The biochemical basis of mitochondrial dysfunction in Zellweger Spectrum Disorder.

Peroxisomal biogenesis disorders (PBDs) are genetic disorders of peroxisome biogenesis and metabolism that are characterized by profound developmental and neurological phenotypes. The most severe class of PBDs-Zellweger spectrum disorder (ZSD)-is caused by mutations in peroxin genes that result in both non-functional peroxisomes and mitochondrial dysfunction. It is unclear, however, how defective peroxisomes contribute to mitochondrial impairment. In order to understand the molecular basis of this inter-organellar relationship, we investigated the fate of peroxisomal mRNAs and proteins in ZSD model systems. We found that peroxins were still expressed and a subset of them accumulated on the mitochondrial membrane, which resulted in gross mitochondrial abnormalities and impaired mitochondrial metabolic function. We showed that overexpression of ATAD1, a mitochondrial quality control factor, was sufficient to rescue several aspects of mitochondrial function in human ZSD fibroblasts. Together, these data suggest that aberrant peroxisomal protein localization is necessary and sufficient for the devastating mitochondrial morphological and metabolic phenotypes in ZSDs.

Activation of PASK by mTORC1 is required for the onset of the terminal differentiation program.

During skeletal muscle regeneration, muscle stem cells (MuSCs) respond to multiple signaling inputs that converge onto mammalian target of rapamycin complex 1 (mTORC1) signaling pathways. mTOR function is essential for establishment of the differentiation-committed progenitors (early stage of differentiation, marked by the induction of myogenin expression), myotube fusion, and, ultimately, hypertrophy (later stage of differentiation). While a major mTORC1 substrate, p70S6K, is required for myotube fusion and hypertrophy, an mTORC1 effector for the induction of myogenin expression remains unclear. Here, we identified Per-Arnt-Sim domain kinase (PASK) as a downstream phosphorylation target of mTORC1 in MuSCs during differentiation. We have recently shown that the PASK phosphorylates Wdr5 to stimulate MuSC differentiation by epigenetically activating the myogenin promoter. We show that phosphorylation of PASK by mTORC1 is required for the activation of myogenin transcription, exit from self-renewal, and induction of the myogenesis program. Our studies reveal that mTORC1-PASK signaling is required for the rise of myogenin-positive committed myoblasts (early stage of myogenesis), whereas mTORC1-S6K signaling is required for myoblast fusion (later stage of myogenesis). Thus, our discoveries allow molecular dissection of mTOR functions during different stages of the myogenesis program driven by two different substrates.

Acupressure and Acupuncture Use in the Peripartum Period.

Acupuncture is the procedure of inserting fine needles into specific points on the body for therapeutic purposes. Acupuncture and its derivatives (acupressure, moxibustion, electroacupuncture, and transcutaneous electric nerve stimulation on acupoints) are a popular treatment choice in the peripartum period (32 wk' gestation to 14 d postdelivery). There is substantial research evidence supporting acupuncture and its derivatives in the peripartum period. Benefits in the use of acupressure to reduce labor pain intensity and a reduction in the duration of labor with acupressure have been found. There is mixed evidence for the use of both moxibustion and moxibustion with acupuncture for noncephalic presentations and for acupressure for reducing intraoperative nausea. There is limited evidence available on acupuncture use in women with high-risk pregnancies or multifetal gestations.

Massage During Pregnancy and Postpartum.

Massage is systematic touch and manipulation of the soft tissues of the body that is increasingly being used as an adjunctive therapy for stress relief and to promote relaxation and wellbeing during pregnancy and as an alternative to pharmacologic or invasive forms of analgesia during labor. Literature to support the use of massage in pregnancy and labor is limited; however, evidence to support its use has been increasing over the past 30 years. Massage has been shown to be valuable to pregnant women with anxiety, depression, leg, and back pain, and has shown significant benefit in perception of pain during labor.

Callyspongiolide Is a Potent Inhibitor of the Vacuolar ATPase.

Callyspongiolide is a marine-derived macrolide that kills cells in a caspase-independent manner. NCI COMPARE analysis of human tumor cell line toxicity data for synthetic callyspongiolide indicated that its pattern of cytotoxicity correlated with that seen for concanamycin A, an inhibitor of the vacuolar-type H+-ATPase (V-ATPase). Using yeast as a model system, we report that treatment with synthetic callyspongiolide phenocopied a loss of V-ATPase activity including (1) inability to grow on a nonfermentable carbon source, (2) rescue of cell growth via supplementation with Fe2+, (3) pH-sensitive growth, and (4) a vacuolar acidification defect visualized using the fluorescent dye quinacrine. Crucially, in an in vitro assay, callyspongiolide was found to dose-dependently inhibit yeast V-ATPase (IC50 = 10 nM). Together, these data identify callyspongiolide as a new and highly potent V-ATPase inhibitor. Notably, callyspongiolide is the first V-ATPase inhibitor known to be expelled by Pdr5p.

