| 1. |
- Belfrage, Anna Karin, et al.
(author)
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Discovery of pyrazinone based compounds that potently inhibit the drug resistant enzyme variant R155K of the hepatitis C virus NS3 protease
- 2016
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In: Bioorganic & Medicinal Chemistry. - : Elsevier BV. - 0968-0896 .- 1464-3391. ; 24:12, s. 2603-2620
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Journal article (peer-reviewed)abstract
- Herein, we present the design and synthesis of 2(1H)-pyrazinone based HCV NS3 protease inhibitors with variations in the C-terminus. Biochemical evaluation was performed using genotype 1a, both the wildtype and the drug resistant enzyme variant, R155K. Surprisingly, compounds without an acidic sulfonamide retained good inhibition, challenging our previous molecular docking model. Moreover, selected compounds in this series showed nanomolar potency against R155K NS3 protease; which generally confer resistance to all HCV NS3 protease inhibitors approved or in clinical trials. These results further strengthen the potential of this novel substance class, being very different to the approved drugs and clinical candidates, in the development of inhibitors less sensitive to drug resistance.
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| 2. |
- Skogh, Anna, et al.
(author)
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An imidazole based H-Phe-Phe-NH2 peptidomimetic with anti-allodynic effect in spared nerve injury mice
- 2018
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In: Bioorganic & Medicinal Chemistry Letters. - : Elsevier BV. - 0960-894X .- 1464-3405. ; 28:14, s. 2446-2450
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Journal article (peer-reviewed)abstract
- The dipeptide amide H-Phe-Phe-NH2 (1) that previously was identified as a ligand for the substance P 1-7 (SP1-7) binding site exerts intriguing results in animal models of neuropathic pain after central but not after peripheral administration. The dipeptide 1 is derived from stepwise modifications of the anti-nociceptive heptapeptide SP1-7 and the tetrapeptide endomorphin-2 that is also binding to the SP1-7 site. We herein report a strong anti-allodynic effect of a new H-Phe-Phe-NH2 peptidomimetic (4) comprising an imidazole ring as a bioisosteric element, in the spare nerve injury (SNI) mice model after peripheral administration. Peptidomimetic 4 was stable in plasma, displayed a fair membrane permeability and a favorable neurotoxic profile. Moreover, the effective dose (ED50) of 4 was superior as compared to gabapentin and morphine that are used in clinic.
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| 3. |
- Jonsson, Anna, 1981-, et al.
(author)
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Small constrained SP1-7 analogues bind to a unique site and promote anti-allodynic effects following systemic injection in mice
- 2015
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In: Neuroscience. - : Elsevier BV. - 0306-4522 .- 1873-7544. ; 298, s. 112-119
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Journal article (peer-reviewed)abstract
- Previous results have shown that the substance P (SP) N-terminal fragment SP1–7 may attenuate hyperalgesia and produce anti-allodynia in animals using various experimental models for neuropathic pain. The heptapeptide was found to induce its effects through binding to and activating specific sites apart from any known neurokinin or opioid receptor. Furthermore, we have applied a medicinal chemistry program to develop lead compounds mimicking the effect of SP1–7. The present study was designed to evaluate the pharmacological effect of these compounds using the mouse spared nerve injury (SNI) model of chronic neuropathic pain. Also, as no comprehensive screen with the aim to identify the SP1–7 target has yet been performed we screened our lead compound H-Phe-Phe-NH2 toward a panel of drug targets. The extensive target screen, including 111 targets, did not reveal any hit for the binding site among a number of known receptors or enzymes involved in pain modulation. Our animal studies confirmed that SP1–7, but also synthetic analogs thereof, possesses anti-allodynic effects in the mouse SNI model of neuropathic pain. One of the lead compounds, a constrained H-Phe-Phe-NH2 analog, was shown to exhibit a significant anti-allodynic effect.
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| 4. |
- Skogh, Anna, et al.
