Heat shock protein 27 as a neuroprotective biomarker and a suitable target for stem cell therapy and pharmacotherapy in ischemic stroke

Ischemic stroke is a major common cause of death and long‐term disability worldwide. Several pathophysiological events including excitotoxicity, oxidative/nitrative stress, inflammation, and apoptosis are involved in ischemic injuries. Recently, the molecular mechanisms involved in cerebral ischemia through a focus on a member of small heat shock proteins family, Hsp27, has been developed. Notably, following exposure to ischemia, Hsp27 expression in the brain could be increased rather than the normal condition and it may play an important role in neuroprotection after ischemic stroke. The neuroprotection effects of Hsp27 may arise from its anti‐oxidant, anti‐inflammatory, anti‐apoptotic, and chaperonic properties. Moreover, some therapeutic strategies such as stem cell therapy and pharmacotherapy have been developed with Hsp27 targeting. In this review, we describe the function and structure of Hsp27 and its possible role in neuroprotection after ischemic stroke. Finally, we present current studies in stroke therapy, which focused on Hsp27 targeting.     

Applicability of airlift draft-tube fluidized bioreactors for binary protein mixture bioseparation

An airlift draft-tube fluidized bioreactor has been designed and tested for applications in protein bioseparation. Operating parameters and geometrical dimensions of the bioreactor were optimized to ensure fluid circulation in a defined cyclic pattern between the riser and the downcomer. The overall directionality of liquid flow generates homogeneous field of low shear and achieves good mixing efficiency. Bioseparation of proteins was achieved from solutions containing both BSA and BHb at different initial concentrations and at pH 7. Similar adsorption capacities of both proteins were observed in single protein adsorption experiments at pH 7. Compressibility of BHb allowed for high adsorption capacity, in addition to the hydrophobic interaction forces. Apparently the homogeneous and lower shear generated by the airlift bioreactor reduces the compressibility of adsorbed BHb. This allowed for higher BSA adsorption from solutions containing BSA and BHb mixtures. Conventional batch adsorption experiments showed more adsorption of BHb, which reduces bioseparation efficiency.     

In silico analysis of antibody triggering biofilm associated protein in Acinetobacter baumannii

Acinetobacter baumannii surface protein, commonly known as biofilm associated protein (Bap), is involved in biofilm formation. A high propensity among the clinical isolates to form biofilm and a significant association of biofilms with multiple drug resistance has been demonstrated. Production of antibodies can be used for inhibition of biofilm and control of the diseases caused by A. baumannii. Large molecular mass of Bap justifies an approach to identifying A. baumannii effective antigens. It has a core domain of seven repeat modules A-G. With the large number of available biofilm gene sequences, bioinformatic tools are needed to identify the genes encoding the antigens. Proteins containing these tandem repeats of Bap domains have high propensities to attach to each other to form biofilm. We hypothesized that conserved and functional domains of tandem repeat could be identified with a search and alignment of the repeats for evaluation of antigenic determinants. Here we demonstrate the results of bioinformatics screening and gene scan of the gene sequence database of homolog sequences to identify conserved domains. Higher scoring hits were found in repeat modules mostly D, B, C and A, respectively. Upon the analysis four regions of highly structural and functional conserved regions from Bap sequence of A. baumannii were selected. 3D structure, antigenicity and solubility predictions revealed that these regions were appropriate candidates for antibody production.     

Assessment of hemolytic activity of bee venom against some physicochemical factors

Bee venom (BV) is a biotoxin with biologically active peptides which have cell lysis and hemolytic activity properties. These properties can be affected under different storage conditions or during the production process. In present study, we investigated effects of a number of physicochemical factors, including temperature, pH, UV radiation, ultrasound waves and storage time on hemolytic activity of BV. Maximum absorption and melting temperature of BV solution were obtained as 280 nm and ~70 °C, respectively. Cell hemolysis 50 (CH₅₀) -concentration of BV that can lyse 50% of red blood cells- was determined as 0.94 μg/ml at ambient temperature. CH₅₀ was shown not to be importantly varied at temperature up to 60 °C, pH value 2 to 13 and under UV/ ultrasound radiation. Storage at ?20, 6 and 25 °C for 6 months made about 2.5, 35 and 1000 times increase in CH₅₀. From the results, it may be concluded that BV is a relatively resistant hemolytic agent and can be used in a variety of laboratory research and product manufacturing methods.     

Validity of using recombinant melon profilin,Cuc m 2, for diagnosis of melon allergy

Background:

Allergy is a clinical disorder affecting humans worldwide. Allergenic extracts prepared from natural source materials remain heterogeneous in composition and content, but are regularly used for diagnosis and immunotherapy. Recombinant allergens are suitable candidates to use in place of natural allergens; however, the recombinant allergens should be assessed and compared with the natural ones. Cuc m 2 (profilin), one of the most important allergens of melon (Cucumis melo), has been cloned and was expressed in Escherichia coli (E. coli). We aimed to evaluate the validity of recombinant Cuc m 2 (rCuc m 2) in the diagnosis of melon allergy and investigate whether rCuc m 2 could be used as a replacement for natural Cuc m 2 (nCuc m 2).

