Shenfu injection ameliorates endotoxemia-associated endothelial dysfunction and organ injury via inhibiting PI3K/Akt-mediated glycolysis

ETHNOPHARMACOLOGICAL RELEVANCE

Microcirculatory dysfunction is one of the main characteristics of sepsis. Shenfu Injection (SFI) as a traditional Chinese medicine is widely applied in clinical severe conditions. Recent studies have shown that SFI has the ability to ameliorate sepsis-induced inflammation and to improve microcirculation perfusion.

AIM OF THE STUDY

This study aims to investigate the underlying mechanism of SFI for ameliorating sepsis-associated endothelial dysfunction and organ injury.

MATERIALS AND METHODS

Side-stream dark-field (SDF) imaging was used to monitor the sublingual microcirculation of septic patients treated with or without SFI. Septic mouse model was used to evaluate the effects of SFI in vivo. Metabolomics and transcriptomics were performed on endothelial cells to identify the underlying mechanism for SFI-related protective effect on endothelial cells.

RESULTS

SFI effectively abolished the disturbance and loss of sublingual microcirculation in septic patients. Twenty septic shock patients with or without SFI administration were enrolled and the data showed that SFI significantly improved the levels of total vessel density (TVD), perfused vessel density (PVD), microvascular flow index (MFI), and the proportion of perfused vessels (PPV). The administration of SFI significantly decreased the elevated plasma levels of Angiopoietin-2 (Ang2) and Syndecan-1, which are biomarkers indicative of endothelial damage in sepsis patients. In the mouse septic model in vivo, SFI inhibited the upregulation of endothelial adhesion molecules and Ly6G + neutrophil infiltration while restored the expression of VE-Cadherin in the vasculature of the lung, kidney, and liver tissue. Additionally, SFI reduced the plasma levels of Ang2, Monocyte Chemoattractant Protein-1(MCP1), and Interleukin-6 (IL6), and alleviated liver and kidney injury in septic mice. Moreover, SFI significantly inhibited the inflammatory activation and increased permeability of endothelial cells induced by endotoxins in vitro. By performing metabolomics and transcriptomics, we identified the activation of PI3K/Akt-mediated glycolysis as the underlying mechanism for SFI-related protective effect on endothelial cells.

CONCLUSIONS

Our findings revealed that SFI may improve microcirculation perfusion and endothelial function in sepsis via inhibiting PI3K/Akt-mediated glycolysis, providing theoretical evidence for the clinical application of SFI.

Tiny clue reveals the general trend: a bibliometric and visualized analysis of renal microcirculation

BACKGROUND

Renal microcirculation plays a pivotal role in kidney function by maintaining structural and functional integrity, facilitating oxygen and nutrient delivery, and waste removal. However, a thorough bibliometric analysis in this area remains lacking. Therefore, we aim to provide valuable insights through a bibliometric analysis of renal microcirculation literature using the Web of Science database.

METHODS

We collected renal microcirculation-related publications from the Web of Science database from January 01, 1990, to December 31, 2022. The co-authorship of authors, organizations, and countries/regions was analyzed with VOSviewer1.6.18. The co-occurrence of keywords and co-cited references were analyzed using CiteSpace6.1.R6 software to generate visualization maps. Additionally, burst detection was applied to keywords and cited references to forecast research hotspots and future trends.

RESULTS

Our search yielded 7462 publications, with the American Journal of Physiology-Renal Physiology contributing the most articles. The United States, Mayo Clinic, and Lerman Lilach O emerged with the highest publication count, indicating their active collaborations. 'Type 2 diabetes' was the most significant keyword cluster, and 'diabetic kidney disease' was the largest cluster of cited references. 'Cardiovascular outcome' and 'diabetic kidney diseases' were identified as keywords in their burst period over the past three years.

CONCLUSION

Our bibliometric analysis illuminates the contours of nephrology and microcirculation research, revealing a landscape ripe for challenges and the seeds of future scientific innovation. While the trends discerned from the literature emerging opportunities in diagnostic innovation, renal microcirculation research, and precision medicine interventions, their translation to clinical practice is anticipated to be a deliberate process.

Heliox ventilation in elderly, hypertensive ICU patients improves microcirculation: A randomized controlled study

BACKGROUND

Conventional mechanical ventilation has adverse impacts on the hemodynamics of elderly, hypertensive ICU patients. Limited studies have addressed ways to ameliorate these negative effects. This study aimed to determine whether heliox ventilation could improve the hemodynamics, especially microcirculation, of elderly, hypertensive patients undergoing mechanical ventilation.

METHODS

Thirty-eight patients, over the age of 65 with essential hypertension who underwent invasive mechanical ventilation treatment, were divided into two groups: a control group of nitrogen‑oxygen ventilation (n = 19) and an experimental group of heliox ventilation (n = 19). The control group received conventional room air ventilation and the experimental group adopted the innovative, closed heliox ventilation technique. Changes in blood pressure, heart rate (HR), peripheral oxygen saturation (SpO2), central venous oxygen saturation (ScvO2), regional cerebral oxygen saturation (rSO2), lactic acid (Lac) and airway pressure were measured at 0,1,2,3 h under volume-controlled ventilation (VCV) mode throughout the study. Sublingual microcirculation parameters were additionally measured at 0 h and 3 h of ventilation treatment.

