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4. Changes in liver metabolic pathways demonstrate efficacy of the combined dietary and microbial therapeutic intervention in MASLD mouse model.

Author

Iannone, Valeria, Babu, Ambrin, Lok, Johnson, Gómez-Gallego, Carlos, DAuria, Giuseppe, Vazquez-Uribe, Ruben, Vaaben, Troels, Bongers, Mareike, Mikkonen, Santtu, Vaittinen, Maija, Tikkanen, Ida, Kettunen, Mikko, Klåvus, Anton, Sehgal, Ratika, Pihlajamaki, Jussi, Hanhineva, Kati, El-Nezami, Hani, Sommer, Morten, Kolehmainen, Marjukka, and Kaminska, Dorota

Subjects
Aldafermin, Genetically modified E.coli Nissle 1917, Non-alcoholic fatty liver disease, Non-targeted metabolomics, Omics integration, Transcriptomics
Abstract

OBJECTIVE: Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is the most prevalent liver disease globally, yet no therapies are approved. The effects of Escherichia coli Nissle 1917 expressing aldafermin, an engineered analog of the intestinal hormone FGF19, in combination with dietary change were investigated as a potential treatment for MASLD. METHODS: MASLD was induced in C57BL/6J male mice by American lifestyle-induced obesity syndrome diet and then switched to a standard chow diet for seven weeks. In addition to the dietary change, the intervention group received genetically engineered E. coli Nissle expressing aldafermin, while control groups received either E. coli Nissle vehicle or no treatment. MASLD-related plasma biomarkers were measured using an automated clinical chemistry analyzer. The liver steatosis was assessed by histology and bioimaging analysis using Fiji (ImageJ) software. The effects of the intervention in the liver were also evaluated by RNA sequencing and liquid-chromatography-based non-targeted metabolomics analysis. Pathway enrichment studies were conducted by integrating the differentially expressed genes from the transcriptomics findings with the metabolites from the metabolomics results using Ingenuity pathway analysis. RESULTS: After the intervention, E. coli Nissle expressing aldafermin along with dietary changes reduced body weight, liver steatosis, plasma aspartate aminotransferase, and plasma cholesterol levels compared to the two control groups. The integration of transcriptomics with non-targeted metabolomics analysis revealed the downregulation of amino acid metabolism and related receptor signaling pathways potentially implicated in the reduction of hepatic steatosis and insulin resistance. Moreover, the downregulation of pathways linked to lipid metabolism and changes in amino acid-related pathways suggested an overall reduction of oxidative stress in the liver. CONCLUSIONS: These data support the potential for using engineered microbial therapeutics in combination with dietary changes for managing MASLD.

Published
2023

6. Subject‐specific biomechanical analysis to estimate locations susceptible to osteoarthritis—Finite element modeling and MRI follow‐up of ACL reconstructed patients

Author

Bolcos, Paul O, Mononen, Mika E, Roach, Koren E, Tanaka, Matthew S, Suomalainen, Juha-Sampo, Mikkonen, Santtu, Nissi, Mikko J, Töyräs, Juha, Link, Thomas M, Souza, Richard B, Majumdar, Sharmila, Ma, C Benjamin, Li, Xiaojuan, and Korhonen, Rami K

Subjects
Engineering, Biomedical Engineering, Arthritis, Aging, Osteoarthritis, Bioengineering, Aetiology, 2.1 Biological and endogenous factors, Musculoskeletal, Anterior Cruciate Ligament Injuries, Cartilage, Articular, Case-Control Studies, Finite Element Analysis, Follow-Up Studies, Humans, Knee Joint, Magnetic Resonance Imaging, biomechanics, cartilage, finite eelement analysis, gait, osteoarthritis-posttraumatic, reconstruction, Clinical Sciences, Human Movement and Sports Sciences, Orthopedics, Biomedical engineering, Sports science and exercise
Abstract

