The p110α/ΔNp63α complex mutations in triple-negative breast cancer: Potential targets for transcriptional-based therapies.

BACKGROUND: Hotspot mutations occurring in the p110α domain of the PIK3CA gene, specifically p110αH1047R/L increase tumor metastasis and cell motility in triple-negative breast cancer (TNBC). These mutations also affect the transcriptional regulation of ΔNp63α, a significant isoform of the p53 protein involved in cancer progression. This study attempts to investigate the transcriptional impact of p110αH1047R/L mutations on the PIK3CA/ΔNp63α complex in TNBC carcinogenesis. METHODS: We performed site-directed mutagenesis to introduce p110αH1047R/L mutations and evaluated their oncogenic effects on the growth, invasion, migration, and apoptosis of three different TNBC cell lines in vitro. We investigated the impact of these mutations on the p110α/ΔNp63α complex and downstream transcriptional signaling pathways at the gene and protein levels. Additionally, we used bioinformatics techniques such as molecular dynamics simulations and protein-protein docking to gain insight into the stability and structural changes induced by the p110αH1047R/L mutations in the p110α/ΔNp63α complex and downstream signaling pathway. RESULTS: The presence of PIK3CA oncogenic hotspot mutations in the p110α/ΔNp63α complex led to increased scattering of TNBC cells during growth, migration, and invasion. Our in vitro mutagenesis assay showed that the p110αH1047R/L mutations activated the PI3K-Akt-mTOR and tyrosine kinase receptor pathways, resulting in increased cell proliferation, invasion, and apoptosis in TNBC cells. These mutations decreased the repressing effect of ΔNp63α on the p110α kinase domain, leading to the enhancement of downstream signaling pathways of PI3K and tyrosine kinase receptors and oncogenic transformation in TNBC. Additionally, our findings suggest that the physical interaction between the DNA binding domain of ΔNp63α and the kinase domain of p110α may be partially impaired, potentially leading to alterations in the conformation of the p110α/ΔNp63α complex. CONCLUSION: Our findings suggest that targeting the p110αH1047R/L mutations in TNBC could be a promising strategy for developing transcriptional-based therapies. Restoring the interaction between ΔNp63α and the p110α kinase domain, which is disrupted by these mutations, may provide a new approach to treating TNBC.

The novel anti-cancer feature of Brazzein through activating of hTLR5 by integration of biological evaluation: molecular docking and molecular dynamics simulation.

Many of plant proteins exhibit the properties similar to the antitumor proteins although the anticancer activity of Brazzein on modulating the autophagy signaling pathway has not been determined so far. The present study aimed to develop a simplified system to enable the rational design of the activating extracellular domain of human Toll-like receptor 5 (hTLR5). To identify the anticancer effect of Brazzein, HADDOCK program and molecular dynamics (MD) simulation were applied to examine the binding of the wild type (WT) and p.A19K mutant of Brazzein to the TLR5. The expression of MAP1S and TNF-α genes was estimated based on real-time PCR. The results clearly confirmed that the WT of Brazzein activated hTLR5 in the MCF-7 cell line since the genes were more and significantly less expressed in the cells treated with the WT and p.A19K mutant than the control, respectively. The snapshots of MD simulation exhibit the consistent close interactions of hTLR5 with the two helices of Brazzein on its lateral side. The results of per residue-free energy decomposition analysis substantiate those of intermolecular contact analysis perfectly one. We propose that the WT of Brazzein can act as an antitumor drug candidate.

Targeting Adenylate Cyclase Family: New Concept of Targeted Cancer Therapy.

