The impact of uric acid on acute coronary syndrome prognosis in elderly patients

BACKGROUND

Uric acid (UA) plays an important role in cardiovascular diseases, yet its implications in elderly patients remains incompletely understood. This study aimed to explore the impact of UA on the prognosis in advanced-age patients with acute coronary syndrome (ACS).

METHODS

We included 526 patients aged 80 and older who were diagnosed with ACS. The UA levels were measured at admission, and patients were divided into four groups based on quartiles of UA levels. Major adverse cardiovascular events (MACE) during follow-up were recorded.

RESULTS

The median UA level was 344.09 μmol/L, while the median follow-up duration was 64 months. Kaplan-Meier curves demonstrated a higher cumulative incidence of MACE during long-term follow-up in the Q4 group (Log-rank p < 0.05). Cox regression analysis revealed an independent correlation between UA levels and an increased risk of MACE (HR 1.002, 95%CI 1.000-1.003, p = 0.021). The ROC curve indicated that the optimal UA value for predicting MACE was 324.25 μmol/L. After matching through PSM, the MACE-free survival rate was lower in both hyperuricemia group (UA> 420.00 μmol/L) and high UA group (324.25 μmol/L < UA≤ 420.00 μmol/L) compared to the control group. Both hyperuricemia and high UA levels were independent risk factors for long-term MACE in advanced-age ACS patients, with HR values of 1.546 (1.049-2.280, p = 0.028) and 1.491 (1.011-2.198, p = 0.044), respectively.

CONCLUSION

Elevated UA levels were identified as independent risk factors for MACE in elderly patients with ACS. The optimal predictive value of UA for poor cardiovascular prognosis was significantly lower than the traditional definition of hyperuricemia.

Protective Effects of Interleukin-1 Inhibition With Anakinra in Mouse Models of Ischemic Stroke With and Without Reperfusion

BACKGROUND

Severe brain ischemia is associated with life-threatening edema and inflammation. Interleukin-1 is a crucial mediator of inflammation, and its blockade showed benefits in experimental stroke. We studied anakinra, a modified recombinant human interleukin-1 receptor antagonist, in mouse models of moderate to severe ischemia/reperfusion and large hemispheric infarctions. Due to anakinra's short half-life, we used a novel subcutaneous infusion protocol and tested 2 drug doses.

METHODS AND RESULTS

We performed transient or permanent intraluminal middle cerebral artery occlusion (MCAo) in male C57BL/6J and Balb/c mice, the latter of which have poorer collaterals. Mice received a subcutaneous anakinra bolus (24 mg/kg), followed by continuous infusion of either 24 or 120 mg/kg per day, starting at reperfusion or 15 minutes after permanent MCAo. We evaluated acute (24 hours/48 hours) infarct volume and edema by magnetic resonance imaging, neurological function, and inflammatory responses. The mortality rate tended to be higher in Balb/c compared with C57BL/6J mice. In both strains, prolonged ischemia expanded the infarct size, with intraluminal permanent MCAo resulting in larger hemispheric infarctions and edema than transient MCAo. The high dose of anakinra reduced infarct volume and inflammation in C57BL/6 mice and improved the functional deficits in Balb/c mice following transient MCAo. It also showed a trend toward reducing infarction and edema after permanent MCAo in C57BL/6 mice.

CONCLUSIONS

The study demonstrates that a high dose of anakinra improves outcomes in mouse models of moderate infarction following ischemia/reperfusion, whereas its effect was less pronounced in a malignant hemispheric infarction model without reperfusion, where only a nonsignificant trend toward protection was observed.

Analysis of canine gene constraint identifies new variants for orofacial clefts and stature

Dog breeding promotes within-group homogeneity through conformation to strict breed standards, while simultaneously driving between-group heterogeneity. There are over 350 recognized dog breeds that provide the foundation for investigating the genetic basis of phenotypic diversity. Typically, breed standard phenotypes such as stature, pelage, and craniofacial structure are analyzed through genetic association studies. However, such analyses are limited to assayed phenotypes only, leaving difficult-to-measure phenotypic subtleties easily overlooked. We investigated coding variation from over 2000 dogs, leading to discoveries of variants related to craniofacial morphology and stature. Breed-enriched variants were prioritized according to gene constraint, which was calculated using a mutation model derived from trinucleotide substitution probabilities. Among the newly found variants is a splice-acceptor variant in PDGFRA associated with bifid nose, a characteristic trait of Çatalburun dogs, implicating the gene's role in midline closure. Two additional LCORL variants, both associated with canine body size are also discovered: a frameshift that causes a premature stop in large breeds (>25 kg) and an intronic substitution found in small breeds (<10 kg), thus highlighting the importance of allelic heterogeneity in selection for breed traits. Most variants prioritized in this analysis are not associated with genomic signatures for breed differentiation, as these regions are enriched for constrained genes intolerant to nonsynonymous variation. This indicates trait selection in dogs is likely a balancing act between preserving essential gene functions and maximizing regulatory variation to drive phenotypic extremes.

Insights from autopsy-initiated pathological studies of the pathogenesis and clinical manifestations of atherosclerosis and ischemic heart disease: Part II. Ischemic heart disease

CONTEXT

Ischemic heart disease (IHD) due to coronary atherosclerosis constitutes the leading cause of morbidity and mortality worldwide. This review was undertaken to retrospectively analyze the lines of research that generated the evidence for our contemporary understanding of atherosclerosis-based coronary artery disease and to provide a rationale for continued support for autopsy-based research in order to make further progress in reduction of the morbidity and mortaility from IHD.

OBJECTIVES

To analyze the contributions of the autopsy to complement and validate other lines of investigation in determining the complex interactions between coronary artery alterations linked to the major manifestations of coronary atherosclerosis, namely, coronary thrombosis, acute myocardial infarction, and sudden cardiac death.

DATA SOURCES

Systematic search on PubMed to gather relevant studies concerning autopsy studies and reviews of the pathology and pathogenesis of atherosclerosis, ischemic heart disease, coronary atherosclerosis, coronary thrombosis, myocardial infarction and sudden cardiac death.

CONCLUSIONS

An extensive search of the published literature has confirmed the continuing importance of the autopsy as a powerful tool to understand the pathogenesis, clinical features, and therapeutic options for the treatment of atherosclerosis and its major manifestation, ischemic heart disease. This has been described in the Part I companion of the present review. Autopsy-initiated studies have documented the prevalence and clinicopathological significance of atherosclerosis in different human populations and its relationship to risk factors. It has been shown that the clinically silent phase of ischemic heart disease (IHD) begins in the first decades of life. Pathological studies have clarified the complex relationship between coronary atherosclerosis, coronary thrombosis, and myocardial ischemic events. These studies also have elucidated the pathological basis of sudden cardiac death. Insights from these studies also have been important in developing and evaluating strategies for continued progress in reducing the morbidity and mortality attributed to atherosclerosis and IHD.

Neurons as Immunomodulators: From Rapid Neural Activity to Prolonged Regulation of Cytokines and Microglia

Regulation of the brain's neuroimmune system is central to development, normal function, and disease. Neuronal communication to microglia, the primary immune cells of the brain, is well known to involve purinergic signaling mediated via ATP secretion and the cytokine fractalkine. Recent evidence shows that neurons release multiple cytokines beyond fractalkine, yet these are less studied and poorly understood. In contrast to ATP, cytokines are a class of signaling molecule that are much larger, with longer signaling and farther diffusion. We posit that neuron-expressed cytokines are an essential mechanism of neuron-microglia communication that arises as part of both normal learning and memory and in response to tissue pathology. Thus, neurons are underappreciated immunomodulatory cells that express diverse immunomodulatory signals. While neuronally sourced cytokines have been understudied, new technical advances make this a timely topic. The goal of this review is to define what is known about the cytokines expressed from neurons, how they are regulated, and the effects of these cytokines on microglia. We delineate key knowledge gaps and needs for new tools to define and analyze neuronal roles in immunomodulation. Given that cytokines are central regulators of microglial function, a broad new body of work is required to illuminate functional links between these neuronally expressed cytokines and sustained and transient microglial function.