RESULTS

SpO2 in both groups increased after 1 h of ventilation compared with 0 h (p < 0.001), subsequently remaining stable. Compared with the control group, the experimental group showed a decrease in airway pressure and Lac, while blood pressure, ScvO2, and rSO2 increased (p < 0.05). Moreover, the sublingual microcirculation indexes in the experimental group improved compared with the control group (p < 0.05).

CONCLUSIONS

Heliox ventilation improves blood pressure and microcirculation in elderly hypertensive patients and may resolve the limitations of traditional nitrogen‑oxygen ventilation.

TRIAL REGISTRATION

This trial was registered. The Chinese trial registration number is ChiCTR2100043945. The date of registration is 6-3-2021.

Association between cytokines, nitric oxide, hemodynamic and microcirculation in a porcine model of sepsis

Systemic inflammation and hemodynamic or microvascular alterations are a hallmark of sepsis and play a role in organs hypoperfusion and dysfunction. Pimobendan, an inodilator agent, could be an interesting option for inotropic support and microcirculation preservation during shock. The objectives of this study were to evaluate effect of pimobendan on cytokine and nitric oxide (NO) release and investigate whether changes of macro and microcirculation parameters are associated with the release of cytokines and NO in pigs sepsis model. After circulatory failure, induced by intravenous inoculation of live Pseudomonas aeruginosa, eight animals were treated with pimobendan and eight with placebo. Pimobendan did not affect cytokines secretion (TNF-α, IL-6 and IL-10), but decreased time-dependently NO release. Data of macro and microcirculation parameters, NO and TNF- α recorded at the time of circulatory failure (Thypotension) and the time maximum of production cytokines was used for analyses. A positive correlation was observed between TNF-α and cardiac index (r = 0.55, p = 0.03) and a negative with systemic vascular resistance (r = -0.52, p = 0.04). Positive correlations were seen both between IL-10, 30 min after resuscitation (T30min), and systolic arterial pressure (r = 0.57, p = 0.03) and cardiac index (r = 0.67, p = 0.01), and also between IL-6, taken 2 h after resuscitation and systolic arterial pressure (r = 0.53, p = 0.04). Negative correlations were found between IL-10 and lactate, measured resuscitation time (r = -0.58, p = 0.03). Regarding microcirculation parameters, we observed a positive correlation between IL-6 and IL-10 with the microvascular flow index (r = 0.52, p = 0.05; r = 0.84, p = 0.0003) and a negative correlation with the heterogeneity index with TNF-α and IL-10 (r = -0.51, p = 0.05; r = -0.74, p = 0.003) respectively. NO derivatives showed a positive correlation with temperature gradient (r = 0.54, p = 0.04). Pimobendan did not show anti-inflammatory effects in cytokines release. Our results also, suggest changes of macro- and microcirculation are associated mainly with low levels of IL-10 in sepsis.

Changes in microcirculation of small intestine end-to-end anastomoses in an experimental model

INTRODUCTION

Sufficient perfusion is essential for a safe intestinal anastomosis. Impaired microcirculation may lead to increased bacterial translocation and anastomosis insufficiency. Thus, it is important to estimate well the optimal distance of the anastomosis line from the last mesenterial vessel. However, it is still empiric. In this experiment the aim was to investigate the intestinal microcirculation at various distances from the anastomosis in a pig model.

MATERIALS AND METHODS

On 8 anesthetized pigs paramedian laparotomy and end-to-end jejuno-jejunostomy were performed. Using Cytocam-IDF camera, microcirculatory recordings were taken before surgery at the planned suture line, and 1 to 3 mesenterial vessel mural trunk distance from it, and at the same sites 15 and 120 min after anastomosis completion. After the microcirculation monitoring, anastomosed and intact bowel segments were removed to test tensile strength.

RESULTS

The proportion and the density of the perfused vessels decreased significantly after anastomosis completion. The perfusion rate increased gradually distal from the anastomosis, and after 120 min these values seemed to be normalized. Anastomosed bowels had significantly lower maximal tensile strength and higher slope of tensile strength curves than intact controls.

CONCLUSION

Alterations in microcirculation and tensile strength were observed. After completing the anastomosis, the improvement in perfusion increased gradually away from the wound edge. The IDF device was useful to monitor intestinal microcirculation providing data to estimate better the optimal distance of the anastomosis from the last order mesenteric vessel.

Sublingual microcirculatory assessment on admission independently predicts the outcome of old intensive care patients suffering from shock

Shock is a life-threatening condition. This study evaluated if sublingual microcirculatory perfusion on admission is associated with 30-day mortality in older intensive care unit (ICU) shock patients. This trial prospectively recruited ICU patients (≥ 80 years old) with arterial lactate above 2 mmol/L, requiring vasopressors despite adequate fluid resuscitation, regardless of shock cause. All patients received sequential sublingual measurements on ICU admission (± 4 h) and 24 (± 4) hours later. The primary endpoint was 30-day mortality. From September 4th, 2022, to May 30th, 2023, 271 patients were screened, and 44 included. Patients were categorized based on the median percentage of perfused small vessels (sPPV) into those with impaired and sustained microcirculation. 71% of videos were of good or acceptable quality without safety issues. Patients with impaired microcirculation had significantly shorter ICU and hospital stays (p = 0.015 and p = 0.019) and higher 30-day mortality (90.0% vs. 62.5%, p = 0.036). Cox regression confirmed the independent association of impaired microcirculation with 30-day mortality (adjusted hazard ratio 3.245 (95% CI 1.178 to 8.943, p = 0.023). Measuring sublingual microcirculation in critically ill older patients with shock on ICU admission is safe, feasible, and provides independent prognostic information about outcomes.Trial registration NCT04169204.