The adenylate cyclase (ADCY) superfamily is a group of glycoproteins regulating intracellular signaling. ADCYs act as key regulators in the cyclic adenosine monophosphate (cAMP) signaling pathway and are related to cell sensitivity to chemotherapy and ionizing radiation. Many members of the superfamily are detectable in most chemoresistance cases despite the complexity and unknownness of the specific mechanism underlying the role of ADCYs in the proliferation and invasion of cancer cells. The overactivation of ADCY, as well as its upstream and downstream regulators, is implicated as a major potential target of novel anticancer therapies and markers of exceptional responders to chemotherapy. The present review focuses on the oncogenic functions of the ADCY family and emphasizes the possibility of the mediating roles of deleterious nonsynonymous single nucleotide polymorphisms (nsSNPs) in ADCY as a prognostic therapeutic target in modulating resistance to chemotherapy and immunotherapy. It assesses the mediating roles of ADCY and its counterparts as stress regulators in reprogramming cancer cell metabolism and the tumor microenvironment. Additionally, the well-evaluated inhibitors of ADCY-related signaling, which are under clinical investigation, are highlighted. A better understanding of ADCY-induced signaling and deleterious nsSNPs (p.E1003K and p.R1116C) in ADCY6 provides new opportunities for developing novel therapeutic strategies in personalized oncology and new approaches to enhance chemoimmunotherapy efficacy in treating various cancers.

A Cobalt-Containing Compound as a Stronger Inhibitor than Galantamine to Inhibit Acetylcholinesterase Activity: A New Drug Candidate for Alzheimer's Disease Treatment.

BACKGROUND: Acetylcholinesterase (AChE) regulates the transmission of neural messages by hydrolyzing acetylcholine in synaptic spaces. OBJECTIVE: The effects of many AChE inhibitors have been evaluated in the treatment of Alzheimer's disease, but the present study examined a synthetic complex containing cobalt (SC) for the first time in the field of enzyme activity to evaluate enzyme inhibitory function. METHODS: Ellman's test was applied. AChE function was assessed in the presence of SC through docking and molecular dynamics analyses. The second structure of AChE was studied through circular dichroism (CD) spectroscopy. RESULTS: Several enzymatic methods were utilized for the kinetics of AChE, which indicated the non-Michaelis and positive homotropic behavior of AChE in the absence of inhibitors (Hill coefficient = 1.33). However, the existence of inhibitors did not eliminate this homotropic state, and even AChE had a more sigmoidal shape than the galantamine at the presence of SC. Based on the CD spectroscopy results, AChE structure changed in the existence of inhibitors and substrates. Bioinformatics analysis revealed SC bonding to the channel of active site AChE. The number of hydrogen bonds was such that the flexibility of the enzyme protein structure due to inhibitor binding reduced AChE function. CONCLUSION: The results reflected that AChE exhibited a non-Michaelis and positive homotropic behavior, leading to a more inhibitory effect on the SC than the galantamine. The positive homotropic behavior of AChE was intensified due to the alteration in AChE protein structure by binding SC to hydrophobic region in the active site pathway and impressing Trp84.

Evaluation of Cyc1 protein stability in Acidithiobacillus ferrooxidans bacterium after E121D mutation by molecular dynamics simulation to improve electron transfer.

Cyc1 (Cytochrome c552) is a protein in the electron transport chain of the Acidithiobacillus ferrooxidans (Af) bacteria which obtain their energy from oxidation Fe2+ to Fe3+. The electrons are directed through Cyc2, RCY (rusticyanin), Cyc1 and Cox aa3 proteins to O2. Cyc1 protein consists of two chains, A and B. In the present study, a novel mutation (E121D) in the A chain of Cyc1 protein was selected due to electron receiving from Histidine 143 of RCY. Then, the changes performed in the E121D mutant were evaluated by MD simulations analyzes. Cyc1 and RCY proteins were docked by a Patchdock server. By E121D mutation, the connection between Zn 1388 of chain B and aspartate 121 of chain A weaken. Asp 121 gets farther from Zn 1388. Therefore, the aspartate gets closer to Cu 1156 of the RCY leading to the higher stability of the RCY/Cyc1 complex. Further, an acidic residue (Glu121) becomes a more acidic residue (Asp121) and improves the electron transfer to Cyc1 protein. The results of RMSF analysis showed further ligand flexibility in mutation. This leads to fluctuation of the active site and increases redox potential at the mutation point and the speed of electron transfer. This study also predicts that in all respiratory chain proteins, electrons probably enter the first active site via glutamate and exit histidine in the second active site of each respiratory chain protein.

