Multiple functions of pyruvate kinase M2 in various cell types.

Glucose metabolism is a mechanism by which energy is produced in form of adenosine triphosphate (ATP) by mitochondria and precursor metabolites are supplied to enable the ultimate enrichment of mature metabolites in the cell. Recently, glycolytic enzymes have been shown to have unconventional but important functions. Among these enzymes, pyruvate kinase M2 (PKM2) plays several roles including having conventional metabolic enzyme activity, and also being a transcriptional regulator and a protein kinase. Compared with the closely related PKM1, PKM2 is highly expressed in cancer cells and embryos, whereas PKM1 is dominant in mature, differentiated cells. Posttranslational modifications such as phosphorylation and acetylation of PKM2 change its cellular functions. In particular, PKM2 can translocate to the nucleus, where it regulates the transcription of many target genes. It is notable that PKM2 also acts as a protein kinase to phosphorylate several substrate proteins. Besides cancer cells and embryonic cells, astrocytes also highly express PKM2, which is crucial for lactate production via expression of lactate dehydrogenase A (LDHA), while mature neurons predominantly express PKM1. The lactate produced in cancer cells promotes tumor progress and that in astrocytes can be supplied to neurons and may act as a major source for neuronal ATP energy production. Thereby, we propose that PKM2 along with its different posttranslational modifications has specific purposes for a variety of cell types, performing unique functions.

Acupuncture for chronic low back pain: a multicenter, randomized, patient-assessor blind, sham-controlled clinical trial.

STUDY DESIGN: Multicenter, randomized, patient-assessor blind, sham-controlled clinical trial. OBJECTIVE: To investigate the efficacy of acupuncture treatment with individualized setting for reduction of bothersomeness in participants with chronic low back pain (cLBP). SUMMARY OF BACKGROUND DATA: Low back pain is one of the main reasons of disability among adults of working age. Acupuncture is known as an effective treatment of cLBP, but it remains unclear whether acupuncture is superior to placebo. METHODS: One hundred thirty adults aged 18 to 65 years with nonspecific LBP lasting for at least last 3 months prior to the trial participated in the study from 3 Korean medical hospitals. Participants received individualized real acupuncture treatments or sham acupuncture treatments for more than 6 weeks (twice a week) from Korean Medicine doctors. Primary outcome was change of visual analogue scale (VAS) score for bothersomeness of cLBP. Secondary outcomes included VAS score for pain intensity and questionnaires including Oswestry Disability Index, general health status (Short Form-36), and Beck Depression Inventory (BDI). RESULTS: There were no baseline differences observed between the 2 groups, except in the Oswestry Disability Index. One hundred sixteen participants finished the treatments and 3- and 6-month follow-ups, with 14 subjects dropping out. Significant difference in VAS score for bothersomeness and pain intensity score of cLBP has been found between the 2 groups (P < 0.05) at the primary end point (8 wk). In addition, those 2 scores improved continuously until 3-month follow-up (P = 0.011, P = 0.005, respectively). Oswestry Disability Index, the Beck Depression Inventory, and Short Form-36 scores were also improved in both groups without group difference. CONCLUSION: This randomized sham-controlled trial suggests that acupuncture treatment shows better effect on the reduction of the bothersomeness and pain intensity than sham control in participants with cLBP.