The impact of carnosine on biological ageing - A geroscience approach.

Biological ageing involves a gradual decline in physiological function and resilience, marked by molecular, cellular, and systemic changes across organ systems. Geroscience, an interdisciplinary field, studies these mechanisms and their role in age-related diseases. Genomic instability, inflammation, telomere attrition, and other indicators contribute to conditions like cardiovascular disease and neurodegeneration. Geroscience identifies geroprotectors, such as resveratrol and metformin, targeting ageing pathways to extend the healthspan. Carnosine, a naturally occurring dipeptide (b-alanine and l-histidine), has emerged as a potential geroprotector with antioxidative, anti-inflammatory, and anti-glycating properties. Carnosine's benefits extend to muscle function, exercise performance, and cognitive health, making it a promising therapeutic intervention for healthy ageing and oxidative stress-related pathologies. In this review, we summarize the evidence describing carnosine's effects in promoting healthy ageing, providing new insights into improving geroscience.

Physical activity and depression symptoms in people with osteoarthritis-related pain: A cross-sectional study.

Osteoarthritis is a leading cause of chronic pain and is associated with high rates of depression. Physical activity reduces depression symptoms and pain levels. It remains unknown if physical activity is associated with lower symptoms of depression irrespective of pain levels in individuals with osteoarthritis. We explored whether pain mediated or moderated the relationship between levels of physical activity engagement and depression symptoms. Individuals with osteoarthritis who were waiting for an orthopaedic consultation at a public hospital in Melbourne, Australia, were recruited. Data collected on pain levels, physical activity engagement and depression symptoms. Descriptive statistics were used to summarise participant characteristics. Moderation and mediation analyses were used to establish the impact of pain on the relationship between physical activity and depression, after adjusting for demographic and joint specific characteristics. The results indicated that the inverse association between physical activity and depression depended on the level of pain, such that the association was stronger in people with greater pain. The mediation results confirm that participating in physical activity is indirectly, inversely associated with symptoms of depression through lower levels of pain. The highest levels of pain were associated with the most potential benefit in terms of reduction in symptoms of depression from engaging in physical activity. Physical activity may be particularly important to manage depression symptoms in people with greater osteoarthritis-related pain as patients with the highest pain may have the greatest benefits.

Density functional theory and enzyme studies support interactions between angiotensin receptor blockers and angiotensin converting enzyme-2: Relevance to coronavirus 2019.

The binding affinities and interactions between eight drug candidates, both commercially available (candesartan; losartan; losartan carboxylic acid; nirmatrelvir; telmisartan) and newly synthesized benzimidazole-N-biphenyltetrazole (ACC519T), benzimidazole bis-N,N'-biphenyltetrazole (ACC519T(2) and 4-butyl-N,N-bis([2-(2H-tetrazol-5-yl)biphenyl-4-yl]) methyl (BV6), and the active site of angiotensin-converting enzyme-2 (ACE2) were evaluated for their potential as inhibitors against SARS-CoV-2 and regulators of ACE2 function through Density Functional Theory methodology and enzyme activity assays, respectively. Notably, telmisartan and ACC519T(2) exhibited pronounced binding affinities, forming strong interactions with ACE2's active center, favorably accepting proton from the guanidinium group of arginine273. The ordering of candidates by binding affinity and reactivity descriptors, emerged as telmisartan > ACC519T(2) > candesartan > ACC519T > losartan carboxylic acid > BV6 > losartan > nirmatrelvir. Proton transfers among the active center amino acids revealed their interconnectedness, highlighting a chain-like proton transfer involving tyrosine, phenylalanine, and histidine. Furthermore, these candidates revealed their potential antiviral abilities by influencing proton transfer within the ACE2 active site. Furthermore, through an in vitro pharmacological assays we determined that candesartan and the BV6 derivative, 4-butyl-N,N0-bis[20-2Htetrazol-5-yl)bipheyl-4-yl]methyl)imidazolium bromide (BV6(K+)2) also contain the capacity to increase ACE2 functional activity. This comprehensive analysis collectively underscores the promise of these compounds as potential therapeutic agents against SARS-CoV-2 by targeting crucial protein interactions.