Protection of Beta Boswellic Acid against Streptozotocin-induced Alzheimer's Model by Reduction of Tau Phosphorylation Level and Enhancement of Reelin Expression.

Alzheimer's disease is a growing general health concern with huge implications for individuals and society. Beta boswellic acid, a major compound of the Boswellia serrata plant, has long been used for the treatment of various inflammatory diseases. The exact mechanism of beta boswellic acid action in Alzheimer's disease pathogenesis remains unclear. In the current study, the protective effect of beta boswellic acid on streptozotocin-induced sporadic Alzheimer's disease was surveyed. Alzheimer's disease model was induced using streptozotocin followed by an assessment of the treatment effects of beta boswellic acid in the presence of streptozotocin. The prevention effect of beta boswellic acid on Alzheimer's disease induction by streptozotocin was evaluated. Behavioral activities in the treated rats were evaluated. Histological analysis was performed. Phosphorylation of tau protein at residues Ser396 and Ser404 and the expression of reelin protein were determined. Glial fibrillary acidic protein immunofluorescence staining was applied in the hippocampus regions. Our findings indicated that beta boswellic acid decreased traveled distance and escape latency in the prevention (beta boswellic acid + streptozotocin) and treatment (streptozotocin + beta boswellic acid) groups compared to control during the acquisition test. It increased "time spent" (%) in the target quadrant. Reelin level was enhanced in rats treated with beta boswellic acid. Tau hyperphosphorylation (p-tau404) and glial fibrillary acidic protein were decreased in the prevention group while the expression of reelin protein in both groups was increased. We could suggest that the anti-inflammatory property of beta boswellic acid is one of the main factors involving in the improvement of learning and memory in rats. Therefore the antineurodegenerative effect of beta boswellic acid may be due to its ability to reactivate reelin protein.

PIK3CA hotspot mutations p. H1047R and p. H1047L sensitize breast cancer cells to thymoquinone treatment by regulating the PI3K/Akt1 pathway.

BACKGROUND: Nigella sativa (N. sativa) exhibits anti-inflammatory, antioxidant, antidiabetic, antimetastatic and antinociceptive effects and has been used to treat dozens of diseases. Thymoquinone (TQ) is an important and active component isolated from N. sativa seeds. Inhibition of cancer-associated activating PIK3CA mutations is a new prospective targeted therapy in personalized metastatic breast cancer (MBC). TQ is reported to be an effective inhibitor of the PI3K/Akt1 pathway in MBC. This study aimed to evaluate the in vitro antitumor effect of TQ in the context of two PIK3CA hotspot mutations, p. H1047R and p. H1047L. METHODS AND RESULTS: Molecular dynamics, free energy landscapes and principal component analyses were also used to survey the mechanistic effects of the p. H1047R and p. H1047L mutations on the PI3K/Akt1 pathway. Our findings clearly confirmed that the p. H1047R and p. H1047L mutants could reduce the inhibitory effect of ΔNp63α on the kinase domain of PIK3CA, resulting in increased activity of PI3K downstream signals. Structurally, the partial disruption of the interaction between the ΔNp63α DNA binding domain and the PIK3CA kinase domain at residues 114-359 and 797-1068 destabilizes the conformation of the activation loop and modifies the PIK3CA/ΔNp63α complex. Alongside these structural changes, we found that TQ treatment resulted in high PI3K/Akt1 pathway inhibition in p. H1047R and p. H1047L-expressing cells versus wild-type cells. CONCLUSIONS: These two PIK3CA hotspot mutations therefore not only contribute to tumor progression in patients with MBC but may also serve as targets for the development of novel small molecule therapeutic strategies.

Comparative mRNA/micro-RNA co-expression network drives melanomagenesis by promoting epithelial-mesenchymal transition and vasculogenic mimicry signaling.

