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The transition from acute kidney injury (AKI) to chronic kidney disease (CKD) is a critical clinical issue. Although previous studies have suggested macrophages as a key player in promoting inflammation and fibrosis during this transition, the heterogeneity and dynamic characterization of macrophages are still poorly understood. Here, we used integrated single‐cell RNA sequencing and spatial transcriptomic to characterize the spatiotemporal heterogeneity of macrophages in murine AKI‐to‐CKD model of unilateral ischemia‐reperfusion injury. A marked increase in macrophage infiltration at day 1 was followed by a second peak at day 14 post AKI. Spatiotemporal profiling revealed that injured tubules and macrophages co‐localized early after AKI, whereas in late chronic stages had spatial proximity to fibroblasts. Further pseudotime analysis revealed two distinct lineages of macrophages in this transition: renal resident macrophages differentiated into the pro‐repair subsets, whereas infiltrating monocyte‐derived macrophages contributed to chronic inflammation and fibrosis. A novel macrophage subset, extracellular matrix remodeling‐associated macrophages (EAMs) originating from monocytes, linked to renal fibrogenesis and communicated with fibroblasts via insulin‐like growth factors (IGF) signalling. In sum, our study identified the spatiotemporal dynamics of macrophage heterogeneity with a unique subset of EAMs in AKI‐to‐CKD transition, which could be a potential therapeutic target for preventing CKD development. [ABSTRACT FROM AUTHOR]

Background and Purpose: Activation of the renin‐angiotensin system, as a hallmark of hypertension and chronic kidney diseases (CKD) is the key pathophysiological factor contributing to the progression of tubulointerstitial fibrosis. LIM and senescent cell antigen‐like domains protein 1 (LIMS1) plays an essential role in controlling of cell behaviour through the formation of complexes with other proteins. Here, the function and regulation of LIMS1 in angiotensin II (Ang II)‐induced hypertension and tubulointerstitial fibrosis was investigated. Experimental Approach: C57BL/6 mice were treated with Ang II to induce tubulointerstitial fibrosis. Hypoxia‐inducible factor‐1α (HIF‐1α) renal tubular‐specific knockout mice or LIMS1 knockdown AAV was used to investigate their effects on Ang II‐induced renal interstitial fibrosis. In vitro, HIF‐1α or LIMS1 was knocked down or overexpressed in HK2 cells after exposure to Ang II. Key Results: Increased expression of tubular LIMS1 was observed in human kidney with hypertensive nephropathy and in murine kidney from Ang II‐induced hypertension model. Tubular‐specific knockdown of LIMS1 ameliorated Ang II‐induced tubulointerstitial fibrosis in mice. Furthermore, we demonstrated that LIMS1 was transcriptionally regulated by HIF‐1α in tubular cells and that tubular HIF‐1α knockout ameliorates LIMS1‐mediated tubulointerstitial fibrosis. In addition, LIMS1 promotes Ang II‐induced tubulointerstitial fibrosis by interacting with vimentin. Conclusion and Implications: We conclude that HIF‐1α transcriptionally regulated LIMS1 plays a central role in Ang II‐induced tubulointerstitial fibrosis through interacting with vimentin. Our finding represents a new insight into the mechanism of Ang II‐induced tubulointerstitial fibrosis and provides a novel therapeutic target for progression of CKD. [ABSTRACT FROM AUTHOR]

Background: Menopause is associated with elevated cardiovascular risk due to the loss of the cardioprotective effect of oestrogens. Postmenopausal women are often prescribed hormone replacement therapy (HRT) in order to control menopause symptoms and correct hormone imbalances; however, HRT can impact serum lipids' concentrations. At present, data on the effect of the administration of medroxyprogesterone acetate plus conjugated equine oestrogens (MPACEE) on the lipid profile in females are uncertain, as the investigations conducted so far have produced conflicting results. Thus, we aimed to clarify the impact of MPACEE prescription on the serum lipids' values in women by means of a systematic review and meta‐analysis of randomized controlled trials (RCTs). Methods: We employed a random‐effects model based on the DerSimonian and Laird method to determine the combined estimates of the intervention's impact on the lipid profile. The computation of the weighted mean difference (WMD) and its corresponding 95% confidence interval (CI) relied on the mean and standard deviation values from both the MPACEE and control group, respectively. Results: A total of 53 RCTs were included in the meta‐analysis with 68 RCT arms on total cholesterol (TC), 70 RCT arms on low‐density lipoprotein cholesterol (LDL‐C) and triglycerides (TG), and 69 RCT arms on high‐density lipoprotein cholesterol (HDL‐C). Administration of MPACEE resulted in a significant reduction of TC (WMD = −11.93 mg/dL; 95% CI: −13.42, −10.44; p <.001) and LDL‐C (WMD = −16.61 mg/dL; 95% CI: −17.97, −15.26; p <.001) levels, and a notable increase in HDL‐C (WMD = 3.40 mg/dL; 95% CI: 2.93, 3.86; p <.001) and TG (WMD = 10.28 mg/dL; 95% CI: 7.92, 12.64; p <.001) concentrations. Subgroup analysis revealed that changes in the lipid profile were influenced by several factors: body mass index (for TC, HDL‐C, TG), MPACEE dosages (for TC, LDL‐C, HDL‐C, TG), age (for TC, LDL‐C, HDL‐C, TG), durations of the intervention (for TC, LDL‐C, HDL‐C, TG), continuous/sequential administration of MPACEE (continuous for TC; sequential for LDL‐C, TG) administration of MPACEE and serum lipids' concentrations before enrolment in the RCT (for TC, LDL‐C, HDL‐C, TG). Conclusions: MPACEE administration can influence serum lipids' concentrations in females by raising HDL‐C and TG levels and reducing LDL‐C and TC values. Therefore, postmenopausal women who suffer from hypercholesterolaemia might benefit from this type of HRT. [ABSTRACT FROM AUTHOR]

The airway epithelia initiate and modulate the inflammatory responses to various pathogens. The cystic fibrosis transmembrane conductance regulator-mediated Cl(-) secretion system plays a key role in mucociliary clearance of inhaled pathogens. We have explored the effects of Toxoplasma gondii, an opportunistic intracellular protozoan parasite, on Cl(-) secretion of the mouse tracheal epithelia. In this study, ATP-induced Cl(-) secretion indicated the presence of a biphasic short-circuit current (Isc) response, which was mediated by a Ca(2+)-activated Cl(-) channel (CaCC) and the cystic fibrosis transmembrane conductance regulator. However, the ATP-evoked Cl(-) secretion in T. gondii-infected mouse tracheal epithelia and the elevation of [Ca(2+)]i in T. gondii-infected human airway epithelial cells were suppressed. Quantitative reverse transcription-PCR revealed that the mRNA expression level of the P2Y2 receptor (P2Y2-R) increased significantly in T. gondii-infected mouse tracheal cells. This revealed the influence that pathological changes in P2Y2-R had on the downstream signal, suggesting that P2Y2-R was involved in the mechanism underlying T. gondii infection in airways. These results link T. gondii infection as well as other pathogen infections to Cl(-) secretion, via P2Y2-R, which may provide new insights for the treatment of pneumonia caused by pathogens including T. gondii.