The experience of women with an eating disorder in the perinatal period: a meta-ethnographic study.

BACKGROUND: Pregnancy is a time of enormous body transformation. For those with an eating disorder during pregnancy this time of transformation can be distressing and damaging to both the mother and the child. In this meta-ethnographic study, we aimed to examine the experiences of women with an Eating Disorder in the perinatal period; that is during pregnancy and two years following birth. METHOD: A meta-ethnographic framework was used in this review. After a systematic online search of the literature using the keywords such as pregnancy, eating disorders, anorexia, bulimia, binge eating disorder, perinatal, postnatal and post-partum, 11 papers, involving 94 women, were included in the review. RESULTS: A qualitative synthesis of the papers identified 2 key themes. The key theme that emerged during pregnancy was: navigating a 'new' eating disorder. The key that emerged in the perinatal period was return to the 'old' eating disorder. CONCLUSION: Following a tumultuous pregnancy experience, many described returning to their pre-pregnancy eating behaviors and thoughts. These experiences highlight the emotional difficulty experienced having an eating disorder whilst pregnant but they also point to opportunities for intervention and a continued acceptance of body image changes. More research is needed on the experiences of targeted treatment interventions specific for pregnant and postpartum women with an eating disorder and the effectiveness of putative treatment interventions during this period.

Instilling hope for a brighter future: A mixed-method mentoring support programme for individuals with and recovered from anorexia nervosa.

AIMS AND OBJECTIVES: To investigate the feasibility of a 13-week mentoring programme in providing social support to promote hope for recovery in anorexia nervosa. BACKGROUND: With no clear first-line psychological treatment for people with anorexia nervosa, mentoring support programmes, as an adjunct to treatment, may provide the social support necessary to promote hope for recovery. DESIGN: A mixed-method study; participatory action research. METHODS: Women (n = 11), recovering and who had recovered from anorexia nervosa, participated in the programme and completed self-report questionnaires related to quality of life, distress and the mentoring relationship at different time points. Qualitative feedback from logbooks, workshop evaluation questionnaires, interviews and focus groups was also collected to assess the programme's acceptability. RESULTS: General compliance for completing most study outcome questionnaires was 90%; however, the mentoring relationship questionnaires were not completed to the same degree. Five key themes emerged from the focus group/interview data: (i) she understands me and could relate to me; (ii) reconnecting with the world-asking questions and being challenged; (iii) mentors' altruistic motivations and the transformation and discovery of self; (iv) instilling hope-recovery is possible; and (v) effective communication-the key to successful mentoring. CONCLUSIONS: Further research is needed; however, the results provide preliminary support for the mentoring programme's feasibility as an adjunct to treatment. We found that having someone who understands, to talk and share with, met a clear need for people with anorexia nervosa. RELEVANCE TO CLINICAL PRACTICE: While further research is warranted mentoring support or recovered mentors, may play a potentially valuable role in supporting those in community settings.

The tipping point of change in Anorexia Nervosa (AN): Qualitative findings from an online study.

The aim of this study was to understand factors related to treatment and/or recovery from self-reported Anorexia Nervosa (AN), including 'the tipping point of change'. An online questionnaire was developed and administered from December 2014 to December 2015 to individuals ≥18 years of age with AN in the past or currently who were recruited through eating disorder organizations in Australia and the United Kingdom. Responses to a specific qualitative question on 'the tipping point of change' were analyzed using conventional content analysis (CCA). One hundred sixty-one participants completed some or all of the questionnaire; only 67 women (41.61%) answered Question six on 'the tipping point of change', and analyses were restricted to data from these women. The themes identified were: 1) realizing the loss of something valuable, 2) the risk of losing something valuable, and 3) something to live for/stay well for. These results are important for health-care providers as they work with patients to identify life experiences, including 'loss/potential loss' and 'the need for preservation', that have personal significance. Some patients may realize that 'enough is enough'; something needs to change. These intrinsic motivating factors may also be the impetus for eventual recovery for some individuals.