This study aimed to identify a novel disease-associated differentially co-expressed mRNA-microRNA (miRNA) that is associated with vasculogenic mimicry (VM) and epithelial-to-mesenchymal transition (EMT) network at different stages of melanoma. By applying weighted gene co-expression network analysis, we constructed a VM+EMT biological network with the available microarray dataset downloaded from a public database. Quantitative real-time PCR, immunohistochemical staining, and CD31-periodic acid solution dual staining were performed to confirm the expression of genes associated with EMT and VM formation in subjects with malignant melanoma (n = 18) and primary melanoma (n = 13) and in healthy subjects (n = 10). Our findings suggested that phosphatidylserine-specific phospholipase A1-alpha (PLA1A) and dermokine (DMKN) genes function as oncogenes that trigger VM and EMT processes during melanomagenesis on interaction with miR-370, miR-563, and miR-770-5p. PLA1A and DMKN genes can be considered potential VM+EMT network-based diagnostic biomarkers for distinguishing between melanoma patients. We postulate that a network with altered PLA1A/miR-563 and DMNK/miR-770-5p/miR-370 may contribute to melanomagenesis by triggering the EMT signaling pathway and VM formation. This study provides a potentially valuable approach for the early diagnosis and prognosis of melanoma progression.

Investigation of Cyc1 protein structure stability after H53I mutation using computational approaches to improve redox potential.

Acidithiobacillus ferrooxidans (Af) is an acidophilic bacterium that grows in rigid surroundings and gets its own energy from the oxidation of Fe2+ to Fe3+. These bacteria are involved in the bioleaching process. Cyc1 is a periplasmic protein with a crucial role in electron transportation in the respiratory chain. His53 of the Cyc1 protein, involved in electron transfer to CoxB, was selected for mutation and bioinformatics studies. His53 was substituted by Ile using PyMol software. Molecular dynamics simulations were performed for wild and mutant types of Cyc1 protein. The conformational changes of mutated protein were studied by analyzing RMSD, RMSF, SASA, Rg, H Bond, and DSSP. The results of the RMSF analysis indicated an increase in the flexibility of the ligand in the mutant. Finally, active site instability leads to an increase in the value of E0 at the mutation point and improving electron transfer. On the other, His53 in Cyc1 is interconnected to Glu126 in CoxB through the water molecule (W76) and hydrogen bonding. In the H53I mutation, there was a decrease in the distance between H2O 2030, 2033, and isoleucine 53, and subsequently, the distance to the water molecule 76 between the two proteins was reduced and strengthens the hydrogen bond between Cyc1 and CoxB, finally improves electron transfer and the bioleaching process.

PLA1A expression as a diagnostic marker of BRAF-mutant metastasis in melanoma cancer.

BRAF and NRAS are the most reported mutations associated to melanomagenesis. The lack of accurate diagnostic markers in response to therapeutic treatment in BRAF/NRAS-driven melanomagenesis is one of the main challenges in melanoma personalized therapy. In order to assess the diagnostic value of phosphatidylserine-specific phospholipase A1-alpha (PLA1A), a potent lysophospholipid mediating the production of lysophosphatidylserine, PLA1A mRNA and serum levels were compared in subjects with malignant melanoma (n = 18), primary melanoma (n = 13), and healthy subjects (n = 10). Additionally, the correlation between histopathological subtypes of BRAF/NRAS-mutated melanoma and PLA1A was analyzed. PLA1A expression was significantly increased during melanogenesis and positively correlated to disease severity and histopathological markers of metastatic melanoma. PLA1A mRNA and serum levels were significantly higher in patients with BRAF-mutated melanoma compared to the patients with NRAS-mutated melanoma. Notably, PLA1A can be used as a diagnostic marker for an efficient discrimination between naïve melanoma samples and advanced melanoma samples (sensitivity 91%, specificity 57%, and AUC 0.99), as well as BRAF-mutated melanoma samples (sensitivity 62%, specificity 61%, and AUC 0.75). Our findings suggest that PLA1A can be considered as a potential diagnostic marker for advanced and BRAF-mutated melanoma.

Genome­wide copy number analysis of circulating tumor cells in breast cancer patients with liver metastasis.