Endothelial Beta 1 Integrins are Necessary for Microvascular Function and Glucose Uptake

Microvascular insulin delivery to myocytes is rate limiting for the onset of insulin-stimulated muscle glucose uptake. The structural integrity of capillaries of the microvasculature is regulated, in part, by a family of transmembrane adhesion receptors known as integrins, which are composed of an α and β subunit. The integrin β1 (itgb1) subunit is highly expressed in endothelial cells (EC). EC itgb1 is necessary for the formation of capillary networks during embryonic during development and its knockdown blunts the reactive hyperemia that manifests during ischemia reperfusion. We investigated the contribution of EC itgb1 in microcirculatory function and glucose uptake with emphasis in skeletal muscle. We hypothesized that loss of EC itgb1 would impair microvascular hemodynamics and glucose uptake during insulin stimulation, creating 'delivery'-mediated insulin resistance. An itgβ1 knockdown mouse model was developed to avoid lethality of embryonic gene knockout and the deteriorating health resulting from early post-natal inducible gene deletion. Mice with (itgb1fl/flSCLcre) and without (itgb1fl/fl) tamoxifen inducible stem cell leukemia cre recombinase (SLCcre) expression at 10 days post cre induction had comparable exercise tolerance and pulmonary and cardiac functions. Using robust in vivo experimental platforms (i.e., intravital microscopy and hyperinsulinemic-euglycemic clamp), we show that itgb1fl/flSCLcre mice compared to itgb1fl/fl littermates have, i) deficits in capillary flow rate, flow heterogeneity, and capillary density; ii) impaired insulin-stimulated glucose uptake despite sufficient transcapillary insulin efflux; and iii) reduced insulin-stimulated glucose uptake due to perfusion-limited glucose delivery. Thus, EC itgb1 is necessary for microcirculatory function and to meet the metabolic challenge of insulin stimulation.

Optical coherence tomography angiography in cardiovascular disease

Endothelial dysfunction and microvascular remodeling underly the development and progression of a host of cardiovascular disease (CVD). However, current methods to assess coronary epicardial microvascular function are invasive, time-intensive, and costly. Optical coherence tomography angiography (OCTA) is an established technology within ophthalmology that provides a quick, noninvasive assessment of vascular structures within the retina. As a growing body of evidence reveals strong associations between the retinal changes on OCTA and the development and progression of CVD, OCTA may indeed be a surrogate test for end-organ dysfunction. OCTA has potential to enhance diagnostic performance, refine cardiovascular risk assessment, strengthen prognostication, and ultimately, improve patient care. We explore the current literature on OCTA in cardiovascular diseases to summarize the clinical utility of retinal OCTA imaging and discuss next-generation cardiovascular applications.

Relationship between microvascular status and diagnostic performance of stress dynamic CT perfusion imaging

OBJECTIVES

This study aimed to investigate the relationship between microvascular status in the non-ischemic myocardium and the diagnostic performance of stress dynamic CT perfusion imaging (CTP) in detecting hemodynamically significant stenosis.

MATERIALS AND METHODS

This study included 157 patients who underwent coronary computed tomography angiography (CTA), CTP, and invasive coronary angiography (ICA), including fractional flow reserve (FFR). Hemodynamically significant stenosis was defined by FFR and ICA. A relative myocardial blood flow (MBF) for each myocardial segment was normalized to the highest MBF (remote MBF) among 16 segments.

RESULTS

The receiver operating characteristic curve analysis for detecting hemodynamically significant stenosis at the vessel level indicated that patients with lower, intermediate, and higher remote MBF had areas under the curve (AUC) of 0.66, 0.70, and 0.80, respectively, for absolute MBF and AUCs of 0.63, 0.70, and 0.83, respectively, for relative MBF. The optimal cut-off values for absolute MBF were proportional to the levels of remote MBFs, while the ones for relative MBF were more consistent across lower to higher remote MBFs. For the patients with high remote MBF, the relative MBF demonstrated a sensitivity of 69%, specificity of 88%, and accuracy of 85% in detecting hemodynamically significant stenosis.

CONCLUSION

The microvascular status in the non-ischemic myocardium influenced the diagnostic performance of dynamic CTP and threshold values of absolute MBFs, suggesting the potential preference for relative MBF over absolute MBF in clinical settings. Dynamic CTP's quantification of MBF offers the benefit of indicating reliability in ischemia detection relative to microvascular status.

KEY POINTS

Question The relationship between microvascular status and diagnostic performance of dynamic CTP imaging has not been fully investigated. Findings The diagnostic performance of dynamic CTP and threshold values of absolute MBF were impacted by microvascular status. Clinical relevance The differences in diagnostic accuracy of dynamic CTP related to varying remote MBF values necessitate a personalized evaluation of myocardial perfusion in dynamic CTP images.

Assessment of coronary endothelial dysfunction using contemporary coronary function testing

BACKGROUND

The established diagnosis of coronary endothelial dysfunction (CED) is through the response to low-dose acetylcholine during invasive coronary function testing (CFT). Current diagnostic criteria encompass deficient epicardial vasodilation and/or insufficient increase in coronary blood flow (CBF) calculated from additional Doppler flow velocity measurements. The aim is to evaluate the diagnostic yield of using angiographic epicardial vasomotion and CBF as single criteria for diagnosing CED during CFT.