The aims of this case-control study were to: (1) Identify cartilage locations and volumes at risk of osteoarthritis (OA) using subject-specific finite element (FE) models; (2) Quantify the relationships between the simulated biomechanical parameters and T2 and T1ρ relaxation times of magnetic resonance imaging (MRI). We created subject-specific FE models for seven patients with anterior cruciate ligament (ACL) reconstruction and six controls based on a previous proof-of-concept study. We identified locations and cartilage volumes susceptible to OA, based on maximum principal stresses and absolute maximum shear strains in cartilage exceeding thresholds of 7 MPa and 32%, respectively. The locations and volumes susceptible to OA were compared qualitatively and quantitatively against 2-year longitudinal changes in T2 and T1ρ relaxation times. The degeneration volumes predicted by the FE models, based on excessive maximum principal stresses, were significantly correlated (r = 0.711, p

Published
2022

8. Eight-year diet and physical activity intervention affects serum metabolites during childhood and adolescence: A nonrandomized controlled trial

Author

Zarei, Iman, Eloranta, Aino-Maija, Klåvus, Anton, Väistö, Juuso, Lehtonen, Marko, Mikkonen, Santtu, Koistinen, Ville M., Sallinen, Taisa, Haapala, Eero A., Lintu, Niina, Soininen, Sonja, Haikonen, Retu, Atalay, Mustafa, Schwab, Ursula, Auriola, Seppo, Kolehmainen, Marjukka, Hanhineva, Kati, and Lakka, Timo A.

Published
2024
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10. Prenatal Urban Environment and Blood Pressure Trajectories From Childhood to Early Adulthood

Author

Gonçalves Soares, Ana, Santos, Susana, Seyve, Emie, Nedelec, Rozenn, Puhakka, Soile, Eloranta, Aino-Maija, Mikkonen, Santtu, Yuan, Wen Lun, Lawlor, Deborah A., Heron, Jon, Vrijheid, Martine, Lepeule, Johanna, Nieuwenhuijsen, Mark, Fossati, Serena, Jaddoe, Vincent W.V., Lakka, Timo, Sebert, Sylvain, Heude, Barbara, Felix, Janine F., Elhakeem, Ahmed, and Timpson, Nicholas J.

Published
2024
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18. Real-world effectiveness of digital and group-based lifestyle interventions as compared with usual care to reduce type 2 diabetes risk – A stop diabetes pragmatic randomised trial

Author

Lakka, Timo A., Aittola, Kirsikka, Järvelä-Reijonen, Elina, Tilles-Tirkkonen, Tanja, Männikkö, Reija, Lintu, Niina, Karhunen, Leila, Kolehmainen, Marjukka, Harjumaa, Marja, Mattila, Elina, Järvenpää, Riia, Ermes, Miikka, Mikkonen, Santtu, Martikainen, Janne, Poutanen, Kaisa, Schwab, Ursula, Absetz, Pilvikki, Lindström, Jaana, and Pihlajamäki, Jussi

Published
2023
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24. Eight-year Combined Diet and Physical Activity Intervention Affects Serum Metabolites during Childhood and Adolescence: A Nonrandomized Controlled Trial

Author

Zarei, Iman, primary, Eloranta, Aino-Maija, additional, Klavus, Anton, additional, Vaisto, Juuso, additional, Lehtonen, Marko, additional, Mikkonen, Santtu, additional, Koistinen, Ville M., additional, Sallinen, Taisa, additional, Haapala, Eero A., additional, Lintu, Niina, additional, Soininen, Sonja, additional, Atalay, Mustafa, additional, Schwab, Ursula, additional, Auriola, Seppo, additional, Kolehmainen, Marjukka, additional, Hanhineva, Kati, additional, and Lakka, Timo A., additional

Published
2024
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26. Loss of collagen content is localized near cartilage lesions on the day of injurious loading and intensified on day 12.

Author

Hamada, Moustafa, Eskelinen, Atte S. A., Florea, Cristina, Mikkonen, Santtu, Nieminen, Petteri, Grodzinsky, Alan J., Tanska, Petri, and Korhonen, Rami K.