(author)
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Impact of N-methylation of the substance P 1-7 amide on anti-allodynic effect in mice after peripheral administration
- 2017
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In: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 109, s. 533-540
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Journal article (peer-reviewed)abstract
- Substance P 1-7 (SP1-7, Arg1-Pro2-Lys3-Pro4-Gln5-Gln6-Phe7) is the major bioactive metabolite formed after proteolytic degradation of the tachykinin substance P (SP). This heptapeptide often opposes the effects of the mother peptide. Hence, SP1-7 is having anti-inflammatory, anti-nociceptive and anti-hyperalgesic effects in experimental models. Despite all encouraging properties of SP1-7 its exact mode of action has not yet been elucidated which has hampered further development of this heptapeptide in drug discovery. Contrary to SP that mediates its biological activity via the NK-1 receptor, the N-terminal fragment SP1-7 acts through an unknown target that is distinct from all known opioid and tachykinin receptors. The SP1-7 amide 1 (Arg1-Pro2-Lys3-Pro4-Gln5-Gln6-Phe7-NH2) was previously shown to be superior to the endogenous SP1-7 in all experimental pain models where the two compounds were compared. Herein, we report that N-methylation scan of the backbone of the SP1-7 amide (1) results in peptides that are significantly less prone to undergo proteolysis in plasma from both mouse and human. However, with the two exceptions of the [MeLys3]SP1-7 amide (3) and the [MeGln5]SP1-7 amide (4), the peptides with a methyl group attached to the backbone are devoid of significant anti-allodynic effects after peripheral administration in the spared nerve injury (SNI) mouse model of neuropathic pain. It is suggested that the N-methylation does not allow these peptides to form the accurate bioactive conformations or interactions required for efficient binding to the macromolecular target. The importance of intact N-terminal Arg1 and C-terminal Phe7, anticipated to serve as address and message residues, respectively, for achieving the anti-allodynic effect is emphasized. Notably, the three heptapeptides: the SP1-7 amide (1), the [MeLys3]SP1-7 amide (3) amide and the [MeGln5]SP1-7 amide (4) are all considerably more effective in the SNI mouse model than gabapentin that is widely used in the clinic for treatment of neuropathic pain.
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| 5. |
- Skogh, Anna, et al.
(author)
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Importance of N-and C-terminal residues of substance P 1-7 for alleviating allodynia in mice after peripheral administration
- 2017
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In: European Journal of Pharmaceutical Sciences. - : Elsevier. - 0928-0987 .- 1879-0720. ; 106, s. 345-351
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Journal article (peer-reviewed)abstract
- The heptapeptide SP1-7 (1, Arg(1)-Pro(2)-Lys(3)-Pro(4)-Gln(5)-Gln(6)-Phe(7)) is the major bioactive metabolite formed after proteolytic processing of the neuropeptide substance P (SP, Arg(1)-Pro(2)-Lys(3)-Pro(4)-GIn(5)-Gln(6)-Phe(7)-Phe(8)-Gly(9)-Leu(10)-Meti(11)-NH2). The heptapeptide 1 frequently exhibits opposite effects to those induced by SP, such as exerting antinociception, or attenuating thermal hyperalgesia and mechanical allodynia. The heptapeptide SP1-7 amide (2, Arg(1)-Pro(2)-Lys(3)-Pro(4)-Gln(5)-Gln(6)-Phe(7)-NH2 ) is often more efficacious than 1 in experimental pain models. We have now assessed the anti-allodynic outcome after systemic administration of 2 and a series of Ala substituted and truncated analogues of 2, in the spared nerve injury (SNI) mice model and the results obtained were correlated with in vitro plasma stability and permeability measurements. It is herein demonstrated that an intact Arg(1) in SP1-7 amide analogues is fundamental for retaining a potent in vivo effect, while Lys(3) of 2 is less important. A displacement with Ala(1) or truncation rendered the peptide analogues either inactive or with a significantly attenuated in vivo activity. Thus, the pentapeptide SP3-7 amide (7, t(1/2) = 11.1 min) proven to be the major metabolite of 2, demonstrated an in vivo effect itself although considerably less significant than 2 in the SNI model. Intraperitoneal administration of 2 in a low dose furnished the most powerful anti-allodynic effect in the SNI model of all the analogous evaluated, despite a fast proteolysis of 2 in plasma (t(1/2) = 6.4 min). It is concluded that not only the C-terminal residue, that we previously demonstrated, but also the N-terminal with its basic side chain, are important for achieving effective pain relief. This information is of value for the further design process aimed at identifying more drug-like SP1-7 amide related peptidomimetics with pronounced antiallodynic effects.
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| 6. |
- Svärd, Anna, et al.