METHODS

A total of 110 patients with angina and non-obstructive coronary arteries who underwent clinically indicated CFT were included. CED was defined as any reduction in epicardial diameter through quantitative coronary angiography and/or < 50 % increase in CBF compared to baseline after low-dose acetylcholine.

RESULTS

Based on current diagnostic criteria, 78 % of patients (N = 86/110) was diagnosed with CED. When only considering epicardial diameter, 24 % CED (N = 21/86) and 50 % severe CED diagnoses (N = 19/38) were missed. When only considering CBF, 27 % CED (N = 23/86) and 18 % severe CED diagnoses (N = 7/38) were missed. A similar diagnostic yield for CED detection was found for both parameters (OR: 0.913, 95 %CI 0.481-1.726, p = 0.763). The incidence of CFT diagnoses was comparable among all groups.

CONCLUSIONS

As single parameters, both epicardial diameter and CBF were ineffective in accurately diagnosing CED compared to the current diagnostic criteria. Combining both parameters is necessary to diagnose the complete spectrum of CED, as missed diagnoses of deficient CBF responses (e.g., microvascular CED) and epicardial vasomotion (e.g., epicardial CED) might occur when relying on these parameters as single diagnostic criteria for CED.

Regulation of Skeletal Muscle Resistance Arteriolar Tone: Temporal Variability in Vascular Responses

INTRODUCTION

A full understanding of the integration of the mechanisms of vascular tone regulation requires an interrogation of the temporal behavior of arterioles across vasoactive challenges. Building on previous work, the purpose of the present study was to start to interrogate the temporal nature of arteriolar tone regulation with physiological stimuli.

METHODS

We determined the response rate of ex vivo proximal and in situ distal resistance arterioles when challenged by one-, two-, and three-parameter combinations of five major physiological stimuli (norepinephrine, intravascular pressure, oxygen, adenosine [metabolism], and intralumenal flow). Predictive machine learning models determined which factors were most influential in controlling the rate of arteriolar responses.

RESULTS

Results indicate that vascular response rate is dependent on the intensity of the stimulus used and can be severely hindered by altered environments, caused by application of secondary or tertiary stimuli. Advanced analytics suggest that adrenergic influences were dominant in predicting proximal arteriolar response rate compared to metabolic influences in distal arterioles.

CONCLUSION

These data suggest that the vascular response rate to physiologic stimuli can be strongly influenced by the local environment. Translating how these effects impact vascular networks is imperative for understanding how the microcirculation appropriately perfuses tissue across conditions.

Changes in bulbar conjunctival microcirculation and microvasculature during short-term scleral lens wearing and their associated factors

OBJECTIVE

To explore the changes in microcirculation and microvasculature of the bulbar conjunctiva during the short-term wearing of the scleral lenses (ScCL). And investigate the factors affecting the microcirculation and microvasculature of the bulbar conjunctiva.

METHODS

In this prospective cross-sectional study, functional slit lamp biomicroscopy (FSLB) was used to image the ocular surface microcirculation and microvascular images at two different sites (under the area of ScCL and outside of the area of ScCL) before (baseline) and during the wearing of ScCL at 0 h, 1 h, 2 h and 3 h. Anterior segment optical coherence tomography (AS-OCT) (RTVue, Optovue Inc, USA) was also used to image central post-lens tear film (PoLTF) and the morphology changes of the conjunctiva under the landing zone at the same time period. The semi-automatic quantification of microcirculation and microvasculature including vessel density (Dbox), vessel diameter (D), axial blood flow velocity (Va) and blood flow volume (Q). And the morphological changes of conjunctiva and PoLTF fogging grading were evaluated manually. The changes in the microcirculation and microvasculature of the ocular surface, PoLTF fogging grade and conjunctival morphology were compared before and during the ScCL wearing at different time periods, and the relationship between them was analyzed.

RESULTS

Nineteen eyes (11 right eyes, 8 left eyes) were analyzed in this study. Outside of the area of ScCL, the Dbox before wearing lenses was less than that at 0 h (P = 0.041). The Q at baseline was greater than that after 1 h ScCL wearing (P = 0.026). Under the area of the ScCL, the Q at 1 h was less than that at baseline and 3 h. During the ScCL wearing, statistically significant conjunctival morphology changes were found among different time stages (baseline (0 μm), 0 h (113.18 μm), 2 h (138.97 μm), 3 h (143.83 μm) (all P ＜0.05). Outside the area of the ScCL, the morphology changes of the conjunctiva were negatively correlated with the changes of Va (P＜0.001,r = -0.471) and Q (P = 0.003,r = -0.348),but positively correlated with the Dbox (P = 0.001,r = 0.386). Under the area of ScCL, the morphology changes of the conjunctiva were negatively correlated with the Q (P = 0.012, r = -0.291). The fogging grade was positively correlated with the Q under the area of the ScCL (P = 0.005, r = 0.331).

CONCLUSIONS

The microcirculation and microvasculature of the ocular surface and conjunctival morphology were changed after wearing ScCL in wearers, which indicated that the microvascular responses happened in the ScCL wearers and the severity of microvascular responses of the ocular surface related to the morphology changes of the conjunctiva. The quantification methods and findings in this study provide clues for the safety of ScCL wearing and may supervise the health of the wearer's ocular surface.