The genome­wide copy number analysis of circulating tumor cells (CTCs) provides a promising prognostic biomarker for survival in breast cancer liver metastasis (BCLM) patients. The present study aimed to confirm the prognostic value of the presence of CTCs in BCLM patients. We previously developed an assay for the genome­wide pattern differences in copy number variations (CNVs) as an adjunct test for the routine imaging and histopathologic diagnosis methods to distinguish newly diagnosed liver metastases and recurrent liver metastases. Forty­three breast cancer patients were selected for this study in which 23 newly diagnosed and 20 recurrent liver metastases were diagnosed by histopathology and 18F­FDG PET/CT imaging. CTCs were counted from all patients using the CellSearch system and were confirmed by cytomorphology and three­color immunocytochemistry. Genomic DNA of single CTCs was amplified using multiple annealing and looping based amplification cycles (MALBAC). Then, we compared the CTC numbers of newly diagnosed and recurrent BCLM patients using Illumina platforms. A high CTC frequency (>15 CTCs/7.5 ml blood) was found to be correlated with disease severity and metastatic progression, which suggests the value for CTCs in the diagnosis of BCLM in comparison with pathohistology and PET/CT imaging (P>0.05). Moreover, CTCs isolated from BCLM patients remained an independent prognostic detection factor associated with overall survival (P=0.0041). Comparison between newly diagnosed and recurrent liver metastases revealed different frequencies of CNVs (P>0.05). Notably, the CNV pattern of isolated CTCs of recurrent BCLM patients was similar to recurrent liver metastases (nearly 82% of the gain/loss regions). Functional enrichment analysis identified 25 genes as a CNV signature of BCLM. Among them, were defensin and ß­defensin genes, which are significantly associated with anti­angiogenesis and immunomodulation signaling pathways. High CTC frequencies are effective in the evaluation and differentiation between newly diagnosed liver metastases from recurrent liver metastases. Future clinical studies will be necessary to fully determine the prognostic potential of CTC cluster signatures in patients with BCLM.

The role of vascular mimicry as a biomarker in malignant melanoma: a systematic review and meta-analysis.

BACKGROUND: Vasculogenic mimicry (VM) a microvascular system consisting of non-endothelial cells that is newly formed by aggressive tumors, has been proposed as an important therapeutic target in malignant melanoma (MM). We performed a systematic literature review to evaluate the diagnostic and prognostic accuracy of VM status for overall survival of MM patients. METHODS: The quality of the included studies was evaluated using the QUADAS-2 tool. Diagnostic capacity of VM variables, including sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under summary receiver operating characteristic (SROC), were pooled using Meta-DiSc software. RESULTS: A retrospective observational study was conducted based on twelve clinical studies including 978 clinically confirmed melanoma patients with proportion (P). VM+ melanoma cells were associated with poor prognosis in 38% of MM group (P = 0.35, 95% confidence intervals (CI): 0.27-0.42, p < 0.001). The pooled sensitivity and specificity were 0.82 (95% CI: 0.79-0.84) and 0.69 (95% CI: 0.66-0.71), respectively. Furthermore, the pooled PLR, NLR, and DOR were 2.56 (95% CI: 1.94-3.93), 0.17 (95% CI: 0.07-0.42), and 17.75 (95% CI: 5.30-59.44), respectively. Furthermore, the AUC of SROC was 0.63, indicating high reliability of VM status as a biomarker. Importantly, subgroup results suggested that VM+ status is a significantly accurate prognostic biomarker when diagnosed by the CD31-/PAS+ staining methods in Asian MM samples (p < 0.001). CONCLUSIONS: Our findings support the potential of VM status of tumors as a promising prognostic biomarker and emphasize an effective adjuvant therapeutic strategy in the prognosis of Asian MM patients.

Novel splicing variant c. 208+2T>C in BBS5 segregates with Bardet-Biedl syndrome in an Iranian family by targeted exome sequencing.