(author)
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Associations to smoking and shared epitope differ between IgA and IgG class antibodies to cyclic citrullinated peptides in early rheumatoid arthritis
- 2015
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In: Arthritis & Rheumatology. - : Wiley-Blackwell. - 2326-5191 .- 2326-5205. ; 67:8, s. 2032-2037
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Journal article (peer-reviewed)abstract
- Background Smoking and HLA-DRB1/shared epitope (SE) are well-known interacting risk factors for developing rheumatoid arthritis (RA) with IgG anticitrullinated protein/peptide antibodies (ACPA). It remains unknown to what extent SE-genes and smoking associate with mucosal immune responses.Objectives This study was done to explore relations between cigarette smoking habits and SE versus circulating IgA and IgG anti-cyclic citrullinated peptide antibodies (anti-CCP) among early RA patients.Methods Patients from two early-RA cohorts were analysed, EIRA-1 (n=1663) and TIRA-2 (n=199). The patients were grouped into four subsets based on anti-CCP: IgG-/IgA-, IgG-/IgA+, IgG+/IgA- and IgG+/IgA+. Interaction between smoking and SE was calculated by the attributable proportion due to deviation from additivity. Analyzed controls (n=1100) were randomly selected from the EIRA-1 study base.Results Anti-CCP occurrence was similar in the two cohorts. Only in EIRA was IgA anti-CCP detected alone in a minority of cases (3%). Smoking was significantly overrepresented among IgA anti-CCP+ patients with or without IgG-class anti-CCP, but not with IgG anti-CCP alone. Presence of SE genes was overrepresented among IgG anti-CCP+ patients with or without IgA-class anti-CCP, but not with IgA anti-CCP alone. Smoking and SE interacted regarding the risk of IgG+/IgA+ RA (AP=0.5, 95 % CI=0.4-0.6), whereas no significant interaction was observed regarding IgG-/IgA+ or IgG+/IgA- RA.Conclusions Association between cigarette smoking and anti-CCP is limited to cases with IgA-class antibodies in addition to IgG anti-CCP. This suggests a causal relation between chronic mucosal irritation/inflammation, induction of a systemic IgA anti-CCP response and subsequent development of RA.
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| 7. |
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| 8. |
- Ighe, Anna, et al.
(author)
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Application of the 2012 systemic lupus international collaborating clinics classification criteria to patients on a Regional Swedish systemic lupus erythematosus register
- 2015
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In: Arthritis Research & Therapy. - : BioMed Central. - 1478-6362 .- 1478-6354. ; 17
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Journal article (peer-reviewed)abstract
- IntroductionIn 2012, the Systemic Lupus International Collaborating Clinics (SLICC) network presented a new set of criteria (SLICC-12) to classify systemic lupus erythematosus (SLE). The present study is the first to evaluate the performance of SLICC-12 in an adult European study population. Thus, SLICC-12 criteria were applied to confirmed SLE cases in our regional SLE register as well as to individuals with a fair suspicion of systemic autoimmune disease who were referred to rheumatology specialists at our unit. MethodsWe included 243 confirmed SLE patients who met the 1982 American College of Rheumatology (ACR-82) classification criteria and/or the Fries ‘diagnostic principle’ (presence of antinuclear antibodies on at least one occasion plus involvement of at least two defined organ systems) and 55 controls with possible systemic autoimmune disease, including the presence of any SLE-related autoantibody. ResultsSLICC-12 showed a diagnostic sensitivity of 94% (95% confidence interval (CI), 0.90 to 0.96) compared with 90% (95% CI, 0.85 to 0.93) for the updated set of ACR criteria from 1997 (ACR-97), whereas ACR-82 failed to identify every fifth true SLE case. However, the disease specificity of SLICC-12 reached only 74% (95% CI, 0.60 to 0.84) and did not change much when involvement of at least two different organs was required as an indicator of systemic disease. In addition, SLICC-12 misclassified more of the controls compared to ACR-82, ACR-97 and Fries. ConclusionsEstablishing a standard definition of SLE continues to challenge lupus researchers and clinicians. We confirm that SLICC-12 has advantages with regard to diagnostic sensitivity, whereas we found the diagnostic specificity to be surprisingly low. To accomplish increased sensitivity and specificity figures, a combination of criteria sets for clinical SLE studies should be considered.
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| 9. |
- Roos, Karin, et al.
