# Atherosclerosis: smooth-muscle state and macrophage clearance mechanisms

**Selected author evidence guide**

[Canonical comparison](https://drgezhang.com/research/atherosclerosis-cell-mechanisms.html)

## Which cell-type-specific pathways regulate smooth-muscle inflammation and macrophage efferocytosis?

A source-linked research-use guide to two complementary cell-specific mechanisms in experimental atherosclerosis: VSMC matrix/inflammatory regulation and macrophage efferocytosis. Original mouse/cell studies, human plaque observations and external review entry points retain their distinct roles.

Start with the cell function and experimental perturbation needed for the argument, then compare molecular, functional and plaque-composition readouts. Follow the original DOI and figure or abstract locator supporting that role.

## Which cell-type-specific pathways regulate smooth-muscle inflammation and macrophage efferocytosis?

哪些细胞类型特异通路分别调控平滑肌炎症与巨噬细胞对凋亡细胞的清除？

**Source-linked methodological synthesis:** Two KIF13B-dependent mechanisms address different plaque functions. In vascular smooth-muscle cells, KIF13B supports KCTD10-dependent ubiquitination and proteasomal turnover of KLF4. KIF13B loss reduces collagen and contractile features and increases inflammatory readouts in primary human aortic smooth-muscle cells; KLF4 knockdown or KCTD10 restoration rescues the collagen/inflammatory phenotype. How KIF13B maintains KCTD10 abundance remains unresolved. In macrophages, KIF13B supports MERTK protein maintenance and efferocytosis: deficient BMDMs have less MERTK and impaired uptake, and MERTK restoration improves clearance in cells. Myeloid deletion and deficient-marrow transfer worsen mouse plaque composition without corresponding plasma-lipid changes in those models. Protein-turnover evidence supports a KIF13B–ITCH/CBL–MERTK model, while the precise proposed ITCH-to-CBL degradation step remains incompletely demonstrated. These axes connect VSMC matrix/inflammatory programs and macrophage apoptotic-cell clearance to plaque composition; they are not one demonstrated cross-cell signaling cascade. For experiment design, CD47 blockade supplies a recognition-checkpoint comparator and cleavage-resistant MerTK supplies a receptor-cleavage comparator, distinct from intracellular receptor-protein maintenance. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/) [5](https://pubmed.ncbi.nlm.nih.gov/27437576/) [6](https://pubmed.ncbi.nlm.nih.gov/28067670/)

两条KIF13B相关通路分别作用于不同的斑块功能。在血管平滑肌细胞中，KIF13B支持KCTD10依赖的KLF4泛素化和蛋白酶体周转；KIF13B缺失降低胶原和收缩表型、增加炎症读数，KLF4敲低或KCTD10恢复可在原代人主动脉平滑肌细胞中纠正胶原下降和炎症增强的表型。KIF13B如何维持KCTD10丰度仍待解释。在巨噬细胞中，KIF13B参与MERTK蛋白维持和凋亡细胞清除；缺失细胞的MERTK减少、清除受损，恢复MERTK可改善BMDM中的清除。髓系删除与缺失骨髓移植在相应小鼠模型中加重斑块表型而未伴随相应血脂变化。蛋白周转证据支持KIF13B–ITCH/CBL–MERTK模型，但所提ITCH促CBL降解的具体步骤尚未完全证明。两轴分别关联基质/炎症状态与清除功能，不应合并为已证实的跨细胞级联。CD47识别检查点与MerTK剪切研究可作为区分受体调控层级的实验对照。

### Evaluation checklist

- **VSMC state and plaque structure:** Pair lesion burden with collagen, fibrous-cap features, inflammatory readouts and contractile function. The VSMC study and the review’s state-preservation argument help distinguish matrix-supporting functions from inflammatory programs. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [3](https://pmc.ncbi.nlm.nih.gov/articles/PMC13607131/)

- **VSMC protein mechanism and rescue:** Measure KCTD10 and KLF4 abundance, KLF4 turnover/ubiquitination and matrix/inflammatory outputs together. Use KLF4 knockdown and KCTD10 restoration to test functional ordering; the upstream control of KCTD10 by KIF13B remains open. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/)

- **Macrophage clearance and receptor maintenance:** Read apoptotic-cell uptake together with MERTK protein, Mertk transcript and protein-turnover evidence. MERTK restoration in deficient BMDMs links receptor abundance to the clearance phenotype; myeloid/marrow models connect this pathway to plaque composition. [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

