The major locus for multifactorial nonsyndromic cleft lip maps to mouse Chromosome 11

Cleft lip with or without cleft palate, CL(P), a common human birth defect, has a genetically complex etiology. An animal model with a similarly complex genetic basis is established in the A/WySn mouse strain, in which 20% of newborn have CL(P). Using a newly created congenic strain, AEJ.A, and SSLP markers, we have mapped a major CL(P)-causing gene derived from the A/WySn strain. This locus, here named clf1 (cleft lip) maps to Chromosome (Chr) 11 to a region having linkage homology with human 17q21-24, supporting reports of association of human CL(P) with the retinoic acid receptor alpha (RARA) locus.     

Maturation and persistence of the anti-SARS-CoV-2 memory B cell response

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The lidgap-Gates (lg Ga) mutation for open eyelids at birth maps to mouse Chromosome 13

Complex nonadditive interactions between specific alleles at multiple loci may underlie many so-called multifactorial threshold birth defects. The open-eyelids-at-birth defect in mice is a good model for these defects, and an understanding of its genetic complexity begins with mapping the participating loci. The open-eyelids defect can be part of a syndrome or can occur with no other obvious phenotypic effects. Of the latter nonsyndromic forms, the lidgap series includes four extant mutations that are considered to be alleles based on complementation tests. All show genetic complexity in segregation ratios. None has been mapped previously. On the basis of a strategy of mapping the mutation with the simplest inheritance pattern first, we generated an extensive exclusion map for lidgap-Gates, lg ^Ga , using morphological and protein polymorphisms. We then screened the non-excluded regions in a congenic strain, AEJ.LGG—lg ^Ga , for SSLP markers and located the differential chromosome segment containing the lg ^Ga locus in a region near the distal end of mouse Chromosome (Chr) 13. This linkage was confirmed and refined by typing SSLPs in 64 F₂ and 74 BC₁ progeny of a cross of LGG/Bc (lg ^Ga /lg ^Ga ) to SWV/Bc. The lg ^Ga mutation maps to a 1- to 2-cM region between D13Mit76 and D13Mit53. Integrin alpha 1 and integrin alpha 2, which map to the same general region, are possible candidate loci, based on their embryonic expression and cellular function. Evidence is also presented for a common unlinked recessive suppressor of the open eyelids trait caused by lg ^Ga . Received: 3 February 1995 / Accepted: 19 February 1996     

Sensitization by docosahexaenoic acid (DHA) of breast cancer cells to anthracyclines through loss of glutathione peroxidase (GPx1) response

Docosahexaenoic acid (DHA, a lipid of marine origin) has been found to enhance the activity of several anticancer drugs through an oxidative mechanism. To examine the relation between chemosensitization by DHA and tumor cells antioxidant status, we used two breast cancer cell lines: MDA-MB-231, in which DHA increases sensitivity to doxorubicin, and MCF-7, which does not respond to DHA. Under these conditions, reactive oxygen species (ROS) level increased on anthracycline treatment only in MDA-MB-231. This was concomitant with a decreased cytosolic glutathione peroxidase (GPx1) activity, a crucial enzyme for protection against hydrogen and lipid peroxides, while major antioxidant enzyme activities increased in both cell lines in response to ROS. GPx-decreased activity was accompanied by an accumulation of glutathione, the GPx cosubstrate, and resulted from a decreased amount of GPx protein. In rat mammary tumors, when a DHA dietary supplementation led to an increased tumor sensitivity to anthracyclines, GPx1 activity was similarly decreased. Furthermore, vitamin E abolished both DHA effects on chemotherapy efficacy enhancement and on GPx1 inhibition. Thus, loss of GPx response to an oxidative stress in transformed cells may account for the ability of peroxidizable targets such as DHA to enhance tumor sensitivity to ROS-generating anticancer drugs.     

The P1 N-isopropyl motif bearing hydroxyethylene dipeptide isostere analogues of aliskiren are in vitro potent inhibitors of the human aspartyl protease renin

Novel nonpeptide small molecule renin inhibitors bearing an N-isopropyl P₁ motif were designed based on initial lead structures 1 and aliskiren (2). (P₃–P₁)-Benzamide derivatives such as 9a and 34, as well as the corresponding P₁ basic tertiary amine derivatives 10 and 35 were found to display low nanomolar inhibition against human renin in vitro.     

Biogenic Synthesis, Purification, and Chemical Characterization of Anti-inflammatory Resolvins Derived from Docosapentaenoic Acid (DPAn-6)

