# Targeting hexokinase-2 in rheumatoid arthritis

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2021 · $337,120

## Abstract

ABSTRACT
Targeting Hexokinase 2 in Rheumatoid Arthritis (changes are underlined)
Hexokinases (HKs) catalyze the first committed step in glucose metabolism. HK2 constitutes the principal
inducible isoform and has a restricted distribution of expression in normal adult tissues. Cell populations with
increased glycolysis and HK2 expression have a powerful growth advantage. HK2 localizes also at
mitochondria, and its interaction increases glucose metabolism and protects mitochondria against apoptosis.
Thus, mitochondrial HK2 translocation promotes an activated phenotype in several cell types.
Fibroblast like synoviocytes (FLS) and macrophages (MO) are a key component of rheumatoid arthritis (RA)
inflamed synovium and contribute to the initiation and perpetuation of destructive joint inflammation. FLS from
patients with RA display unique aggressive features, which are autonomous and vertically transmitted. MO are
also critical in the pathogenesis of RA. The increase in the number of sublining MO in the synovium is an early
hallmark of active rheumatic disease, and high numbers of MO are a prominent feature of inflammatory
lesions. Of note, a critical role of glucose metabolism in both activated FLS and MO, have been highlighted by
our recent work among others.
Our preliminary data demonstrate that while HK1 expression is expressed in both OA and RA synovium, HK2
expression co-localizes with MO and FLS markers, and is only observed in RA and not in OA synovial
samples. We also show that HK2 regulates key FLS function as HK2 knockdown impaired FLS invasion.
Conversely, HK2 overexpression increases FLS invasion and migration rate. Of note, lactate and PLOD2,
which are involved in cell migration and invasion, are upregulated after HK2 expression. Up-regulation of
extracellular lactate also suggests a metabolic shift towards accelerated glycolytic metabolism. An HK2 mutant
lacking its mitochondrial-binding motif (HK2ΔN) reversed the invasive phenotype. In MO, a peptide that
dissociates HK2 from mitochondria, impaired IL-6 secretion. Importantly, adenovirus-mediated expression of
HK2 in the knee by intra-articular injection induced synovial thickness, which was much less evident when
HK2ΔN was intra-articular injected. Finally, HK2F/F-Col1a1 mice, which deletes HK2 in FLS among other non-
hematopoietic cells, and treatment with clotrimazole, which dissociated HK2 from mitochondria, significantly
decreased arthritis severity. Thus, we will test the hypothesis that mitochondrial HK2 is key regulator of FLS
phenotype and MO activation, which contributes to joint destruction in RA. The identification of HK2, an
isoform-specific contributor to elevated cell glucose metabolism in RA synovial tissue offers a safer
approach than global glycolysis inhibition. HK2 could be selectively targeted without compromising
systemic homeostasis or corresponding metabolic function in normal cells as a novel additional
approach for combination therapy in RA joint disease indepen...

## Key facts

- **NIH application ID:** 10190836
- **Project number:** 5R01AR073324-04
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Monica Guma
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $337,120
- **Award type:** 5
- **Project period:** 2018-08-15 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10190836

## Citation

> US National Institutes of Health, RePORTER application 10190836, Targeting hexokinase-2 in rheumatoid arthritis (5R01AR073324-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10190836. Licensed CC0.

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