Recent Developments in Protein Lactylation in PTSD and CVD: Novel Strategies and Targets

In 1938, Corneille Heymans received the Nobel Prize in physiology for discovering that oxygen sensing in the aortic arch and carotid sinus was mediated by the nervous system. The genetics of this process remained unclear until 1991 when Gregg Semenza while studying erythropoietin, came upon hypoxia-inducible factor 1, for which he obtained the Nobel Prize in 2019. The same year, Yingming Zhao found protein lactylation, a posttranslational modification that can alter the function of hypoxia-inducible factor 1, the master regulator of cellular senescence, a pathology implicated in both post-traumatic stress disorder (PTSD) and cardiovascular disease (CVD). The genetic correlation between PTSD and CVD has been demonstrated by many studies, of which the most recent one utilizes large-scale genetics to estimate the risk factors for these conditions. This study focuses on the role of hypertension and dysfunctional interleukin 7 in PTSD and CVD, the former caused by stress-induced sympathetic arousal and elevated angiotensin II, while the latter links stress to premature endothelial cell senescence and early vascular aging. This review summarizes the recent developments and highlights several novel PTSD and CVD pharmacological targets. They include lactylation of histone and non-histone proteins, along with the related biomolecular actors such as hypoxia-inducible factor 1α, erythropoietin, acid-sensing ion channels, basigin, and Interleukin 7, as well as strategies to delay premature cellular senescence by telomere lengthening and resetting the epigenetic clock.

Associations Among Nitric Oxide and Enkephalinases With Fibromyalgia Symptoms

BACKGROUND

Fibromyalgia (FM) is a complex syndrome of uncertain etiology, characterized by the presence of widespread pain. Both nitric oxide and enkephalinases modulate pain perception.

OBJECTIVES

The aim of this study was to evaluate the relationships among serum nitric oxide levels, oxytocinase activity, and enkephalin-degrading aminopeptidase (EDA) activity with pain-related clinical manifestations in women with FM.

METHODS

We performed an observational case study in a population of 58 women diagnosed with FM. Serum nitric oxide levels were analyzed by an ozone chemiluminescence-based assay. Both serum oxytocinase and EDA activities were fluorometrically determined. Pain threshold and pain magnitude were evaluated using the PainMatcher. The pressure pain thresholds were measured using a digital pressure algometer. We used a visual analog scale, the Central Sensitization Inventory, the Revised Fibromyalgia Impact Questionnaire, and the Beck Anxiety Inventory to assess the global level of pain, the symptoms associated with the central sensitization syndrome, the severity of FM, and the anxiety level, respectively.

RESULTS

Multiple linear regression analysis adjusted by age, body mass index, and menopause status revealed significant associations between nitric oxide levels and dominant occiput pressure pain thresholds, nondominant occiput pressure pain thresholds, and FM effects. Significant associations of oxytocinase activity with the visual analog scale and dominant knee pressure pain thresholds were also found. Moreover, results showed a significant association between high EDA activity levels and dominant second-rib pressure pain thresholds.

DISCUSSION

Our data have shown significant relationships of serum nitric oxide levels and oxytocinase and EDA activities with some body pressure pain thresholds, the daily activity level, and the global intensity of pain in women with FM. These results suggest that pain, which is the main symptom of this syndrome, may be related to alterations in nitric oxide levels and in oxytocinase and EDA activities in patients with FM.

Sex differences exist in brain renin-angiotensin system-regulating aminopeptidase activities in transplacental ethyl-nitrosourea-induced gliomas

INTRODUCTION

The renin angiotensin system (RAS) is emerging as an important target for the treatment of glioma. We had described that the local RAS is involved in vivo in tumor growth in the rat model of experimental C6 glioma implanted at the subcutaneous region, through the modification of several proteolytic regulatory enzymes of aminopeptidase type.

METHODS

We analyze RAS-regulating aminopeptidase activities in plasma and brain tissue of control male and female rats and rats with transplacental ethylnitrosourea-induced gliomas.

RESULTS

No differences were found either the mean total number of tumors per animal or the tumor volume between male and female animals. However, we have found increased levels in aspartyl aminopeptidase in both males and females and of aminopeptidase B only in males. On the contrary, decreased levels were found in aminopeptidase N and insulin-regulated aminopeptidase activities in both males and females, whereas aminopeptidase A only decreased in females. Decreased levels of aminopeptidase N, aminopeptidase B and insulin-regulated aminopeptidase were also shown in plasma of only female rats.