Perspectives for capillary refill time in clinical practice for sepsis

BACKGROUND

Capillary refill time (CRT) is defined as the time taken for color to return to an external capillary bed after pressure is applied to cause blanching. Recent studies demonstrated the benefits of CRT in guiding fluid therapy for sepsis. However, lack of consistency among physicians in how to perform and interpret CRT has led to a low interobserver agreement for this assessment tool, which prevents its availability in sepsis clinical settings.

OBJECTIVE

To give physicians a concise overview of CRT and explore recent evidence on its reliability and value in the management of sepsis.

RESEARCH DESIGN

A narrative review.

RESULTS

This narrative review summarizes the factors affecting CRT values, for example, age, sex, temperature, light, observation techniques, work experience, training level and differences in CRT measurement methods. The methods of reducing the variability of CRT are synthesized. Based on studies with highly reproducible CRT measurements and an excellent inter-rater concordance, we recommend the standardized CRT assessment method. The threshold of normal CRT values is discussed. The application of CRT in different phases of sepsis management is summarized.

CONCLUSIONS

Recent data confirm the value of CRT in critically ill patients. CRT should be detected by trained physicians using standardized methods and reducing the effect of ambient-related factors. Its association with severe infection, microcirculation, tissue perfusion response, organ dysfunction and adverse outcomes makes this approach a very attractive tool in sepsis. Further studies should confirm its value in the management of sepsis.

IMPLICATIONS FOR CLINICAL PRACTICE

As a simple assessment, CRT deserves more attention even though it has not been widely applied at the bedside. CRT could provide nursing staff with patient's microcirculatory status, which may help to develop individualized nursing plans and improve the patient's care quality and treatment outcomes.

Micro- and macrovascular function in the highest city in the world: a cross sectional study

Background

Since vascular responses to hypoxia in both healthy high-altitude natives and chronic mountain sickness (a maladaptive high-altitude pathology characterised by excessive erythrocytosis and the presence of symptoms-CMS) remain unclear, the role of inflammation and oxidative/nitrosative stress on the endothelium-dependent and -independent responses in both the micro- and macrocirculation, in healthy Andeans at different altitudes and in CMS patients, was examined.

Methods

94 men were included: 18 lowlanders (LL), 38 healthy highlanders permanently living at 3800 m (n = 21-HL-3800) or in La Rinconada, the highest city in the world (5100-5300 m) (n = 17-HL-5100/No CMS). Moreover, 14 participants with mild (Mild CMS) and 24 with moderate to severe CMS (Mod/Sev CMS) were recruited. All undertook two reactivity tests: i) local thermal hyperaemia (microcirculation) and ii) flow-mediated dilation (macrocirculation). Endothelium-independent function (glyceryl trinitrate) was also assessed only in La Rinconada.

Findings

Conductance and skin blood flow velocity during the microcirculation test, as well as macrocirculation progressively decreased with altitude (LL > HL-3800 > HL-5100/No CMS). CMS also induced a decrease in macrocirculation (HL-5100/No CMS > Mild CMS = Mod/Sev CMS), while glyceryl trinitrate restored vascular function. Both oxidative stress and nitric oxide metabolites increased with altitude only. Principal component analysis revealed that increasing inflammation with altitude was associated with a progressive decline in both micro- and macrovascular function in healthy highlanders.

Interpretation

Both micro and macrovascular function are affected by chronic exposure to hypoxia, the latter being further compounded by CMS.

Funding

The "Fonds de dotation AGIR pour les maladies chroniques", the "Air Liquide Foundation", and the "French National Research Agency".

Single-cell transcriptomes and chromatin accessibility of endothelial cells unravel transcription factors associated with dysregulated angiogenesis in systemic sclerosis

OBJECTIVES

Vasculopathy emerges early in systemic sclerosis (SSc) and links to endothelial cell (EC) injury and angiogenesis. Understanding EC transcriptomes and epigenomes is crucial for unravelling the mechanisms involved.

METHODS

Transcriptomes and chromatin accessibility were assessed by single-cell RNA sequencing and single-nucleus transposase-accessible chromatin sequencing. Immunofluorescent staining of skin and proteomics assay were employed to confirm the altered SSc EC phenotypes. Gain-of-function assay was used to evaluate the effects of ETS transcription factors on human dermal ECs (hDECs).

RESULTS

Both control and SSc ECs shared transcriptomic signatures of vascular linages (arterial, capillary and venous ECs) and lymphatic ECs. Arterial ECs in SSc showed reduced number and increased expression of genes associated with apoptosis. Two distinct EC subpopulations, tip and proliferating ECs, were markedly upregulated in SSc, indicating enhanced proangiogenic and proliferative activities. Molecular features of aberrant SSc-ECs were associated with disease pathogenesis and clinical traits of SSc, such as skin fibrosis and digital ulcers. Ligand-receptor analysis demonstrated altered intercellular networks of SSc EC subpopulations with perivascular and immune cells. Furthermore, the integration of open chromatin profiles with transcriptomic analysis suggested an increased accessibility of regulatory elements for ETS family transcription factors in SSc ECs. Overexpression of ETS genes in hDECs suggested ELK4, ERF and ETS1 may orchestrate arterial apoptosis and dysregulated angiogenesis in SSc.

