CD271+, CXCR7+, CXCR4+, and CD133+ Stem/Progenitor Cells and Clinical Characteristics of Acute Ischemic Stroke Patients

Danshen injection mitigated the cerebral ischemia/reperfusion injury by suppressing neuroinflammation via the HIF-1α/CXCR4/NF-κB signaling pathway

Danshen injection (DI) is effective in treating cardiovascular and cerebrovascular diseases, including ischemic stroke (IS), including IS, but its mechanism is unclear. A middle cerebral artery occlusion model was used to simulate ischemia/reperfusion (I/R) injury in SD rats. Overexpression of hypoxia-inducible factor 1α (HIF-1α) was achieved by AAV-HIF-1α. Rats were treated with DI or saline. Neurological scores and infarction rates were assessed. I/R damage was examined by HE, 2,3,5-triphenyltetrazolium and Nissl stainings. Expression levels of relative proteins [TNF-α, IL-6, IL-1β, SOD, MDA, ROS, HIF-1α, CXC chemokine receptor 4 (CXCR4) and NF-κB] were measured. DI treatment improved neurological scores and reduced infarction rates, suggesting that it inhibits inflammation and oxidative stress. The expression levels of HIF-1α, CXCR4 and NF-κB were decreased. However, the effectiveness of DI on inflammation inhibition was lost after HIF-1α overexpression. DI may directly target HIF-1α to suppress neuroinflammation and reduce I/R injury by suppressing the HIF-1α/CXCR4/NF-κB signaling pathway.

Safety and Efficacy of Bone Marrow and Adipose Tissue-Derived Mesenchymal Stem Cells for the Treatment of Ischemic Stroke: A Systematic Review

Neurological diseases, including ischemic stroke, are considered a big challenge for public health due to their high prevalence and lack of definitive and effective treatments. Addressing these issues requires innovative therapeutic approaches and among the limited methods available, stem cells have shown promise in improving central nervous system repair by enhancing myelin regeneration and neuronal recovery. To advance this field of research, this systematic review aims to assess the safety and effectiveness of mesenchymal stem cells (MSCs) derived from both bone marrow and adipose tissue for the treatment of ischemic stroke. This study conducted a systematic review in the electronic databases PubMed, Scopus, Web of Science, Embase, ScienceDirect, and Google Scholar to assess the efficacy and safety of MSCs generated from bone marrow and adipose tissue for the treatment of ischemic stroke. It was extracted without a time limit until April 2023. The studies were then transferred to the information management program (EndNote) and duplicates were eliminated. The remaining studies were then examined using the entry and exit criteria and the 3 stages of primary, secondary, and qualitative evaluation, and finally, the results of the final studies were extracted. According to the initial search in the desired databases, 1028 possible related articles were identified and transferred to the information management software (EndNote). After removing 390 duplicate studies, 608 studies were excluded based on inclusion and exclusion criteria. Finally, 37 final studies were included in the systematic review process. Based on the investigations, it was evident that the administration of MSCs derived from both bone marrow and adipose tissue holds significant promise as an effective and safe treatment approach for ischemic stroke. The results consistently showed acceptable outcomes in the studies and this evidence can be recommended for the clinical application of this treatment. Also, the findings of this study report that the use of adipose tissue and bone marrow MSCs in the treatment of ischemic stroke can be used as a practical method.

Repair of Limb Ischemia Is Dependent on Hematopoietic Stem Cell Specific-SHP-1 Regulation of TGF-β1

BACKGROUND

Hematopoietic stem cell (HSC) therapy has shown promise for tissue regeneration after ischemia. Therefore, there is a need to understand mechanisms underlying endogenous HSCs activation in response to ischemic stress and coordination of angiogenesis and repair. SHP-1 plays important roles in HSC quiescence and differentiation by regulation of TGF-β1 signaling. TGF-β1 promotes angiogenesis by stimulating stem cells to secrete growth factors to initiate the formation of blood vessels and later aid in their maturation. We propose that SHP-1 responds to ischemia stress in HSC and progenitor cells (HSPC) via regulation of TGF-β1.

METHODS

A mouse hind limb ischemia model was used. Local blood perfusion in the limbs was determined using laser doppler perfusion imaging. The number of positive blood vessels per square millimeter, as well as blood vessel diameter (μm) and area (μm²), were calculated. Hematopoietic cells were analyzed using flow cytometry. The bone marrow transplantation assay was performed to measure HSC reconstitution.

RESULTS

After femoral artery ligation, TGF-β1 was initially decreased in the bone marrow by day 3 of ischemia, followed by an increase on day 7. This pattern was opposite to that in the peripheral blood, which is concordant with the response of HSC to ischemic stress. In contrast, SHP-1 deficiency in HSC is associated with irreversible activation of HSPCs in the bone marrow and increased circulating HSPCs in peripheral blood following limb ischemia. In addition, there was augmented auto-induction of TGF-β1 and sustained inactivation of SHP-1-Smad2 signaling, which impacted TGF-β1 expression in HSPCs in circulation. Importantly, restoration of normal T GF-β1 oscillations helped in the recovery of limb repair and function.

CONCLUSIONS

HSPC-SHP-1-mediated regulation of TGF-β1 in both bone marrow and peripheral blood is required for a normal response to ischemic stress.