Bardet-Biedl syndrome (BBS) is a rare genetically heterogeneous ciliopathy which accompanies retinitis pigmentosa (RP). However, the BBS5 mutation remains unclear in Iranians with BBS. The purpose of study is to evaluate genetic analyses of a BBS Iranian family using targetted exome sequencing (TES). A male 11-year-old proband and three related family members were recruited. Biochemical tests, electrocardiography and visual acuity testing, such as funduscopic, fundus photography (FP), optical coherence tomography (OCT), and standard electroretinography, were conducted. Molecular analysis and high-throughput DNA sequence analysis were performed. The proband was diagnosed with possible BBS based on the presence of three primary features and two secondary features. The TES analysis of the proband with BBS resulted in the identification of a novel, homozygous splicing variant c. 208+2T>C of the BBS5 gene (NM_152384.2) in this Iranian BBS family. This variant was confirmed and was completely co-segregated with the disease in this family by Sanger sequencing. Thus, we report a novel, homozygous splicing site variant c.208+2T>C in the BBS5 gene for the first time in the Iranian family.

In silico data analyses of the hotspot mutations of CHM gene in choroideremia disease.

This data article provides compelling computational analysis of the hotspot CHM gene mutations that contribute to the progressive causativeness and susceptibility of Choroideremia in patients. We performed structural and molecular dynamics (MD) simulation analysis on abnormal states of the CHM protein caused by deleterious and disease-causing hotspot mutant forms of CHM: S89C, E177K, and V529H. Within 40 ns, MD simulation time composed of the E177K mutant shows conformational alteration especially in several parts of the variant. Mathematically, we applied eigenvector analysis to determine the modes of flexibility and atomic positional fluctuations that contribute significantly to the overall motion of the CHM protein in terms of structural alteration, free energy landscapes (FEL), entropy, enthalpy, and principal component analysis (PCA). The data described here are related to the article entitled "Molecular Genetics Characterization and Homology Modeling of the CHM Gene Mutation: A study on Its Association with Choroideremia" (Imani et al., 2018) [1].

Molecular genetics characterization and homology modeling of the CHM gene mutation: A study on its association with choroideremia.

Choroideremia (CHM) is a rare form of X-linked chorioretinal dystrophy that is caused by mutations in the CHM gene. Mutations in the Rab escort protein-1 (REP-1), an ubiquitously encoded protein of the CHM gene, lead to prenylation and vesicle trafficking deficiency in the protein, resulting in the progressive degeneration of choriocapillaris, retinal pigment epithelium (RPE), and photoreceptors. Despite previous studies concerning this disease, no effective diagnostic tests or established therapeutic interventions currently exist for CHM. In this paper, we reviewed the pathogenic effects of synonymous hotspot mutation in the CHM gene and the genotypic-phenotypic associations in families with CHM. In addition, we employed a combination of molecular dynamics simulations and principal component analysis to gain insight into the underlying molecular basis of these deleterious and disease-causing hotspot mutation analogs. These computer predictions provide strong evidence that the C > T nonsynonymous hotspot mutations of CHM spectrum contribute to overall RPE retinopathy. These findings increase our understanding of the CHM pathogenesis, which may potentially define a new approach in developing novel symbiotic strategies for genetic diagnosis and specific treatment of inherited retinal diseases.

Genetic identification and molecular modeling characterization reveal a novel PROM1 mutation in Stargardt4-like macular dystrophy.

Stargardt disease-4 (STGD4) is an autosomal dominant complex, genetically heterogeneous macular degeneration/dystrophy (MD) disorder. In this paper, we used targeted next generation sequencing and multiple molecular dynamics analyses to identify and characterize a disease-causing genetic variant in four generations of a Chinese family with STGD4-like MD. We found a novel heterozygous missense mutation, c.734T>C (p.L245P) in the PROM1 gene. Structurally, this mutation most likely impairs PROM1 protein stability, flexibility, and amino acid interaction network after changing the amino acid residue Leucine into Proline in the basic helix-loop-helix leucine zipper domain. Molecular dynamic simulation and principal component analysis provide compelling evidence that this PROM1 mutation contributes to disease causativeness or susceptibility variants in patients with STGD4-like MD. Thus, this finding defines new approaches in genetic characterization, accurate diagnosis, and prevention of STGD4-like MD.