CONCLUSIONS

Under the complexity of RAS cascade, the changes found suggest the predominant actions of angiotensin III against a decreased action of angiotensin II and angiotensin IV. We conclude that angiotensin peptides are involved in tumor growth in this rat model of glioma and that their role in tumor growth can be analyzed through their corresponding proteolytic regulatory enzymes, which make them new and attractive therapeutic targets beyond the use or angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).

Influence of Oxidative Stress-Related Genes on Susceptibility to Fibromyalgia

BACKGROUND

Fibromyalgia (FM) is a complex syndrome to diagnose and treat because of its unknown etiology. However, previous studies reported that patients with FM experience oxidative stress.

OBJECTIVES

In this study, we investigated single-nucleotide polymorphisms (SNPs) in genes encoding enzymes involved in oxidative stress (superoxide dismutase 1 [SOD1], catalase, and NADPH oxidase [CYBA]) in patients with FM and in healthy subjects, as well as the possible relation with demographic and clinical manifestations of FM.

METHODS

A total of 141 patients with FM and 73 healthy subjects participated in this case-control study. For DNA extraction, buccal swabs were collected from patients with FM, and a peripheral blood sample was extracted from controls. We analyzed SNPs in genes related to oxidative stress (rs10432782 in SOD1, rs1001179 in catalase, and rs4673 in CYBA) using TaqMan probes. In patients with FM, severity of FM, fatigue, and pain were assessed by Fibromyalgia Impact Questionnaire, Multidimensional Fatigue Inventory, and Visual Analogue Scale (VAS), respectively. Physical (PCS-12) and mental (MCS-12) health statuses were evaluated by the 12-Item Short-Form Health Survey.

RESULTS

The selected SNPs did not show significant differences between patients with FM and controls. The rs10432782 (SOD1) was associated with Fibromyalgia Impact Questionnaire scores in patients with FM, whereas the rs4673 (CYBA) was associated with the Multidimensional Fatigue Inventory score, MCS-12 score, and duration of the disease.

DISCUSSION

We have identified significant correlations between SOD1 and CYBA variants with clinical manifestations of FM. These results provide new insights into the pathogenesis of FM that could be useful for guiding future studies along the way to find the cause(s) of this syndrome.

Synovial fluid peptidase activity as a biomarker for knee osteoarthritis clinical progression

AIMS

To analyze the potential role of synovial fluid peptidase activity as a measure of disease burden and predictive biomarker of progression in knee osteoarthritis (KOA).

METHODS

A cross-sectional study of 39 patients (women 71.8%, men 28.2%; mean age of 72.03 years (SD 1.15) with advanced KOA (Ahlbäck grade ≥ 3 and clinical indications for arthrocentesis) recruited through the (Orthopaedic Department at the Complejo Asistencial Universitario de León, Spain (CAULE)), measuring synovial fluid levels of puromycin-sensitive aminopeptidase (PSA), neutral aminopeptidase (NAP), aminopeptidase B (APB), prolyl endopeptidase (PEP), aspartate aminopeptidase (ASP), glutamyl aminopeptidase (GLU) and pyroglutamyl aminopeptidase (PGAP).

RESULTS

Synovial fluid peptidase activity varied significantly as a function of clinical signs, with differences in levels of PEP (p = 0.020), ASP (p < 0.001), and PGAP (p = 0. 003) associated with knee locking, PEP (p = 0.006), ASP (p = 0.001), GLU (p = 0.037), and PGAP (p = 0.000) with knee failure, and PEP (p = 0.006), ASP (p = 0.001), GLU (p = 0.037), and PGAP (p < 0.001) with knee effusion. Further, patients with the greatest functional impairment had significantly higher levels of APB (p = 0.005), PEP (p = 0.005), ASP (p = 0.006), GLU (p = 0.020), and PGAP (p < 0.001) activity, though not of NAP or PSA, indicating local alterations in the renin-angiotensin system. A binary logistic regression model showed that PSA was protective (p = 0.005; Exp (B) 0.949), whereas PEP (p = 0.005) and GLU were risk factors (p = 0.012).

CONCLUSION

These results suggest synovial fluid peptidase activity could play a role as a measure of disease burden and predictive biomarker of progression in KOA. Cite this article: Bone Joint Res 2020;9(11):789-797.