(author)
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Circulating secretory IgA antibodies against cyclic citrullinated peptides in early rheumatoid arthritis associate with inflammatory activity and smoking
- 2016
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In: Arthritis Research & Therapy. - : BIOMED CENTRAL LTD. - 1478-6362. ; 18:119
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Journal article (peer-reviewed)abstract
- Background: A possible association between mucosal immunization and inflammation, as well as the initiation and propagation of rheumatoid arthritis (RA), is attracting renewed interest. The aim of this study was to evaluate the possible occurrence and clinical correlations of circulating secretory immunoglobulin A (SIgA) antibodies against the second-generation cyclic citrullinated peptides (CCP) among patients with recent-onset RA followed prospectively over 3 years. Methods: Baseline serum samples from 636 patients with recent-onset RA were analyzed for SIgA anti-CCP antibodies by using an enzyme-linked immunosorbent assay with a secondary antibody directed against secretory component. SIgA anti-CCP status at baseline was analyzed in relation to smoking, HLA-DRB1/shared epitope (SE), and the disease course over 3 years. Significant findings were evaluated in regression analysis that included age, sex, smoking, and SE. Results: Seventeen percent of the patients tested positive for circulating SIgA anti-CCP, and the occurrence was confirmed by detection of secretory component in an affinity-purified IgA anti-CCP fraction. SIgA anti-CCP positivity at baseline was associated with slightly higher baseline erythrocyte sedimentation rate (ESR) (mean 38 vs. 31 mm/first hour, p = 0.004) and C-reactive protein (CRP) (mean 30 vs. 23 mg/L, p = 0.047). During follow-up, SIgA anti-CCP-positive patients had a higher mean AUC regarding ESR (adjusted p = 0.003), although there were no significant differences regarding CRP, tender and swollen joint counts, or radiological joint damage (median Larsen progression 1.0 vs. 1.0, p = 0.22). SIgA anti-CCP was associated significantly with smoking (79 % ever smokers among SIgA anti-CCP-positive patients vs. 59 % in SIgA anti-CCP-negative patients, adjusted OR 2.19, 95 % CI 1.01-4.37, p = 0.027) but not with carriage of the SE (80 % vs. 73 %, p = 0.62). Conclusions: Circulating SIgA anti-CCP, which is present in a subgroup of patients with early RA, is not related to SE, but it is environmentally linked to cigarette smoking. This finding strengthens the hypothesis that immunization against citrullinated peptides and/or proteins may occur at mucosal surfaces of the airways. Analysis of SIgA antibodies in serum may be a convenient and more versatile means to investigate the "mucosal connection" in RA compared with analyses in mucosal fluid samples.
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| 10. |
- Roos Ljungberg, Karin, et al.
(author)
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Secretory anti-citrullinated protein antibodies in serum associate with lung involvement in early rheumatoid arthritis
- 2020
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In: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 59:4, s. 852-859
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Journal article (peer-reviewed)abstract
- Objective. A 'mucosal connection' in RA presently attracts increasing attention. We recently described the occurrence of secretory antibodies to citrullinated protein (SC-ACPA) in sera from patients with recent-onset RA. The current study was performed to evaluate possible associations between serum levels of secretory ACPA and signs of lung involvement in patients with early, untreated RA. Methods. One hundred and forty-two RA patients were included as part of the 'LUng Investigation in newly diagnosed RA' study. One hundred and six patients were examined with high-resolution CT (HRCT) and 20 patients underwent bronchoscopy, where bronchial biopsies and bronchoalveolar lavage fluid (BALF) samples were obtained. SC-ACPA in serum and BALF were detected by an enzyme-linked immunoassay. Antibody levels were related to smoking history, pulmonary function, HRCT, BALF cell counts and findings in bronchial biopsies. Results. SC-ACPA occurred in 16% of the serum samples and in 35% of the BALF samples. SC-ACPA levels in serum correlated with SC-ACPA levels in BALF (sigma = 0.50, P = 0.027) and were higher among patients with HRCT parenchymal lung abnormalities (P = 0.022) or bronchiectasis (P = 0.042). Also, ever smoking was more frequent among serum SC-ACPA-positive patients (91% vs 67%, P = 0.023), and the SC-ACPA levels correlated with the number of pack-years (sigma=0.20, P = 0.020). Conclusion. In early, untreated RA, serum levels of SC-ACPA reflect lung involvement in terms of local ACPA levels, smoking and lung abnormalities on HRCT. These findings strengthen the link between mucosal ACPA responses and the lungs in RA.
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