Cells of the macula densa (MD) sense changes in tubular fluid to control functions such as renal blood flow and renin release. New findings identify a broader role for MD cells in the remodelling of kidney tissue. “The identified cell … features … suggest that the MD is a much more complex and key sensory and regulatory cell type in the nephron than previously thought,” say the researchers.

To study the dynamics of kidney tissue remodelling, Georgina Gyarmati and colleagues performed serial intravital multiphoton microscopy and genetic cell-fate tracking in reporter mice, which demonstrated that loss of body fluid and salt — but not ischemia–reperfusion-induced kidney injury — act as MD-activating stimuli to recruit mesenchymal and endothelial precursor cells. Following their recruitment, the precursors differentiated and induced remodelling of the vasculature, interstitium and glomerulus in regions closest to the MD.

致密斑 (MD) 细胞感知肾小管液的变化，以控制肾血流量和肾素释放等功能。新发现确定了 MD 细胞在肾组织重塑中发挥更广泛的作用。研究人员表示：“所鉴定的细胞……特征……表明 MD 是肾单位中一种比之前认为的更为复杂和关键的感觉和调节细胞类型。”

为了研究肾组织重塑的动态，Georgina Gyarmati 及其同事对报告小鼠进行了连续活体多光子显微镜观察和遗传细胞命运追踪，结果表明体液和盐的流失（而非缺血再灌注引起的肾损伤）起到了作用MD激活刺激以募集间充质和内皮前体细胞。募集后，前体细胞分化并诱导最接近 MD 区域的脉管系统、间质和肾小球重塑。