- **Recognition versus cleavage versus protein maintenance:** Recognition: CD47 antibody blockade tests an anti-phagocytic checkpoint. Cleavage: cleavage-resistant myeloid MerTK links lesional receptor/soluble Mer with clearance, necrotic core and cap thickness. Protein maintenance: the KIF13B study links intracellular MERTK regulation with BMDM loss and restoration. These are complementary comparators, not a treatment ranking. [5](https://pubmed.ncbi.nlm.nih.gov/27437576/) [6](https://pubmed.ncbi.nlm.nih.gov/28067670/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

- **Cell identity and experimental denominators:** State the genetic cell-targeting strategy and model, and distinguish human tissue association from mouse/cell perturbation. The JCI primary VSMC comparison used n=8 mice per group; the EHJ myeloid comparison used n=9 controls versus n=6 deletion mice. Pooled aortic single-cell data are one library per genotype, not five independent libraries. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

### How the selected papers contribute

- **[VSMC matrix/inflammatory states and KCTD10–KLF4 turnover](https://drgezhang.com/papers/doi-10-1172-jci194175.html):** Provides human plaque associations plus VSMC-specific mouse perturbation, primary HASMC gain/loss experiments and KLF4/KCTD10 rescue. Its contribution is the relationship between smooth-muscle state, matrix function and inflammatory remodeling. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/)

- **[Macrophage MERTK maintenance and efferocytosis](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html):** Provides human tissue association, myeloid/marrow mouse perturbation and macrophage protein-turnover and rescue evidence. Its contribution is a receptor-homeostasis route to apoptotic-cell clearance, distinct from the VSMC KCTD10–KLF4 route. [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

### Two cell-specific mechanisms: perturbation, functional readout and plaque endpoint

| Paper / design | Population | Endpoint / horizon | Validation | Reported evaluation | Original source |

| --- | --- | --- | --- | --- | --- |

| [Vascular smooth muscle cell-derived KIF13B inhibits proinflammatory responses to protect against atherosclerosis](https://drgezhang.com/papers/doi-10-1172-jci194175.html); Mechanistic mouse and primary-cell perturbation/rescue study with associative human plaque and multi-omic evidence. | Paired carotid plaque regions from 6 patients; independent human plaque datasets; male AAV8-PCSK9 VSMC-Kif13b models and primary human aortic smooth-muscle cells. | Plaque burden/composition; collagen and matrix/contractile features; inflammatory VSMC readouts; KCTD10-dependent KLF4 ubiquitination and turnover. | Convergent mouse genetics, HASMC gain/loss and KLF4/KCTD10 rescue; human plaque evidence is associative. Pooled single-cell state evidence has one library per genotype. | Primary VSMC-specific mouse comparison: 20-week Western diet, n=8/group (Figure 2). Key HASMC biochemical/rescue assays generally n=3 biological replicates (Figures 6–8); matrix and inflammatory phenotypes are read together. | [10.1172/jci194175](https://doi.org/10.1172/jci194175) [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) |

| [The macrophage-derived motor protein KIF13B enhances MERTK-mediated efferocytosis and prevents atherosclerosis in mice](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html); Mechanistic preclinical study combining myeloid/marrow mouse perturbation, macrophage functional assays and human tissue association. | Lyz2-Cre conditional mice and donor-marrow recipients; BMDMs and THP-1 cells; human arterial-wall and carotid-plaque tissue observations. | Efferocytosis and MERTK protein regulation; lesion/necrotic-core, macrophage and apoptotic-cell outcomes; plasma lipids in the specified genetic models. | Myeloid deletion and marrow transfer support the tested myeloid/hematopoietic contribution; they are not macrophage-exclusive. MERTK restoration rescues the BMDM phenotype in cells; the exact proposed ITCH-to-CBL step remains incomplete. | Conditional model: n=9 controls versus n=6 deletion mice; marrow transfer n=6/group, each after 12-week Western diet (Figure 4). BMDM MERTK-restoration efferocytosis assay n=10/group (Figure 5). | [10.1093/eurheartj/ehaf523](https://doi.org/10.1093/eurheartj/ehaf523) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/) |

Choose the study by the cell function and perturbation that support the intended claim. Human plaque observations are associative; the functional pathway evidence comes from the stated mouse and cell experiments. Keep the global Kif13b/Ldlr lipid increase separate from the conditional or marrow comparisons. The two papers do not establish a single cross-cell cascade or a head-to-head intervention ranking. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

### Research applications

- **Introduction and Discussion:** Use the JCI pathway for matrix-preserving versus inflammatory VSMC functions and the EHJ pathway for macrophage receptor maintenance and apoptotic-cell clearance. Connect each claim to its cell type, original DOI and actual experimental role. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