CONCLUSIONS

This study unveils transcriptional and chromatin alterations in driving endovascular dysregulation in SSc, proposing ELK4, ERF and ETS1 as novel targets in ECs for addressing vascular complications in the condition.

Acute effects of cold, heat and contrast pressure therapy on forearm muscles regeneration in combat sports athletes: a randomized clinical trial

Due to the specific loads that occur in combat sports athletes' forearm muscles, we decided to compare the immediate effect of monotherapy with the use of compressive heat (HT), cold (CT), and alternating therapy (HCT) in terms of eliminating muscle tension, improving muscle elasticity and tissue perfusion and forearm muscle strength. This is a single-blind, randomized, experimental clinical trial. Group allocation was performed using simple 1:1 sequence randomization using the website randomizer.org. The study involved 40 40 combat sports athletes divided into four groups and four therapeutic sessions lasting 20 min. (1) Heat compression therapy session (HT, n = 10) (2) (CT, n = 10), (3) alternating (HCT, n = 10), and sham, control (ShT, n = 10). All participants had measurements of tissue perfusion (PU, [non-reference units]), muscle tension (T-[Hz]), elasticity (E-[arb- relative arbitrary unit]), and maximum isometric force (Fmax [kgf]) of the dominant hand at rest (Rest) after the muscle fatigue protocol (PostFat.5 min), after therapy (PostTh.5 min) and 24 h after therapy (PostTh.24 h). A two-way ANOVA with repeated measures: Group (ColdT, HeatT, ContrstT, ControlT) × Time (Rest, PostFat.5 min, PostTh.5 min, Post.24 h) was used to examine the changes in examined variables. Post-hoc tests with Bonferroni correction and ± 95% confidence intervals (CI) for absolute differences (△) were used to analyze the pairwise comparisons when a significant main effect or interaction was found. The ANOVA for PU, T, E, and Fmax revealed statistically significant interactions of Group by Time factors (p < 0.0001), as well as main effects for the Group factors (p < 0.0001; except for Fmax). In the PostTh.5 min. Period, significantly (p < 0.001) higher PU values were recorded in the HT (19.45 ± 0.91) and HCT (18.71 ± 0.67) groups compared to the ShT (9.79 ± 0.35) group (△ = 9.66 [8.75; 10.57 CI] > MDC(0.73), and △ = 8.92 [8.01; 9.83 CI] > MDC(0.73), respectively). Also, significantly (p < 0.001) lower values were recorded in the CT (3.69 ± 0.93) compared to the ShT (9.79 ± 0.35) group △ = 6.1 [5.19; 7.01 CI] > MDC(0.73). For muscle tone in the PostTh.5 m period significantly (p < 0.001) higher values were observed in the CT (20.08 ± 0.19 Hz) group compared to the HT (18.61 ± 0.21 Hz), HCT (18.95 ± 0.41 Hz) and ShT (19.28 ± 0.33 Hz) groups (respectively: △ = 1.47 [1.11; 1.83 CI] > MDC(0.845); △ = 1.13 [0.77; 1.49 CI] > MDC(0.845), and △ = 0.8 [0.44; 1.16 CI], < MDC(0.845)). The highest elasticity value in the PostTh.5 m period were observed in the CT (1.14 ± 0.07) group, and it was significantly higher than the values observed in the HT (0.97 ± 0.03, △ = 0.18 [0.11; 0.24 CI] > MDC(0.094), p < 0.001), HCT (0.90 ± 0.04, △ = 0.24 [0.17; 0.31 CI] > MDC(0.094), p < 0.001) and ShT (1.05 ± 0.07, △ = 0.094 [0.03; 0.16 CI] = MDC(0.094), p = 0.003) groups. For Fmax, there were no statistically significant differences between groups at any level of measurement. The results of the influence of the forearm of all three therapy forms on the muscles' biomechanical parameters confirmed their effectiveness. However, the effect size of alternating contrast therapy cannot be confirmed, especially in the PostTh24h period. Statistically significant changes were observed in favor of this therapy in PU and E measurements immediately after therapy (PostTh.5 min). Further research on contrast therapy is necessary.

Vascular changes in the retinal capillary network in fellow eye of the patients with central retinal artery occlusion

BACKGROUND

We aimed to evaluate the retinal vascular changes in the superficial and deep retinal vascular networks in the fellow eye of patients with central retinal artery occlusion (CRAO) and compare them with controls using optical coherence tomography angiography (OCT-A).

METHODS

In a cross-sectional study, 27 patients with CRAO and 189 normal controls were included. Ophthalmic examination and OCT-A images were performed on all participants.

RESULTS

The total vascular density of the superficial capillary network in the 6-mm scan was significantly lower in the fellow eye of patients with CRAO than in the control group (p = 0.02). No significant difference was observed in the FAZ area of the affected eyes and their fellow eyes compared with the controls. Total vascular density at 300 microns around the fovea was lower in the fellow eye compared with the control group (p = 0.034).

CONCLUSIONS

The retinal vascular network changes in the fellow eyes of patients with CRAO suggest that persistent microvascular changes may be present before the onset of CRAO. This finding indicates that such changes could serve as an early diagnostic window for systemic vascular changes before catastrophic vascular events occur.