A survey of study participants' understanding of informed consent to participate in a randomised controlled trial of acupuncture.

BACKGROUND: It is important that potential study participants are appropriately informed and understand what is involved with their research participation. A few studies have examined study participants' understanding of the informed consent process and the adequacy of the information they received when agreeing to participate in a randomised controlled trial. Deficiencies in the consent process have been found. This topic remains an under researched area of acupuncture research. The aim of this study was to examine participants' understanding of their informed consent and the adequacy of the information presented when agreeing to participate in a randomised controlled trial of acupuncture. METHODS: All women who participated in a randomised controlled trial over an 11 month period were invited to participate in a survey. An anonymous self-completion questionnaire was designed and covered participants' understanding of informed consent in the clinical trial, their views of the information provided, the opportunity to ask questions, the use of sham acupuncture, their recall of study visits and processes for withdrawal, and their reason for participating in the trial. RESULTS: A response rate of 59% was obtained. Over 90% of subjects indicated there was plenty of opportunity to discuss the study prior to giving consent, and 89% indicated that questions asked were answered to their satisfaction. The majority of women indicated the amount of information describing acupuncture was about right, however 24% would have liked more. Information describing sham acupuncture was not considered adequate by 48% of women, and 35% would have liked more information, 30% could not recall why, or were uncertain why a sham group was used. Participants indicated less understanding of the information relating to payment if they became ill due to study participation, risks and discomforts from the study interventions, which of the procedures were experimental and for how long they would be involved in the study. CONCLUSION: Trial participants' understanding of informed consent was overall satisfactory but highlighted some areas of deficiency. Future studies could consider use of supplementary material such as Q and A fact sheets.

Participatory action research for women with anorexia nervosa.

AIM: To discuss the application of the principles of participatory action research (PAR) in a project that developed and evaluated a mentor-mentee support programme for women with anorexia nervosa. BACKGROUND: A programme was developed and implemented in which mentors and mentees participated in workshops, social activities and focus groups that sought to support and develop resilience for those experiencing anorexia nervosa. DISCUSSION: PAR principles were mirrored in the programme, paying respect to the views and needs of each participant, an open trajectory to possible conclusions and a continuous feedback cycle. Mentees had a sense of empowerment, ownership of the programme and hope that recovery was possible. It allowed their voices to be heard and provided them with belief they could begin new relationships and friendships. CONCLUSION: The principles of PAR suited a project aimed at developing self-determination and resilience in women with anorexia nervosa. IMPLICATIONS FOR RESEARCH/PRACTICE: PAR would be readily transferable to a number of mental health settings where empowerment is of paramount concern.

A randomised cross-over pilot study investigating the use of acupuncture to promote weight loss and mental health in overweight and obese individuals participating in a weight loss program.

BACKGROUND: Acupuncture is widely used as an alternative modality for weight loss. Despite its increasing use, few acupuncture studies have evaluated the effect of a weight loss program on the mental health of obese/overweight participants and none have looked at the effect on those with eating, weight and shape concerns. OBJECTIVES: To investigate the feasibility of conducting an acupuncture study involving overweight or obese individuals undertaking a weight loss program with particular reference to those with eating concerns. METHODS: Thirty-five overweight/obese males and females participated in a single-blinded randomised cross-over study. The two intervention phases were: (1) nutritional counselling plus Traditional Chinese Medicine (TCM) acupuncture and (2) nutritional counselling plus sham acupuncture. OUTCOME MEASURES: This study evaluates the feasibility and practicalities of the study including recruitment, retention, adverse events, effectiveness for defining eating and weight concerns, study design and statistics for power calculations. CONCLUSION: The outcome measures, the recruitment of those with eating and weight concerns and the acceptability of the intervention demonstrate a larger trial investigating the use of acupuncture for weight loss in those who have elevated eating and weight concerns is feasible.

Per-Arnt-Sim kinase regulates pancreatic duodenal homeobox-1 protein stability via phosphorylation of glycogen synthase kinase 3ß in pancreatic ß-cells.