Alterations in tryptophan metabolism and de novo NAD+ biosynthesis within the microbiota-gut-brain axis in chronic intestinal inflammation.

Background: Inflammatory bowel disease is an incurable and idiopathic disease characterized by recurrent gastrointestinal tract inflammation. Tryptophan metabolism in mammalian cells and some gut microbes comprise intricate chemical networks facilitated by catalytic enzymes that affect the downstream metabolic pathways of de novo nicotinamide adenine dinucleotide (NAD+) synthesis. It is hypothesized that a correlation exists between tryptophan de novo NAD+ synthesis and chronic intestinal inflammation. Methods: Transcriptome analysis was performed using high-throughput sequencing of mRNA extracted from the distal colon and brain tissue of Winnie mice with spontaneous chronic colitis and C57BL/6 littermates. Metabolites were assessed using ultra-fast liquid chromatography to determine differences in concentrations of tryptophan metabolites. To evaluate the relative abundance of gut microbial genera involved in tryptophan and nicotinamide metabolism, we performed 16S rRNA gene amplicon sequencing of fecal samples from C57BL/6 and Winnie mice. Results: Tryptophan and nicotinamide metabolism-associated gene expression was altered in distal colons and brains of Winnie mice with chronic intestinal inflammation. Changes in these metabolic pathways were reflected by increases in colon tryptophan metabolites and decreases in brain tryptophan metabolites in Winnie mice. Furthermore, dysbiosis of gut microbiota involved in tryptophan and nicotinamide metabolism was evident in fecal samples from Winnie mice. Our findings shed light on the physiological alterations in tryptophan metabolism, specifically, its diversion from the serotonergic pathway toward the kynurenine pathway and consequential effects on de novo NAD+ synthesis in chronic intestinal inflammation. Conclusion: The results of this study reveal differential expression of tryptophan and nicotinamide metabolism-associated genes in the distal colon and brain in Winnie mice with chronic intestinal inflammation. These data provide evidence supporting the role of tryptophan metabolism and de novo NAD+ synthesis in IBD pathophysiology.

Structural Features Influencing the Bioactive Conformation of Angiotensin II and Angiotensin A: Relationship between Receptor Desensitization, Addiction, and the Blood-Brain Barrier.

The N-terminal portion of the octapeptide angiotensin II (DRVYIHPF; AngII), a vasopressor peptide that favorably binds to, and activates, AngII type 1 receptor (AT1R), has an important role in maintaining bioactive conformation. It involves all three charged groups, namely (i) the N-terminal amino group cation, (ii) the Asp sidechain anion and (iii) the Arg guanidino cation. Neutralization of any one of these three charged groups results in a substantial reduction (<5%) in bioactivity, implicating a specialized function for this cluster. In contrast, angiotensin A (ARVYIHPF; AngA) has reduced bioactivity at AT1R; however, replacement of Asp in AngII with sarcosine (N-methyl-glycine) not only restores bioactivity but increases the activity of agonist, antagonist, and inverse agonist analogues. A bend produced at the N-terminus by the introduction of the secondary amino acid sarcosine is thought to realign the functional groups that chaperone the C-terminal portion of AngII, allowing transfer of the negative charge originating at the C-terminus to be transferred to the Tyr hydroxyl-forming tyrosinate anion, which is required to activate the receptor and desensitizes the receptor (tachyphylaxis). Peptide (sarilesin) and nonpeptide (sartans) moieties, which are long-acting inverse agonists, appear to desensitize the receptor by a mechanism analogous to tachyphylaxis. Sartans/bisartans were found to bind to alpha adrenergic receptors resulting in structure-dependent desensitization or resensitization. These considerations have provided information on the mechanisms of receptor desensitization/tolerance and insights into possible avenues for treating addiction. In this regard sartans, which appear to cross the blood-brain barrier more readily than bisartans, are the preferred drug candidates.

Novel benzimidazole angiotensin receptor blockers with anti-SARS-CoV-2 activity equipotent to that of nirmatrelvir: computational and enzymatic studies.