Identification of TNFAIP2 as a unique cellular regulator of CSF-1 receptor activation

The receptor of CSF-1 (CSF1R) encoding tyrosine kinase is essential for tissue macrophage development, and the therapeutic target for many tumors. However, it is not completely understood how CSF1R activation is regulated. Here, we identify the cellular protein TNF-α-induced protein 2 (TNFAIP2) as a unique regulator of CSF1R. CSF1R forms large aggregates in macrophages via unknown mechanisms. The inhibition or knockdown of TNFAIP2 reduced CSF1R aggregate formation and functional response of macrophages to CSF-1, which was consistent with reduced CSF1R activation after CSF-1 stimulation. When expressed in 293 cells, TNFAIP2 augmented CSF1R aggregate formation and CSF-1-induced CSF1R activation. CSF1R and TNFAIP2 bind the cellular phosphatidylinositol 4,5-bisphosphate (PIP2). The removal of the PIP2-binding motif of CSF1R or TNFAIP2, or the depletion of cellular PIP2 reduced CSF1R aggregate formation. Moreover, TNFAIP2 altered the cellular distribution of PIP2. Because CSF-1-induced dimerization of CSF1R is critical for its activation, our findings suggest that TNFAIP2 augments CSF1R aggregate formation via PIP2, which brings CSF1R monomers close to each other and enables the efficient dimerization and activation of CSF1R in response to CSF-1.

Gamma-glutamyl transferase to high-density lipoprotein cholesterol ratio: A valuable predictor of coronary heart disease incidence

BACKGROUND AND AIM

Existing studies have found that serological markers for predicting coronary heart disease (CHD) have relatively low predictive value for the severity of coronary arteries and the types of CHD. GGT to HDL-C ratio (GHR) has been shown to be associated with T2DM and non-alcoholic fatty liver disease. Therefore, we explore the relationship among GHR, CHD and its subgroups.

METHODS AND RESULTS

The study retrospectively analyzed 2703 participants from August 2022 to August 2023. The patients were divided into CHD group (N = 1911) and control group (N = 792) according to the diagnostic criteria of CHD. Adjustments for all covariates found that GHR was an independent risk factor for CHD (OR: 1.025, 95 % CI 1.016-1.033) and had the highest AUC of 0.767 (95 % CI 0.744-0.790) in identifying CHD. Additionally, GHR was significantly associated with multi-vessel CHD (OR: 1.018, 95 % CI 1.012-1.023) and showed excellent diagnostic capability for patients with multi-vessel CHD (AUC: 0.638). Moreover, compared with chronic coronary syndromes (CCS) and unstable angina (UA) groups, the level of GHR was significantly increased in acute myocardial infarction (AMI) (ST elevation myocardial infarction and Non-ST elevation myocardial infarction) group (P < 0.05). GHR had the higher AUC in STMETI [0.819 (95 % CI 0.796-0.854)] and NASTEMI [0.792 (95 % CI 0.766-0.816)] than the CCS and UA groups.

CONCLUSIONS

Our study analyses found that GHR is an independent risk factor for CHD and can predict the severity of coronary artery stenosis. Moreover, GHR has a high predictive value for AMI than CCS and UA in CHD patients.

miR-484 in Hippocampal Astrocytes of Aged and Young Rats Targets CSF-1 to Regulate Neural Progenitor/Stem Cell Proliferation and Differentiation Into Neurons

AIM

Aging-related cognitive decline is closely linked to the reduced function of neural progenitor/stem cells (NPSCs), which can be influenced by the neural microenvironment, particularly astrocytes. The aim of this study was to explore how astrocytes affect NPSCs and cognitive function during aging.

METHODS

H2O2-treated astrocytes were used to mimic the aging phenotype of astrocytes. Proteomic analysis identified altered protein expression, revealing high levels of colony-stimulating factor-1 (CSF-1) in the supernatant of H2O2-treated astrocytes. Primary NPSCs were isolated and cultured in vitro, then stimulated with varying concentrations of recombinant CSF-1 protein to assess its effects on NPSC proliferation, differentiation, and apoptosis. Transcriptome sequencing identified miR-484 related to CSF-1 in H2O2-treated astrocytes, and a dual-luciferase assay verified the interaction between miR-484 and CSF-1. The impact of miR-484 overexpression on NPSC function and cognitive restoration was evaluated both in vitro and in vivo (in 20-month-old rats).

RESULTS

High concentration of CSF-1 inhibited the NPSC proliferation and differentiation into neurons while inducing apoptosis. Overexpression of miR-484 downregulated CSF-1 expression by binding to its 3' untranslated region, thereby promoting the NPSC proliferation and differentiation into neurons. In 20-month-old rats, miR-484 overexpression improved spatial learning and memory in the Morris water maze, increased NPSC proliferation, and reduced apoptosis.

CONCLUSION

Our findings reveal that miR-484 regulates CSF-1 to influence NPSC proliferation, differentiation into neurons, and apoptosis, consequently improving cognitive function in 20-month-old rats. This study provides a foundation for developing therapeutic strategies targeting age-related hippocampal cognitive impairments.

Regulation of nc886 (vtRNA2-1) RNAs is associated with cardiometabolic risk factors and diseases

Non-coding 886 (nc886, vtRNA2-1) is a polymorphically imprinted gene. The methylation status of this locus has been shown to be associated with periconceptional conditions, and both the methylation status and the levels of nc886 RNAs have been shown to associate with later-life health traits. We have previously shown that nc886 RNA levels are associated not only with the methylation status of the locus, but also with a genetic polymorphism upstream from the locus. In this study, we describe the genetic and epigenetic regulators that predict lifelong nc886 RNA levels, as well as their association with cardiometabolic disease (CMD) risk factors and events. We utilised six population cohorts and one CMD cohort comprising 9058 individuals in total. The association of nc886 RNA levels, as predicted by epigenetic and genetic regulators, with CMD phenotypes was analysed using regression models, with a meta-analysis of the results. The meta-analysis showed that individuals with upregulated nc886 RNA levels have higher diastolic blood pressure (β = 0.07, p = 0.008), lower HDL levels (β =  - 0.07, p = 0.006) and an increased incidence of type 2 diabetes (OR = 1.260, p = 0.013). Moreover, CMD patients with upregulated nc886 RNA levels have an increased incidence of stroke (OR = 1.581, p = 0.006) and death (OR = 1.290, p = 0.046). In conclusion, we show that individuals who are predicted to present elevated nc886 RNA levels have poorer cardiovascular health and are at an elevated risk of complications in secondary prevention. This unique mechanism yields metabolic variation in human populations, constituting a CMD risk factor that cannot be modified through lifestyle choices.

Microglial and TREM2 dialogues in the developing brain

From the migration of precursor cells to the refinement of neural circuits, the immune system plays a critical role in the development of the central nervous system. As the brain resident macrophages, microglia are integral to these processes, influencing key developmental stages and contributing to circuit remodeling. Recent years have brought a wealth of new insights into how microglia regulate key stages of brain development, particularly through their continuous crosstalk with various brain cell types. In this review, we synthesize this growing body of literature on microglia and neurodevelopment, highlighting the involvement of the TREM2 receptor, known for its role in aging and neurodegeneration, which profoundly affects the state of microglia and guides target cells by shaping their transcriptional and functional fate. We examine microglial communication with four major cell types-neural precursors, neurons, astrocytes, and oligodendrocytes-also delving into the described mechanisms that underpin these interactions.

Calciprotein particle-activated endothelial cells aggravate smooth muscle cell calcification via paracrine signalling

BACKGROUND

Vascular calcification is highly prevalent in Chronic Kidney Disease (CKD) and is associated with markedly increased cardiovascular risk. High serum phosphate in CKD increases calcification propensity via generation of circulating calciprotein particles (CPP2), crystalline nanoaggregates composed of calcium, phosphate, and serum proteins. CPP2 induce vascular calcification in vascular smooth muscle cells (VSMCs) in vitro. In vivo, endothelial cells, rather than VSMCs are primarily exposed to CPP2, yet understanding the influence of endothelial cells on vascular calcification is limited.

METHODS

We investigated calcification-promoting signalling by endothelial cells on VSMCs. Effects of CPP2 exposure to endothelial cells on CPP2 uptake, endothelial cell activation, and endothelial cell-derived secretome were studied. Effects of the secretome on VSMC calcification were investigated. Using NanoString nCounter analysis the effects of CPP2-activated endothelial cell-conditioned medium on VSMCs gene expression were mapped.

RESULTS

Endothelial cells internalise CPP2 and elevate ICAM-1, E-selectin, and VCAM-1-mRNA expression, indicating endothelial activation. VSMCs cultured in conditioned medium from CPP2-activated endothelial cells demonstrated enhanced calcification, suggesting that CPP2-activated endothelial cells release pro-calcifying soluble factors. Mass spectrometry was utilized to identify 1171 proteins in the CPP2-activated endothelial cells' secretome. Among these, 76 proteins were differentially expressed compared to control endothelial cells' secretome, including proteins related to blood vessel development, extracellular matrix remodelling, and oxidative stress-related processes. Finally, endothelial cell-derived paracrine factors present in conditioned medium enhanced mRNA-expression of calcification-related factors in VSMCs.