In pancreatic ß-cells, glucose induces the binding of the transcription factor pancreatic duodenal homeobox-1 (PDX-1) to the insulin gene promoter to activate insulin gene transcription. At low glucose levels, glycogen synthase kinase 3ß (GSK3ß) is known to phosphorylate PDX-1 on C-terminal serine residues, which triggers PDX-1 proteasomal degradation. We previously showed that the serine/threonine Per-Arnt-Sim domain-containing kinase (PASK) regulates insulin gene transcription via PDX-1. However, the mechanisms underlying this regulation are unknown. In this study, we aimed to identify the role of PASK in the regulation of PDX-1 phosphorylation, protein expression, and stability in insulin-secreting cells and isolated rodent islets of Langerhans. We observed that glucose induces a decrease in overall PDX-1 serine phosphorylation and that overexpression of WT PASK mimics this effect. In vitro, PASK directly phosphorylates GSK3ß on its inactivating phosphorylation site Ser(9). Overexpression of a kinase-dead (KD), dominant negative version of PASK blocks glucose-induced Ser(9) phosphorylation of GSK3ß. Accordingly, GSK3ß Ser(9) phosphorylation is reduced in islets from pask-null mice. Overexpression of WT PASK or KD GSK3ß protects PDX-1 from degradation and results in increased PDX-1 protein abundance. Conversely, overexpression of KD PASK blocks glucose-induction of PDX-1 protein. We conclude that PASK phosphorylates and inactivates GSK3ß, thereby preventing PDX-1 serine phosphorylation and alleviating GSK3ß-mediated PDX-1 protein degradation in pancreatic ß-cells.

Explaining the Impact of the COVID-19 Pandemic on Massage Therapists in Australia and Canada: A Mixed Methods Study.

Background: The COVID-19 pandemic was a time of rapid change and uncertainty, with individual jurisdictions within countries implementing a variety of preventative measures. At the onset of the pandemic, as little was known about how COVID-19 was transmitted, restrictions, such as lockdowns, were implemented to prevent further spread of this virus. In many jurisdictions, massage therapists were deemed as nonessential for a period. This disruption to their livelihood, as a professional group and without autonomy to decide, was unprecedented. This prompted the question as to whether this experience had impacted massage therapists' professional identity. Methods: A sequential explanatory mixed methods design was used and massage therapists in Australia and Canada were recruited to participate. Results from a quantitative questionnaire completed by 649 respondents and from 31 semistructured interviews from a subset of the questionnaire participants were used in the mixed analysis. Results: Massage therapists, impacted by the pandemic, experienced a discord between what it means to be a massage therapist, providing patient-centered care and the public health initiatives implemented during the pandemic. This discord occurred in multiple situations and the type of discord was influenced by a number of factors, including how therapists identified themselves within the workforce (i.e., as a health care provider or a service provider). Conclusion: This study sought to understand how the COVID-19 pandemic impacted massage therapists' professional identity. Massage therapists reported that the pandemic impacted their professional identity through a lack of congruence and discord between their identity-constituting beliefs and what it means to be a massage therapist. The sequela to this discord was therapists experiencing different types of moral distress and or moral injury. Future research is needed to determine the longer-term impacts of COVID-19 on massage therapists.

Swedish massage as an adjunct approach to Help suppOrt individuals Pregnant after Experiencing a prior Stillbirth (HOPES): a convergent parallel mixed-methods single-arm feasibility trial protocol.

BACKGROUND: Women experiencing pregnancy after stillbirth experience high levels of anxiety, fear and depression. Standard antenatal care may be emotionally unsuitable for many women at this time, and there is a lack of evidence on what interventions or approaches to care might benefit these women. Therapeutic massage may assist women after stillbirth by decreasing anxiety, worry and stress. OBJECTIVE: This paper outlines the objectives, methodology, outcome and assessment measures for the Helping suppOrt individuals Pregnant after Experiencing a Stillbirth (HOPES) feasibility trial which evaluates massage as an adjunct approach to care for pregnant women who have experienced a prior stillbirth. It also outlines data collection timing and considerations for analysing the data. METHODS: HOPES will use a convergent parallel mixed-methods, single-arm repeated measures trial design in trained massage therapists' private clinics across Australia. HOPES aims to recruit 75 individuals pregnant after a previous stillbirth. The intervention is massage therapy treatments, and participants will receive up to five massages within a 4-month period at intervals of their choosing. Primary quantitative outcomes are the feasibility and acceptability of the massage intervention. Secondary outcomes include determining the optimal timing of massage therapy delivery and the collection of measures for anxiety, worry, stress and self-management. A thematic analysis of women's experiences undertaking the intervention will also be conducted. A narrative and joint display approach to integrate mixed-methods data is planned. DISCUSSION: The HOPES study will determine the feasibility and preliminary evidence for massage therapy as an intervention to support women who are pregnant after a stillbirth. CLINICALTRIALS: gov NCT05636553. Registered on December 3, 2022, and the trial is ongoing.

