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Calcium (Ca2+) homeostasis is maintained through coordination between intestinal absorption, renal reabsorption, and bone remodeling. Intestinal and renal (re)absorption occurs via transcellular and paracellular pathways. The latter contributes the bulk of (re)absorption under conditions of adequate intake. Epithelial paracellular permeability is conferred by tight-junction proteins called claudins. However, the molecular identity of the paracellular Ca2+ pore remains to be delineated. Claudins (Cldn)-2 and -12 confer Ca2+ permeability, but deletion of either claudin does not result in a negative Ca2+ balance or increased calciotropic hormone levels, suggesting the existence of additional transport pathways or parallel roles for the two claudins. To test this, we generated a Cldn2/12 double knockout mouse (DKO). These animals have reduced intestinal Ca2+ absorption. Colonic Ca2+ permeability is also reduced in DKO mice and significantly lower than single-null animals, while small intestine Ca2+ permeability is unaltered. The DKO mice display significantly greater urinary Ca2+ wasting than Cldn2 null animals. These perturbations lead to hypocalcemia and reduced bone mineral density, which was not observed in single-KO animals. Both claudins were localized to colonic epithelial crypts and renal proximal tubule cells, but they do not physically interact in vitro. Overexpression of either claudin increased Ca2+ permeability in cell models with endogenous expression of the other claudin. We find claudin-2 and claudin-12 form partially redundant, independent Ca2+ permeable pores in renal and colonic epithelia that enable paracellular Ca2+ (re)absorption in these segments, with either one sufficient to maintain Ca2+ balance.

The renal proximal tubule (PT) is responsible for the reabsorption of approximately 65% of filtered calcium, primarily via a paracellular pathway. However, which protein(s) contribute this paracellular calcium pore is not known. The claudin family of tight junction proteins confers permeability properties to an epithelium. Claudin-12 is expressed in the kidney and when overexpressed in cell culture contributes paracellular calcium permeability (PCa). We therefore examined claudin-12 renal localization and its contribution to tubular paracellular calcium permeability. Claudin-12 null mice (KO) were generated by replacing the single coding exon with β-galactosidase from Escherichia coli. X-gal staining revealed that claudin-12 promoter activity colocalized with aquaporin-1, consistent with the expression in the PT. PTs were microperfused ex vivo and PCa was measured. PCa in PTs from KO mice was significantly reduced compared with WT mice. However, urinary calcium excretion was not different between genotypes, including those on different calcium containing diets. To assess downstream compensation, we examined renal mRNA expression. Claudin-14 expression, a blocker of PCa in the thick ascending limb (TAL), was reduced in the kidney of KO animals. Thus, claudin-12 is expressed in the PT, where it confers paracellular calcium permeability. In the absence of claudin-12, reduced claudin-14 expression in the TAL may compensate for reduced PT calcium reabsorption.

Abstract Rationale Apoptosis is essential for removal of neutrophils from inflamed tissues and efficient resolution of inflammation. Myeloperoxidase (MPO), abundantly expressed in neutrophils, not only generates cytotoxic oxidants but also signals through the β2 integrin Mac-1 to rescue neutrophils from constitutive apoptosis, thereby prolonging inflammation. Objectives Because aspirin-triggered 15-epi-lipoxin A4 (15-epi-LXA4) modulates Mac-1 expression, we investigated the impact of 15-epi-LXA4 on MPO suppression of neutrophil apoptosis and MPO-mediated neutrophil-dependent acute lung injury. Methods Human neutrophils were cultured with MPO with or without 15-epi-LXA4 to investigate development of apoptosis. Acute lung injury was produced by intratracheal injection of carrageenan plus MPO or intraperitoneal injection of live Escherichia coli in mice, and the animals were treated with 15-epi-LXA4 at the peak of inflammation. Measurements and Main Results 15-Epi-LXA4 through down-regulation of Mac-1 expression promoted apoptosis of human neutrophils by attenuating MPO-induced activation of extracellular signal–regulated kinase and Akt-mediated phosphorylation of Bad and by reducing expression of the antiapoptotic protein Mcl-1, thereby aggravating mitochondrial dysfunction. The proapoptotic effect of 15-epi-LXA4 was dominant over MPO-mediated effects even when it was added at 4 hours post MPO. In mice, treatment with 15-epi-LXA4 accelerated the resolution of established carrageenan plus MPO-evoked as well as E. coli–induced neutrophil-dependent pulmonary inflammation through redirecting neutrophils to caspase-mediated cell death and facilitating their removal by macrophages. Conclusions These results demonstrate that aspirin-triggered 15-epi-LXA4 enhances resolution of inflammation by overriding the powerful antiapoptosis signal from MPO, thereby demonstrating a hitherto unrecognized mechanism by which aspirin promotes resolution of inflammation.