CONCLUSIONS

CPP2-activated endothelial cells promote VSMC calcification via paracrine signalling. In response to these paracrine factors, VSMCs increase the expression of pro-calcification genes.

Interleukin-34-dependent perivascular macrophages promote vascular function in the brain

The development of most macrophages depends on the colony-stimulating factor 1 (CSF-1) receptor, which has two ligands: CSF-1 and interleukin-34 (IL-34). While IL-34 is required for the homeostasis of microglia, the parenchymal macrophages in the central nervous system (CNS), it is unclear whether brain border-associated macrophages (BAMs) also depend on this cytokine. Here, we demonstrated that the embryonic development of murine BAMs in the choroid plexus, leptomeninges, and perivascular spaces required CSF-1, while IL-34 was critical for their maintenance in adulthood. In the brain, Il34 was expressed by mural cells and perivascular fibroblasts, and its transgenic deletion in these cells interrupted BAM maintenance. Il34 deficiency coincided with transcriptional changes in vascular cells, leading to increased flow velocity and vasomotion in pial and penetrating arterioles. Similarly, Mrc1CreCsf1rfl/fl mice lacking CD206+ perivascular BAMs exhibited increased hemodynamics in arterial networks. These findings reveal a crosstalk between vascular cells and CNS macrophages regulating cerebrovascular function.

A multi-trait genome-wide association study of coronary artery disease and subclinical atherosclerosis traits

Measures of subclinical atherosclerosis, such as coronary artery calcification (CAC) and carotid intima-media thickness (CIMT), reflect the underlying pathophysiology of coronary artery disease (CAD) and are genetically correlated with CAD and related risk factors. Leveraging summary statistics from genome-wide association studies of CAD, CIMT, CAC, type 2 diabetes, low-density lipoprotein cholesterol, and systolic blood pressure, we performed 15 separate multi-trait GWAS to identify shared susceptibility loci and elucidate the pleiotropic architecture underlying atherosclerosis. We identified 442 shared risk loci across all analyses that met an experiment-wide Bonferroni threshold of 3.3 × 10-9, uncovering 195 novel atherosclerosis loci. Multi-trait colocalization confirmed a shared causal signal in 25 shared novel loci for atherosclerosis. Trait-eQTL colocalization identified evidence of a shared causal signal in arterial, subcutaneous adipose, and cardiac tissues, implicating genes such as PRRX2, BNC2, CLIC4, SCAI, and PPP6C, and pathways related to vascular remodeling, inflammation, and metabolic regulation.

Tandem inactivation of inositol pyrophosphatases Asp1, Siw14, and Aps1 illuminates functional redundancies in inositol pyrophosphate catabolism in fission yeast

Inositol pyrophosphates 5-IP7, 1-IP7, and 1,5-IP8 are eukaryal signaling molecules that influence cell physiology, especially phosphate homeostasis. In fission yeast, 1,5-IP8 and 1-IP7 impact gene expression by acting as agonists of RNA 3'-processing and transcription termination. 1,5-IP8 is synthesized by position-specific kinases Kcs1 and Asp1 that convert IP6 to 5-IP7 and 5-IP7 to 1,5-IP8, respectively. Inositol pyrophosphatase enzymes Asp1 (a histidine acid phosphatase), Siw14 (a cysteinyl phosphatase), and Aps1 (a Nudix hydrolase) are agents of inositol pyrophosphate catabolism in fission yeast. Whereas Asp1, Siw14, and Aps1 are individually inessential, double pyrophosphatase mutants asp1-H397A aps1∆ and siw14∆ aps1∆ display severe growth defects caused by overzealous 3'-processing/termination. By applying CE-ESI-MS to profile the inositol pyrophosphate content of fission yeast mutants in which inositol pyrophosphate toxicity is genetically suppressed, we elucidated the functional redundancies of the Asp1, Siw14, and Aps1 pyrophosphatases. Asp1, which exclusively cleaves the 1-β-phosphate, and Aps1, which prefers to cleave the 1-β-phosphate, play essential overlapping roles in guarding against the accumulation of toxic levels of 1-IP7. Aps1 and Siw14 together catabolize the inositol-5-pyrophosphates, and their simultaneous inactivation results in overaccumulation of 5-IP7. Cells lacking all three pyrophosphatases amass high levels of 1,5-IP8 and 1-IP7, with concomitant depletion of IP6. A genetic screen identified three missense mutations in the catalytic domain of Kcs1 kinase that suppressed inositol-1-pyrophosphate toxicosis. The screen also implicated the 3'-processing factor Swd22, the inositol pyrophosphate sensor Spx1, and the nuclear poly(A)-binding protein Nab2 as mediators of inositol-1-pyrophosphate toxicity.IMPORTANCEInositol pyrophosphates are key effectors of eukaryal cellular phosphate homeostasis. They are synthesized by kinases that add a β-phosphate to the 5- or 1-phosphate groups of IP6 and catabolized by three classes of pyrophosphatases that hydrolyze the β-phosphates of 5-IP7, 1-IP7, or 1,5-IP8. Whereas the fission yeast inositol pyrophosphatases-Asp1 (histidine acid phosphatase), Siw14 (cysteinyl phosphatase), and Aps1 (Nudix hydrolase)-are inessential for growth, Asp1/Aps1 and Aps1/Siw14 double mutations and Asp1/Siw14/Aps1 triple mutations elicit severe or lethal growth defects. By profiling the inositol pyrophosphate content of pyrophosphatase mutants in which this toxicity is genetically suppressed, we reveal the functional redundancies of the Asp1, Siw14, and Aps1 pyrophosphatases. Their synergies are manifested as excess accumulation of 1-IP7 upon dual inactivation of Asp1 and Aps1 or an excess of 5-IP7 in aps1∆ siw14∆ cells. In the absence of all three pyrophosphatases, cells accrue high levels of 1,5-IP8 and 1-IP7 while IP6 declines.

Targeted Dual Microdroplets for Modulating Osteoclast Differentiation and Function: A Novel Therapeutic Approach to Combat Osteoporosis

Osteoporosis, a condition marked by reduced bone mass and structural deterioration, continues to be a major public health concern, especially as global populations age. Excessive osteoclast formation is a hallmark of osteoporosis. The transcription factor nuclear factor of activated T-cells cytoplasmic 1 (NFATc1) is indispensable for the early differentiation of osteoclasts, orchestrating the expression of essential genes, while at the later stages, cathepsin K (CTSK) is essential for bone resorption activities of mature osteoclasts. Here, we fabricated ultrasound-responsive microdroplets (MDs) by modulating both the early stages of osteoclast differentiation and the functions of mature osteoclasts via targeting the NFATc1 and CTSK. The internalization of these dual MDs was evaluated in human bone marrow-derived mesenchymal stromal cells (hBMSCs) and murine RAW 264.7 macrophages, alongside the biocompatibility assay. Their effects on osteogenesis and osteoclastogenesis were further investigated in vitro, followed by in vivo analysis in osteoporotic rat models. The dual MDs exhibited a well-defined core-shell structure and demonstrated efficient cellular uptake with minimal cytotoxicity. Furthermore, dual MDs showed a minimal effect on the osteogenic differentiation of the hBMSCs. In in vitro osteoclastogenesis assays, dual MDs effectively suppressed both osteoclast differentiation and formation through a synergistic inhibitory effect. In vivo studies demonstrated that osteoporotic rats receiving dual MDs showed significant protection against bone loss induced by ovariectomy. These results highlight the potential of dual MDs as a sophisticated, targeted therapeutic approach to osteoporosis treatment.

Fission yeast metabolome dynamics during phosphate starvation and replenishment

Inorganic phosphate is an essential nutrient acquired by cells from their environment and assimilated into myriad intracellular metabolites and macromolecules. Here, we characterize the metabolic responses of fission yeast to a 24 h interval of phosphate starvation, during which cells enter a state of G0 quiescence. Time-resolved profiling revealed that many key phosphometabolites were progressively depleted, including (i) NTPs, NDPs, and dNTPs; (ii) coenzyme A, NAD+, NADP+, NADH, and ADP-ribose; (iii) glycolysis pathway intermediates upstream of pyruvate; (iv) pentose phosphate pathway intermediates from 6-phosphogluconate to sedoheptulose-7-phosphate; (v) nucleotide sugars GDP-hexose, UDP-glucose/galactose, and UDP-GalNAc/GlcNAc; and (vi) phospholipid precursors glycerol-3-phosphate, CDP-choline, and glycerophosphocholine. By contrast, early Krebs cycle intermediates accumulated during phosphate starvation. Other metabolic changes included the following: (i) interdiction of de novo pyrimidine synthesis; (ii) depletion of S-adenosylmethionine and S-adenosylhomocysteine; (iii) transient accumulation of polyamine biosynthetic intermediates putrescine and 5-methylthioadenosine; (iv) accumulation of betaine (correlating with an increase in expression of atd1 mRNA encoding aldehyde dehydrogenase); and (v) depletion of aminoadipate pathway intermediates 2-oxoadipate, 2-aminoadipate, and saccharopine. Replenishing phosphate after 24 h of starvation resulted in restoration of the pre-starvation metabolome (over 2 to 12 h) as cells exited quiescence and resumed growth.

