Mechanism underlying vascular remodeling in relation to circulating CD34-positive cells among older Japanese men

Beneficial influence of low-density lipoprotein cholesterol on the endothelium in relation to endothelial repair

BACKGROUND

Low-density lipoprotein cholesterol (LDLc) is regarded as a risk factor for endothelial dysfunction. However, LDLc stimulates the proliferation of hematopoietic stem cells (CD34-positive cells), which contribute to endothelial repair. Therefore, LDLc may have a beneficial influence on the endothelium of individuals with lower endothelial repair activity.

METHODS

This cross-sectional study included 245 men aged 60-69 years. Endothelial repair activity was categorized by the circulating levels of CD34-positive cells based on median values. The status of endothelium was evaluated using the cardio-ankle vascular index (CAVI).

RESULTS

Among individuals with low levels of circulating CD34-positive cells, LDL-c levels were significantly inversely correlated with CAVI and positively correlated with circulating CD34-positive cells. No significant correlations were observed among the participants with high levels of circulating CD34-positive cells. Among low levels of CD34-positive cells, the adjusted standardized parameter (β) and p value were -0.24 (p = 0.021) for CAVI and 0.41 (p < 0.001) for CD34-positive cells, whereas among high levels of CD34-positive cells, the corresponding values were 0.03 (p = 0.738) and -0.09 (p = 0.355).

CONCLUSION

LDLc has a beneficial influence on endothelial health among individuals with low endothelial repair activity, possibly by stimulating the proliferation of hematopoietic stem cells.

The impact of acute and chronic aerobic and resistance exercise on stem cell mobilization: A review of effects in healthy and diseased individuals across different age groups

Stem cells (SCs) play a crucial role in tissue repair, regeneration, and maintaining physiological homeostasis. Exercise mobilizes and enhances the function of SCs. This review examines the effects of acute and chronic aerobic and resistance exercise on the population of SCs in healthy and diseased individuals across different age groups. Both acute intense exercise and moderate regular training increase circulating precursor cells CD34+ and, in particular, the subset of angiogenic progenitor cells (APCs) CD34+/KDR+. Conversely, chronic exercise training has conflicting effects on circulating CD34+ cells and their function, which are likely influenced by exercise dosage, the health status of the participants, and the methodologies employed. While acute activity promotes transient mobilization, regular exercise often leads to an increased number of progenitors and more sustainable functionality. Short interventions lasting 10-21 days mobilize CD34+/KDR + APCs in sedentary elderly individuals, indicating the inherent capacity of the body to rapidly activate tissue-reparative SCs during activity. However, further investigation is needed to determine the optimal exercise regimens for enhancing SC mobilization, elucidating the underlying mechanisms, and establishing functional benefits for health and disease prevention. Current evidence supports the integration of intense exercise with chronic training in exercise protocols aimed at activating the inherent regenerative potential through SC mobilization. The physical activity promotes endogenous repair processes, and research on exercise protocols that effectively mobilize SCs can provide innovative guidelines designed for lifelong tissue regeneration. An artificial neural network (ANN) was developed to estimate the effects of modifying elderly individuals and implementing chronic resistance exercise on stem cell mobilization and its impact on individuals and exercise. The network's predictions were validated using linear regression and found to be acceptable compared to experimental results.

Association between serum uric acid levels and cardio-ankle vascular index stratified by circulating level of CD34-positive cells among elderly Japanese men: a cross-sectional study

Although serum uric acid (UA) has been reported to be positively associated with increased arterial stiffness as evaluated by cardio-ankle vascular index (CAVI), UA also has an antioxidative effect that prevents endothelial damage. Therefore, the status of endothelial repair induced by endothelial damage might affect the correlation between UA and CAVI. To clarify the correlation between UA and CAVI in relation to endothelial repair activity, we performed a cross-sectional study with 246 Japanese men aged 60-69 years undergoing a general health check-up. The analysis was stratified by the median circulating level of CD34-positive cells because circulating levels of CD34-positive cells could indicate the degree of endothelial repair activity. Independent of known cardiovascular risk factors, among participants with high circulating levels of CD34-positive cells (0.95 cells/μL ≤), UA was significantly positively correlated with CAVI (standardized parameter estimate β = 0.23, p = 0.009), but not among participants with low circulating levels of CD34-positive cells (< 0.95 cells/μL) (β = 0.07, p = 0.445). Independent of established cardiovascular risk factors, UA levels were significantly positively correlated with increased arterial stiffness only among participants with aggressive endothelial repair as evaluated by circulating levels of CD34-positive cells. These results might help clarify some background mechanisms related to endothelial activity.