BACKGROUND: Hypertension worsens outcomes in SARS-CoV-2 patients. Sartans, a type of antihypertensive angiotensin receptor blocker-(ARB), reduce COVID-19 morbidity and mortality by targeting angiotensin-converting enzyme-2 (ACE2). This study aimed to evaluate the antiviral and antihypertensive effects of nirmatrelvir, commercial sartans (candesartan, losartan, and losartan carboxylic (Exp3174)), and newly synthesized sartans (benzimidazole-N-biphenyl carboxyl (ACC519C) and benzimidazole-N-biphenyl tetrazole (ACC519T)), compared to nirmatrelvir, the antiviral component of Paxlovid. RESEARCH DESIGN AND METHODS: Surface plasmon resonance (SPR) and enzymatic studies assessed drug effects on ACE2. Antiviral abilities were tested with SARS-CoV-2-infected Vero E6 cells, and antihypertensive effects were evaluated using angiotensin II-contracted rabbit iliac arteries. RESULTS: Benzimidazole-based candesartan and ACC519C showed antiviral activity comparable to nirmatrelvir (95% inhibition). Imidazole-based losartan, Exp3174, and ACC519T were less potent (75%-80% and 50%, respectively), with Exp3174 being the least effective. SPR analysis indicated high sartans-ACE2 binding affinity. Candesartan and nirmatrelvir combined had greater inhibitory and cytopathic effects (3.96%) than individually (6.10% and 5.08%). ACE2 enzymatic assays showed varying effects of novel sartans on ACE2. ACC519T significantly reduced angiotensin II-mediated contraction, unlike nirmatrelvir and ACC519T(2). CONCLUSION: This study reports the discovery of a new class of benzimidazole-based sartans that significantly inhibit SARS-CoV-2, likely due to their interaction with ACE2.

Differential Responses to Aging Among the Transcriptome and Proteome of Mesenchymal Progenitor Populations.

The biological aging of stem cells (exhaustion) is proposed to contribute to the development of a variety of age-related conditions. Despite this, little is understood about the specific mechanisms which drive this process. In this study, we assess the transcriptomic and proteomic changes in 3 different populations of mesenchymal progenitor cells from older (50-70 years) and younger (20-40 years) individuals to uncover potential mechanisms driving stem cell exhaustion in mesenchymal tissues. To do this, we harvested primary bone marrow mesenchymal stem and progenitor cells (MPCs), circulating osteoprogenitors (COP), and adipose-derived stem cells (ADSCs) from younger and older donors, with an equal number of samples from men and women. These samples underwent RNA sequencing and label-free proteomic analysis, comparing the younger samples to the older ones. There was a distinct transcriptomic phenotype in the analysis of pooled older stem cells, suggestive of suppressed proliferation and differentiation; however, these changes were not reflected in the proteome of the cells. Analyzed independently, older MPCs had a distinct phenotype in both the transcriptome and proteome consistent with altered differentiation and proliferation with a proinflammatory immune shift in older adults. COP cells showed a transcriptomic shift to proinflammatory signaling but no consistent proteomic phenotype. Similarly, ADSCs displayed transcriptomic shifts in physiologies associated with cell migration, adherence, and immune activation but no proteomic change with age. These results show that there are underlying transcriptomic changes with stem cell aging that may contribute to a decline in tissue regeneration. However, the proteome of the cells was inconsistently regulated.

Myelin Oligodendrocyte Glycoprotein (MOG)35-55 Mannan Conjugate Induces Human T-Cell Tolerance and Can Be Used as a Personalized Therapy for Multiple Sclerosis.