IMPORTANCE

Fission yeast Schizosaccharomyces pombe is a valuable model system to study cellular phosphate homeostasis and the adaptive responses to chronic phosphate starvation. Previous analyses focused on changes in the fission yeast transcriptome and proteome during phosphate starvation-induced durable G0 quiescence. Here, we deployed metabolomics to survey the scope and temporal order of metabolite changes during 24 h of phosphate starvation and the kinetics of metabolic recovery after cells starved for 24 h are replenished with phosphate. These results contribute to a multi-omics understanding of how phosphate status impacts cell cycle, gene expression, metabolism, and chronological lifespan.

Physiological roles of embryonic microglia and their perturbation by maternal inflammation

The interplay between the nervous and immune systems is well documented in the context of adult physiology and disease. Recent advances in understanding immune cell development have highlighted a significant interaction between neural lineage cells and microglia, the resident brain macrophages, during developmental stages. Throughout development, particularly from the embryonic to postnatal stages, diverse neural lineage cells are sequentially generated, undergo fate determination, migrate dynamically to their appropriate locations while maturing, and establish connections with their surroundings to form neural circuits. Previous studies have demonstrated that microglia contribute to this highly orchestrated process, ensuring the proper organization of brain structure. These findings underscore the need to further investigate how microglia behave and function within a broader framework of neurodevelopment. Importantly, recent epidemiological studies have suggested that maternal immune activation (MIA), triggered by various factors, such as viral or bacterial infections, environmental stressors, or other external influences, can affect neurogenesis and neural circuit formation, increasing the risk of neurodevelopmental disorders (NDDs) in offspring. Notably, many studies have revealed that fetal microglia undergo significant changes in response to MIA. Given their essential roles in neurogenesis and vascular development, inappropriate activation or disruption of microglial function may impair these critical processes, potentially leading to abnormal neurodevelopment. This review highlights recent advances in rodent models and human studies that have shed light on the behaviors and multifaceted roles of microglia during brain development, with a particular focus on the embryonic stage. Furthermore, drawing on insights from rodent MIA models, this review explores how MIA disrupts microglial function and how such disturbances may impair brain development, ultimately contributing to the onset of NDDs.

Microglial Depletion, a New Tool in Neuroinflammatory Disorders: Comparison of Pharmacological Inhibitors of the CSF-1R

A growing body of evidence highlights the importance of microglia, the resident immune cells of the CNS, and their pro-inflammatory activation in the onset of many neurological diseases. Microglial proliferation, differentiation, and survival are highly dependent on the CSF-1 signaling pathway, which can be pharmacologically modulated by inhibiting its receptor, CSF-1R. Pharmacological inhibition of CSF-1R leads to an almost complete microglial depletion whereas treatment arrest allows for subsequent repopulation. Microglial depletion has shown promising results in many animal models of neurodegenerative diseases (Alzheimer's disease (AD), Parkinson's disease, or multiple sclerosis) where transitory microglial depletion reduced neuroinflammation and improved behavioral test results. In this review, we will focus on the comparison of three different pharmacological CSF-1R inhibitors (PLX3397, PLX5622, and GW2580) regarding microglial depletion. We will also highlight the promising results obtained by microglial depletion strategies in adult models of neurological disorders and argue they could also prove promising in neurodevelopmental diseases associated with microglial activation and neuroinflammation. Finally, we will discuss the lack of knowledge about the effects of these strategies on neurons, astrocytes, and oligodendrocytes in adults and during neurodevelopment.

Embracing diversity: macrophage complexity in cancer

Macrophages are myeloid cells that receive, integrate, and respond to tumoral cues. Tumors evolve and are shaped by macrophages, with tumor-associated macrophage (TAM)-tumor sculpting capacities going beyond an increase in their cellular mass. Longitudinal and local heterogeneity of TAM states is now possible with the use of single-cell and spatial transcriptomics. However, understanding TAM biology and its fundamental functional programs is still challenging, probably because of the lack of models that fully integrate TAM complexity. Here, we aim to review TAM diversity not only at the level of single-cell phenotypes but also by integrating complex physiological signals that determine their complexity and plasticity in tumors.

Synergistic and antagonistic activities of IRF8 and FOS enhancer pairs during an immune-cell fate switch

Cell fate instructive genes tend to be regulated by large clusters of enhancers. Whether and how individual enhancers within such clusters cooperate in regulating gene expression is poorly understood. We have previously developed a computational method, SEGCOND, which identifies hubs that we termed Putative Transcriptional Condensates (PTCs), consisting of enhancer clusters and associated target genes. Here, we use SEGCOND to identify PTCs in a CEBPA-induced B-cell-to-macrophage transdifferentiation system. We find that PTCs are enriched for highly expressed, lineage-restricted genes and associate with BRD4, a component of transcriptional condensates. Further, we performed single and combinatorial deletions of enhancers within two PTCs active during induced transdifferentiation, harboring IRF8 and FOS. Two enhancers within the IRF8 PTC were found to provide a backup mechanism when combined, safeguarding IRF8 expression and efficient transdifferentiation. Unexpectedly, two individual enhancers within the FOS PTC antagonize each other on day 1 of transdifferentiation, delaying the conversion of B-cells into macrophages and reducing FOS expression, while on day 7, they cooperate to increase FOS levels induced cells. Our results reveal complex, differentiation-stage-specific interactions between individual enhancers within enhancer clusters.

Myeloid cells: key players in tumor microenvironments

Cancer is the result of evolving crosstalk between neoplastic cell and its immune microenvironment. In recent years, immune therapeutics targeting T lymphocytes, such as immune checkpoint blockade (ICB) and CAR-T, have made significant progress in cancer treatment and validated targeting immune cells as a promising approach to fight human cancers. However, responsiveness to the current immune therapeutic agents is limited to only a small proportion of solid cancer patients. As major components of most solid tumors, myeloid cells played critical roles in regulating the initiation and sustentation of adaptive immunity, thus determining tumor progression as well as therapeutic responses. In this review, we discuss emerging data on the diverse functions of myeloid cells in tumor progression through their direct effects or interactions with other immune cells. We explain how different metabolic reprogramming impacts the characteristics and functions of tumor myeloid cells, and discuss recent progress in revealing different mechanisms-chemotaxis, proliferation, survival, and alternative sources-involved in the infiltration and accumulation of myeloid cells within tumors. Further understanding of the function and regulation of myeloid cells is important for the development of novel strategies for therapeutic exploitation in cancer.

The combination of ultraviolet mutagenesis and PPX1 overexpression synergistically enhanced S-adenosyl-L-methionine synthesis in industrial Saccharomyces cerevisiae

S-adenosyl-L-methionine (SAM) is the only injectable drug among the hepatoprotective and choleretic drugs, which has remarkable efficacy and is favored by hepatopaths. The demand for SAM is constantly increasing in clinical settings. Therefore, many efforts have been made to increase SAM biosynthesis from L-methionine and ATP in Saccharomyces cerevisiae. This study aimed to construct a stable and high-accumulating SAM industrial strain through successive ultraviolet irradiation (UV) mutations coupled with three resistant (ethionine, nystatin, and cordycepin, respectively) screening procedures and metabolic engineering strategies. Following multiple UV mutagenesis, a higher production mutant strain ZJT15-33 was successfully obtained. In addition, the recombinant strain spe2△-PPX1 was derived from ZJT15-33 by deleting the SPE2 and overexpressing the PPX1, resulting in a 2.5-fold enhanced ATP accumulation, which promoted the synthesis of 2.41 g/L SAM in the shake-flask, representing an 11.4-fold enhancement over the original strain (0.21 g/L). Furthermore, 11.65 g/L SAM was accumulated with 113 mg/g DCW SAM content in a 5-L fermenter at 96 h, marking a 36.57 % increase compared to strain ZJT15-33 (8.53 g/L). These results indicated that UV mutagenesis combined with PPX1 overexpression could effectively improve SAM synthesis in S. cerevisiae, providing a feasible approach for developing highly SAM industrial production.