Association between eating speed and atherosclerosis in relation to growth differentiation factor-15 levels in older individuals in a cross-sectional study

Although fast eating speed has been associated with cardiovascular risk factors, no studies have reported an association between fast eating speed and atherosclerosis as evaluated by carotid intima-media thickness (CIMT). Rapid glucose ingestion is known to cause glucose spikes, which may accelerate atherogenesis and increase levels of growth differentiation factor 15 (GDF-15). Therefore, GDF-15 levels may influence the association between fast eating speed and atherosclerosis. To evaluate the association between eating speed and atherosclerosis in relation to GDF-15, this cross-sectional study analyzed 742 Japanese aged 60-69 years. They were required to have normal thyroid hormone levels, because both GDF-15 levels and atherosclerosis (CIMT ≥ 1.1 mm) can be influenced by thyroid dysfunction. Participants were stratified by the median GDF-15 level. A significant positive association was observed between fast eating speed and atherosclerosis, but only among participants with a high GDF-15 level: the sex- and age-adjusted odds ratios (95% confidence intervals) were 1.95 (1.09, 3.48) in participants with a high GDF-15 level, and 0.83 (0.37, 1.88) in those with a low GDF-15 level. This association remained even after further adjustment for thyroid function and metabolic factors. Serum concentrations of GDF-15 may mediate the association between fast eating speed and atherosclerosis.

SARS-CoV-2 Infection during Delivery Causes Histopathological Changes in the Placenta

BACKGROUND

SARS-CoV-2 can damage human placentas, leading to pregnancy complications, such as preeclampsia and premature birth. This study investigates the histopathological changes found in COVID-19-affected placentas.

MATERIALS AND METHODS

This study included 23 placentas from patients with active COVID-19 during delivery and 22 samples from patients without COVID-19 infection in their medical history. The samples underwent histopathological examination for pathology, such as trophoblast necrosis, signs of vessel damage, or fetal vascular malperfusion.

RESULTS

Newborns from the research group have lower weights and Apgar scores than healthy newborns. In the COVID-19 group, calcifications and collapsed intervillous space were more frequent, and inflammation was more severe than in the healthy group. At the same time, the placenta of SARS-CoV-2-positive patients showed signs of accelerated vascular maturation. Trophoblast necrosis was found only in the placentas of the research group. The expression of CD68+ was elevated in the COVID-19 cohort, suggesting that macrophages constituted a significant part of the inflammatory infiltrate. The increase in lymphocyte B markers was associated with placental infarctions, while high levels of CD3+, specific for cytotoxic T lymphocytes, correlated with vascular injury.

CONCLUSIONS

SARS-CoV-2 is associated with pathological changes in the placenta, including trophoblast necrosis, calcification, and accelerated villous maturation. Those changes appear to be driven by T cells and macrophages, whose increased expression reflects ongoing histiocytic intervillositis in the placenta.

Association between underweight, serum albumin levels, and height loss in the Japanese male population: a retrospective study

BACKGROUND

Previous study has shown that height loss (defined as the highest quartile of height loss per year) was inversely associated with serum albumin levels. Furthermore, comparatively healthy hyponutrition has been linked with being underweight; as such, underweight might be inversely associated with serum albumin levels and positively associated with height loss.

METHODS

To clarify the associations between serum albumin level, underweight status, and height loss, we conducted a retrospective study of 8,096 men over 4.0 years (median).

RESULTS

Serum albumin level at baseline was inversely associated with being underweight (body mass index [BMI]: < 18.5 kg/m2) at baseline and height loss. The known cardiovascular risk factor adjusted odds ratio (OR) and 95% confidence interval (CI) of underweight at baseline and of height loss for 1 standard deviation increment of serum albumin (0.28 g/dL) was 0.79 (0.70, 0.90) and 0.84 (0.80, 0.88). Underweight was also shown to be positively associated with height loss: with the reference of normal-low weight (BMI: 18.5-22.9 kg/m2), the adjusted OR (95% CI) was 1.60 (1.21, 2.10).

CONCLUSION

Comparative healthy hyponutrition, which is related to low serum albumin levels and being underweight, is a significant risk factor for height loss among Japanese men. These results help to clarify the mechanisms underlying height loss.