Abstract

Joint injury can lead to articular cartilage damage, excessive inflammation, and post‐traumatic osteoarthritis (PTOA). Collagen is an essential component for cartilage function, yet current literature has limited understanding of how biochemical and biomechanical factors contribute to collagen loss in injured cartilage. Our aim was to investigate spatially dependent changes in collagen content and collagen integrity of injured cartilage, with an explant model of early‐stage PTOA. We subjected calf knee cartilage explants to combinations of injurious loading (INJ), interleukin‐1α‐challenge (IL) and physiological cyclic loading (CL). Using Fourier transform infrared microspectroscopy, collagen content (Amide I band) and collagen integrity (Amide II/1338 cm−1 ratio) were estimated on days 0 and 12 post‐injury. We found that INJ led to lower collagen content near lesions compared to intact regions on day 0 (p < 0.001). On day 12, near‐lesion collagen content was lower compared to day 0 (p < 0.05). Additionally, on day 12, INJ, IL, and INJ + IL groups exhibited lower collagen content along most of tissue depth compared to free‐swelling control group (p < 0.05). CL groups showed higher collagen content along most of tissue depth compared to corresponding groups without CL (p < 0.05). Immunohistochemical analysis revealed higher MMP‐1 and MMP‐3 staining intensities localized within cell lacunae in INJ group compared to CTRL group on day 0. Our results suggest that INJ causes rapid loss of collagen content near lesions, which is intensified on day 12. Additionally, CL could mitigate the loss of collagen content at intact regions after 12 days. [ABSTRACT FROM AUTHOR]

Published
2025
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27. Impact of three decades of warming, increased nutrient availability, and increased cloudiness on the fluxes of greenhouse gases and biogenic volatile organic compounds in a subarctic tundra heath.

Author

Ndah, Flobert A., Michelsen, Anders, Rinnan, Riikka, Maljanen, Marja, Mikkonen, Santtu, and Kivimäenpää, Minna

Subjects
GLOBAL warming, ORGANONITROGEN compounds, CLIMATE feedbacks, VOLATILE organic compounds, SOIL moisture, GREENHOUSE gases
Abstract

Climate change is exposing subarctic ecosystems to higher temperatures, increased nutrient availability, and increasing cloud cover. In this study, we assessed how these factors affect the fluxes of greenhouse gases (GHGs) (i.e., methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)), and biogenic volatile organic compounds (BVOCs) in a subarctic mesic heath subjected to 34 years of climate change related manipulations of temperature, nutrient availability, and light. GHGs were sampled from static chambers and gases analyzed with gas chromatograph. BVOCs were measured using the push‐pull method and gases analyzed with chromatography–mass spectrometry. The soil temperature and moisture content in the warmed and shaded plots did not differ significantly from that in the controls during GHG and BVOC measurements. Also, the enclosure temperatures during BVOC measurements in the warmed and shaded plots did not differ significantly from temperatures in the controls. Hence, this allowed for assessment of long‐term effects of the climate treatment manipulations without interference of temperature and moisture differences at the time of measurements. Warming enhanced CH4 uptake and the emissions of CO2, N2O, and isoprene. Increased nutrient availability increased the emissions of CO2 and N2O but caused no significant changes in the fluxes of CH4 and BVOCs. Shading (simulating increased cloudiness) enhanced CH4 uptake but caused no significant changes in the fluxes of other gases compared to the controls. The results show that climate warming and increased cloudiness will enhance CH4 sink strength of subarctic mesic heath ecosystems, providing negative climate feedback, while climate warming and enhanced nutrient availability will provide positive climate feedback through increased emissions of CO2 and N2O. Climate warming will also indirectly, through vegetation changes, increase the amount of carbon lost as isoprene from subarctic ecosystems. [ABSTRACT FROM AUTHOR]

Published
2024
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30. Effects of fuel composition and vehicle operating temperature on in vitro toxicity of exhaust emissions

Author

Hakkarainen, Henri, primary, Järvinen, Anssi, additional, Lepistö, Teemu, additional, Kuittinen, Niina, additional, Markkula, Lassi, additional, Ihantola, Tuukka, additional, Yang, Mo, additional, Martikainen, Maria-Viola, additional, Mikkonen, Santtu, additional, Timonen, Hilkka, additional, Aurela, Minna, additional, Barreira, Luis, additional, Ihalainen, Mika, additional, Saarikoski, Sanna, additional, Rönkkö, Topi, additional, Aakko-Saksa, Päivi, additional, and Jalava, Pasi, additional

Published
2024
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31. The effects of a 2-year physical activity and dietary intervention on plasma lipid concentrations in children: the PANIC Study