Atrial fibrillation is one of the major risk factors of ischemic stroke. Endovascular thrombectomy (EVT) has become the standard treatment for acute ischemic stroke with large vessel occlusion. However, data regarding the impact of AF on the outcome of patients with acute ischemic stroke treated with mechanical thrombectomy are controversial. The aim of our study was to determine whether atrial fibrillation modifies the functional outcome of patients with anterior circulation acute ischemic stroke receiving EVT. We reviewed 273 eligible patients receiving EVT from January 2019 to January 2022 from 3 comprehensive Chinese stroke centers, of whom 221 patients were recruited. Demographics, clinical, radiological and treatment characteristics, safety outcomes, and functional outcomes were collected. Modified Rankin scale (mRS) score ≤ 2 at 90 days was defined as a good functional outcome. In our cohort, 79 patients (35.74%) were eventually found to have AF. Patients with AF were elder (70.08 ± 11.72 vs. 61.82 ± 13.48 years, = 0.000) and less likely to be males (54.43 vs. 73.94%, = 0.03). The significant reperfusion rate (modified thrombolysis in cerebral infarction 2b-3) was 73.42 and 83.80% in patients with and without AF, respectively ( = 0.064). The good functional outcome (90-day modified Rankin scale: 0 to 2) rate was 39.24 and 44.37% in patients with and without AF, respectively ( = 0.460) after adjusting multiple confounding factors. There was no difference in the presence of symptomatic intracerebral hemorrhage between the two groups (10.13 vs. 12.68%, = 0.573). Despite their older age, AF patients achieved similar outcomes as non-AF patients with anterior circulation occlusion treated with endovascular therapy.

This narrative review aims to evaluate strategies for reducing door-to-balloon (D2B) time in ST-elevation myocardial infarction (STEMI) patients, focusing on pre-hospital, in-hospital, and technological innovations, as well as addressing challenges to ensure sustainability. We reviewed recent literature from 2004 onward, examining various approaches to streamline STEMI care and improve D2B time. The review encompasses pre-hospital interventions such as advanced ECG monitoring and pre-hospital alerts, in-hospital strategies such as standardized protocols and streamlined processes, and technological innovations such as automated ECG interpretation, mobile applications, and telemedicine. Pre-hospital strategies have demonstrated significant benefits in reducing D2B times through early diagnosis and rapid communication. In-hospital approaches, including the use of clinical pathways and decision support systems, contribute to minimizing delays and enhancing coordination among healthcare providers. Technological innovations, such as automated ECG systems and telemedicine, facilitate quicker diagnosis and treatment initiation. However, challenges such as resource limitations, staff turnover, and variability in care processes persist. Addressing these challenges through continuous quality improvement, standardized care protocols, and data-driven analytics is crucial for sustaining improvements. Effective reduction in D2B time in STEMI care requires a multifaceted approach involving pre-hospital and in-hospital strategies, as well as leveraging technological advancements. Overcoming challenges and ensuring sustainability demands ongoing commitment to quality improvement, resource management, and standardized protocols. By integrating these strategies, healthcare systems can enhance the timeliness of STEMI care and improve patient outcomes.

Objective Medical staff, especially nurses, suffered great anxiety and stress from the COVID-19 pandemic, which negatively affected their sleep quality. In this study, we aimed to analyze the sleep quality of nursing staff after terminating the Zero-COVID-19 policy in China. Methods 506 participants were involved in our study. The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate the sleep status of the participants. Binary regression was performed to evaluate the impact factors related to sleep difficulty. Results The majority of participants (96.44%) suffered from sleep disturbances. There were significant differences in age, education level and front-line activity between participants with good sleep quality and sleep difficulty. Younger age (16–25 years old) was independently associated with less sleep difficulty, while front-line activity was independently associated with severe sleep difficulty. Conclusion Sleep disorder was very common among nurses after ending the Zero-COVID-19 policy in China. More front-line nurses suffered severe sleep difficulty in particular, which should be worthy of attention.