Association between atherosclerosis and height loss among older individuals

Atherosclerosis and height loss are each reportedly associated with cardiovascular disease. However, no studies have found an association between atherosclerosis and height loss. A retrospective study of 2435 individuals aged 60-89 years who underwent annual health check-ups was conducted. Atherosclerosis was defined as carotid intima-media thickness (CIMT) ≥ 1.1 mm. Height loss was defined as being in the highest quintile of height decrease per year, as in our previous studies. Among study participants, 555 were diagnosed as having atherosclerosis. Independent of known cardiovascular risk factors, atherosclerosis was positively associated with height loss. The adjusted odds ratio (OR) was 1.46 (95% confidence interval, 1.15, 1.83). Essentially the same associations were observed for men and women. The adjusted OR (95% CI) was 1.43 (1.01, 2.04) for men and 1.46 (1.07, 1.99) for women. Among older individuals, atherosclerosis is associated with height loss. This result can help clarify the mechanism underlying the association between height loss and cardiovascular disease.

Association between smoking and height loss in Japanese workers: A retrospective study

Height loss is reported to be an independent risk factor for all-cause and cardiovascular mortality. Smoking, which is responsible for a considerable proportion of deaths due to any cause, is also associated with lumbar disc degeneration, a major risk factor for height loss. Therefore, smoking could be an independent risk factor for height loss. To clarify the association between smoking status and height loss, a retrospective study with 8,984 (5,518 men and 3,466 women) Japanese workers was conducted. The present study population comprised 9,681 workers aged 40-74 years who participated in annual medical examinations between 2011 and 2017 (baseline). Subjects without a height measurement during 2012-2018 (endpoint) were excluded from the analysis (n = 697). Height loss was defined as being in the highest quartile of annul height decrease (1.48 mm/year for men and 1.79 mm/year for women). Independent of known cardiovascular risk factors, smoking was positively associated with height loss among men but not among women. With never smokers as the referent group, the adjusted odds ratio (95% confidence interval) was 1.15 (0.98, 1.35) for former smokers and 1.24 (1.05, 1.46) for current smokers among men, respectively. Among women, the corresponding values were 0.98 (0.79, 1.21) and 0.90 (0.71, 1.16), respectively. Since height loss and smoking are independent risk factors for all-cause and cardiovascular mortality, these results help clarify the mechanisms underlying the association between height loss and mortality risk.

TGF-β Isoforms and GDF-15 in the Development and Progression of Atherosclerosis

The effect of oxidised lipoproteins on the endothelium, monocytes, platelets, and macrophages is a key factor in the initiation and development of atherosclerosis. Antioxidant action, lipoprotein metabolism, and chronic inflammation are the fields of research interest for better understanding the development of the disease. All the fields are related to inflammation and hence to the secretion of cytokines, which are being investigated as potential diagnostic markers for the onset of atherosclerosis. Pathways of vascular damage are crucial for the development of new laboratory readouts. The very early detection of endothelial cell damage associated with the onset of atherosclerosis, allowing the initiation of therapy, remains a major research goal. This article summarises the latest results on the relationship of tumour growth factor beta (TGF-β) isoforms and growth differentiation factor 15 (GDF-15) to the pathogenesis of atherosclerosis: which cells involved in atherosclerosis produce them, which effectors stimulate their synthesis and secretion, how they influence atherosclerosis development, and the relationship between the levels of TGF-β and GDF-15 in the blood and the development and extent of atherosclerosis.

Molecular Mechanisms Underlying Vascular Remodeling in Hypertension

Hypertension, a common cardiovascular disease, is primarily characterized by vascular remodeling. Recent extensive research has led to significant progress in understanding its mechanisms. Traditionally, vascular remodeling has been described as a unidirectional process in which blood vessels undergo adaptive remodeling or maladaptive remodeling. Adaptive remodeling involves an increase in vessel diameter in response to increased blood flow, while maladaptive remodeling refers to the narrowing or thickening of blood vessels in response to pathological conditions. However, recent research has revealed that vascular remodeling is much more complex. It is now understood that vascular remodeling is a dynamic interplay between various cellular and molecular events. This interplay process involves different cell types, including endothelial cells, smooth muscle cells, and immune cells, as well as their interactions with the extracellular matrix. Through these interactions, blood vessels undergo intricate and dynamic changes in structure and function in response to various stimuli. Moreover, vascular remodeling involves various factors and mechanisms such as the renin-angiotensin-aldosterone system (RAS), oxidative stress, inflammation, the extracellular matrix (ECM), sympathetic nervous system (SNS) and mechanical stress that impact the arterial wall. These factors may lead to vascular and circulatory system diseases and are primary causes of long-term increases in systemic vascular resistance in hypertensive patients. Additionally, the presence of stem cells in adventitia, media, and intima of blood vessels plays a crucial role in vascular remodeling and disease development. In the future, research will focus on examining the underlying mechanisms contributing to hypertensive vascular remodeling to develop potential solutions for hypertension treatment. This review provides us with a fresh perspective on hypertension and vascular remodeling, undoubtedly sparking further research efforts aimed at uncovering more potent treatments and enhanced preventive and control measures for this disease.