Methods:

nCuc m 2 was purified by immuno-affinity chromatography and rCuc m 2 was purified by metal-affinity chromatography. SDS-PAGE and western blotting were carried out to evaluate the purification methods. Skin prick tests (SPT), and enzyme immunoassays to determine specific IgE, were performed with the natural and recombinant purified allergens on 53 patients with melon allergy.

Results:

rCuc m 2 elicited no significantly different responses in skin compared with nCuc m 2. All patients'' sera showed similar ODs in ELISAs with natural and recombinant profilin.

Conclusion:

rCuc m 2 evoked strong immuno-reactivity equivalent to nCuc m 2, and has potential for diagnosis of melon allergy. Key Words: Allergy, Cuc m 2, Melon, Natural allergen, Recombinant allergen     

Heterologous Expression,Purification and Characterization of a Peroxidase Isolated from <Emphasis Type="Italic">Lepidium draba</Emphasis>

Peroxidase is one of the most widely used enzymes in biotechnology and medicine. In the current study, cDNA encoding peroxidase from Lepidium draba (LDP) was cloned and expressed in Escherichia coli BL21 (DE3) cells in the form of inclusion bodies (IBs). To achieve purified active enzyme, IBs were solubilized before being purified and refolded. The deduced amino acid sequence (308) of the LDP gene (924 bp) revealed 88.96% identity to horseradish peroxidase C1A (HRP C1A). The results of basic local alignment search tool (BLAST) and phylogenetic analysis of the protein sequence showed that this enzyme belongs to the neutral group of class III plant peroxidases. According to sequence analysis and structural modeling, critical amino acids in heme and calcium binding domain as well as cysteine residues were conserved as HRP C1A except for calcium binding domain where valine228 was replaced with isoleucine. The far-UV circular dichroism (CD) results were confirmed by homology modeling data showing the enzyme consists mainly of α-helices as other plant peroxidases. Overall, according to the results of catalytic activity and refolding yield, LDP can be introduced as a novel peroxidase for medical and biotechnology applications.     

Focus: Rare Disease: Sinonasal Glomangiopericytoma: Review of Imaging Appearance and Clinical Management Update for a Rare Sinonasal Neoplasm

Introduction: Glomangiopericytoma (GPC) is a rare tumor in the nasal cavity or paranasal sinuses with low malignant potential. Initially deemed a hemangiopericytoma, in 2005 it was classified as a distinct entity by the World Health Organization (WHO). Case Presentation: A male patient in his early 60s presented with new-onset right arm and leg weakness/numbness, who was incidentally found to have a left ethmoid sinus mass with extension in the olfactory fossa. On CT and MRI, the mass enhanced with well-defined borders and eroded the bone, but without dural enhancement. The mass was surgically excised, and pathology confirmed the diagnosis of glomangiopericytoma by microscopic appearance and staining. Discussion: Glomangiopericytoma has less than 0.5% incidence of all neoplasms of the sinonasal cavity, making it rare. Most diagnosed patients are in their 6th or 7th decade of age, with a slight female predominance. Treatment is complete surgical excision, with excellent prognosis, although there is up to 17% local recurrence. Despite the non-specific appearance on CT and MRI, imaging can help provide differential diagnosis, tumor extent, size, and reassuring non-aggressive characteristics of the tumor prior to surgery. GPC tumors are relatively resistant to radiation and chemotherapy. Conclusion: It is important to recognize glomangiopericytoma in the differential of masses of the nasal cavities or paranasal sinuses, as they rarely warrant aggressive treatment beyond local excision. Each reported case of glomangiopericytoma helps to build guidance for imaging and treatment since GPC is rare and not well-represented in the medical literature.     

Degree of modification of Ro60 by the lipid peroxidation by-product 4-hydroxy-2-nonenal may differentially induce Sjögren syndrome or systemic lupus erythematosus in BALB/c mice

Our previous work showed that immunization of rabbits with 4-hydroxy-2-nonenal-modified Ro60 (HNE-Ro60) accelerates autoimmunity. We extended this model into mice, hypothesizing that the severity of autoimmunity would be dependent on the degree of HNE modification of Ro60. Five groups of BALB/c mice (10/group) were used. Group I was immunized with Ro60. Groups II to IV were immunized with Ro60 modified with 0.4 mM (low), 2 mM (medium), and 10 mM (high) HNE, respectively. Group V controls received Freund's adjuvant. A rapid abrogation of tolerance to Ro60/La antigens occurred in mice immunized with HNE-modified Ro60, especially in the low and medium HNE-Ro60 groups. Lymphocytic infiltration and significantly high decrement in salivary flow (37%) compared to controls was observed only in the high HNE-Ro60 group, suggesting induction of a Sjögren syndrome-like condition in this group. Anti-dsDNA occurred only in mice immunized with medium HNE-Ro60. This group did not have a significant decrement in salivary flow, suggesting induction of a systemic lupus erythematosus-like manifestation in this group. Significantly high antibodies to Ro60 were found in saliva of mice in the low and medium HNE-Ro60 and the Ro60 groups, as well as anti-HNE Ro60 in the low and medium HNE-Ro60 groups. Understanding the mechanism of this differential induction may help discriminate between these two autoimmune diseases.