- **Experimental readout selection:** Build a readout panel around the perturbed step: KCTD10/KLF4 turnover plus collagen/inflammatory outputs for VSMCs; receptor abundance/cleavage plus uptake and plaque composition for efferocytosis. CD47 and cleavage-resistant MerTK provide distinct original-study comparators for recognition and receptor processing. [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/) [5](https://pubmed.ncbi.nlm.nih.gov/27437576/) [6](https://pubmed.ncbi.nlm.nih.gov/28067670/)

- **Review-to-original reading route:** The cell-surface-target review sections 4.1/4.4 lead through reference 89 to the VSMC original study. The MedComm atherosclerosis section leads through reference 148 to the macrophage original study and retains CD47/MerTK-cleavage comparators in the surrounding group. Use these as citation locators; the reviews are synthesis rather than additional independent experiments. [3](https://pmc.ncbi.nlm.nih.gov/articles/PMC13607131/) [4](https://pmc.ncbi.nlm.nih.gov/articles/PMC12703062/) [1](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) [2](https://pubmed.ncbi.nlm.nih.gov/40709729/)

### Sources and locators

- [Vascular smooth muscle cell-derived KIF13B inhibits proinflammatory responses to protect against atherosclerosis](https://pmc.ncbi.nlm.nih.gov/articles/PMC12987658/) · DOI: [10.1172/jci194175](https://doi.org/10.1172/jci194175) — Results: VSMC-specific deletion and plaque composition (Figure 2); primary HASMC state and matrix phenotypes (Figure 5L–Q); KLF4 genetic rescue (Figure 6); KCTD10/KLF4 protein turnover and rescue (Figures 7–8).

- [The macrophage-derived motor protein KIF13B enhances MERTK-mediated efferocytosis and prevents atherosclerosis in mice](https://pubmed.ncbi.nlm.nih.gov/40709729/) · DOI: [10.1093/eurheartj/ehaf523](https://doi.org/10.1093/eurheartj/ehaf523) — Original structured Abstract (Methods and Results); reviewed original Figure 4 (myeloid and marrow models), Figure 5 (MERTK/BMDM restoration), and Figure 6 (MERTK protein turnover and ITCH/CBL model). The current public record is an abstract; detailed figure evidence is retained in the linked reviewed paper summary.

- [Cell-Surface Signatures and Targets of Modulated Vascular Smooth Muscle Cells in Atherosclerosis: From State Identification to Precision Intervention](https://pmc.ncbi.nlm.nih.gov/articles/PMC13607131/) · DOI: [10.3390/jcdd13090472](https://doi.org/10.3390/jcdd13090472) — Section 4.1, second paragraph: references 89–90 on matrix/collagen/cap-supporting VSMC states; section 4.4, second paragraph: reference 89 on preserving protective states. Reference 89 identifies the JCI KIF13B study. This is a rationale for state preservation, not evidence that the JCI study tested FAP-targeted treatment.

- [Efferocytosis in Health and Disease](https://pmc.ncbi.nlm.nih.gov/articles/PMC12703062/) · DOI: [10.1002/mco2.70546](https://doi.org/10.1002/mco2.70546) — Section 4.1.1 Atherosclerosis, first paragraph: the grouped references 145–148 accompany recognition, metabolic and MerTK-related mechanisms. Reference 148 identifies the EHJ KIF13B study; 145 and 146 identify CD47 and MerTK-cleavage original studies. The grouped citation does not assign every listed submechanism to every cited paper.

- [CD47-blocking antibodies restore phagocytosis and prevent atherosclerosis](https://pubmed.ncbi.nlm.nih.gov/27437576/) · DOI: [10.1038/nature18935](https://doi.org/10.1038/nature18935) — Complete original Abstract: anti-phagocytic CD47, antibody perturbation, restored efferocytosis and reduced atherosclerosis in multiple mouse models. This guide uses the abstract-level comparison.

- [MerTK receptor cleavage promotes plaque necrosis and defective resolution in atherosclerosis](https://pubmed.ncbi.nlm.nih.gov/28067670/) · DOI: [10.1172/jci90520](https://doi.org/10.1172/jci90520) — Complete original Abstract: human carotid-plaque cleavage associations and fat-fed Ldlr-deficient mice with myeloid cleavage-resistant MerTK; lesional receptor, soluble Mer, efferocytosis, necrotic-core and fibrous-cap readouts. This guide uses the abstract-level comparison.