HbA1c and height loss among Japanese workers: A retrospective study

Evaluating the risk of height loss could be an efficient way to evaluate endothelial health, which might be associated with all-cause and cardiovascular mortality. Diabetes is an established risk factor both for intervertebral disk degeneration and osteoporosis-related fractures, which are major risk factors for height loss among adults. Therefore, hemoglobin A1c (HbA1c), as an indicator of the presence of diabetes, could be positively associated with height loss. A retrospective study of 10,333 workers aged 40 to 74 years was conducted. Height loss was defined as being in the highest quintile of height decrease per year. HbA1c in the normal range was positively associated with height loss. The known cardiovascular risk factors-adjusted odds ratio (OR) and 95% confidence interval (CI) for height loss with a 1-standard deviation (SD) increase in HbA1c (0.38% for both men and women) was 1.06 (1.02, 1.10) for men and 1.15 (1.07, 1.23) for women, respectively. When limit those analysis among those without diabetes, the magnitude was slightly higher; the fully adjusted OR and 95% CI for height loss with a 1-SD increase in HbA1c was 1.19 (1.11, 1.28) for men and 1.32 (1.20, 1.44) for women, respectively. Even when HbA1c is within the normal range, higher HbA1c is a significant risk factor for height loss among workers.

Association between serum albumin levels and height loss in Japanese workers: a retrospective study

BACKGROUND

Height loss starting in middle age was previously shown to be associated with high cardiovascular mortality in later life. However, the factors associated with height loss remain unknown. Since low serum albumin levels are reported to be associated with high mortality caused by cardiovascular disease, they may also contribute to height loss.

METHODS

To clarify the association between serum albumin and height loss, we conducted a retrospective study of 7637 Japanese workers who participated in general health check-ups from 2008 to 2019. Height loss was defined as the highest quartile of height loss per year.

RESULTS

Individual with high serum concentration of albumin possess beneficial influence on preventing incidence of height loss. In both men and women, serum albumin level was significantly inversely associated with height loss. After adjustment for known cardiovascular risk factors, the adjusted odd ratio (OR) and 95% confidence interval (CI) for height loss per 1 standard deviation of albumin (0.2 g/dL for both men and women) were 0.92 (0.86, 0.98) in men and 0.86 (0.79, 0.95) in women. Even when the analysis was limited to participants without hypoalbuminemia, essentially same association was observed, with fully adjusted corresponding ORs (95%CI) of 0.92 (0.86, 0.98) in men and 0.86 (0.78, 0.94) in women.

CONCLUSION

Independent of known cardiovascular risk factors, higher serum albumin levels may prevent height loss among Japanese workers. While several different diseases cause hypoalbuminemia, they may not be the main reasons for the association between serum albumin and height loss. Though further research is necessary, this finding may help clarify the mechanisms underlying the association between height loss and higher mortality in later life.

Progression of Carotid Intima-Media Thickness Partly Indicates the Prevention of Hypertension among Older Individuals in the General Population

Structural atherosclerosis, as evaluated by carotid intima-media thickness (CIMT), is reported to be positively associated with hypertension. However, angiogenesis, which plays an important role in the progression of structural atherosclerosis, prevents hypertension by reducing peripheral vascular resistance. These associations evoke a contradiction: characteristics associated with the progression of structural atherosclerosis, which is related to hypertension, might prevent hypertension. To clarify novel mechanisms underlying the association between structural atherosclerosis and hypertension, multifaceted analyses are necessary. We performed several epidemiological studies based on this concept. This study summarizes those epidemiological studies and adds some discussion. Studies focusing on circulating CD34-positive cells, single-nucleotide polymorphisms (SNPs) of vascular endothelial growth factor (VEGF), SNPs in BRACA1-associated protein (BRAP), platelets, human T-cell leukemia virus type 1 (HTLV-1), and SNPs in aldehyde dehydrogenase 2 (ALDH2) have shown that active endothelial repair, which leads to the progression of structural atherosclerosis, helps prevent hypertension. These associations indicate that the progression of structural atherosclerosis could act as a marker of angiogenesis, which reduces peripheral vascular resistance. In general, a positive association between structural atherosclerosis and hypertension has been reported. However, the progression of structural atherosclerosis could act as a marker of activity that prevents hypertension via reductions in peripheral vascular resistance.