Tissue-resident macrophages and renal diseases: landscapes and treatment directions

Tissue-resident macrophage (TRM) is a specialized subset of macrophage that resides within specific tissues and organs. TRMs play crucial roles in resisting pathogen invasion, maintaining the homeostasis of the immune microenvironment, and promoting tissue repair and regeneration. The development and function of TRMs exhibit significant heterogeneity across different tissues. Kidney TRMs (KTRMs) originate from both embryonic yolk sac erythro-myeloid progenitors and the fetal liver, demonstrating the capacity for self-renewal independent of bone marrow hematopoiesis. KTRMs are not only essential for the maintenance of renal homeostasis and the monitoring of microvascular environment, but contribute to renal injury due to inflammation, fibrosis and immune dysfunction in kidneys. In this review, we summarize currently available studies on the regulatory role of KTRMs in processes of renal injury and repair. The altering effects and underlying mechanisms of KTRMs in regulating local tissue cells and immune cells in different renal diseases are reviewed, primarily including lupus nephritis, diabetic nephropathy, renal fibrosis, and renal carcinoma. Understanding the plasticity and immune regulatory functions of KTRMs may offer new insights into the pathogenesis and the exploration of therapeutic strategies of kidney diseases.

Macrophage KDM2A promotes atherosclerosis via regulating FYN and inducing inflammatory response

Macrophage inflammatory response is the key driver in atherosclerosis development. However, transcriptional remodeling of macrophage inflammatory response remains largely unknown. In this study, transcriptional regulatory networks were constructed from human plaque microarray datasets. Differential analysis and subsequent machine learning algorithms were used to identify key transcriptional regulons. Multiple immune cell inference methods (including CIBERSORT, ssGSEA, MCP-counter, and xCell), single-cell RNA-seq of human plaques and immunofluorescence of human and mouse plaque samples reveal that the macrophage-specific transcriptional regulator, KDM2A, is critical for inflammatory response. Diagnostic analyses validate KDM2A expression in peripheral monocytes/macrophages is an excellent predictor of atherosclerosis development and progression. RNA-seq of mouse bone marrow-derived macrophages under oxidized low-density lipoprotein stimulation reveal KDM2A knockdown significantly represses pro-inflammatory, oxidative, and lipid uptake pathways. In vitro experiments confirmed KDM2A activates inflammation, oxidative stress and lipid accumulation in macrophages. Mechanistically, FYN was identified as a direct target of KDM2A by chromatin immunoprecipitation followed by sequencing and qPCR analysis. Specific inhibition of FYN restored the inflammatory response, oxidative stress, and intracellular lipid accumulation after transfection with KDM2A overexpression plasmid. Importantly, macrophage-specific knockdown of KDM2A in ApoE-/- mice fed a high-fat diet apparently attenuated plaque progression. Furthermore, the genetic association of KDM2A with atherosclerosis was validated by Mendelian randomization and colocalization analysis. A group of small molecules with the potential to target KDM2A has been identified through virtual screening, offering promising strategies for atherosclerosis treatment. The current study provides the novel role of KDM2A in macrophage inflammatory response of atherosclerosis through transcriptional regulation of FYN.

Clinical characteristics and outcomes of acute myocardial infarction during the COVID-19 pandemic: a multicenter retrospective cohort study in Northern China

BACKGROUND

The impacts of COVID-19 on acute myocardial infarction (AMI) care were heterogeneous. The study aims to analyze the clinical characteristics and outcomes of AMI patients in China during different stages of the COVID-19 pandemic.

METHODS

This is a multicenter retrospective cohort study in Shanxi Province of northern China. Patients diagnosed with AMI during the zero-case, lockdown, and outbreak periods were included. Characteristics and outcomes were analyzed according to time periods and COVID-19 infection. The primary outcome was in-hospital mortality. Additional outcomes included reperfusion times, coronary angiographic measures, procedure or AMI-associated complications, arrhythmia, other adverse events, and left ventricular systolic dysfunction (LVSD).

RESULTS

The study included 1021 AMI patients, with 393, 250, and 378 from the zero-case, lockdown, and outbreak periods. No differences in in-hospital mortality or other adverse events were found by time periods. By infection status, 264 patients were COVID-positive, and 706 were COVID-negative. The COVID-positive ST-elevation myocardial infarction population had longer symptom-to-first medical contact (3.07 vs. 2.31, p = 0.026), pre-hospital time (4.58 vs. 3.67, p = 0.032), door-to-balloon (1.20 vs. 1.08, p = 0.046), and total ischemic time (5.80 vs. 4.70, p = 0.011). No differences in other in-hospital outcomes were found, except that multivariate logistic regression analysis demonstrated COVID-19 infection was correlated with increased risks of LVSD (OR 1.73, 95% CI 1.11-2.69, p = 0.015).

CONCLUSIONS

In-hospital mortality did not differ by time period or COVID-19 infection status. The COVID-positive AMI patients had longer reperfusion times and higher risks of LVSD. AMI treatments were impacted during the pandemic, and measures are warranted to minimize the reperfusion time.

Structure and function of human XPR1 in phosphate export

Xenotropic and polytropic retrovirus receptor 1 (XPR1) functions as a phosphate exporter and is pivotal in maintaining human phosphate homeostasis. It has been identified as a causative gene for primary familial brain calcification. Here we present the cryogenic electron microscopy (cryo-EM) structure of human XPR1 (HsXPR1). HsXPR1 exhibits a dimeric structure in which only TM1 directly constitutes the dimer interface of the transmembrane domain. Each HsXPR1 subunit can be divided spatially into a core domain and a scaffold domain. The core domain of HsXPR1 forms a pore-like structure, along which two phosphate-binding sites enriched with positively charged residues are identified. Mutations of key residues at either site substantially diminish the transport activity of HsXPR1. Phosphate binding at the central site may trigger a conformational change at TM9, leading to the opening of the extracellular gate. In addition, our structural analysis reveals a new conformational state of HsXPR1 in which the cytoplasmic SPX domains form a V-shaped structure. Altogether, our results elucidate the overall architecture of HsXPR1 and shed light on XPR1-mediated phosphate export.

Microglial NOX2 as a therapeutic target in traumatic brain injury: Mechanisms, consequences, and potential for neuroprotection

Traumatic brain injury (TBI) is a leading cause of long-term disability worldwide, with secondary injury mechanisms, including neuroinflammation and oxidative stress, driving much of its chronic pathology. While NADPH oxidase 2 (NOX2)-mediated reactive oxygen species (ROS) production is a recognized factor in TBI, the specific role of microglial NOX2 in perpetuating oxidative and inflammatory damage remains underexplored. Addressing this gap is critical, as current therapeutic approaches primarily target acute symptoms and fail to interrupt the persistent neuroinflammation that contributes to progressive neurodegeneration. Besides NOX, other ROS-generating enzymes, such as CYP1B1, COX2, and XO, also play crucial roles in triggering oxidative stress and neuroinflammatory conditions in TBI. However, this review highlights the pathophysiological role of microglial NOX2 in TBI, focusing on its activation following injury and its impact on ROS generation, neuroinflammatory signaling, and neuronal loss. These insights reveal NOX2 as a critical driver of secondary injury, linked to worsened outcomes, particularly in aged individuals where NOX2 activation is more pronounced. In addition, this review evaluates emerging therapeutic approaches targeting NOX2, such as GSK2795039 and other selective NOX2 inhibitors, which show potential in reducing ROS levels, limiting neuroinflammation, and preserving neurological functions. By highlighting the specific role of NOX2 in microglial ROS production and secondary neurodegeneration, this study advocates for NOX2 inhibition as a promising strategy to improve TBI outcomes by addressing the unmet need for therapies targeting long-term inflammation and neuroprotection. Our review highlights the potential of NOX2-targeted interventions to disrupt the cycle of oxidative stress and inflammation, ultimately offering a pathway to mitigate the chronic impact of TBI.

