Spatio-temporal dynamics of microglia phenotype in human and murine cSVD: impact of acute and chronic hypertensive states

Vascular risk factors such as chronic hypertension are well-established major modifiable factors for the development of cerebral small vessel disease (cSVD). In the present study, our focus was the investigation of cSVD-related phenotypic changes in microglia in human disease and in the spontaneously hypertensive stroke-prone rat (SHRSP) model of cSVD. Our examination of cortical microglia in human post-mortem cSVD cortical tissue revealed distinct morphological microglial features specific to cSVD. We identified enlarged somata, an increase in the territory occupied by thickened microglial processes, and an expansion in the number of vascular-associated microglia. In parallel, we characterized microglia in a rodent model of hypertensive cSVD along different durations of arterial hypertension, i.e., early chronic and late chronic hypertension. Microglial somata were already enlarged in early hypertension. In contrast, at late-stage chronic hypertension, they further exhibited elongated branches, thickened processes, and a reduced ramification index, mirroring the findings in human cSVD. An unbiased multidimensional flow cytometric analysis revealed phenotypic heterogeneity among microglia cells within the hippocampus and cortex. At early-stage hypertension, hippocampal microglia exhibited upregulated CD11b/c, P2Y12R, CD200R, and CD86 surface expression. Detailed analysis of cell subpopulations revealed a unique microglial subset expressing CD11b/c, CD163, and CD86 exclusively in early hypertension. Notably, even at early-stage hypertension, microglia displayed a higher association with cerebral blood vessels. We identified several profound clusters of microglia expressing distinct marker profiles at late chronic hypertensive states. In summary, our findings demonstrate a higher vulnerability of the hippocampus, stage-specific microglial signatures based on morphological features, and cell surface protein expression in response to chronic arterial hypertension. These results indicate the diversity within microglia sub-populations and implicate the subtle involvement of microglia in cSVD pathogenesis.

Linking Sepsis with chronic arterial hypertension, diabetes mellitus, and socioeconomic factors in the United States: A scoping review

RATIONALE

Sepsis is a syndrome of life-threatening organ dysfunction caused by a dysregulated host immune response to infection. Social risk factors including location and poverty are associated with sepsis-related disparities. Understanding the social and biological phenotypes linked with the incidence of sepsis is warranted to identify the most at-risk populations. We aim to examine how factors in disadvantage influence health disparities related to sepsis.

METHODS

A scoping review was performed for English-language articles published in the United States from 1990 to 2022 on PubMed, Web of Science, and Scopus. Of the 2064 articles found, 139 met eligibility criteria and were included for review.

RESULTS

There is consistency across the literature of disproportionately higher rates of sepsis incidence, mortality, readmissions, and associated complications, in neighborhoods with socioeconomic disadvantage and significant poverty. Chronic arterial hypertension and diabetes mellitus also occur more frequently in the same geographic distribution as sepsis, suggesting a potential shared pathophysiology.

CONCLUSIONS

The distribution of chronic arterial hypertension, diabetes mellitus, social risk factors associated with socioeconomic disadvantage, and sepsis incidence, are clustered in specific geographical areas and linked by endothelial dysfunction. Such population factors can be utilized to create equitable interventions aimed at mitigating sepsis incidence and sepsis-related disparities.

[How to manage a patient with chronic arterial hypertension during pregnancy and the postpartum period]

The management of chronic arterial hypertension during pregnancy and postpartum requires first to estimate the risk of the pregnancy, linked with the severity of hypertension, with cardiac and renal involvement, with its cause as well as with the background (obesity, diabetes, possible history of placental vascular pathology). On a very practical approach, antihypertensive drug has to be started or increased if systolic pressure reaches or exceeds 160 mmHg or if diastolic pressure reaches or exceeds 105 mmHg. Below this level, there are no evidence-based medicine data, but it seems reasonable to treat if pressure increases over 150/100 mmHg (140/90 mmHg in case of ambulatory monitoring). Excessive pressure figures control must be avoided as much as insufficient ones: in practice, it is necessary to decrease the treatment dose if figures are below 130/80 mmHg. Three antihypertensive drugs are consensually recommended today: alphametyldopa, calcium-channel blockers and labetalol. Monotherapy is most often sufficient; if needed, two of these drugs can easily be associated, and even three if necessary. Converting enzyme inhibitors and angiotensin receptor II antagonists should not be prescribed to pregnant women. Betablockers and diuretics are not recommended. Whatever is the antihypertensive drug used, it is necessary to detect the signs of bad placenta blood circulation with uterine Doppler ultrasound and regular controls of fetal growth, and to check for appearance of proteinuria, defining then over-imposed pre-eclampsia needing immediate admission to the maternity. After delivery, lacatation suppresion with bromocriptin should not be prescribed.