Initiation of Post-Primary Tuberculosis of the Lungs: Exploring the Secret Role of Bone Marrow Derived Stem Cells

Mycobacterium tuberculosis (Mtb), the causative organism of pulmonary tuberculosis (PTB) now infects more than half of the world population. The efficient transmission strategy of the pathogen includes first remaining dormant inside the infected host, next undergoing reactivation to cause post-primary tuberculosis of the lungs (PPTBL) and then transmit via aerosol to the community. In this review, we are exploring recent findings on the role of bone marrow (BM) stem cell niche in Mtb dormancy and reactivation that may underlie the mechanisms of PPTBL development. We suggest that pathogen's interaction with the stem cell niche may be relevant in potential inflammation induced PPTBL reactivation, which need significant research attention for the future development of novel preventive and therapeutic strategies for PPTBL, especially in a post COVID-19 pandemic world. Finally, we put forward potential animal models to study the stem cell basis of Mtb dormancy and reactivation.

Arterial Stiffness and Indices of Left Ventricular Diastolic Dysfunction in Patients with Embolic Stroke of Undetermined Etiology

Purpose

The study is aimed at identifying echocardiographic and circulating biomarkers as well as hemodynamic indices of embolic stroke of undetermined etiology (ESUS) in patients aged <65.

Methods

We prospectively investigated 520 patients with confirmed ischemic stroke and selected those 65 patients who were diagnosed with ESUS (age 54 (47-58) years, 42% male). An additional 36 without stroke but with a similar risk profile were included as a control group (age 53 (47-58) years, 61% male). All patients underwent echocardiography, noninvasive assessment of hemodynamic parameters using a SphygmoCor tonometer (AtCor Med., Australia), and measurements of selected biomarkers.

Results

ESUS patients and controls were well matched for baseline characteristics including blood pressure and left ventricular ejection fraction (LVEF). Compared to controls, patients with ESUS had lower mean early diastolic (E') and systolic (S') mitral annular velocities and a higher ratio of the peak velocity of early diastolic transmitral flow to the peak velocity of early diastolic mitral annular motion (all p < 0.01). The peak velocity flow in the late diastole (A wave) value and LV mass indexed to the body surface area (LVMI) (g/m²) were higher in the ESUS group than in the control group (both p < 0.01). The isovolumetric relaxation time (IVRT) was longer and the mean left atrial volume index (LAVI) was higher in ESUS patients compared to the control group. Parameters of arterial stiffness such as augmentation pressure, augmentation index, and augmentation index adjusted to a heart rate of 75 bpm (AIx75) were higher in ESUS patients compared to controls (p < 0.05). Patients in the ESUS group had higher levels of asymmetric dimethylarginine, interleukin 6, and N-terminal probrain natriuretic peptide (NT-proBNP, all p < 0.05) than those in the control group. In multivariate analysis, the following factors were significantly associated with the presence of ESUS: AIx75 (odds ratio (OR) 1.095, 95% confidence interval (CI) 1.004-1.194; p = 0.04), IVRT (OR 1.045, 95% CI: 1.009-1.082; p = 0.014), LAVI (OR 1.3, 95% CI: 1.099-1.537; p = 0.002), and NT-proBNP (OR 1.003, 95% CI: 1.001-1.005; p = 0.005).

Conclusions

Increased arterial stiffness and indices of diastolic dysfunction as well as a higher NT-proBNP level are significantly associated with ESUS. These parameters require further scrutiny over time to understand their impact on the development of symptomatic heart failure. The ClinicalTrials.gov identifier is NCT03377465.

CXCR7+ and CXCR4+ stem cells and neuron specific enolase in acute ischemic stroke patients

Stroke causes an efflux of various groups of progenitor/stem cells from bone marrow to bloodstream and a rise in neuron specific enolase (NSE) serum concentrations. The aim of this study was to identify activity of chosen stem/progenitor cells during first 7 days after stroke through correlations between these cells levels and NSE values. Additional goal was to confirm the role of NSE as a prognostic marker of ischemic stroke. Venous blood was collected repeatedly from 67 acute ischemic stroke patients and 15 control subjects, in order to assess NSE with ELISA, and CD45^-CD34 ⁺ CD271+, CD45^-CD34 + CXCR4+, CD45^-CD34 + CXCR7+ and CD45^-CD34 ⁺ CD133 + stem/progenitor cells by means of flow cytometry. Patients underwent repeated assessment with the National Ischemic Stroke Scale and modified Rankin Scale. Ischemic lesion volumes were assessed twice by MRI-DWI (day 1 and 5 ± 2). NSE correlated negatively with MFI levels of the CD45^-CD34 + CXCR7+ cells, and percentage levels of the CD45^-CD34 ⁺ and CD45^-CD34 + CXCR4+ cells. NSE concentrations were significantly higher in patients compared to control subjects. NSE on day 2 positively correlated with lesion volume on both MRI. NSE on day 2 and 6-7 correlated positively with initial NIHSS scores, and on day 1 with mRS score on day 9. In conclusion, in this study NSE indicated some activity of the CD45^-CD34 + CXCR7+, CD45^-CD34 ⁺ and CD45^-CD34 + CXCR4+ stem/progenitor cells in the first 7 days after ischemic stroke. Additionally, this study supports the thesis that NSE might be a valuable prognostic marker in acute ischemic stroke.