Author

Eloranta, Aino-Maija, Sallinen, Taisa, Viitasalo, Anna, Lintu, Niina, Väistö, Juuso, Jalkanen, Henna, Tompuri, Tuomo T., Soininen, Sonja, Haapala, Eero A., Kiiskinen, Sanna, Schnurr, Theresia M., Kilpeläinen, Tuomas O., Mikkonen, Santtu, Savonen, Kai, Atalay, Mustafa, Brage, Soren, Laaksonen, David E., Lindi, Virpi, Ågren, Jyrki, Schwab, Ursula, Jääskeläinen, Jarmo, and Lakka, Timo A.

Published
2021
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32. A 2 year physical activity and dietary intervention attenuates the increase in insulin resistance in a general population of children: the PANIC study

Author

Lakka, Timo A., Lintu, Niina, Väistö, Juuso, Viitasalo, Anna, Sallinen, Taisa, Haapala, Eero A., Tompuri, Tuomo T., Soininen, Sonja, Karjalainen, Panu, Schnurr, Theresia M., Mikkonen, Santtu, Atalay, Mustafa, Kilpeläinen, Tuomas O., Laitinen, Tomi, Laaksonen, David E., Savonen, Kai, Brage, Soren, Schwab, Ursula, Jääskeläinen, Jarmo, Lindi, Virpi, and Eloranta, Aino-Maija

Published
2020
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35. LongITools: Dynamic longitudinal exposome trajectories in cardiovascular and metabolic noncommunicable diseases

Author

Ronkainen, Justiina, Nedelec, Rozenn, Atehortua, Angelica, Balkhiyarova, Zhanna, Cascarano, Anna, Ngoc Dang, Vien, Elhakeem, Ahmed, van Enckevort, Esther, Goncalves Soares, Ana, Haakma, Sido, Halonen, Miia, Heil, Katharina F., Heiskala, Anni, Hyde, Eleanor, Jacquemin, Bénédicte, Keikkala, Elina, Kerckhoffs, Jules, Klåvus, Anton, Kopinska, Joanna A., Lepeule, Johanna, Marazzi, Francesca, Motoc, Irina, Näätänen, Mari, Ribbenstedt, Anton, Rundblad, Amanda, Savolainen, Otto, Simonetti, Valentina, de Toro Eadie, Nina, Tzala, Evangelia, Ulrich, Anna, Wright, Thomas, Zarei, Iman, d’Amico, Enrico, Belotti, Federico, Brunius, Carl, Castleton, Christopher, Charles, Marie-Aline, Gaillard, Romy, Hanhineva, Kati, Hoek, Gerard, Holven, Kirsten B., Jaddoe, Vincent W. V., Kaakinen, Marika A., Kajantie, Eero, Kavousi, Maryam, Lakka, Timo, Matthews, Jason, Piano Mortari, Andrea, Vääräsmäki, Marja, Voortman, Trudy, Webster, Claire, Zins, Marie, Atella, Vincenzo, Bulgheroni, Maria, Chadeau-Hyam, Marc, Conti, Gabriella, Evans, Jayne, Felix, Janine F., Heude, Barbara, Järvelin, Marjo-Riitta, Kolehmainen, Marjukka, Landberg, Rikard, Lekadir, Karim, Parusso, Stefano, Prokopenko, Inga, de Rooij, Susanne R., Roseboom, Tessa, Swertz, Morris, Timpson, Nicholas, Ulven, Stine M., Vermeulen, Roel, Juola, Teija, Sebert, Sylvain, Sebert, Sylvain, Juola, Teija, Nedelec, Rozenn, Ronkainen, Justiina, Heiskala, Anni, Halonen, Miia, He, Yiyan, Miettunen, Jouko, Karhunen, Ville, Kajantie, Eero, Vääräsmäki, Marja, Keikkala, Elina, Nyberg, Pia, Serpi, Raisa, Felix, Janine, Jaddoe, Vincent, Marques, Irene, Moreira da Silva Santos, Susana, Kavousi, Maryam, Voortman, Trudy, Ginos, Bigina, Chadeau-Hyam, Marc, Järvelin, Marjo-Riitta, Tzala, Evangelia, De Toro, Nina, Wright, Thomas, Bodinier, Barbara, Dagnino, Sonia, Evans, Jayne, Webster, Claire, Kolehmainen, Marjukka, Hanhineva, Kati, Lakka, Timo, Savolainen, Otto, Zarei, Iman, Näätänen, Mari, Klåvus, Anton, Eloranta, Aino-Maija, Väistö, Juuso, Kårlund, Anna, Mikkonen, Santtu, Atalay, Merja, Atalay, Mustafa, Landberg, Rikard, Brunius, Carl, Ribbenstedt, Anton, Swertz, Morris, Hyde, Eleanor, Haakma, Sido, van Enckevort, Esther, Heude, Barbara, Charles, Marie-Aline, Zins, Marie, Lepeule, Johanna, Jacquemin, Bénédicte, Calas, Lucinda, Lequy-Flahault, Emeline, Lun Yuan, Wen, Seyve, Emie, Conti, Gabriella, Vermeulen, Roel, Hoek, Gerard, Kerckhoffs, Jules, Prokopenko, Inga, Kaakinen, Marika, Balkhiyarova, Zhanna, Ulrich, Anna, Roseboom, Tessa, De Rooij, Susanne, Motoc, Irina, Marie Ulven, Stine, Holven, Kirsten B., Matthews, Jason, Rundblad, Amanda, Das, Siddhartha, Timpson, Nicholas, Elhakeem, Ahmed, Luiza Goncalves Soares, Ana, Lekadir, Karim, Maria Cascarano, Anna, Maria Atehortua Labrador, Angélica, Ngoc Dang, Vien, Heil, Katharina F., Gallin, Catherine, Díaz, Oliver, Bulgheroni, Maria, Simonetti, Valentina, D’Amico, Enrico, Giani, Laura, Manzino, Fabrizio, Parusso, Stefano, Castleton, Christopher, Moimas, Diego, Atella, Vincenzo, Piano Mortari, Andrea, Kopinska, Joanna, Marazzi, Francesca, Giaccherini, Matilde, and Belotti, Federico