Identification of a novel RPGRIP1 mutation in an Iranian family with leber congenital amaurosis by exome sequencing.

Leber congenital amaurosis (LCA) is a heterogeneous, early-onset inherited retinal dystrophy, which is associated with severe visual impairment. We aimed to determine the disease-causing variants in Iranian LCA and evaluate the clinical implications. Clinically, a possible LCA disease was found through diagnostic imaging, such as fundus photography, autofluorescence and optical coherence tomography. All affected patients showed typical eye symptoms associated with LCA including narrow arterioles, blindness, pigmentary changes and nystagmus. Target exome sequencing was performed to analyse the proband DNA. A homozygous novel c. 2889delT  (p.P963 fs) mutation in the RPGRIP1 gene was identified, which was likely the deleterious and pathogenic mutation in the proband. Structurally, this mutation lost a retinitis pigmentosa GTPase regulator (RPGR)-interacting domain at the C-terminus which most likely impaired stability in the RPGRIP1 with the distribution of polarised proteins in the cilium connecting process. Sanger sequencing showed complete co-segregation  in this pedigree. This study provides compelling evidence that the c. 2889delT  (p.P963 fs) mutation in the RPGRIP1 gene works as a pathogenic mutation that contributes to the progression of LCA.

The Effects of Alpha Boswellic Acid on Reelin Expression and Tau Phosphorylation in Human Astrocytes.

Reelin is an extracellular glycoprotein which contributes to synaptic plasticity and function of memory in the adult brain. It has been indicated that the Reelin signaling cascade participates in Alzheimer's disease (AD). Besides the neurons, glial cells such as astrocytes also express Reelin protein. While functional loss of astrocytes has been reported to be associated with AD, dysfunction of astrocytic Reelin signaling pathway has not received much attention. Therefore, we investigated the effects of α-boswellic acid (ABA) as one of the major component of Boswellia serrata resin on primary fetal human astrocytes under a stress paradigm as a possible model for AD through study on Reelin cascade. For this aim, we used streptozotocin (STZ), in which from an outlook generates Alzheimer's hallmarks in astrocytes, and assayed Reelin expression, Tau and Akt phosphorylation as well as reactive oxygen species (ROS) generation and apoptosis in the presences of ABA. Our results indicated that while STZ (100 µM) down-regulated the expression of Reelin, ABA (25 µM) up-regulated its expression (p < 0.01) for 24 h. ABA efficiently reduced hyperphosphorylated Tau (Ser404) in STZ-treated astrocytes (p < 0.01). Furthermore, STZ-induced apoptosis by increasing cleaved caspase three (p < 0.01) and ROS generation (p < 0.01), a further pathological hallmark of Tauopathy. On the other hand, ABA decreased ROS generation and promoted proliferation of astrocytes through elevating Survivin expression (p < 0.01). These results showed that ABA could be considered as a potent therapeutic agent for prevention and decreasing the progression of Alzheimer's hallmarks in astrocytes; however, more in vivo studies would be needed.

Cane molasses as a source of precursors in the bioproduction of tryptophan by Bacillus subtilis.

BACKGROUND AND OBJECTIVES: The essential amino acid L-tryptophan can be produced by a condensation reaction between indole and L-serine, catalyzed by B. subtilis with tryptophan synthase activity. Application of the tryptophan is widespread in the biotechnology domain and is sometimes added to feed products as a food fortifier. MATERIALS AND METHODS: The optimum concentration of the Iranian cane molasses was determined by measuring the amount of biomass after growth in 1 to 30 g/mL of molasses. The maximum amount of biomass was obtained in 10 g/mL molasses. Chromatographic methods, TLC and HPLC, were used to assay the amount of tryptophan produced in the presence of precursors of tryptophan production (indole and serine) and/or molasses. RESULTS: Our results indicate the importance of the Iranian cane molasses not only as carbon source, but also as a source of precursors for tryptophan production. CONCLUSION: This report evaluates the potential of cane molasses as an economical source for tryptophan production by B. subtilis, hence eliminating the requirement for additional serine and indole as precursors.