Keith Baar, Ph.D.

195 Briggs Hall
Davis Campus
Lab Website

Research Interests

The goal of my laboratory is to understand the molecular determinants of musculoskeletal development and the role of exercise in improving health and performance. To achieve this goal, we work on muscle, tendon, and ligaments from 2- and 3-dimensional tissue culture, in vivo wild type and genetically modified animals, and humans. Of particular interest are: 1) the interplay between nutrition and exercise and the mammalian target of rapamycin complex 1 (mTORC1) in the maintenance of muscle mass; 2) the role of the amino acid transceptor LAT1 in the activation of protein synthesis and maintenance of muscle mass; 3) the mechanism of ER stress-induced loss of protein synthesis and how this leads to anabolic resistance in muscle; and 4) the role of growth factors and loading on the activation of the Egr-1 transcription factor and the development and mechanics of ligaments. Our laboratory discovered that mTORC1 was activated by resistance exercise and that this correlates with the degree of skeletal muscle hypertrophy. Since then, we have focused on mTORC1 and its regulation by loading and nutrients. We have shown that: 1) mTORC1 is activated directly by load in a growth factor-independent manner; 2) a1-AMPK regulates mTORC1 activity during overload; 3) following a high fat diet the unfolded protein response, through inhibition of PKB, can attenuate mTORC1 activation; and 4) muscle signaling and protein synthesis after exercise are modified by nutritional interventions that are rich in leucine. Our laboratory has also developed a number of 2- and 3-dimensional tissue culture assays that can be used to study the effects of genes and nutrients on muscle, tendon, and ligament function. These studies have a direct clinical application and we work closely with colleagues in orthopedics, internal medicine, and the cancer center to develop resistance exercise, nutritional, and novel small molecule interventions that prevent muscle wasting from cachexia and sarcopenia and improve muscle function and quality of life.

Graduate Group Affiliations

An updated list of current publications: PubMed | Google Scholar

Langer HT, Mossakowski AA, Avey AM, Wohlgemuth RP, Smith LR, Zbinden-Foncea H, Baar K. A mutation in desmin makes skeletal muscle less vulnerable to acute muscle damage after eccentric loading in rats. FASEB J. 2021 Sep;35(9):e21860. doi: 10.1096/fj.202100711RR. PMID: 34411340.

Avey AM, Baar K. Muscle-tendon Crosstalk During Muscle Wasting. Am J Physiol Cell Physiol. 2021 Jul 28. doi: 10.1152/ajpcell.00260.2021. Epub ahead of print. PMID: 34319830.

Zhou Z, Vidales J, González-Reyes JA, Shibata B, Baar K, Rutkowsky JM, Ramsey JJ. A 1-Month Ketogenic Diet Increased Mitochondrial Mass in Red Gastrocnemius Muscle, but Not in the Brain or Liver of Middle-Aged Mice. Nutrients. 2021 Jul 24;13(8):2533. doi: 10.3390/nu13082533. PMID: 34444693; PMCID: PMC8401881.

Osipov B, Paralkar MP, Emami AJ, Cunningham HC, Tjandra PM, Pathak S, Langer HT, Baar K, Christiansen BA. Sex differences in systemic bone and muscle loss following femur fracture in mice. J Orthop Res. 2021 Jun 3. doi: 10.1002/jor.25116. Epub ahead of print. PMID: 34081357.

Davidyan A, Pathak S, Baar K, Bodine SC. Maintenance of muscle mass in adult male mice is independent of testosterone. PLoS One. 2021 Mar 25;16(3):e0240278. doi: 10.1371/journal.pone.0240278. PMID: 33764986; PMCID: PMC7993603.

Zhou Z, Hagopian K, López-Domínguez JA, Kim K, Jasoliya M, Roberts MN, Cortopassi GA, Showalter MR, Roberts BS, González-Reyes JA, Baar K, Rutkowsky J, Ramsey JJ. A ketogenic diet impacts markers of mitochondrial mass in a tissue specific manner in aged mice. Aging (Albany NY). 2021 Mar 18;13(6):7914-7930. doi: 10.18632/aging.202834. Epub 2021 Mar 18. PMID: 33735837; PMCID: PMC8034930.

Wallace MA, Aguirre NW, Marcotte GR, Marshall AG, Baehr LM, Hughes DC, Hamilton KL, Roberts MN, Lopez-Dominguez JA, Miller BF, Ramsey JJ, Baar K. The ketogenic diet preserves skeletal muscle with aging in mice. Aging Cell. 2021 Apr;20(4):e13322. doi: 10.1111/acel.13322. Epub 2021 Mar 6. PMID: 33675103; PMCID: PMC8045940.

Langer HT, Mossakowski AA, Pathak S, Mascal M, Baar K. Cannabidiol Does Not Impair Anabolic Signaling Following Eccentric Contractions in Rats. Int J Sport Nutr Exerc Metab. 2021 Feb 23;31(2):93-100. doi: 10.1123/ijsnem.2020-0270. PMID: 33621949.

Pechanec MY, Boyd TN, Baar K, Mienaltowski MJ. Adding exogenous biglycan or decorin improves tendon formation for equine peritenon and tendon proper cells in vitro. BMC Musculoskelet Disord. 2020 Sep 23;21(1):627. doi: 10.1186/s12891-020-03650-2. PMID: 32967653; PMCID: PMC7513506.

Langer HT, Mossakowski AA, Willis BJ, Grimsrud KN, Wood JA, Lloyd KCK, Zbinden-Foncea H, Baar K. Generation of desminopathy in rats using CRISPR-Cas9. J Cachexia Sarcopenia Muscle. 2020 Oct;11(5):1364-1376. doi: 10.1002/jcsm.12619. Epub 2020 Sep 7. PMID: 32893996; PMCID: PMC7567154.

