [21]. The paradox of the Corfu deletion first suggested the potential of the HBD-HBG1 intergenic area, the site of the 268 C-T SNP, as a silencer of HBG expression [22]. One potential functional area is the polypyrimidine (PYR) binding site about 960 bp upstream of HBD; however, polymorphisms

Protective Effect of Naringenin against Lipopolysaccharide-Induced Acute Lung Injury in Rats

Background/Aims: Lipopolysaccharide (LPS) induces acute lung injury (ALI) through oxidative stress and inflammation. Naringenin exerts antioxidant and anti-inflammatory effects. The possible protective effect of naringenin was investigated against ALI induced by LPS in rats. Methods: Rats received a single injection of LPS (5 mg/kg, i.v.). Naringenin was given for 4 consecutive days, at 2 doses (50 and 100 mg/kg/day, p.o.), starting 3 days before LPS administration. Results: LPS significantly increased wet/dry lung weight ratio, malondialdehyde, nitric oxide (NO), interleukin-6, and myeloperoxidase activity in the lung tissues. Naringenin, particularly the higher dose, significantly ameliorated the LPS-induced changes in the measured parameters. Also, naringenin markedly reduced the histopathological lung tissue injury that resulted from LPS. Naringenin significantly decreased the LPS-induced expression of nuclear factor-κB, inducible NO synthase, tumor necrosis factor-a, caspase-3, and significantly increased heat shock protein 70 expression in the lungs. Conclusion: Naringenin significantly protected against LPS-induced ALI in rats through its anti-inflammatory, antioxidant, antinitrosative, and antiapoptotic effects.

Protective effect of telmisartan treatment against arsenic-induced testicular toxicity in rats.

Abstract Oxidative/nitrosative stress, inflammation, and apoptosis play a crucial role in the pathogenesis of arsenic-induced testicular injury. Telmisartan, the angiotensin II-receptor antagonist, possesses antioxidant and anti-inflammatory activities. The protective effect of telmisartan against arsenic-induced testicular damage was investigated in rats. Testicular damage was induced by sodium arsenite (10 mg kg–1/day, p.o., for 2 consecutive days). Telmisartan (10 mg kg–1/day, i.p.) was given for 3 consecutive days, starting 1 day before sodium arsenite administration. Telmisartan significantly attenuated the arsenic-induced decrease in the levels of serum testosterone and testicular reduced glutathione, and significantly decreased the elevation of the levels of testicular malondialdehyde, nitric oxide, and arsenic levels, as well as myeloperoxidase activity resulting from sodium arsenite administration. Histopathological and immunohistochemical examination revealed that telmisartan markedly attenuated testicular tissue changes, and decreased the arsenic-induced expression of vascular endothelial growth factor, inducible nitric oxide synthase, tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, and caspase-3. Telmisartan, via its antioxidant and/or anti-inflammatory effects, may represent a potential candidate to protect against the deleterious effects of arsenic on testicular tissue.

Evaluation of oxidant-antioxidant status in overweight and morbidly obese Saudi children.

AIM To evaluate the antioxidant enzymes and oxidative products in overweight and obese Saudi children before the onset of metabolic complications. METHODS The study was carried out on 231 Saudi children. They were classified into three groups: uncomplicated overweight, uncomplicated morbid obesity, and the matched age group as control. All subjects underwent anthropometric measurements and activities of superoxide dismutase, catalase, glutathione peroxidase (GSH-Px), glutathione reductase, the concentrations of reduced GSH, malondialdehyde (MDA) oxidized low-density lipoprotein (ox-LDL) and advanced oxidation protein products (AOPPs) were measured in the blood of these groups. RESULTS Overweight and obese children had a significantly higher body mass index, while obese children only had a significantly higher waist-to-hip ratio compared to that of the control group. The enzyme activities under study were significantly elevated in the overweight group, although they were significantly reduced among obese children. The concentration of GSH was reduced in both the overweight and obese groups. The mean values of ox-LDL, MDA and AOPP were non-significantly increased in overweight children, while they were significantly elevated in obese children compared to that of normal weight children. A significant disturbance of oxidant-antioxidant status was observed in severely morbid children. CONCLUSION The increase of oxidative stress in obese children is associated with the increase in AOPPs and MDA which reflects an imbalance between reactive oxygen species production and antioxidant defense.