## VSMC matrix and inflammatory-state regulation

### Vascular smooth muscle cell-derived KIF13B inhibits proinflammatory responses to protect against atherosclerosis

**Authors:** Guolin Miao; Yufei Han; Jingxuan Chen; Yiran Liu; Ge Zhang; Shaotong Pei; Yinqi Zhao; Yitong Xu; Liwen Zheng; Zhaoling Li; Xiangru Liu; Sijing Shi; Xuya Kang; Yahan Liu; Ling Zhang; Wei Huang; Yuhui Wang; Junnan Tang; Erdan Dong; Xunde Xian

**Year:** 2026 · **Journal:** Journal of Clinical Investigation · **Publication type:** Article

[Author evidence page](https://drgezhang.com/papers/doi-10-1172-jci194175.html) · [Formal publication DOI](https://doi.org/10.1172/jci194175) · [BibTeX](https://drgezhang.com/citations/doi-10-1172-jci194175.bib) · [RIS](https://drgezhang.com/citations/doi-10-1172-jci194175.ris) · [CSL JSON](https://drgezhang.com/citations/doi-10-1172-jci194175.csl.json)

### How does KIF13B affect primary human vascular smooth muscle cells?

Under oxLDL, KIF13B knockdown reduced contractile/matrix features, collagen secretion and collagen-gel contraction and increased inflammatory features, while KIF13B overexpression produced reciprocal effects. These are in vitro primary-HASMC perturbation data, not human treatment outcomes.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1172-jci194175.html#qa-5)

- [KF4](https://drgezhang.com/papers/doi-10-1172-jci194175.html#kf4) — Results: Inhibiting KIF13B promotes proinflammatory fibroblast-like VSMC transition; Figure 5L-Q and Supplemental Figure 3.

### Is KLF4 functionally downstream of KIF13B?

In primary HASMC experiments, KIF13B loss increased KLF4, and concomitant KLF4 knockdown rescued the collagen-suppressive and inflammatory phenotype caused by KIF13B knockdown. This supports a downstream functional relationship in the tested cell system.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1172-jci194175.html#qa-6)

- [KF5](https://drgezhang.com/papers/doi-10-1172-jci194175.html#kf5) — Results: KLF4 mediates KIF13B-dependent proinflammatory VSMC reprogramming; Figure 6.

### What evidence supports the KIF13B-KCTD10-KLF4 mechanism?

KIF13B knockdown stabilized KLF4 in CHX/proteasome experiments and reduced KLF4 ubiquitination. Integrated analyses nominated KCTD10, co-IP supported KCTD10-KLF4 association, KCTD10 increased KLF4 ubiquitination, and KCTD10 overexpression rescued KIF13B-loss phenotypes. The study does not resolve how KIF13B itself controls KCTD10 abundance.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1172-jci194175.html#qa-7)

- [KF6](https://drgezhang.com/papers/doi-10-1172-jci194175.html#kf6) — Results: KIF13B facilitates KCTD10-mediated ubiquitination and degradation of KLF4; Figures 7-8 and Supplemental Figure 4.

### How does this JCI study differ from the European Heart Journal KIF13B study?

The JCI study focuses on vascular smooth muscle cells and a KIF13B-KCTD10-KLF4 mechanism controlling matrix/inflammatory VSMC states. The European Heart Journal study focuses on macrophage KIF13B, MERTK-dependent efferocytosis and an ITCH/CBL regulatory network. Together they describe distinct cell-type-specific KIF13B mechanisms in experimental atherosclerosis.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1172-jci194175.html#qa-9)

- [KF1](https://drgezhang.com/papers/doi-10-1172-jci194175.html#kf1) — Results: Decreased expression of KIF13B in VSMCs is linked to the progression of atherosclerosis in humans; Figure 1; Supplemental Figure 1; Methods: Human studies.

- [KF6](https://drgezhang.com/papers/doi-10-1172-jci194175.html#kf6) — Results: KIF13B facilitates KCTD10-mediated ubiquitination and degradation of KLF4; Figures 7-8 and Supplemental Figure 4.

