iPSC-derived cortical neurons to study sporadic Alzheimer disease: A transcriptome comparison with post-mortem brain samples.

Alzheimer's disease (AD) is the most common cause of dementia, characterized by the progressive impairment of cognition and memory loss. Sporadic AD (sAD) represents approximately 95 % of the AD cases and is induced by a complex interplay between genetic and environmental factors called "Alzheimerogens". Heavy metals (e.g. copper) and pesticides (e.g. fipronil) can affect many AD-related processes, including neuroinflammation (considered as AD-inducing factor). Research would benefit from in vitro models to investigate effects of Alzheimerogens. We compared transcriptomics changes in sAD induced pluripotent stem cell (iPSC) derived cortical neurons to differentially expressed genes (DEGs) identified in post-mortem AD brain tissue. These analyses showed that many AD-related processes could be identified in the sAD iPSC-derived neurons, and furthermore, could even identify more DEGs functioning in these processes than post-mortem AD-brain tissue. Thereafter, we exposed the iPSCs to AD-inducing factors (copper(II)chloride, fipronil sulfone and an inflammatory cytokine cocktail). Cytokine exposure induced expression of immune related genes while copper-exposure affected genes involved in lipid and cholesterol metabolism, which are known AD-related processes. Fipronil-exposure did not result in significant transcriptomic changes, although prolonged exposures or higher doses may be necessary. Overall, we show that iPSC-derived cortical neurons can be beneficial in vitro models to identify Alzheimerogens and AD-related molecular mechanisms.

A double-blind randomized placebo-controlled study on the clinical and microbial effects of an essential oil mouth rinse used by patients in supportive periodontal care.

AIM: This 3-month double-blind randomized placebo-controlled study evaluated the clinical and microbial effects of an essential oil mouth rinse used as an adjunct to mechanical plaque control by patients in supportive periodontal care. MATERIAL AND METHODS: Fifty patients were randomly allocated to an essential oil group (Listerine(®) Coolmint; Johnson & Johnson, New Brunswick, NJ, USA) or placebo group to rinse twice per day as an adjunct to mechanical plaque control. At baseline and after 3 months, plaque index (PI), gingivitis index (GI), probing pocket depth, bleeding on probing (BoP) and clinical attachment level were registered. Subgingival plaque samples were collected for the detection and quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Micromonas micros, Prevotella intermedia, Fusobacterium genus and Streptococcus mutans by means of real-time PCR (qPCR). Patient's compliance, satisfaction and side effects were registered. RESULTS: Twenty-three patients in the essential oil group (mean age: 57) and 21 in the placebo group (mean age: 55) with acceptable oral hygiene at intake (mean PI <1.5 on a scale of 5) adhered to the study protocol. Gingivitis index, PI and BoP significantly reduced over time (P ≤ 0.029); however, between group analyses revealed no significant differences. There was no significant change over time neither in detection frequency nor load for any of the microbiota. Daily rinsing with an essential oil rinse was found safe and perceived beneficial by the patients. CONCLUSION: Patients in supportive periodontal care who are fairly compliant with oral hygiene may not benefit from additional mouth rinsing using an essential oil solution.

Mutation of Asp(171) and Asp(262) of the chemokine receptor CXCR4 impairs its coreceptor function for human immunodeficiency virus-1 entry and abrogates the antagonistic activity of AMD3100.

The bicyclam AMD3100 is a highly potent and selective CXCR4 antagonist with strong antiviral activity against human immunodeficiency virus (HIV)-1 and HIV-2, which use CXCR4 as coreceptor for host cell entry. Here, we investigated the interaction of AMD3100 with CXCR4 at the molecular level by mutational analysis. We established a set of stably transfected U87.CD4 cell lines expressing different mutant forms of CXCR4 (i.e., CXCR4[WT], CXCR4[D171N], CXCR4[D262N], CXCR4[D171N,D262N], and CXCR4[H281A]), to compare the activity of the compound against mutated versus wild-type CXCR4. We found that the antagonistic action of AMD3100 against CXCR4--as assessed by the inhibitory effects of the compound on stromal cell-derived factor (SDF-1) binding to its receptor and on SDF-1-induced intracellular calcium signaling, and by displacement of the CXCR4-specific antibody, clone 12G5--was greatly reduced by substitution of Asp(171) and/or Asp(262) by neutral asparagine residue(s). Both aspartates, but most particularly Asp(262), also proved essential for the anti-HIV-1 activity of AMD3100 against the viruses NL4.3, IIIB, and HE. In contrast, substitution of His(281) by a neutral alanine potentiated the antagonistic and antiviral effects of the compound in the different assay systems. Importantly, compared with the wild-type receptor, CXCR4[D262N] was much less effective, whereas CXCR4[D171N,D262N] completely failed as a coreceptor for infection by HIV-1 NL4.3. Thus, the negatively charged aspartate residues at positions 171 and 262, located in transmembrane domains 4 and 6 of the 7-transmembrane receptor, respectively, may represent crucial sites for electrostatic interaction of the positive charges of the bicyclams, as well as for the highly basic V3 loop of the gp120 envelope protein of certain HIV-1 strains.

Molecular cloning and expression of a chicken pituitary adenylate cyclase-activating polypeptide receptor.

Although, since the isolation of pituitary adenylate cyclase-activating polypeptide (PACAP), a wealth of literature has been published describing its localization, binding sites, and biological activities in a variety of mammalian tissues, only very little is known about PACAP in avian species. Therefore, in order to find out the sites of actions of PACAP and to elucidate its physiological significance in birds, we identified a chicken PACAP receptor homologue of the mammalian type I receptors (PAC(1)-Rs). The chicken PACAP type I cDNA sequence was obtained using reverse transcriptase-polymerase chain reaction (RT-PCR) in combination with 3'- and 5'-RACE PCR. This cDNA encodes a 471 amino acid precursor protein, sharing 81-83% sequence identity with mammalian analogs and 76% amino acid identity with the goldfish type I PACAP receptor. Northern blot analysis of chicken brain poly(A)(+)-rich RNA revealed the presence of a 5.5 kb and 7.5 kb PAC(1) receptor transcript. RT-PCR revealed that the chicken PACAP receptor is mainly expressed in the brain and gonads. A smaller amount of the receptor mRNA was found in pituitary, adrenal gland, kidney, intestine, pancreas, lung, and heart tissue. In situ hybridization with specific antisense oligodeoxynucleotide probes showed a widespread distribution of PAC(1) receptor mRNA in the chicken brain, with the highest expression being found in the dorsal telencephalon, olfactory bulb, hypothalamus, optic tectum, and cerebellar cortex. These findings suggest that PACAP affect a variety of functions both in the brain and peripheral tissues of the chicken.