Published
2022
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36. PM2.5 concentration and composition in the urban air of Nanjing, China: Effects of emission control measures applied during the 2014 Youth Olympic Games

Author

Miettinen, Mirella, Leskinen, Ari, Abbaszade, Gülcin, Orasche, Jürgen, Sainio, Maija, Mikkonen, Santtu, Koponen, Hanna, Rönkkö, Teemu, Ruusunen, Jarno, Kuuspalo, Kari, Tiitta, Petri, Jalava, Pasi, Hao, Liqing, Fang, Die, Wang, Qingeng, Gu, Cheng, Zhao, Yu, Michalke, Bernhard, Schnelle-Kreis, Jürgen, Lehtinen, Kari E.J., Zimmermann, Ralf, Komppula, Mika, Jokiniemi, Jorma, Hirvonen, Maija-Riitta, and Sippula, Olli

Published
2019
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37. Association between active commuting and low-grade inflammation: a population-based cross-sectional study.

Author

Allaouat, Sara, Halonen, Jaana I., Jussila, Juuso J., Tiittanen, Pekka, Ervasti, Jenni, Ngandu, Tiia, Mikkonen, Santtu, Yli-Tuomi, Tarja, Jousilahti, Pekka, and Lanki, Timo

Subjects
CROSS-sectional method, EMPLOYEES, RESEARCH funding, DESCRIPTIVE statistics, TRANSPORTATION, WALKING, CYCLING, SERUM, LEISURE, MATHEMATICAL models, INFLAMMATION, THEORY, COMPARATIVE studies, CONFIDENCE intervals, PHYSICAL activity, C-reactive protein, REGRESSION analysis, INDUSTRIAL hygiene, DIET
Abstract