Transport and InsP8 gating mechanisms of the human inorganic phosphate exporter XPR1

Inorganic phosphate (Pi) has essential metabolic and structural roles in living organisms. The Pi exporter, XPR1/SLC53A1, is critical for cellular Pi homeostasis. When intercellular Pi is high, cells accumulate inositol pyrophosphate (1,5-InsP8), a signaling molecule required for XPR1 function. Inactivating XPR1 mutations lead to brain calcifications, causing neurological symptoms including movement disorders, psychosis, and dementia. Here, cryo-electron microscopy structures of dimeric XPR1 and functional characterization delineate the substrate translocation pathway and how InsP8 initiates Pi transport. Binding of InsP8 to XPR1, but not the related inositol polyphosphate InsP6, rigidifies the intracellular SPX domains, with InsP8 bridging the dimers and SPX and transmembrane domains. Locked in this state, the C-terminal tail is sequestered, revealing the entrance to the transport pathway, thus explaining the obligate roles of the SPX domain and InsP8. Together, these findings advance our understanding of XPR1 transport activity and expand opportunities for rationalizing disease mechanisms and therapeutic intervention.

Ultrasound-mediated cardiovascular thrombolysis: from Sonothrombolysis to Sonoperfusion

The incidence of coronary artery disease has been increasing in recent years, with acute myocardial infarction as its most severe onset. The major aim for clinical treatment is to restore myocardial blood supply with the recanalization of coronary circulation as early as possible, while the still existed issue of microcirculation thromboembolism has become a serious obstacle. Thus, thrombus elimination in coronary microcirculation is crucial and essential to improve the treatment outcome of acute myocardial infarction. In recent years, from sonothrombolysis to sonoperfusion, ultrasound-mediated cardiovascular thrombolysis can effectively solve the problem of vascular thromboembolism, including microcirculation thromboembolism, and the treatment method is expected to obtain satisfied thrombolytic treatment effect with microthrombus elimination in coronary microvessels and function recovery of terminal microcirculation, which has potential clinical value for the establishment of novel treatment for coronary thromboembolism. Therefore, this paper reviews ultrasound-mediated cardiovascular thrombolysis including sonothrombolysis and sonoperfusion for the application exploration in the treatment of coronary artery thromboembolism, the mechanism of action, and its research progress.

A microglia clonal inflammatory disorder in Alzheimer's disease

Somatic genetic heterogeneity resulting from post-zygotic DNA mutations is widespread in human tissues and can cause diseases, however, few studies have investigated its role in neurodegenerative processes such as Alzheimer's disease (AD). Here, we report the selective enrichment of microglia clones carrying pathogenic variants, that are not present in neuronal, glia/stromal cells, or blood, from patients with AD in comparison to age-matched controls. Notably, microglia-specific AD-associated variants preferentially target the MAPK pathway, including recurrent CBL ring-domain mutations. These variants activate ERK and drive a microglia transcriptional program characterized by a strong neuro-inflammatory response, both in vitro and in patients. Although the natural history of AD-associated microglial clones is difficult to establish in humans, microglial expression of a MAPK pathway activating variant was previously shown to cause neurodegeneration in mice, suggesting that AD-associated neuroinflammatory microglial clones may contribute to the neurodegenerative process in patients.

Collateral blood vessels in stroke and ischemic disease: Formation, physiology, rarefaction, remodeling

Collateral blood vessels are unique, naturally occurring endogenous bypass vessels that provide alternative pathways for oxygen delivery in obstructive arterial conditions and diseases. Surprisingly however, the capacity of the collateral circulation to provide protection varies greatly among individuals, resulting in a significant fraction having poor collateral circulation in their tissues. We recently reviewed evidence that the presence of naturally-occurring polymorphisms in genes that determine the number and diameter of collaterals that form during development (ie, genetic background), is a major contributor to this variation. The purpose of this review is to summarize current understanding of the other determinants of collateral blood flow, drawing on both animal and human studies. These include the level of smooth muscle tone in collaterals, hemodynamic forces, how collaterals form during development (collaterogenesis), de novo formation of additional new collaterals during adulthood, loss of collaterals with aging and cardiovascular risk factor presence (rarefaction), and collateral remodeling (structural lumen enlargement). We also review emerging evidence that collaterals not only provide protection in ischemic conditions but may also serve a physiological function in healthy individuals. Primary focus is on studies conducted in brain, however relevant findings in other tissues are also reviewed, as are questions for future investigation.

High-Frequency 64-Element Ring-Annular Array Transducer: Development and Preclinical Validation for Intravascular Ultrasound Imaging

Intravascular ultrasound (IVUS) imaging has become an essential method for diagnosing coronary artery disease. However, traditional mechanically rotational IVUS catheters encounter issues such as mechanical wear and imaging distortions in curved vessels. The ring-annular IVUS array has gained attention because it offers superior imaging performance without the need for mechanical rotational parts, thereby avoiding rotational imaging distortion. An optimized mechanical micromachining process employing precision dicing technology is proposed in this study, with the objective of achieving higher operating frequencies and minimized outer diameters for a 64-element ring-annular array. This method broadens the range of fabrication options and improves the imaging sensitivity of ring-annular IVUS arrays, as well as eliminating imaging distortion in rotational IVUS catheters, particularly in curved vessels. The probe has a 7.5 Fr (2.5 mm) outer diameter, with key fabrication steps including precision dicing, flexible circuit integration, and Parylene C encapsulation. The ring-annular array has a center frequency of 21.51 MHz with 67.87% bandwidth, with a 56 µm axial resolution and a 276 µm lateral resolution. The imaging performance is further validated by in vitro phantom imaging and ex vivo imaging.

Temporal Decomposition Analysis of Noncommunicable Disease Burden: The Interplay of Population Aging, Population Growth, and Low Physical Activity, 2010-2019

BACKGROUND

To analyze global trends in the noncommunicable diseases (NCDs) burden attributable to low physical activity, considering the impacts of population aging and growth.

METHOD

Based on the Global Burden Disease 2019 Study, the NCDs-related death and disability-adjusted life years attributable to low physical activity (defined as <3000 metabolic equivalent-min/wk) were obtained from 2010 to 2019. The average annual percent change was calculated using the joinpoint analysis. Decomposition analysis was applied to assess the separated contributions of 3 components (population aging, population growth, and death change due to all other factors) on the overall change in NCDs death attributed to low physical activity.

RESULTS

From 2010 to 2019, the average annual percent change of age-standardized rates of NCDs due to low physical activity was -0.09% for death and -0.06% for disability-adjusted life years. However, the global absolute number of deaths from NCDs attributable to low physical activity increased from 672,215 to 831,502, and disability-adjusted life years rose from 12,813,793 to 15,747,938. This rise was largely driven by population aging and growth, contributing to a 13.0% and 14.7% increase, respectively. The most significant impact of population aging on NCD deaths was observed in high-middle socio-demographic index countries (17.6%), whereas population growth had the greatest effect in low socio-demographic index countries (24.3%).

CONCLUSIONS

The reduction in NCDs death rates attributed to low physical activity is insufficient to counteract the effects of population aging and growth. Targeted interventions for physical activity promotion should focus on the older population with special attention to diseases most sensitive to physical inactivity.

Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases

Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity.

Microbial crosstalk with dermal immune system: A review on emerging analytical methods for macromolecular detection and therapeutics

According to global health metrics, clinical symptoms such as cellulitis and pyoderma associated with skin diseases are a significant burden worldwide, affecting 2.2 million disability-adjusted life years in 2020. There is a strong correlation between the commensal bacteria and the host immune system. Classical methods deployed in dermal biofilm crosstalk studies often hamper many individuals from early diagnosis and rationalized therapy. Herein, the present report aims to study the role of skin microbiota and mechanisms of microbial crosstalk with host immune system. The emerging analytical tools devised for sensor/biosensor platforms, including molecularly imprinted polymers, microarrays, aptamers, CRISPR-cas9, and optical/electrochemical approaches, are discussed as alternative methods for important biomarker analysis. Further, the types and characteristics of microorganism-derived macromolecules and the recent skin organoid toward personalized therapy are highlighted. This information will largely benefit researchers involved in the pathophysiology of skin disease, wound dressing materials, including diagnostic and healing patch designs, in addition to biological macromolecules devoted to wound repair.

The true cost of phosphate control in chronic kidney disease

The loss of kidney function entails the development of a positive phosphate balance. The burden of addressing elevated phosphate levels is high. Both parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) are increased to promote phosphaturia, thereby preventing the rise in serum phosphate. However, if the phosphate load is excessive, the corresponding phosphaturia is maximal, kidney function deteriorates and hyperphosphataemia becomes clinically evident in advanced stages of chronic kidney disease (CKD). In addition to its role in CKD progression, hyperphosphataemia has been linked to a multitude of adverse outcomes, including overt inflammation, vascular calcifications, endothelial dysfunction, cardiovascular disease, renal osteodystrophy and secondary hyperparathyroidism. Collectively, these factors contribute to the markedly elevated mortality rates observed among individuals with CKD. Furthermore, hyperphosphataemia has been identified as a significant contributor to the development of inflammatory processes, oxidative stress and fibrosis, which underlie the aetiology of numerous comorbidities. Additionally, elevated levels of PTH and FGF23 have been demonstrated to independently induce organ and tissue injury, which is associated with poor outcomes in CKD. This article provides a concise overview of the current understanding of phosphate handling by the kidney in the context of CKD. It outlines the detrimental effects of phosphate on various organs and the mechanisms through which it contributes to CKD progression. Additionally, we discuss the tools available for clinicians to identify patients at risk of an excessive phosphate load.