We have previously performed preclinical studies with the oxidized mannan-conjugated peptide MOG35-55 (OM-MOG35-55) in vivo (EAE mouse model) and in vitro (human peripheral blood) and demonstrated that OM-MOG35-55 suppresses antigen-specific T cell responses associated with autoimmune demyelination. Based on these results, we developed different types of dendritic cells (DCs) from the peripheral blood monocytes of patients with multiple sclerosis (MS) or healthy controls presenting OM-MOG35-55 or MOG-35-55 to autologous T cells to investigate the tolerogenic potential of OM-MOG35-55 for its possible use in MS therapy. To this end, monocytes were differentiated into different DC types in the presence of IL-4+GM-CSF ± dexamethasone (DEXA) ± vitamin D3 (VITD3). At the end of their differentiation, the DCs were loaded with peptides and co-cultured with T cells +IL-2 for 4 antigen presentation cycles. The phenotypes of the DC and T cell populations were analyzed using flow cytometry and the secreted cytokines using flow cytometry or ELISA. On day 8, the monocytes had converted into DCs expressing the typical markers of mature or immature phenotypes. Co-culture of T cells with all DC types for 4 antigen presentation cycles resulted in an increase in memory CD4+ T cells compared to memory CD8+ T cells and a suppressive shift in secreted cytokines, mainly due to increased TGF-ß1 levels. The best tolerogenic effect was obtained when patient CD4+ T cells were co-cultured with VITD3-DCs presenting OM-MOG35-55, resulting in the highest levels of CD4+PD-1+ T cells and CD4+CD25+Foxp3+ Τ cells. In conclusion, the tolerance induction protocols presented in this work demonstrate that OM-MOG35-55 could form the basis for the development of personalized therapeutic vaccines or immunomodulatory treatments for MS.

The protective role of carnosine against type 2 diabetes-induced cognitive impairment.

The morbidity and mortality associated with type 2 diabetes mellitus (T2DM) have grown exponentially over the last 30 years. Together with its associated complications, the mortality rates have increased. One important complication in those living with T2DM is the acceleration of age-related cognitive decline. T2DM-induced cognitive impairment seriously affects memory, executive function, and quality of life. However, there is a lack of effective treatment for both diabetes and cognitive decline. Thus, finding novel treatments which are cheap, effective in both diabetes and cognitive impairment, are easily accessible, are needed to reduce impact on patients with diabetes and health-care systems. Carnosine, a histidine containing dipeptide, plays a protective role in cognitive diseases due to its antioxidant, anti-inflammation, and anti-glycation properties, all of which may slow the development of neurodegenerative diseases and ischemic injury. Furthermore, carnosine is also involved in regulating glucose and insulin in diabetes. Herein, we discuss the neuroprotective role of carnosine and its mechanisms in T2DM-induced cognitive impairment, which may provide a theoretical basis and evidence base to evaluate whether carnosine has therapeutic effects in alleviating cognitive dysfunction in T2DM patients.

The Effect of Therapeutic Doses of Culinary Spices in Metabolic Syndrome: A Randomized Controlled Trial.

Non-communicable diseases (NCDs) place a significant burden on global health and the healthcare systems which support it. Metabolic syndrome is a major risk factor for a large number of NCDs; however, treatments remain limited. Previous research has shown the protective benefits of edible dietary spices on key components of metabolic syndrome. Therefore we performed a 12-week double-blind, placebo-controlled, randomized, clinical trial to evaluate the effect of ginger (Zingiber officinale), cinnamon (Cinnamomum), and black seed (Nigella sativa) consumption on blood glucose, lipid profiles, and body composition in 120 participants with, or at risk of, metabolic syndrome. Each participant consumed 3 g/day of powder (spice or placebo). Data related to different parameters were collected from participants at the baseline, midpoint, and endpoint of the intervention. Over the 12-week interventions, there was an improvement in a number of biochemical indices of metabolic syndrome, including fasting blood glucose, HbA1c, LCL, and total cholesterol associated with supplementation with the spices when compared to a placebo. This study provides evidence to support the adjunct use of supplementation for those at risk of metabolic syndrome and its sequelae.

Adverse drug reactions associated with COVID-19 management.

The emergence of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak, which causes COVID-19, had a devastating impact on both people's lives and the global economy. During the course of the pandemic, the lack of specific drugs or treatments tailored for COVID-19 led to extensive repurposing of existing drugs in the pursuit of effective treatments. Some drug molecules demonstrated efficacy, while others proved ineffective. In this context, the approach of drug repurposing emerged as a novel strategy for combating COVID-19. Repurposed drugs and biologics have shown effectiveness, leading to improved clinical outcomes among patients with COVID-19. Similarly, It is equally important to assess the risk-benefit ratio associated with drugs and biologics adapted for COVID-19 treatment. Herein, we primarily focus on evaluating adverse drug events linked to repurposed COVID-19 medications, repurposed biologics, and COVID-specific drug molecules.