Follow-up assessment of the microvascular function in patients with long COVID

Long COVID is a complex pathophysiological condition. However, accumulating data suggests that COVID-19 is a systemic microvascular endothelial dysfunction with different clinical manifestations. In this study, a microvascular function was assessed in long COVID patients (n = 33) and healthy controls (n = 30) using flow-mediated skin fluorescence technique (FMSF), based on measurements of nicotinamide adenine dinucleotide fluorescence intensity during brachial artery occlusion (ischemic response, IR) and immediately after occlusion (hyperemic response, HR). Microcirculatory function readings were taken twice, 3 months apart. In addition, we quantified biochemical markers such as the serum L-arginine derivatives and hypoxia-inducible factor 1α (HIF1α) to assess their relation with microvascular parameters evaluated in vivo. In patients with long COVID, serum HIF1α was significantly correlated to IRindex (r = -0.375, p < 0.05). Similarly, there was a significant inverse correlation of serum asymmetric dimethyl-L-arginine levels to both HRmax (r = -0.343, p < 0.05) and HRindex (r = -0.335, p < 0.05). The IR parameters were found lower or negative in long COVID patients and recovered in three-month follow-up. Hypoxia sensitivity value was significantly higher in long COVID patients examined after three months of treatment based on the combination of ACE-inhibitors and beta-adrenolytic compared to baseline condition (85.2 ± 73.8 vs. 39.9 ± 51.7 respectively, p = 0.009). This study provides evidence that FMSF is a sensitive, non-invasive technique to track changes in microvascular function that was impaired in long COVID and recovered after 3 months, especially in patients receiving a cardioprotective therapy.

The Usefulness of Microcirculatory Assessment After Cardiac Surgery: Illustrative Case Report

Cardiac surgery causes a series of disturbances in human physiology. The correction of systemic hemodynamic variables is frequently ineffective in improving microcirculatory perfusion and delivering oxygen to the tissues. We present the case of a 52-year-old male submitted to mitral valve replacement (metallic valve) and subaortic membrane resection. Sublingual microcirculatory density and perfusion were evaluated using a handheld CytoCam camera before surgery and in the early postoperative period. In this case, systemic hemodynamic variables were compromised despite an actual improvement in the microcirculatory parameters in comparison to the preoperative evaluation, possibly due to the correction of the structural cardiac defects.

Lactated Ringers, albumin and mannitol as priming during cardiopulmonary bypass reduces pulmonary edema in rats compared with hydroxyethyl starch

BACKGROUND

Endothelial disorders with edema formation and microcirculatory perfusion disturbances are common in cardiac surgery with cardiopulmonary bypass (CPB) and contribute to disturbed tissue oxygenation resulting in organ dysfunction. Albumin is protective for the endothelium and could be a useful additive to CPB circuit priming. Therefore, this study aimed to compare organ edema and microcirculatory perfusion in rats on CPB primed with lactated Ringers, albumin and mannitol (LR/albumin/mannitol) compared to 6% hydroxyethyl starch (HES).

RESULTS

Male rats were subjected to 75 min of CPB primed with either LR/albumin/mannitol or with 6% HES. Renal and lung edema were determined by wet/dry weight ratio. Pulmonary wet/dry weight ratio was lower in rats on CPB primed with LR/albumin/mannitol compared to HES (4.77 [4.44-5.25] vs. 5.33 [5.06-6.33], p = 0.032), whereas renal wet/dry weight ratio did not differ between groups (4.57 [4.41-4.75] vs. 4.51 [4.47-4.73], p = 0.813). Cremaster microcirculatory perfusion was assessed before, during and after CPB with intravital microscopy. CPB immediately impaired microcirculatory perfusion compared to baseline (LR/albumin/mannitol: 2 [1-7] vs. 14 [12-16] vessels per recording, p = 0.008; HES: 4 [2-6] vs. 12 [10-13] vessels per recording, p = 0.037), which persisted after weaning from CPB without differences between groups (LR/albumin/mannitol: 5 [1-9] vs. HES: 1 [0-4], p = 0.926). In addition, rats on CPB primed with LR/albumin/mannitol required less fluids to reach sufficient flow rates (0.5 [0.0-5.0] mL vs. 9 [4.5-10.0], p < 0.001) and phenylephrine (20 [0-40] µg vs. 90 [40-200], p = 0.004). Circulating markers for inflammation (interleukin 6 and 10), adhesion (ICAM-1), glycocalyx shedding (syndecan-1) and renal injury (NGAL) were determined by ELISA or Luminex. Circulating interleukin-6 (16 [13-25] vs. 33 [24-51] ng/mL, p = 0.006), interleukin-10 (434 [295-782] vs. 2120 [1309-3408] pg/ml, p < 0.0001), syndecan-1 (5 [3-7] vs. 15 [11-16] ng/mL, p < 0.001) and NGAL (555 [375-1078] vs. 2200 [835-3671] ng/mL, p = 0.008) were lower in rats on CPB primed with LR/albumin/mannitol compared to HES.

CONCLUSION

CPB priming with LR, albumin and mannitol resulted in less pulmonary edema, renal injury, inflammation and glycocalyx degradation compared to 6% HES. Furthermore, it enhanced hemodynamic stability compared with HES. Further research is needed to explore the specific role of albumin as a beneficial additive in CPB priming.

Role of arterial blood glucose and interstitial fluid glucose difference in evaluating microcirculation and clinical prognosis of patients with septic shock: a prospective observational study

BACKGROUND

Microcirculation abnormality in septic shock is closely associated with organ dysfunction and mortality rate. It was hypothesized that the arterial blood glucose and interstitial fluid (ISF) glucose difference (GA-I) as a marker for assessing the microcirculation status can effectively evaluate the severity of microcirculation disturbance in patients with septic shock.