### Reviewed study profile

- **profile type:**
  multicohort_omics
- **study design:**
  Mechanistic translational preclinical study integrating associative human plaque observations and public multi-omic datasets with causal mouse genetics, pooled single-cell RNA sequencing, primary HASMC perturbation, biochemical rescue and preclinical pharmacologic intervention.
- **evidence type:**
  Associative human tissue and multi-omic evidence; causal mouse genetics; primary human VSMC perturbation; biochemical mechanism and rescue; preclinical pharmacologic rescue.
- **population:**
  Paired carotid endarterectomy plaque regions from 6 patients; independent public human plaque datasets; male mouse atherosclerosis models; primary human aortic smooth muscle cells. No treated human atherosclerosis cohort.
- **primary endpoint:**
  Experimental atherosclerotic lesion burden, plaque-stability features and VSMC phenotypic remodeling across genetic models.
- **secondary endpoint:**
  Collagen and extracellular-matrix programs, inflammatory cytokines, VSMC contractile function, KLF4 protein regulation, KCTD10-dependent ubiquitination and preclinical pharmacologic rescue.
- **data modalities:**
  - Paired human carotid plaque histology and protein analysis
  - Human plaque bulk RNA sequencing
  - Human plaque proteomics
  - Human plaque DNA methylation
  - Human plaque single-cell and spatial transcriptomic analysis
  - Mouse plaque histology and plasma phenotyping
  - Mouse aortic single-cell RNA sequencing
  - Primary HASMC gain- and loss-of-function assays
  - Protein stability, ubiquitination and co-immunoprecipitation assays
  - Genetic and preclinical pharmacologic rescue
- **external validation:**
  true
- **scale metrics:**
  - - **label:**
      Local paired carotid CEA cohort
    - **value:**
      6 patients. Each plaque supplied an advanced/culprit region and an adjacent upstream region from the same patient. Figure 1 reports scRNA analysis n=4 regions per condition and Western/histologic analyses n=6 regions per condition; these are paired regions, not 10 or 12 independent participants.
  - - **label:**
      GSE120521
    - **value:**
      4 carotid endarterectomy patients, each contributing paired stable and unstable plaque regions: 4 stable and 4 unstable RNA-seq samples.
  - - **label:**
      PXD062283
    - **value:**
      The ProteomeXchange repository contains 87 human carotid plaques overall; the JCI Figure 1 comparison uses stable n=19 and unstable n=38. Do not substitute the repository total for the study subset.
  - - **label:**
      Human methylation evidence
    - **value:**
      Three independent public methylation datasets were reanalyzed in the Supplement. Dataset-specific denominators must remain separate and must not be summed into a synthetic human cohort.
  - - **label:**
      Human spatial evidence
    - **value:**
      Public human plaque spatial-transcriptomic data associated with GSE274572 were reanalyzed for fibrous-cap VSMC states; no new participant count is inferred here.
  - - **label:**
      VSMC-specific PCSK9 mouse model
    - **value:**
      8-week-old male Kif13b floxed and Tagln-Cre Kif13b VSMC-KO mice received AAV8-PCSK9-D377Y and Western diet for 20 weeks; primary pathology, lipid and cytokine comparisons n=8 per group; aortic-ring assays n=4 per group.
  - - **label:**
      Mouse single-cell experiment
    - **value:**
      Ldlr-deficient versus Ldlr-deficient Kif13b-deficient mice; five mice were pooled into one aortic single-cell library per genotype. Figure 5/Results report 20-week Western diet, while downstream Figure 6/7 captions reference 12-week Western diet.
  - - **label:**
      Primary HASMC perturbation
    - **value:**
      KIF13B knockdown and overexpression under oxLDL were assessed with Western blot/ELISA biological replicates generally n=3; collagen-gel contraction used n=5 for knockdown and n=6 for overexpression.
  - - **label:**
      KLF4 and KCTD10 rescue
    - **value:**
      KLF4 dual-knockdown and KCTD10-overexpression biochemical and phenotypic rescue assays generally used n=3 independent biological replicates; selected immunofluorescence assays used n=10.
  - - **label:**
      Kenpaullone intervention
    - **value:**
      HASMC experiments used 10 µM Kenpaullone. Male PCSK9 mice received 1 mg/kg/day orally during the final 12 weeks of a 20-week Western-diet protocol; n=6 per group.
- **counting note:**
  Human participants, paired plaque regions, public dataset samples, mice, pooled single-cell libraries and independent cell-culture replicates are different denominators and must not be summed. External human datasets provide cross-source corroboration, not prospective clinical validation. Five mice pooled into one library per genotype are not five independent single-cell libraries. Preserve the paper's figure-specific 20-week versus 12-week single-cell duration descriptions rather than harmonizing them.