C5aR expression in kidney tubules, macrophages and fibrosis

The anaphylatoxin C5a and its receptor C5aR (CD88) are complement pathway effectors implicated in renal diseases, including ANCA-associated vasculitis. We investigated the kidney expression of C5aR and a second C5a receptor C5L2 by using immunohistochemistry, in situ hybridization, and spatial gene expression on formalin-fixed, paraffin-embedded human and mouse kidney. C5aR was detected on interstitial macrophages and in multiple tubular regions, including distal and proximal; C5L2 had a similar expression pattern. The 5/6 nephrectomy model of chronic kidney injury exhibited increased C5aR expression by infiltrating cells within the fibrotic regions. C5aR expression was confirmed on human leukocytes and in vitro differentiated macrophages by flow cytometry, and treatment with C5a induced the expression of chemokines and remodeling factors by macrophages, including CCL-3/-4/-7, -20, MMP-1/-3/-8/-12, and F3, and promoted leukocyte survival. C5a activity was C5aR dependent, as demonstrated by reversal with the C5aR inhibitor avacopan. Collectively, these results suggest that myeloid C5aR may induce excessive inflammation in the kidney via immune cell recruitment, extracellular matrix destruction, and remodeling, resulting in fibrotic tissue deposition.

Variable Curvature Flexible Transducer for Abdominal Expandable Imaging

Expanding the imaging field of view (FOV) of medical ultrasound transducers will more effectively detect pathological behaviors of tissues or organs. Conventional rigid transducers can be realized by increasing the number of array elements or the curvature; however, the imaging aperture is fixed by the original size and shape during the manufacturing process. This article presented a 128-element, 3-MHz flexible curvature abdominal array (FCAA) with the goal of dynamically expanding the FOV within a 120° range. The piezoelectric stack was divided into small pitches through a double-cut process, and two-component viscoelastic substrates (TCVSs) were filled between adjacent array elements to generate tensile and compressive stresses during decomposition deformation. A 3-D-printed push-pull device provides sufficient mechanical support, resulting in a conformal minimum curvature radius of 46 mm. The innovative rigid-flexible composite backing layer was used to balance mechanical flexibility and high bandwidth (BW) of -6 dB to 67.6%. The results showed that the axial and lateral resolutions of the commercial phantom line target are 0.35 and 0.77 mm, respectively, and the axial and lateral resolutions of FOV 120° are 0.36 and 1.02 mm, respectively. The imaging performance of FCAA was verified by B-model imaging of the kidneys, intestines, uterus, and bladder of volunteers with a different body mass index (BMI). In addition, the 5-mm renal artery phantom verified the Doppler imaging function of FCAA. All the results demonstrated that FCPA has great potential clinical value in abdominal ultrasound and gynecological examination.

Rural-urban disparity in survival and use of PCI in patients who develop STEMI while hospitalized for a non-cardiac condition

BACKGROUND

The development of ST-segment elevation myocardial infarction (STEMI) in patients hospitalized for non-cardiac indications carries a high mortality rate.

OBJECTIVES

Determine the impact of rural vs. urban hospital location and hospital percutaneous coronary intervention (PCI) volumes on clinical outcomes.

METHODS

The New York Statewide Planning and Research Cooperative System database was queried for STEMI claims from 2011 to 2018. The 2010 Rural-Urban Commuting Area classification scheme was used to stratify hospitals as urban or rural.

RESULTS

64960 STEMI patients were identified from 231 hospitals with 2880 (4.4%) being classified as inpatient STEMI (IPS). IPS patients were older (73.5 ± 13.3 years vs 64.6 ± 14.2 years; p < .0001) and more frequently female (49.3% vs 33.1%; p < .0001), had more comorbidities, were less likely to receive PCI (13.1% vs 69.4%; p < .0001), and had higher 1-year mortality (59.6% vs 16.4%; p < .0001) than outpatient STEMI (OPS). IPS that occurred in rural hospitals were less often treated with PCI (3.8% vs 13.8%; p < 0.01) and had higher one-year mortality (68.6% vs 58.9%; p < 0.01) than those occurring in urban hospitals. Similar results were observed when hospitals were divided into rural vs suburban vs urban based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme for Counties. Patients with IPS admitted to low-volume PCI centers were significantly less likely to receive PCI and had higher one-year mortality, after adjustment for demographics and comorbidities, compared to those admitted to high-volume PCI centers.

CONCLUSIONS

IPS treated at rural hospitals and/or low-volume PCI centers were less likely to be treated with PCI and had higher one-year mortality rates.

UNSTRUCTURED ABSTRACT

The development of ST-Segment Elevation Myocardial Infarction (STEMI) in patients hospitalized for non-cardiac indications carries a high mortality rate. Using a large retrospective cohort study, we investigated the impact of hospital location and PCI volume on outcomes in inpatient STEMI (IPS). Patients with IPS were generally older, more frequently female, and had more comorbidities than those with outpatient STEMI. After adjustment for demographics and comorbidities, those with IPS admitted to rural and/or low-volume PCI centers were less likely to receive PCI and experienced higher one-year mortality rates.

Recent advances in biomimetic nanodelivery systems for the treatment of myocardial ischemia reperfusion injury

Myocardial ischemia/reperfusion injury (MIRI) is a significant challenge in the treatment of myocardial infarction, a leading cause of global mortality due to irreversible cardiac damage. Biomimetic nanodelivery systems offer promising therapeutic strategies to address MIRI. In this review, we comprehensively investigate the underlying pathophysiological mechanisms of MIRI and discuss recent advances in biomimetic nanodelivery systems including cell membrane-coated nanoparticles, exosomes, and nanoenzymes as innovative approaches for MIRI treatment. We emphasize the advantages and potential of biomimetic strategies in enhancing therapeutic efficacy, assess the preclinical effectiveness of these nanodelivery systems, and discuss the challenges associated with translating these approaches into clinical practice. This paper aims to provide new perspectives on biomimetic strategies for MIRI treatment, contributing to the development of effective drug delivery systems.

CLEC16A in astrocytes promotes mitophagy and limits pathology in a multiple sclerosis mouse model

Astrocytes promote neuroinflammation and neurodegeneration in multiple sclerosis (MS) through cell-intrinsic activities and their ability to recruit and activate other cell types. In a genome-wide CRISPR-based forward genetic screen investigating regulators of astrocyte proinflammatory responses, we identified the C-type lectin domain-containing 16A gene (CLEC16A), linked to MS susceptibility, as a suppressor of nuclear factor-κB (NF-κB) signaling. Gene and small-molecule perturbation studies in mouse primary and human embryonic stem cell-derived astrocytes in combination with multiomic analyses established that CLEC16A promotes mitophagy, limiting mitochondrial dysfunction and the accumulation of mitochondrial products that activate NF-κB, the NLRP3 inflammasome and gasdermin D. Astrocyte-specific Clec16a inactivation increased NF-κB, NLRP3 and gasdermin D activation in vivo, worsening experimental autoimmune encephalomyelitis, a mouse model of MS. Moreover, we detected disrupted mitophagic capacity and gasdermin D activation in astrocytes in samples from individuals with MS. These findings identify CLEC16A as a suppressor of astrocyte pathological responses and a candidate therapeutic target in MS.