METHODS

The present observational study enrolled patients with septic shock admitted to and treated in the intensive care unit (ICU) of a tertiary teaching hospital. The parameters reflecting organ and tissue perfusion, including lactic acid (Lac), skin mottling score, capillary refill time (CRT), venous-to-arterial carbon dioxide difference (Pv-aCO2), urine volume, central venous oxygen saturation (ScvO2) and GA-I of each enrolled patient were recorded at the time of enrollment (H0), H2, H4, H6, and H8. With ICU mortality as the primary outcome measure, the ICU mortality rate at any GA-I interval was analyzed.

RESULTS

A total of 43 septic shock patients were included, with median sequential organ failure assessment (SOFA) scores of 10.5 (6-16), and median Acute Physiology and Chronic Health Evaluation (APACHAE) II scores of 25.7 (9-40), of whom 18 died during ICU stay. The GA-I levels were negative correlation with CRT (r = 0.369, P < 0.001), Lac (r = -0.269, P < 0.001), skin mottling score (r=-0.223, P < 0.001), and were positively associated with urine volume (r = 0.135, P < 0.05). The ICU mortality rate of patients with septic shock presenting GA-I ≤ 0.30 mmol/L and ≥ 2.14 mmol/L was significantly higher than that of patients with GA-I at 0.30-2.14 mmol/L [65.2% vs. 15.0%, odds ratio (OR) = 10.625, 95% confidence interval (CI): 2.355-47.503].

CONCLUSION

GA-I was correlated with microcirculation parameters, and with differences in survival. Future studies are needed to further explore the potential impact of GA-I on microcirculation and clinical prognosis of septic shock, and the bedside monitoring of GA-I may be beneficial for clinicians to identify high-risk patients.

Nitroglycerin challenge identifies microcirculatory target for improved resuscitation in patients with circulatory shock

BACKGROUND

Circulatory shock and multi-organ failure remain major contributors to morbidity and mortality in critically ill patients and are associated with insufficient oxygen availability in the tissue. Intrinsic mechanisms to improve tissue perfusion, such as up-regulation of functional capillary density (FCD) and red blood cell velocity (RBCv), have been identified as maneuvers to improve oxygen extraction by the tissues; however, their role in circulatory shock and potential use as resuscitation targets remains unknown. To fill this gap, we examined the baseline and maximum recruitable FCD and RBCv in response to a topical nitroglycerin stimulus (FCDNG, RBCvNG) in patients with and without circulatory shock to test whether this may be a method to identify the presence and magnitude of a microcirculatory reserve capacity important for identifying a resuscitation target.

METHODS

Sublingual handheld vital microscopy was performed after initial resuscitation in mechanically ventilated patients consecutively admitted to a tertiary medical ICU. FCD and RBCv were quantified using an automated computer vision algorithm (MicroTools). Patients with circulatory shock were retrospectively identified via standardized hemodynamic and clinical criteria and compared to patients without circulatory shock.

RESULTS

54 patients (57 ± 14y, BMI 26.3 ± 4.9 kg/m2, SAPS 56 ± 19, 65% male) were included, 13 of whom presented with circulatory shock. Both groups had similar cardiac index, mean arterial pressure, RBCv, and RBCvNG. Heart rate (p < 0.001), central venous pressure (p = 0.02), lactate (p < 0.001), capillary refill time (p < 0.01), and Mottling score (p < 0.001) were higher in circulatory shock after initial resuscitation, while FCD and FCDNG were 10% lower (16.9 ± 4.2 and 18.9 ± 3.2, p < 0.01; 19.3 ± 3.1 and 21.3 ± 2.9, p = 0.03). Nitroglycerin response was similar in both groups, and circulatory shock patients reached FCDNG similar to baseline FCD found in patients without shock.

CONCLUSION

Critically ill patients suffering from circulatory shock were found to present with a lower sublingual FCD. The preserved nitroglycerin response suggests a dysfunction of intrinsic regulation mechanisms to increase the microcirculatory oxygen extraction capacity associated with circulatory shock and identifies a potential resuscitation target. These differences in microcirculatory hemodynamic function between patients with and without circulatory shock were not reflected in blood pressure or cardiac index.

Shaping the Neurovascular Unit Exploiting Human Brain Organoids

Brain organoids, three-dimensional cell structures derived from pluripotent stem cells, closely mimic key aspects of the human brain in vitro, providing a powerful tool for studying neurodevelopment and disease. The neuroectodermal induction protocol employed for brain organoid generation primarily gives rise to the neural cellular component but lacks the vital vascular system, which is crucial for the brain functions by regulating differentiation, migration, and circuit formation, as well as delivering oxygen and nutrients. Many neurological diseases are caused by dysfunctions of cerebral microcirculation, making vascularization of human brain organoids an important tool for pathogenetic and translational research. Experimentally, the creation of vascularized brain organoids has primarily focused on the fusion of vascular and brain organoids, on organoid transplantation in vivo, and on the use of microfluidic devices to replicate the intricate microenvironment of the human brain in vitro. This review summarizes these efforts and highlights the importance of studying the neurovascular unit in a forward-looking perspective of leveraging their use for understanding and treating neurological disorders.