### Complete reviewed evidence scope

- **supports:**
  - Association between lower KIF13B and more advanced or unstable human atherosclerotic plaque features across local tissue and independent public datasets.
  - A causal contribution of VSMC Kif13b loss to measured atherosclerotic plaque phenotypes in the tested male mouse models.
  - Cell-autonomous effects of KIF13B gain and loss on matrix, inflammatory and contractile programs in primary HASMCs.
  - Functional placement of KLF4 downstream of KIF13B in HASMC perturbation and rescue experiments.
  - Evidence consistent with KCTD10-mediated KLF4 ubiquitination and proteasomal turnover downstream of KIF13B.
  - Preclinical cellular and mouse rescue after Kenpaullone exposure under the tested conditions.
- **does not establish:**
  - That low KIF13B expression or KIF13B methylation causes plaque instability in humans.
  - That KIF13B, KCTD10, KLF4 or Kenpaullone has proven therapeutic efficacy or safety in patients with atherosclerosis.
  - That Kenpaullone is selective for KLF4 or that all Kenpaullone effects in this study are mediated specifically through KLF4.
  - A universal lipid-independent KIF13B mechanism in humans; the reported absence of TC/TG differences applies to the tested mouse comparison.
  - Independent replication of the study-generated single-cell comparison, because five mice were pooled into one library per genotype.
  - One definitive single-cell diet duration or one unambiguous cluster assignment for every Figure 5-7 subpanel where the article text and captions disagree.
  - The molecular mechanism by which KIF13B regulates KCTD10 abundance.
  - Generalization of the causal or pharmacologic mouse findings to females, because only male mice were used.

### Complete reviewed limitations

- The local human cohort contained six carotid endarterectomy patients with paired within-plaque regions; human observations are associative and small-sample.
- The local advanced-versus-adjacent classification was based on anatomical location and macroscopic surgical appearance rather than molecular or histopathological criteria.
- Stable/unstable public datasets and local advanced/adjacent paired regions use different plaque definitions and should not be treated as interchangeable cohorts.
- Human methylation observations are associative and do not establish that KIF13B hypermethylation causes KIF13B downregulation or plaque instability.
- The PXD062283 repository contains 87 plaques overall, whereas the JCI stable/unstable comparison uses a subset of 19 and 38; repository size and analytical subset must not be conflated.
- Five mice were pooled into one single-cell library per genotype, limiting independent biological replication at the single-cell library level.
- Figure 5/Results report a 20-week Western-diet single-cell experiment, whereas downstream Figure 6/7 captions reference 12 weeks; this discrepancy is unresolved.
- Results describe inflammatory genes in VSMC-Fib4 while the Figure 5K caption labels the panel VSMC-Fib1; the evidence page therefore avoids treating that subpanel label as unambiguous.
- Only male mice were used, and sex was not analyzed as a biological variable.
- Tagln-Cre targets smooth-muscle compartments beyond plaque VSMCs; reported intestine/bladder measurements do not establish general systemic safety of pathway targeting.
- The study establishes KCTD10-dependent KLF4 ubiquitination/rescue evidence but does not identify the mechanism by which KIF13B regulates KCTD10 abundance.
- Kenpaullone is pharmacologically nonselective; its rescue does not prove KLF4-selective target engagement or exclude contributions from other kinase targets.
- Kenpaullone was evaluated only in cells and mice. No human atherosclerosis efficacy, dosing, pharmacokinetic or safety trial was performed.

## Macrophage MERTK maintenance and apoptotic-cell clearance

### The macrophage-derived motor protein KIF13B enhances MERTK-mediated efferocytosis and prevents atherosclerosis in mice

**Authors:** Yitong Xu; Jingxuan Chen; Yiran Liu; Ge Zhang; Guolin Miao; Jingdong Wu; Kaikai Lu; Yinqi Zhao; Wenxi Zhang; Liwen Zheng; Lianxin Zhang; Jinxuan Chen; Zihao Zhou; Yufei Han; Pingping Lai; Jiabao Guo; Donghui Wu; Si Mei; Ling Zhang; Yang Zhao; Wei Huang; Yuhui Wang; Junnan Tang; Dongyu Zhao; Xunde Xian

**Year:** 2025 · **Journal:** European Heart Journal · **Publication type:** Article

[Author evidence page](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html) · [Formal publication DOI](https://doi.org/10.1093/eurheartj/ehaf523) · [BibTeX](https://drgezhang.com/citations/doi-10-1093-eurheartj-ehaf523.bib) · [RIS](https://drgezhang.com/citations/doi-10-1093-eurheartj-ehaf523.ris) · [CSL JSON](https://drgezhang.com/citations/doi-10-1093-eurheartj-ehaf523.csl.json)

### Did Kif13b loss worsen mouse plaques independently of circulating lipids?

Global Kif13b deletion in the Ldlr-deficient model worsened plaques and increased total cholesterol and triglycerides, so that comparison is lipid-confounded. Lyz2-Cre myeloid deletion and Kif13b-deficient donor-marrow transfer worsened lesion, necrotic-core, macrophage and apoptotic-cell outcomes without corresponding plasma-lipid changes in their tested mouse models. These approaches are not macrophage-exclusive.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#qa-2)

- [KF2](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#kf2) — Results: Deletion of Kif13b in Ldlr−/− mice exacerbates atherosclerosis; Figure 2 and Supplementary Figure S2.