Background: Prior studies suggest that physical activity lowers circulating C-reactive protein (CRP) levels. However, little is known about the association between regular active commuting, i.e. walking or cycling to work, and CRP concentrations. This study examines whether active commuting is associated with lower CRP. Methods: We conducted a cross-sectional study using population-based FINRISK data from 1997, 2002, 2007 and 2012. Participants were working adults living in Finland (n = 6208; mean age = 44 years; 53.6% women). We used linear and additive models adjusted for potential confounders to analyze whether daily active commuting, defined as the time spent walking or cycling to work, was associated with lower high-sensitivity (hs-) CRP serum concentrations compared with passive commuting. Results: We observed that daily active commuting for 45 min or more (vs. none) was associated with lower hs-CRP [% mean difference in the main model: -16.8%; 95% confidence interval (CI) -25.6% to -7.0%), and results were robust to adjustment for leisure-time and occupational physical activity, as well as diet. Similarly, active commuting for 15-29 min daily was associated with lower hs-CRP in the main model (-7.4; 95% CI -14.1 to -0.2), but the association attenuated to null after further adjustments. In subgroup analyses, associations were only observed for women. Conclusions: Active commuting for at least 45 min a day was associated with lower levels of low-grade inflammation. Promoting active modes of transport may lead not only to reduced emissions from motorized traffic but also to population-level health benefits. [ABSTRACT FROM AUTHOR]

Published
2024
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39. Changes in liver metabolic pathways demonstrate efficacy of the combined dietary and microbial therapeutic intervention in MASLD mouse model

Author

Iannone, Valeria, primary, Babu, Ambrin Farizah, additional, Lok, Johnson, additional, Gómez-Gallego, Carlos, additional, D’Auria, Giuseppe, additional, Vazquez-Uribe, Ruben, additional, Vaaben, Troels Holger, additional, Bongers, Mareike, additional, Mikkonen, Santtu, additional, Vaittinen, Maija, additional, Tikkanen, Ida, additional, Kettunen, Mikko, additional, Klåvus, Anton, additional, Sehgal, Ratika, additional, Kaminska, Dorota, additional, Pihlajamaki, Jussi, additional, Hanhineva, Kati, additional, El-Nezami, Hani, additional, Alexander Sommer, Morten Otto, additional, and Kolehmainen, Marjukka, additional

Published
2023
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47. 3‐D T 1 relaxation time measurements in an equine model of subtle post‐traumatic osteoarthritis using MB‐SWIFT

Author

Pala, Swetha, primary, Hänninen, Nina E., additional, Mohammadi, Ali, additional, Ebrahimi, Mohammadhossein, additional, te Moller, Nikae C.R., additional, Brommer, Harold, additional, René van Weeren, P., additional, Mäkelä, Janne T.A., additional, Korhonen, Rami K., additional, Afara, Isaac O., additional, Töyräs, Juha, additional, Mikkonen, Santtu, additional, Nissi, Mikko J., additional, and Nykänen, Olli, additional

Published
2023
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48. 3D T1 relaxation time measurements in an equine model of subtle post-traumatic osteoarthritis using MB-SWIFT

Author

Pala, Swetha, Hänninen, Nina E, Mohammadi, Ali, Ebrahimi, Mohammadhossein, Te Moller, Nikae C R, Brommer, Harold, René van Weeren, P, Mäkelä, Janne T A, Korhonen, Rami K, Afara, Isaac O, Töyräs, Juha, Mikkonen, Santtu, Nissi, Mikko J, Nykänen, Olli, Pala, Swetha, Hänninen, Nina E, Mohammadi, Ali, Ebrahimi, Mohammadhossein, Te Moller, Nikae C R, Brommer, Harold, René van Weeren, P, Mäkelä, Janne T A, Korhonen, Rami K, Afara, Isaac O, Töyräs, Juha, Mikkonen, Santtu, Nissi, Mikko J, and Nykänen, Olli

