Deciphering the mechanism of PSORI-CM02 in suppressing keratinocyte proliferation through the mTOR/HK2/glycolysis axis

by Selleckchem | Jun 26 2023

Hyperplasia of epidermal keratinocytes that depend on glycolysis is a new hallmark of psoriasis pathogenesis. Our previous studies demonstrated that PSORI-CM02 could halt the pathological progression of psoriasis by targeting inflammatory response and angiogenesis, but its effect(s) and mechanism(s) on proliferating keratinocytes remained unclear. In this study, we aim to identify components of PSORI-CM02 that are absorbed into the blood and to determine the effect(s) of PSORI-CM02 on keratinocyte proliferation and its molecular mechanism(s). We used the immortalized human epidermal keratinocyte cell line, HaCaT, as an in vitro model of proliferating keratinocytes and the imiquimod-induced psoriasis mouse (IMQ) as an in vivo model. Metabolite profiles of vehicle pharmaceutic serum (VPS), PSORI-CM02 pharmaceutic serum (PPS), and water extraction (PWE) were compared, and 23 components of PSORI-CM02 were identified that were absorbed into the blood of mice. Both PPS and PWE inhibited the proliferation of HaCaT cells and consequently reduced the expression of the proliferation marker ki67. Additionally, PPS and PWE reduced phosphorylation levels of mTOR pathway kinases. Seahorse experiments demonstrated that PPS significantly inhibited glycolysis, glycolytic capacity, and mitochondrial respiration, thus reducing ATP production in HaCaT cells. Upon treatments of PPS or PWE, hexokinase 2 (HK2) expression was significantly decreased, as observed from the set of glycolytic genes we screened. Finally, in the IMQ model, we observed that treatment with PSORI-CM02 or BPTES, an inhibitor of mTOR signaling, reduced hyperproliferation of epidermal keratinocytes, inhibited the expression of p-S6 and reduced the number of proliferating cell nuclear antigen (PCNA)-positive cells in lesioned skin. Taken together, we demonstrate that PSORI-CM02 has an anti-proliferative effect on psoriatic keratinocytes, at least in part, by inhibiting the mTOR/HK2/glycolysis axis.

Comments:

The passage you provided describes a study aimed at understanding the effects and mechanisms of PSORI-CM02, a therapeutic compound, on proliferating keratinocytes in psoriasis. The researchers used both in vitro and in vivo models to investigate the impact of PSORI-CM02 on keratinocyte proliferation and its underlying molecular mechanisms.

The researchers first compared the metabolite profiles of vehicle pharmaceutic serum (VPS), PSORI-CM02 pharmaceutic serum (PPS), and water extraction (PWE) to identify components of PSORI-CM02 that were absorbed into the blood of mice. They identified 23 components of PSORI-CM02 that were present in the blood.

Next, the researchers evaluated the effect of PSORI-CM02 on the proliferation of human epidermal keratinocyte cells (HaCaT) in vitro. Both PPS and PWE inhibited the proliferation of HaCaT cells, as evidenced by reduced expression of the proliferation marker ki67. Furthermore, PPS and PWE decreased the phosphorylation levels of kinases in the mTOR pathway, a signaling pathway involved in cell growth and proliferation.

To understand the metabolic changes induced by PSORI-CM02, the researchers performed Seahorse experiments. They found that PPS significantly inhibited glycolysis, glycolytic capacity, and mitochondrial respiration in HaCaT cells, leading to reduced ATP production. The expression of hexokinase 2 (HK2), a key enzyme in glycolysis, was also significantly decreased upon treatment with PPS or PWE.

In the in vivo model using imiquimod-induced psoriasis mice (IMQ), the researchers examined the effects of PSORI-CM02 and an mTOR signaling inhibitor called BPTES. They observed that treatment with both PSORI-CM02 and BPTES reduced the hyperproliferation of epidermal keratinocytes in the lesioned skin. These treatments also inhibited the expression of p-S6, a marker of mTOR pathway activation, and decreased the number of proliferating cell nuclear antigen (PCNA)-positive cells, indicating reduced cell proliferation.

In conclusion, the study demonstrated that PSORI-CM02 has an anti-proliferative effect on psoriatic keratinocytes, partially mediated by inhibiting the mTOR/HK2/glycolysis axis. These findings provide insights into the potential mechanisms of action of PSORI-CM02 and suggest it may be a promising therapeutic approach for psoriasis by targeting proliferating keratinocytes.