- [KF4](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#kf4) — Results: Myeloid-specific deletion of Kif13b aggravates atherosclerosis in a lipid-independent manner; Figure 4 and Supplementary Figures S3–S4.

### Is MERTK involved in the efferocytosis phenotype, and was it rescued in vivo?

Kif13b-deficient BMDMs had lower MERTK protein and impaired efferocytosis. Restoring MERTK in deficient BMDMs improved efferocytosis, supporting functional involvement in cells. This was not a demonstrated in vivo MERTK-restoration therapy or human treatment.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#qa-4)

- [KF5](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#kf5) — Results: Loss of Kif13b inhibits MERTK-mediated macrophage efferocytosis; Figure 5.

### How certain is the proposed KIF13B–ITCH–CBL–MERTK mechanism?

Unchanged Mertk mRNA, faster MERTK protein loss, proteasome-sensitive degradation, increased MERTK ubiquitination, KIF13B–ITCH interaction and ITCH overexpression rescue support a post-translational model. The precise proposed ITCH-mediated CBL ubiquitination/degradation step was not fully demonstrated; alternative routes including CBL self-ubiquitination remain possible.

[Unchanged reviewed answer](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#qa-5)

- [KF6](https://drgezhang.com/papers/doi-10-1093-eurheartj-ehaf523.html#kf6) — Results: KIF13B decreases CBL-mediated ubiquitination of MERTK by interacting with itch in macrophages; Figure 6.

### Reviewed study profile

- **profile type:**
  multicohort_omics
- **study design:**
  Mechanistic translational preclinical study combining associative human arterial and plaque observations with mouse atherosclerosis genetics, public and study-generated transcriptomics, macrophage experiments, genetic rescue and pharmacologic intervention.
- **evidence type:**
  Human tissue association; causal mouse and macrophage experiments; public dataset reanalysis; preclinical pharmacologic rescue.
- **population:**
  Human arterial-wall and carotid-plaque tissue samples; Ldlr-deficient and Apoe-deficient mouse models; mouse bone-marrow-derived macrophages and THP-1 cells. No treated human atherosclerosis cohort.
- **primary endpoint:**
  Experimental atherosclerotic lesion burden and macrophage efferocytosis across genetic and pharmacologic models.
- **secondary endpoint:**
  Plaque necrotic core, macrophage and apoptotic-cell accumulation, circulating lipids, MERTK protein regulation and reported safety observations.
- **data modalities:**
  - Human tissue expression and immunostaining
  - Mouse plaque histology and plasma lipids
  - Public and pooled aortic single-cell RNA sequencing
  - BMDM RNA sequencing
  - Macrophage efferocytosis and protein assays
  - Genetic rescue and preclinical pharmacology
- **external validation:**
  true
- **scale metrics:**
  - - **label:**
      GSE40231 arterial-wall samples
    - **value:**
      STAGE/CABG human dataset: 40 non-atherosclerotic arterial-wall samples and 40 atherosclerotic arterial-wall samples; these are sample counts, not 80 unique participants.
  - - **label:**
      Human carotid lesion tissues
    - **value:**
      Early lesions n=6 and advanced lesions n=6.
  - - **label:**
      Mouse plaque progression
    - **value:**
      Ldlr-deficient mice after Western diet for 12 or 20 weeks; n=6 mice per group.
  - - **label:**
      Global Kif13b loss
    - **value:**
      Ldlr-deficient control and Kif13b-deficient Ldlr-deficient mice after 12 weeks of Western diet; n=6 mice per group.
  - - **label:**
      Public single-cell GSE155513
    - **value:**
      Figure 3 describes n=1 single-cell library at each 8-week and 26-week dietary time point; do not treat library counts as mouse counts.
  - - **label:**
      Study-generated aortic single-cell experiment
    - **value:**
      Five mice pooled into one single-cell library per genotype; the Results state 20 weeks of Western diet while Figure 3E states 12 weeks of high-fat diet.
  - - **label:**
      Public macrophage single-cell GSE215103
    - **value:**
      Reanalysis of Apoe-deficient mouse peritoneal macrophages; no unique mouse or library count inferred here.
  - - **label:**
      Myeloid conditional model
    - **value:**
      Kif13b-floxed controls n=9 versus Lyz2-Cre;Kif13b-floxed mice n=6, AAV8-PCSK9 and 12 weeks of Western diet.
  - - **label:**
      Bone-marrow transplantation
    - **value:**
      Ldlr-deficient recipients of control or Kif13b-deficient donor marrow; n=6 mice per group after 12 weeks of Western diet.
  - - **label:**
      BMDM transcriptomics
    - **value:**
      Wild-type versus Kif13b-deficient BMDMs n=3 per group, including apoptotic-cell co-incubation transcriptomics n=3 per group.
  - - **label:**
      NX-1607 mouse intervention
    - **value:**
      Ldlr-deficient and Kif13b-deficient Ldlr-deficient mice, n=6 per group; 20 weeks total Western diet with 5 mg/kg/day NX-1607 only during the final 16 weeks.
- **counting note:**
  Counts have different denominators: human tissue samples, mice, pooled single-cell libraries, independent cultures or experiments. They cannot be summed as unique participants or independent biological replicates. Five mice pooled to one library per genotype are not five independent libraries; the generated single-cell experiment has conflicting Results and Figure 3E diet durations.