Halson SL, Shaw G, Versey N, Miller DJ, Sargent C, Roach GD, Nyman L, Carter JM, Baar K. Optimisation and Validation of a Nutritional Intervention to Enhance Sleep Quality and Quantity. Nutrients. 2020 Aug 25;12(9):2579. doi: 10.3390/nu12092579. PMID: 32854375; PMCID: PMC7551573.

Jannas-Vela S, Langer HT, Marambio H, Baar K, Zbinden-Foncea H. Effect of a 12-week endurance training program on force transfer and membrane integrity proteins in lean, obese, and type 2 diabetic subjects. Physiol Rep. 2020 May;8(9):e14429. doi: 10.14814/phy2.14429. PMID: 32358862; PMCID: PMC7195556.

Lis DM, Baar K. Effects of Different Vitamin C-Enriched Collagen Derivatives on Collagen Synthesis. Int J Sport Nutr Exerc Metab. 2019 Sep 1;29(5):526-531. doi: 10.1123/ijsnem.2018-0385. PMID: 30859848.

Baar K. Stress Relaxation and Targeted Nutrition to Treat Patellar Tendinopathy. Int J Sport Nutr Exerc Metab. 2019 Jul 1;29(4):453–457. doi: 10.1123/ijsnem.2018-0231. PMID: 30299199.

Shaw G, Serpell B, Baar K. Rehabilitation and nutrition protocols for optimising return to play from traditional ACL reconstruction in elite rugby union players: A case study. J Sports Sci. 2019 Aug;37(15):1794-1803. doi: 10.1080/02640414.2019.1594571. Epub 2019 Apr 9. PMID: 30967011.

Close GL, Sale C, Baar K, Bermon S. Nutrition for the Prevention and Treatment of Injuries in Track and Field Athletes. Int J Sport Nutr Exerc Metab. 2019 Mar 1;29(2):189-197. doi: 10.1123/ijsnem.2018-0290. Epub 2019 Mar 8. PMID: 30676133.

Chidi-Ogbolu N, Baar K. Effect of Estrogen on Musculoskeletal Performance and Injury Risk. Front Physiol. 2019 Jan 15;9:1834. doi: 10.3389/fphys.2018.01834. PMID: 30697162; PMCID: PMC6341375.

West DWD, Marcotte GR, Chason CM, Juo N, Baehr LM, Bodine SC, Baar K. Normal Ribosomal Biogenesis but Shortened Protein Synthetic Response to Acute Eccentric Resistance Exercise in Old Skeletal Muscle. Front Physiol. 2019 Jan 14;9:1915. doi: 10.3389/fphys.2018.01915. PMID: 30692935; PMCID: PMC6339931.

West DWD, Marcotte GR, Chason CM, Juo N, Baehr LM, Bodine SC, Baar K. Normal Ribosomal Biogenesis but Shortened Protein Synthetic Response to Acute Eccentric Resistance Exercise in Old Skeletal Muscle. Front Physiol. 2019 Jan 14;9:1915. doi: 10.3389/fphys.2018.01915. PMID: 30692935; PMCID: PMC6339931.

Cunningham HC, West DWD, Baehr LM, Tarke FD, Baar K, Bodine SC, Christiansen BA. Age-dependent bone loss and recovery during hindlimb unloading and subsequent reloading in rats. BMC Musculoskelet Disord. 2018 Jul 18;19(1):223. doi: 10.1186/s12891-018-2156-x. PMID: 30021585; PMCID: PMC6052521.

Hughes DC, Marcotte GR, Baehr LM, West DWD, Marshall AG, Ebert SM, Davidyan A, Adams CM, Bodine SC, Baar K. Alterations in the muscle force transfer apparatus in aged rats during unloading and reloading: impact of microRNA-31. J Physiol. 2018 Jul;596(14):2883-2900. doi: 10.1113/JP275833. PMID: 29726007; PMCID: PMC6046073.

Hughes DC, Ellefsen S, Baar K. Adaptations to Endurance and Strength Training. Cold Spring Harb Perspect Med. 2018 Jun 1;8(6):a029769. doi: 10.1101/cshperspect.a029769. PMID: 28490537; PMCID: PMC5983157.

Roberts MN, Wallace MA, Tomilov AA, Zhou Z, Marcotte GR, Tran D, Perez G, Gutierrez-Casado E, Koike S, Knotts TA, Imai DM, Griffey SM, Kim K, Hagopian K, McMackin MZ, Haj FG, Baar K, Cortopassi GA, Ramsey JJ, Lopez-Dominguez JA. A Ketogenic Diet Extends Longevity and Healthspan in Adult Mice. Cell Metab. 2018 May 1;27(5):1156. doi: 10.1016/j.cmet.2018.04.005. Erratum for: Cell Metab. 2017 Sep 5;26(3):539-546.e5. PMID: 29719228; PMCID: PMC5957496.

Hodson N, Brown T, Joanisse S, Aguirre N, West DWD, Moore DR, Baar K, Breen L, Philp A. Characterisation of L-Type Amino Acid Transporter 1 (LAT1) Expression in Human Skeletal Muscle by Immunofluorescent Microscopy. Nutrients. 2017 Dec 26;10(1):23. doi: 10.3390/nu10010023. PMID: 29278358; PMCID: PMC5793251.

Heaton LE, Davis JK, Rawson ES, Nuccio RP, Witard OC, Stein KW, Baar K, Carter JM, Baker LB. Selected In-Season Nutritional Strategies to Enhance Recovery for Team Sport Athletes: A Practical Overview. Sports Med. 2017 Nov;47(11):2201-2218. doi: 10.1007/s40279-017-0759-2. PMID: 28702900; PMCID: PMC5633631.