FAM111A gene mutations cause Kenney–Caffey syndrome (KCS) and Osteocraniostenosis (OCS), conditions characterized by short stature, low serum ionized calcium (Ca2+), low parathyroid hormone (PTH), and bony abnormalities. The molecular mechanism mediating this phenotype is unknown. The c‐terminal domain of FAM111A harbors all the known disease‐causing variations and encodes a domain with high homology to serine proteases. However, whether this serine protease domain contributes to the maintenance of Ca2+ homeostasis is not known. We hypothesized the disruption of the serine protease domain of FAM111A would disrupt Ca2+ homeostasis. To test this hypothesis, we generated with CRISPR/Cas9, mice with a frameshift insertion (c.1450insA) or large deletion (c.1253‐1464del) mutation in the Fam111a serine protease domain. Serum‐ionized Ca2+ and PTH levels were not significantly different between wild type, heterozygous, or homozygous Fam111a mutant mice. Additionally, there were no significant differences in fecal or urine Ca2+ excretion, intestinal Ca2+ absorption or overall Ca2+ balance. Only female homozygous (c.1450insA), but not heterozygous mice displayed differences in bone microarchitecture and mineral density compared to wild‐type animals. We conclude that frameshift mutations that disrupt the c‐terminal serine protease domain do not induce a KCS or OCS phenotype in mice nor alter Ca2+ homeostasis.

Apoptosis is essential for removal of neutrophils from inflamed tissues and efficient resolution of inflammation. Myeloperoxidase (MPO), abundantly expressed in neutrophils, not only generates cytotoxic oxidants but also signals through the beta(2) integrin Mac-1 to rescue neutrophils from constitutive apoptosis, thereby prolonging inflammation. Because aspirin-triggered 15-epi-lipoxin A(4) (15-epi-LXA(4)) modulates Mac-1 expression, we investigated the impact of 15-epi-LXA(4) on MPO suppression of neutrophil apoptosis and MPO-mediated neutrophil-dependent acute lung injury. Human neutrophils were cultured with MPO with or without 15-epi-LXA(4) to investigate development of apoptosis. Acute lung injury was produced by intratracheal injection of carrageenan plus MPO or intraperitoneal injection of live Escherichia coli in mice, and the animals were treated with 15-epi-LXA(4) at the peak of inflammation. 15-Epi-LXA(4) through down-regulation of Mac-1 expression promoted apoptosis of human neutrophils by attenuating MPO-induced activation of extracellular signal-regulated kinase and Akt-mediated phosphorylation of Bad and by reducing expression of the antiapoptotic protein Mcl-1, thereby aggravating mitochondrial dysfunction. The proapoptotic effect of 15-epi-LXA(4) was dominant over MPO-mediated effects even when it was added at 4 hours post MPO. In mice, treatment with 15-epi-LXA(4) accelerated the resolution of established carrageenan plus MPO-evoked as well as E. coli-induced neutrophil-dependent pulmonary inflammation through redirecting neutrophils to caspase-mediated cell death and facilitating their removal by macrophages. These results demonstrate that aspirin-triggered 15-epi-LXA(4) enhances resolution of inflammation by overriding the powerful antiapoptosis signal from MPO, thereby demonstrating a hitherto unrecognized mechanism by which aspirin promotes resolution of inflammation.

Serotonin (5-HT) is a phylogenetically conserved monoamine neurotransmitter modulating important processes in the brain. To directly visualize the release of 5-HT, we developed a genetically encoded G-protein-coupled receptor (GPCR)-activation-based 5-HT (GRAB 5-HT ) sensor with high sensitivity, high selectivity, subsecond kinetics and subcellular resolution. GRAB 5-HT detects 5-HT release in multiple physiological and pathological conditions in both flies and mice and provides new insights into the dynamics and mechanisms of 5-HT signaling. The authors develop a genetically encoded GPCR-based sensor to image serotonin dynamics in behaving animals with high specificity, sensitivity and spatiotemporal resolution.

The ability to directly measure acetylcholine (ACh) release is an essential step toward understanding its physiological function. Here we optimized the GRAB ACh (GPCR-activation-based ACh) sensor to achieve substantially improved sensitivity in ACh detection, as well as reduced downstream coupling to intracellular pathways. The improved version of the ACh sensor retains the subsecond response kinetics, physiologically relevant affinity and precise molecular specificity for ACh of its predecessor. Using this sensor, we revealed compartmental ACh signals in the olfactory center of transgenic flies in response to external stimuli including odor and body shock. Using fiber photometry recording and two-photon imaging, our ACh sensor also enabled sensitive detection of single-trial ACh dynamics in multiple brain regions in mice performing a variety of behaviors. A genetically encoded acetylcholine sensor with improved sensitivity allows detection of cholinergic neurotransmission in vivo in the Drosophila and mouse brain.