### Complete reviewed evidence scope

- **supports:**
  - Association between lower KIF13B and advanced human arterial or carotid-plaque tissue, and progression in mouse plaque observations.
  - Causal worsening of mouse plaque phenotypes after global, myeloid or hematopoietic Kif13b perturbation within their respective experimental models.
  - A myeloid or hematopoietic contribution without corresponding plasma-lipid differences in conditional and transplantation models, separate from the lipid increase in global Ldlr-deficient knockout mice.
  - Reduced MERTK protein and efferocytosis after Kif13b loss and improvement of BMDM efferocytosis following MERTK restoration.
  - Evidence consistent with post-translational ITCH/CBL/MERTK regulation and article-reported NX-1607 rescue in macrophages and mice.
- **does not establish:**
  - Human KIF13B causality, prediction of clinical outcomes or human atherosclerosis treatment efficacy.
  - That the global Ldlr-deficient knockout plaque phenotype is lipid independent.
  - Macrophage-exclusive effects of Lyz2-Cre deletion or bone-marrow transplantation, or five independent single-cell libraries from five pooled mice.
  - One definitive diet duration for the study-generated pooled aortic single-cell comparison, because Results and Figure 3E disagree.
  - That MERTK restoration is an effective in vivo or human therapy, or that every proposed ITCH-to-CBL ubiquitination and degradation step has been directly resolved.
  - That NX-1607 reverses 20 weeks of established disease, has proven human atherosclerosis benefit, or unequivocally validates endogenous CBL rather than the distinct CBLB target described by external sources.

### Complete reviewed limitations

- Human arterial-wall and carotid-plaque results are associative tissue observations with small carotid groups, not causal human intervention evidence.
- The global Kif13b-deficient Ldlr model had higher circulating cholesterol and triglycerides, limiting attribution of its plaque phenotype solely to local plaque biology.
- Lyz2-Cre targets myeloid lineages and donor-marrow transplantation changes hematopoietic compartments; neither isolates macrophages exclusively.
- Study-generated single-cell data pooled five mice to one library per genotype, limiting independent biological replication at the library level.
- The Results and Figure 3E give discordant 20-week Western-diet and 12-week high-fat-diet descriptions for the pooled aortic single-cell experiment.
- GSE155513 Figure 3 time points use one single-cell library each; sample and library counts must not be conflated.
- MERTK restoration rescue was demonstrated in Kif13b-deficient BMDMs, not as an in vivo MERTK treatment.
- The exact ITCH-mediated CBL ubiquitination/degradation step in the proposed network remains incompletely demonstrated; MERTK regulation is not fully assigned to one mechanism.
- The article's CBL-inhibitor description of NX-1607 conflicts with external CBL-B/CBLB target identification, preventing unambiguous pharmacologic validation of endogenous CBL.
- NX-1607 was tested preclinically during the final 16 of 20 Western-diet weeks, not as reversal after 20 weeks of established disease; no human atherosclerosis efficacy was assessed.
- Mouse NX-1607 measurements found no reported ALT/AST liver-toxicity signal but did report lower white blood cells and lymphocytes, so safety is not established.