Single-cell transcriptomics predict novel potential regulators of acute epithelial restitution in the ischemia-injured intestine

Intestinal ischemic injury damages the epithelial barrier and predisposes patients to life-threatening sepsis unless that barrier is rapidly restored. There is an age dependency in intestinal recovery in that neonates are the most susceptible to succumb to disease of the intestinal barrier compared with older patients. We have developed a pig model that demonstrates age-dependent failure of intestinal barrier restitution in neonatal pigs, which can be rescued by the direct application of juvenile pig mucosal tissue, but the mechanisms of rescue remain undefined. We hypothesized that by identifying a subpopulation of restituting enterocytes by their expression of cell migration transcriptional pathways, we can then predict novel upstream regulators of age-dependent restitution response programs. Superficial mucosal epithelial cells from recovering ischemic jejunum of juvenile pigs underwent single-cell transcriptomics and the predicted upstream regulator, colony stimulating factor-1 (CSF-1), was interrogated in our model. A subcluster of absorptive enterocytes expressed several cell migration pathways key to restitution. Differentially expressed genes in this subcluster predicted their upstream regulation by colony stimulating factor-1 (CSF-1). We validated age-dependent induction of CSF-1 by ischemia and documented that CSF-1 and colony-stimulating factor-1 receptor (CSF1R) co-localized in ischemic juvenile, but not neonatal, wound-adjacent epithelial cells and in the restituted epithelium of juveniles and rescued neonates. Furthermore, the CSF-1 blockade reduced restitution in vitro, and CSF-1 improved barrier function in injured neonatal pigs in preliminary ex vivo experiments. These studies validate an approach to inform potential novel therapeutic targets, such as CSF-1, to improve outcomes in neonates with intestinal injury in a unique pig model.NEW & NOTEWORTHY These studies validate an approach to identify and predict upstream regulation of restituting epithelium in a unique pig intestinal ischemic injury model. Identification of potential molecular mediators of restitution, such as CSF-1, will inform the development of targeted therapeutic interventions for the medical management of patients with ischemia-mediated intestinal injury.

Therapeutic potential of microalgae-derived natural compounds in diabetic wound healing: A comprehensive review

A variety of cell types and chemical systems are known to interact throughout the complex process of wound healing. In addition to being very uncomfortable for patients, wounds that do not heal properly or become chronic can place a heavy burden on society. The creation of novel treatment approaches can expedite the healing process, reduce the societal burden, and improve patient outcomes. Due to advancements in the field of biomedical science, microalgae have significant potential for use in diabetic wound healing and other wound healing applications. This review delves into the physiological process of wound healing, the use of microalgae in wound healing, and a detailed explanation of the wound healing roles of various microalgal originated bioactive compounds including alginate, pigments, fatty acids, proteins, polysaccharides, flavonoids and phenols. The study discusses the efficacy of photosynthetic hydrogels in drugs and oxygen delivery to the wounded area that is crucial for promoting a good healing process, as well as highlights the drawbacks and challenges involved in using microalgae for wound healing. Given the current state of the art in utilizing microalgae for wound care, this review provides new perspectives for further research, along with insightful advice and innovative suggestions for academics engaged in this area.

Early precursor-derived pituitary gland tissue-resident macrophages play a pivotal role in modulating hormonal balance

The pituitary gland is the central endocrine regulatory organ producing and releasing hormones that coordinate major body functions. The physical location of the pituitary gland at the base of the brain, though outside the protective blood-brain barrier, leads to an unexplored special immune environment. Using single-cell transcriptomics, fate mapping, and imaging, we characterize pituitary-resident macrophages (pitMØs), revealing their heterogeneity and spatial specialization. Microglia-like macrophages (ml-MACs) are enriched in the posterior pituitary, while other pitMØs in the anterior pituitary exhibit close interactions with hormone-secreting cells. Importantly, all pitMØs originate from early yolk sac progenitors and maintain themselves through self-renewal, independent of bone marrow-derived monocytes. Macrophage depletion experiments unveil the role of macrophages in regulating intrapituitary hormonal balance through extracellular ATP-mediated intercellular signaling. Altogether, these findings provide information on pituitary gland macrophages and advance our understanding of immune-endocrine system crosstalk.

Langerhans Cells Drive Tfh and B Cell Responses Independent of Canonical Cytokine Signals

Dendritic cells (DCs) are key regulators of adaptive immunity, guiding T helper (Th) cell differentiation through antigen presentation, co-stimulation, and cytokine production. However, in steady-state conditions, certain DC subsets, such as Langerhans cells (LCs), induce T follicular helper (Tfh) cells and B cell responses without inflammatory stimuli. Using multiple mouse models and in vitro systems, we investigated the mechanisms underlying steady-state LC-induced adaptive immune responses. We found that LCs drive germinal center Tfh and B cell differentiation and antibody production independently of interleukin-6 (IL-6), type-I interferons, and ICOS ligand (ICOS-L) signaling, which are critical in inflammatory settings. Instead, these responses relied on CD80/CD86-mediated co-stimulation. Our findings challenge the conventional three-signal paradigm by demonstrating that cytokine signaling is dispensable for LC-mediated Tfh and B cell responses in steady-state. These insights provide a framework for understanding homeostatic immunity and the immune system's role in maintaining tolerance or developing autoimmunity under non-inflammatory conditions.

A small signaling domain controls PPIP5K phosphatase activity in phosphate homeostasis

Inositol pyrophosphates (PP-InsPs) are eukaryotic nutrient messengers. The N-terminal kinase domain of diphosphoinositol pentakisphosphate kinase (PPIP5K) generates the messenger 1,5-InsP8, the C-terminal phosphatase domain catalyzes PP-InsP breakdown. The balance between kinase and phosphatase activities regulates 1,5-InsP8 levels. Here, we present crystal structures of the apo and substrate-bound PPIP5K phosphatase domain from S. cerevisiae (ScVip1PD). ScVip1PD is a phytase-like inositol 1-pyrophosphate histidine phosphatase with two conserved catalytic motifs. The enzyme has a strong preference for 1,5-InsP8 and is inhibited by inorganic phosphate. It contains an α-helical insertion domain stabilized by a structural Zn2+ binding site, and a unique GAF domain that channels the substrate to the active site. Mutations that alter the active site, restrict the movement of the GAF domain, or change the substrate channel's charge inhibit the enzyme activity in vitro, and Arabidopsis VIH2 in planta. Our work reveals the structure, enzymatic mechanism and regulation of eukaryotic PPIP5K phosphatases.

Impact of the COVID-19 pandemic on patients with coronary artery disease requiring cardiac surgery at a German university hospital

BACKGROUND

Studies show conflicting results regarding the impact of the COVID-19 pandemic on the treatment of patients with coronary artery disease requiring cardiac surgery and data from Germany are lacking. In this study, two patient cohorts who underwent coronary artery bypass graft surgery before and after the start of the COVID-19 pandemic were compared.

METHODS

Patients who presented for coronary artery bypass graft surgery before (01.05.18-30.04.19; group "B") or during the COVID-19 pandemic (01.05.20-30.04.21; group "P") at the University Hospital Münster in Germany were retrospectively identified and compared regarding demographics, preoperative status, surgical data, and postoperative outcome.

RESULTS

513 (group "B") and 501 patients (group "P") were included, demographics were comparable. In group "P", preoperative myocardial infarction and emergency indications were more frequent, heart-lung machine and aortic clamping times were longer. Postoperative ICU-days and inpatient stay did not differ. Postoperative need of an extracorporeal life support system and intrahospital mortality tended to be higher in group "P", without reaching statistical significance.

CONCLUSION

The COVID-19 pandemic had a significant impact on cardiac surgical care with the prioritization of emergency procedures. Patients treated during the pandemic were in a more critical preoperative condition, duration of surgery was longer, but post-operative mortality was comparable.

Intestinal epithelium-derived IL-34 reprograms macrophages to mitigate gastrointestinal tract graft-versus-host disease

Gastrointestinal (GI) tract graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic stem cell transplantation and is attributable to dysregulation that occurs between the effector and regulatory arms of the immune system. Whereas regulatory T cells have a primary role in counterbalancing GVHD-induced inflammation, identifying and harnessing other pathways that promote immune tolerance remain major goals in this disease. Herein, we identified interleukin-34 (IL-34) as an intestinal epithelium-derived cytokine that was able to mitigate the severity of GVHD within the GI tract. Specifically, we observed that the absence of recipient IL-34 production exacerbated GVHD lethality, promoted intestinal epithelial cell death, and compromised barrier integrity. Mechanistically, the absence of host IL-34 skewed donor macrophages toward a proinflammatory phenotype and augmented the accumulation of pathogenic CD4+ granulocyte-macrophage colony-stimulating factor (GM-CSF)+ T cells within the colon. Conversely, the administration of recombinant IL-34 substantially reduced GVHD mortality and inflammation, which was dependent on the expression of apolipoprotein E in donor macrophages. Complementary genetic and imaging approaches in mice demonstrated that intestinal epithelial cells were the relevant source of IL-34. These results were supported by colonic biopsies from patients with GVHD, which displayed IL-34 expression in intestinal epithelial cells and apolipoprotein E in lamina propria macrophages, validating similar cellular localization in humans. These studies indicate that IL-34 acts as a tissue-intrinsic cytokine that regulates GVHD severity in the GI tract and could serve as a potential therapeutic target for amelioration of this disease.