Abstract

The aim of this study is to assess whether articular cartilage changes in an equine model of post-traumatic osteoarthritis (PTOA), induced by surgical creation of standard (blunt) grooves, and very subtle sharp grooves, could be detected with ex vivo T1 relaxation time mapping utilizing three-dimensional (3D) readout sequence with zero echo time. Grooves were made on the articular surfaces of the middle carpal and radiocarpal joints of nine mature Shetland ponies and osteochondral samples were harvested at 39 weeks after being euthanized under respective ethical permissions. T1 relaxation times of the samples (n = 8 + 8 for experimental and n = 12 for contralateral controls) were measured with a variable flip angle 3D multiband-sweep imaging with Fourier transform sequence. Equilibrium and instantaneous Young's moduli and proteoglycan (PG) content from OD of Safranin-O-stained histological sections were measured and utilized as reference parameters for the T1 relaxation times. T1 relaxation time was significantly (p < 0.05) increased in both groove areas, particularly in the blunt grooves, compared with control samples, with the largest changes observed in the superficial half of the cartilage. T1 relaxation times correlated weakly (Rs ≈ 0.33) with equilibrium modulus and PG content (Rs ≈ 0.21). T1 relaxation time in the superficial articular cartilage is sensitive to changes induced by the blunt grooves but not to the much subtler sharp grooves, at the 39-week timepoint post-injury. These findings support that T1 relaxation time has potential in detection of mild PTOA, albeit the most subtle changes could not be detected.

Published
2023

49. 3D T1 relaxation time measurements in an equine model of subtle post-traumatic osteoarthritis using MB-SWIFT

Author

Equine Musculoskeletal Biology, CS_Locomotion, Heelkunde, Dep Clinical Sciences, Locomotion - Equine Sciences, Pala, Swetha, Hänninen, Nina E, Mohammadi, Ali, Ebrahimi, Mohammadhossein, Te Moller, Nikae C R, Brommer, Harold, René van Weeren, P, Mäkelä, Janne T A, Korhonen, Rami K, Afara, Isaac O, Töyräs, Juha, Mikkonen, Santtu, Nissi, Mikko J, Nykänen, Olli, Equine Musculoskeletal Biology, CS_Locomotion, Heelkunde, Dep Clinical Sciences, Locomotion - Equine Sciences, Pala, Swetha, Hänninen, Nina E, Mohammadi, Ali, Ebrahimi, Mohammadhossein, Te Moller, Nikae C R, Brommer, Harold, René van Weeren, P, Mäkelä, Janne T A, Korhonen, Rami K, Afara, Isaac O, Töyräs, Juha, Mikkonen, Santtu, Nissi, Mikko J, and Nykänen, Olli

Published
2023

50. Carbon and nitrogen-based gas fluxes in subarctic ecosystems under climate warming and increased cloudinessElectronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d4ea00017j

Author

Ndah, Flobert A., Maljanen, Marja, Rinnan, Riikka, Bhattarai, Hem Raj, Davie-Martin, Cleo L., Mikkonen, Santtu, Michelsen, Anders, and Kivimäenpää, Minna

Abstract

Climate warming is projected to be particularly pronounced in the northern high latitudes coupled with reduced light availability due to increased cloudiness. The changing climate may alter the fluxes of greenhouse gases (GHGs) and atmospherically reactive trace gases, which can drive important climate feedbacks. We investigated the individual and combined effects of warming and increased cloudiness on methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O), nitric oxide (NO), nitrous acid (HONO) and biogenic volatile organic compound (BVOC) fluxes in mesocosms from two tundra and one palsa mire ecosystems kept under strict environmental control in climate chambers. We also examined whether and how prevailing soil physiochemical properties and plant species composition affected the fluxes. In control conditions, all sites were net sinks of CH4and CO2during both growing seasons except for the palsa site which was a net source of CO2in the second growing season. Warming enhanced CH4uptake, mostly observed in the palsa site, and turned the palsa site from a sink to a source of CO2in the first growing season and increased the CO2source strength in the second growing season. Warming increased BVOC emissions while increased cloudiness mostly decreased the emissions. The combined treatment of warming and increased cloudiness decreased CH4uptake, mostly observed in the palsa site, and BVOC emissions. Fluxes of CO2were linked to availability of soil carbon and organic matter, litter input, soil pH and bulk density, and cover of mosses. Low emissions of N2O, NO, and HONO could mainly be explained by limited availability of mineral nitrogen. Warming-enhanced CH4uptake and BVOC emissions will provide a negative feedback to climate while enhanced CO2release from palsa mires will exacerbate global warming. Under combined warming and increased cloudiness, subarctic ecosystems may shift from sinks to sources of CH4, providing a positive feedback to climate. Prevailing soil physiochemical properties and vegetation composition will play a significant role in controlling the fluxes, hence contributing to the overall climate change effects and feedback.

Published
2024
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