Enzymatically oxygenated derivatives of the ω-3 fatty acids cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) and cis-5,8,11,14,17-eicosapentaenoic acid, known as resolvins, have potent inflammation resolution activity (Serhan, C. N., Clish, C. B., Brannon, J., Colgan, S. P., Chiang, N., and Gronert, K. (2000) J. Exp. Med. 192, 1197–1204; Hong, S., Gronert, K., Devchand, P. R., Moussignac, R., and Serhan, C. N. (2003) J. Biol. Chem. 278, 14677–14687). Our objective was to determine whether similar derivatives are enzymatically synthesized from other C-22 fatty acids and whether these molecules possess inflammation resolution properties. The reaction of DHA, DPAn-3, and DPAn-6 with 5-, 12-, and 15-lipoxygenases produced oxylipins, which were identified and characterized by liquid chromatography coupled with tandem mass-spectrometry. DPAn-6 and DPAn-3 proved to be good substrates for 15-lipoxygenase. 15-Lipoxygenase proved to be the most efficient enzyme of the three tested for conversion of long chain polyunsaturated fatty acids to corresponding oxylipins. Since DPAn-6 is a major component of Martek DHA-S™ oil, we focused our attention on reaction products obtained from the DPAn-6 and 15-lipoxygenase reaction. (17S)-hydroxy-DPAn-6 and (10,17S)-dihydroxy-DPAn-6 were the main products of this reaction. These compounds were purified by preparatory high performance liquid chromatography techniques and further characterized by NMR, UV spectrophotometry, and tandem mass spectrometry. We tested both compounds in two animal models of acute inflammation and demonstrated that both compounds are potent anti-inflammatory agents that are active on local intravenous as well as oral administration. These oxygenated DPAn-6 compounds can thus be categorized as a new class of DPAn-6-derived resolvins.Enzymatically formed oxygenation products of C-20 and C-22 long chain polyunsaturated fatty acids (LC-PUFAs),⁴ have important biological roles in inflammation, allergies, and blood clotting and are thus believed to have therapeutic potential in several chronic immune diseases (1–10) Several biologically important products of cis-5,8,11,14-eicosatetraenoic acid/arachidonic acid (ARA), cis-5,8,11,14,17-eicosapentaenoic acid (EPA), and cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) have been described (4, 11, 12). Proinflammatory oxylipins, such as leukotrienes and some prostaglandins, are derived from ARA, an ω-6 fatty acid. Interestingly, the same fatty acid also serves as a precursor to anti-inflammatory or proresolution molecules like lipoxins (13, 14). Stable analogues of lipoxins are being developed as drugs for asthma and other inflammatory airway diseases (15, 16). Oxylipins derived from ω-3 fatty acids, such as DHA and EPA, known as resolvins, are primarily anti-inflammatory in nature (17). EPA acts as a precursor to the E-series resolvins that have shown potential in the treatment of colitis, arthritis, and periodontitis (18–20). The resolvins of the D-series derived from DHA are useful as neuroprotective agents. 10,17-Dihydroxy-4,7,11,13,15,19-docosahexaenoic acid (10,17-HDHA) or neuroprotectin D1 is a resolvin that is formed endogenously in the human brain and eye and is believed to exert its protective effect against cell injury-induced oxidative stress (21–23).The main enzymes responsible for the production of these oxygenated LC-PUFA products are primarily lipoxygenases and, in addition, cyclo-oxygenases and cytochromes P450. These enzymes produce oxylipins via transcellular activity, often involving multiple cell types (24). This activity mainly results in mono-, di-, and tri-hydroxylation products of fatty acids that have varying potencies, depending on the exact structure of the compound. Lipoxygenases are non-heme, iron-containing dioxygenases that catalyze the regioselective and enantioselective oxidation of polyunsaturated fatty acids containing one or more cis,cis-1,4-pentadienoic moieties to give the corresponding hydroperoxy derivatives (25, 26). We thus considered that, in addition to DHA and EPA, other C-22 PUFAs containing such methylene interrupted double bonds may also be substrates for lipoxygenases and that resulting products may have anti-inflammatory activity similar to DHA-derived resolvins. DPAn-6 (cis-4,7,10,13,16-docosapentaenoic acid) is present in algal oils, and recent studies have demonstrated that this fatty acid has anti-inflammatory activities in vitro and, in conjunction with DHA, also has anti-inflammatory activity in vivo.⁵ Also, it has been suggested that a combination of DHA and DPAn-6 could be a beneficial natural therapy in neuroinflammatory conditions like Alzheimer disease. Specifically, in a 3×Tg-AD mouse model of Alzheimer disease, DPAn-6 was shown to reduce levels of early stage phospho-Tau epitopes, which in turn correlated with a reduction in phosphorylated c-Jun N-terminal kinase, a putative Tau kinase (27). Although the precise mechanism of action of DPAn-6 in these inflammatory milieus is not known, it suggests a possible role for oxylipin products of DPAn-6 in resolution of inflammation. Also, another LC-PUFA, DPAn-3 (cis-7,10,13,16,19-docosapentaenoic acid) usually present along with DHA and EPA in marine oils is known to be a potent inhibitor of platelet aggregation (28–30). In addition, this LC-PUFA has a potent inhibitory effect on angiogenesis through the suppression of VEGFR-2 (vascular endothelial-cell growth factor receptor 2) expression. Angiogenesis is known to contribute to tumor growth, inflammation, and microangiopathy, again pointing to the possibility that anti-inflammatory activity of DPAn-3 might be mediated through resolvin-like products as in the case of DHA and EPA (31).The purpose of this research was to determine whether oxylipins are formed from the C-22 LC-PUFAs, DPAn-6 and DPAn-3, by lipoxygenase activity; to compare them to products formed from DHA; to chemically characterize products; to purify key oxylipin products from the DPAn-6/15-lipoxygenase reaction; and to test whether these compounds have resolvin-like anti-inflammatory activity. This research also sets the stage for preparation and isolation of a wide range of other C-22 oxylipins that could be evaluated as potential anti-inflammatory compounds.