Applying Scientific Rationale to the Current Perceptions and Explanations of Massage and Miscarriage in the First Trimester.

Miscarriage is a relatively common occurrence, impacting 8-15% of clinically recognised pregnancies, and up to 30% of all conceptions. The public perception of the risk factors associated with miscarriage does not match the evidence. Evidence indicates that there are very few modifiable factors to prevent miscarriage, and the majority of the time little could have been done to prevent a spontaneous miscarriage. However, the public perception is that consuming drugs, lifting a heavy object, previous use of an intrauterine device, or massage can all contribute to miscarriage. While misinformation about the causes and risk factors of miscarriage continues to circulate, pregnant women will experience confusion about what activities they can (and cannot) do in early pregnancy, including receiving a massage. Pregnancy massage is an important component of massage therapy education. The resources that underpin pregnancy massage coursework consist of educational print content that includes direction and caution that massage in the first trimester, if done 'incorrectly' or in the 'wrong' location, can contribute to adverse outcomes such as miscarriage. The most common statements, perceptions and explanations for massage and miscarriage cover three broad areas: 1) maternal changes from massage affects the embryo/fetus; 2) massage leads to damage of the fetus/placenta; and 3) aspects of the massage treatment in the first trimester initiate contractions. The goal of this paper is to use scientific rationale to critically consider the validity of the current perceptions and explanations of massage therapy and miscarriage. Whilst direct evidence from clinical trials was lacking, considerations of physiological mechanisms regulating pregnancy and known risk factors associated with miscarriage provide no evidence that massage in pregnancy would increase a patient's risk of miscarriage. This scientific rationale should be addressed when teaching pregnancy massage courses.

The paradox of the impact of the COVID-19 pandemic on massage therapists in Australia and Canada: The reporting of a qualitative strand of a mixed methods study.

INTRODUCTION: In both Australia and Canada, healthcare providers considered essential were allowed to operate during the COVID-19 pandemic. The impact of the global pandemic on professional identity included opportunities for role expansion, a focus on ethical principles and social accountability, and professional pride. These results were found only for those considered to be essential and do not likely resonate with those classified as non-essential, such as massage therapists, leaving a gap in understanding. MATERIALS AND METHODS: This qualitative strand of a sequential explanatory mixed methods study used qualitative description. Individuals who expressed interest were purposefully selected, based on age, gender, type of practice, and experience with the four key phenomena of interest. Data collected through semi-structured interviews was analyzed using qualitative content analysis. Member checking enhanced the trustworthiness of the results. RESULTS: Thirty-one (16 Australian and 15 Canadian) participants were interviewed. The main theme described was the pandemic paradox. At some point during the pandemic, most participants were labelled by government agencies as a non-essential service. However, participants reported feeling both essential and non-essential. Two subthemes were also described: factors contributing to creating the paradox and consequences of the paradox. CONCLUSION: A number of pre-existing factors around professional identity, such as patient relationships combined with the conditions instituted to manage the COVID-19 pandemic included designating health care services as essential or non-essential, created the paradox experienced by respondents and the subsequent experience of moral distress. Further research into moral distress experienced by massage therapists is needed.

The Effectiveness of Massage in Managing Pregnant Women with Pelvic Girdle Pain: a Randomised Controlled Crossover Feasibility Study.

Introduction: Pelvic girdle pain is a common problem experienced during pregnancy, with high incidence rates and significant impacts on quality of life. Remedial massage might be able to provide some reduction in pain. Aim: This study aimed to investigate the feasibility of conducting a randomised controlled trial on the effectiveness of massage in treating pregnant women with pelvic girdle pain to determine its merits and viability for use in a large-scale study. Methods: A two-arm pilot randomised feasibility crossover-controlled trial. The two treatment phases were a) remedial pregnancy massage, and b) exercise. Results: Twenty-four women started the study and 19 women completed the study. Data were collected on recruitment and retention rates, crossover study design methodology, participant sub-characteristics, and acceptability of the outcome measures (pain, quality of life, and disability). Conclusion: Recruiting participants for a pregnancy-related pelvic girdle pain study is indeed feasible; however, a crossover study design is not appropriate and future studies should consider a mixed methods study design.

Protein-metabolite interactomics of carbohydrate metabolism reveal regulation of lactate dehydrogenase.

