Cyclic Glycine-Proline (cGP) Normalises Insulin-Like Growth Factor-1 (IGF-1) Function: Clinical Significance in the Ageing Brain and in Age-Related Neurological Conditions
Abstract
:1. Introduction
1.1. Decline in IGF-1 Function with Age and Its Association with Age-Related Conditions
1.2. Regulation of Bioavailablility of IGF-1 in Circulation
2. cGP Is a Bioactive Compound
2.1. Formation of Endogenous cGP
2.2. cGP as a Bioactive Peptide
3. Mode of Action of cGP
4. Clinical Relevance
4.1. Hypertension
4.2. Stroke
4.3. Age-Related Cognitive Decline
4.4. Parkinson’s Disease (PD)
4.5. Alzheimer’s Disease (AD)
4.6. A Plasma Biomarker for Age-Related Neurological Diseases
5. Discovery of Natural cGP
6. Limitations of the Review and Future Studies
7. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
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Dependent Variable (Confounders) | cGP (ng/mL) | IGF-1 (ng/mL) | IGFBP-3 (ng/mL) | |
---|---|---|---|---|
UPDRS (Age and MoCA) | B | −0.01 | 0.01 | 0.004 |
P | 0.98 | 0.60 | 0.02 | |
95%CI | −0.50, 0.48 | −0.03, 0.05 | 0.001, 0.007 | |
UPDRS (Age and Global Z) | B | 0.20 | 0.004 | 0.004 |
P | 0.38 | 0.85 | 0.02 | |
95%CI | −0.25, 0.66 | −0.04, 0.05 | 0.001, 0.007 | |
UPDRS (Age and LMD) | B | 0.26 | 0.01 | 0.004 |
P | 0.27 | 0.61 | 0.01 | |
95%CI | −0.21, 0.72 | −0.03, 0.06 | 0.001, 0.01 |
Before | After | t-Test | p | ||
---|---|---|---|---|---|
Total HADS | Mean Score | 9.5 | 5.4 | t9 = 3.45 | 0.007 |
SD | 6.8 | 3.9 | |||
Anxiety Subscale | Mean Score | 5.4 | 2.5 | t9 = 2.69 | 0.025 |
SD | 3.6 | 1.8 | |||
Depression Subscale | Mean Score | 4.1 | 2.9 | t9 = 2.03 | 0.074 |
SD | 3.5 | 2.7 |
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Guan, J.; Li, F.; Kang, D.; Anderson, T.; Pitcher, T.; Dalrymple-Alford, J.; Shorten, P.; Singh-Mallah, G. Cyclic Glycine-Proline (cGP) Normalises Insulin-Like Growth Factor-1 (IGF-1) Function: Clinical Significance in the Ageing Brain and in Age-Related Neurological Conditions. Molecules 2023, 28, 1021. https://doi.org/10.3390/molecules28031021
Guan J, Li F, Kang D, Anderson T, Pitcher T, Dalrymple-Alford J, Shorten P, Singh-Mallah G. Cyclic Glycine-Proline (cGP) Normalises Insulin-Like Growth Factor-1 (IGF-1) Function: Clinical Significance in the Ageing Brain and in Age-Related Neurological Conditions. Molecules. 2023; 28(3):1021. https://doi.org/10.3390/molecules28031021
Chicago/Turabian StyleGuan, Jian, Fengxia Li, Dali Kang, Tim Anderson, Toni Pitcher, John Dalrymple-Alford, Paul Shorten, and Gagandeep Singh-Mallah. 2023. "Cyclic Glycine-Proline (cGP) Normalises Insulin-Like Growth Factor-1 (IGF-1) Function: Clinical Significance in the Ageing Brain and in Age-Related Neurological Conditions" Molecules 28, no. 3: 1021. https://doi.org/10.3390/molecules28031021