Serum Concentration of Growth Differentiation Factor 15 and Atherosclerosis among General Older Japanese Individuals with Normal Weight

Growth differentiation factor 15 (GDF-15), which modulates cellular energy balance, is reported to be positively associated with cardiovascular disease. However, there have been no reports about the association between serum GDF-15 concentration and atherosclerosis as evaluated by carotid intima-media thickness (CIMT) among the general population. A cross-sectional study of 536 Japanese individuals aged 60 to 69 years was conducted. To avoid the influence of abnormal cellular energy balance, this study only included participants who had a normal body mass index (BMI) and normal thyroid hormone (free thyroxine and free triiodothyronine) levels. A significant positive association between serum GDF-15 concentration and atherosclerosis was observed. In the sex- and age-adjusted model (Model 1), the odds ratio (OR) (95% confidence interval (CI)) for the logarithmic value of GDF-15 and atherosclerosis was 2.62 (1.67, 5.87). This association remained after adjusting for thyroid function and renal function (Model 2) and further adjusting for known cardiovascular risk factors (Model 3). The corresponding values were 2.61 (1.15, 5.93) for Model 2 and 2.49 (1.08, 5.71) for Model 3, respectively. Serum GDF-15 concentrations could help us to estimate the risk of atherosclerosis by indicating the status of cellular energy balance, which is related to mitochondrial activity among comparative healthy older individuals.

Eating speed and height loss in relation to overweight: A retrospective study

Fast eating is an independent risk factor for weight gain. Our previous study involving Japanese workers revealed that overweight (body mass index ≥ 25.0 kg/m2) is an independent risk factor for height loss. However, no studies have clarified the association between eating speed and height loss in relation to overweight status. A retrospective study of 8,982 Japanese workers was conducted. Height loss was defined as being in the highest quintile of height decrease per year. Compared with slow eating, fast eating was revealed to be positively associated with overweight; the fully adjusted odds ratio (OR) and 95% confidence interval (CI) was 2.92 (2.29, 3.72). Among non-overweight participants, fast eaters had higher odds of height loss than slow eaters. Among overweight participants, fast eaters had lower odds of height loss; the fully adjusted OR (95% CI) was 1.34 (1.05, 1.71) for non-overweight individuals and 0.52 (0.33, 0.82) for overweight individuals. Since overweight was significantly positively associated with height loss [1.17(1.03, 1.32)], fast eating is not favorable for reducing the risk of height loss among overweight individuals. Those associations indicate that weight gain is not the main cause of height loss among Japanese workers who eat fast.

Low-Density Lipoprotein Cholesterol, Structural Atherosclerosis, and Functional Atherosclerosis in Older Japanese

Aggressive endothelial repair results in the progression of both structural and functional atherosclerosis, while insufficient endothelial repair worsens functional but not structural atherosclerosis. Aging increases the risk of inadequate endothelial repair. Since low-density lipoprotein cholesterol (LDLc) activates endothelial repair, LDLc may be positively associated with structural atherosclerosis but inversely associated with functional atherosclerosis in older individuals. This cross-sectional study analyzed 1458 participants aged 60 to 79 years. We defined structural atherosclerosis as a carotid intima-media thickness (CIMT) of at least 1.1 mm and functional atherosclerosis as a cardio-ankle vascular index (CAVI) of at least 9.0. LDLc was significantly positively associated with structural atherosclerosis and significantly inversely associated with functional atherosclerosis, independently of known cardiovascular risk factors. For 1 standard increment of LDLc (28 mg/dL for men and 29 mg/dL for women), the odds ratios and 95% confidence intervals after adjustment for known cardiovascular risk factors were 1.28 (1.10, 1.50) for structural atherosclerosis and 0.85 (0.75, 0.96) for functional atherosclerosis. LDLc activates endothelial repair, which results in the development of structural atherosclerosis but maintains endothelial function in older individuals. To evaluate atherosclerosis in clinical practice, the combination of structural and functional assessment of atherosclerosis could be informative.