# CaMKK2 in macrophages promotes obesity-induced insulin resistance and inflammation

> **NIH NIH F31** · BAYLOR COLLEGE OF MEDICINE · 2022 · $46,752

## Abstract

Project Summary/Abstract
The obesity pandemic is a growing crisis that predisposes afflicted individuals to comorbidities of the metabolic
syndrome including hypertension, Type 2 diabetes and liver disease. Clinically, obesity is defined as a low-grade
inflammatory disease that is influenced by macrophage infiltration and activation. Resolving this perturbed
inflammatory response could be a means by which the onset and progression of metabolic syndrome is
circumvented. Activation of the calcium/calmodulin kinase cascade has been implicated in abnormal metabolic
processes and a contributor to diet-induced obesity. We identified that Ca2+/Calmodulin-Dependent Protein
Kinase Kinase 2 (CaMKK2) is highly expressed in macrophages and is synergistically activated by Ca2+ and
long-chain fatty acids, two signals that are elevated during obesity. We have shown that mice devoid of CaMKK2
are refractory to diseases typically associated with caloric overload, and that pharmacological inhibition of
CaMKK2 reverses hepatic steatosis and regresses hepatic tumor growth. Furthermore, loss of CaMKK2 reduces
expression of several inflammatory markers, indicating the importance of CaMKK2 in regulating the inflammatory
response. To clarify the role of CaMKK2 in macrophages, we developed a myeloid-specific CaMKK2 knockout
(CaMKK2MKO) and evaluated its response to chronic high-fat diet feeding. Resulting macrophage ablation of
CaMKK2 conferred protection against the detrimental effects of caloric overload by improving peripheral insulin
sensitivity, reducing hepatic steatosis and decreasing central adiposity. Additionally, RNA-Seq analysis from
epidydimal white adipose tissue (eWAT) shows that CaMKK2MKO mice have a robust activation of fatty-acid
metabolic programs and a concomitant reduction in pro-inflammatory signaling. Assessment of mitochondrial
performance reveals that loss or inhibition of CaMKK2 confers a reprogramming of naïve macrophages to more
efficiently metabolize fatty-acid substrates. These results are corroborated with b-oxidation assays that show
macrophages devoid of CaMKK2 have a significantly improved capacity to utilize fatty-acids and retain elevated
oxidation levels despite inflammatory stimuli. Based on these findings, we hypothesize that CaMKK2 functions
as a metabolic sensor in macrophages to modulate the balance of fuel utilization between glycolytic and oxidative
pathways, reprogramming the cell’s ability to respond to metabolic stimuli. I will test this hypothesis in Aim 1 by
determining the role of CaMKK2 in the regulation of macrophage fuel preference and function. Building on this
information, Aim 2 will focus on characterizing the mechanism(s) by which CaMKK2 reprograms macrophage
metabolic capability by examining the downstream functions of Mitofusin-2 (Mfn2) on mitochondrial dynamics.
We have developed the necessary tools to identify novel interactants and substrates of CaMKK2 in macrophages
in the hopes of providing a mechanistic exp...

## Key facts

- **NIH application ID:** 10360487
- **Project number:** 5F31DK127536-02
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Andrea Ortiz
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $46,752
- **Award type:** 5
- **Project period:** 2021-02-22 → 2023-08-21

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10360487

## Citation

> US National Institutes of Health, RePORTER application 10360487, CaMKK2 in macrophages promotes obesity-induced insulin resistance and inflammation (5F31DK127536-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10360487. Licensed CC0.

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