Metabolic networks are interconnected and influence diverse cellular processes. The protein-metabolite interactions that mediate these networks are frequently low affinity and challenging to systematically discover. We developed mass spectrometry integrated with equilibrium dialysis for the discovery of allostery systematically (MIDAS) to identify such interactions. Analysis of 33 enzymes from human carbohydrate metabolism identified 830 protein-metabolite interactions, including known regulators, substrates, and products as well as previously unreported interactions. We functionally validated a subset of interactions, including the isoform-specific inhibition of lactate dehydrogenase by long-chain acyl-coenzyme A. Cell treatment with fatty acids caused a loss of pyruvate-lactate interconversion dependent on lactate dehydrogenase isoform expression. These protein-metabolite interactions may contribute to the dynamic, tissue-specific metabolic flexibility that enables growth and survival in an ever-changing nutrient environment.

Human mutation within Per-Arnt-Sim (PAS) domain-containing protein kinase (PASK) causes basal insulin hypersecretion.

PAS kinase (PASK) is a glucose-regulated protein kinase involved in the control of pancreatic islet hormone release and insulin sensitivity. We aimed here to identify mutations in the PASK gene that may be associated with young-onset diabetes in humans. We screened 18 diabetic probands with unelucidated maturity-onset diabetes of the young (MODY). We identified two rare nonsynonymous mutations in the PASK gene (p.L1051V and p.G1117E), each of which was found in a single MODY family. Wild type or mutant PASKs were expressed in HEK 293 cells. Kinase activity of the affinity-purified proteins was assayed as autophosphorylation at amino acid Thr307 or against an Ugp1p-derived peptide. Whereas the PASK p.G1117E mutant displayed a ∼25% increase with respect to wild type PASK in the extent of autophosphorylation, and a ∼2-fold increase in kinase activity toward exogenous substrates, the activity of the p.L1051V mutant was unchanged. Amino acid Gly1117 is located in an α helical region opposing the active site of PASK and may elicit either: (a) a conformational change that increases catalytic efficiency or (b) a diminished inhibitory interaction with the PAS domain. Mouse islets were therefore infected with adenoviruses expressing wild type or mutant PASK and the regulation of insulin secretion was examined. PASK p.G1117E-infected islets displayed a 4-fold decrease in glucose-stimulated (16.7 versus 3 mM) insulin secretion, chiefly reflecting a 4.5-fold increase in insulin release at low glucose. In summary, we have characterized a rare mutation (p.G1117E) in the PASK gene from a young-onset diabetes family, which modulates glucose-stimulated insulin secretion.

Counter-modulation of fatty acid-induced pro-inflammatory nuclear factor κB signalling in rat skeletal muscle cells by AMP-activated protein kinase.

Sustained over-supply of saturated non-esterified 'free' fatty acids has been shown to promote skeletal muscle insulin resistance, which may be driven, in part, by an increase in inflammatory signalling within this tissue. In the present manuscript we show that exposure of L6 myotubes to palmitate, a saturated fatty acid, induces activation of the NF-κB (nuclear factor κB) pathway {based on increased IKK [IκB (inhibitory κB) kinase] phosphorylation, IκBα loss and elevated interleukin-6 mRNA expression} and that this was associated with enhanced phosphorylation/activation of p38 MAPK (mitogen-activated protein kinase), JNK (c-Jun N-terminal kinase) and ERK (extracellular-signal-regulated kinase) as well as impaired insulin-dependent activation of PKB (protein kinase B)/Akt and glucose transport. NF-κB activation by palmitate was unaffected by pharmacological inhibition of p38 MAPK or JNK, but was suppressed significantly by inhibition of MEK (MAPK/ERK kinase)/ERK signalling. The importance of ERK with respect to downstream NF-κB signalling was underscored by the finding that PMA, a potent ERK activator, enhanced IKK phosphorylation. Strikingly, both palmitate- and PMA-induced activation of IKK/NF-κB were antagonized by AMPK (AMP-activated protein kinase) activators because of reduced ERK signalling. Although palmitate-induced activation of NF-κB was repressed by AMPK activation and by cellular overexpression of a mutated IκBα (S32A/S36A) super-repressor, this did not ameliorate the loss in insulin-stimulated PKB activation or glucose transport. Our results from the present study indicate that ERK plays a pivotal role in palmitate-induced activation of the IKK/NF-κB signalling axis and that AMPK can restrain the activity of this pro-inflammatory pathway. The finding that insulin resistance persists in myotubes in which NF-κB signalling has been repressed implies that palmitate and/or its lipid derivatives retain the capacity to impair insulin-regulated events independently of the increase in inflammatory signalling.