Commentary: Obesity and Weight Gain in Pregnancy and Postpartum: an Evidence Review of Lifestyle Interventions to Inform Maternal and Child Health Policies

We read with interest the recent review published in Frontiers in Endocrinology that was focused on obesity and weight gain in pregnancy and postpartum. The review of systematic reviews and meta-analyses, investigating the effects of lifestyle interventions on gestational weight gain (GWG) and postpartum weight retention (PPWR), provides evidence showing that lifestyle interventions can reduce excess weight gain and associated risk factors. We agree unconditionally that the burden of maternal and childhood obesity needs to be reduced urgently.Funding for this research has been provided from the Australian Government's Medical Research Future Fund (MRFF)

CTX-injury and muscular dystrophy activate Lin- SP cells <i>in vivo</i> and alter their <i>in vitro</i> proliferation and morphology.

<p><b>A</b>: Histological comparison of tissue sections from wild type (WT), CTX-injured (CTX), and <i>mdx^5cv</i> (MDX) tibialis anterior muscle stained with Hematoxylin and Eosin. Wild type muscle shows closely apposed muscle fibers with peripherally located nuclei. CTX-injured muscle at 3 days post-injection has only a few degenerating myofibers surrounded by large numbers of mononuclear cells. Muscle from 8 week old <i>mdx^5cv</i> mice shows areas of active regeneration (white arrow), and areas of muscle degeneration with accumulations of inflammatory cells (green arrow). Scale bar  = 50 μm. <b>B</b>: Comparison of the number of Lin-SP cells isolated by FACS per gram of muscle from wild type, CTX-injured and <i>mdx^5cv</i> mice. Asterisks indicate a significant difference (p<0.01, Student's t-test) from wild type muscle. <b>C</b>: Quantification of <i>in vitro</i> Lin- SP cell proliferation using the Alamar Blue vital dye assay. Asterisks indicate a significant difference (p<0.001, linear regression analysis) from wild type muscle. <b>C</b>: Phase pictures of wild type, CTX and <i>mdx^5cv</i> Lin- SP cells at days 3, 8 and 11 in culture showing differences in cell adhesion, proliferation and morphology. Scale bar  = 50 μm.</p

Muscle damage abolishes <i>in vitro</i> myogenesis of Lin- SP cells and favors their differentiation into FAPs, fibroblasts and adipocytes.

<p>Cultures of Lin- SP cells isolated from wild type (WT) CTX-injured (CTX), or <i>mdx^5cv</i> mice were immunolabelled with antibodies to the myogenic (green) or mesenchymal (red) markers indicated. Labeling for Pax7 (satellite cells), PDGFRα (FAPs) and Collagen 1 (fibroblasts) was done on day 7 cultures. Labeling for α-actinin (myotubes) and C/ebpα (adipocytes) was performed at day 11. Scale bar for α-actinin pictures is 500 μm. Scale bar shown in WT Pax7 picture applies to all other pictures and is 100 μm.</p

In vitro lineage choices of Lin-SP cells isolated from wild type, mdx5cv, or cardiotoxin-injured muscle.

<p>Values represent mean ± standard deviation from 3 biological replicates.</p

Freshly isolated Lin-SP cells express FAPs surface markers but are capable of myogenic differentiation.

<p><b>A</b>: RT-PCR analysis of freshly isolated Lin- SP cells from wild type (WT) and <i>mdx^5cv</i> (MDX) muscle for myogenic markers (Pax7 and Myf5) and FAPs markers (PDGFRα and Sca1). Positive controls (PC) are sorted Sca1-positive cells for Sca1 and Lin- MP cells for Pax7, Myf5 and PDGFRα. Negative controls (NC) are sorted Sca1-negative cells for Sca1 and CD45-positive MP cells for Pax7, Myf5 and PDGFRα. <b>B, C</b>: FACS analysis of PDGFRα and Sca1 protein expression in Lin- SP cells (<b>B</b>) and Lin- MP cells (<b>C</b>) from wild type (WT) and <i>mdx^5cv</i> (MDX) muscle. Percentages of cells double positive (red) and double negative (green) for PDGFRα and Sca1 are shown. <b>D</b>: Confirmation by RT-PCR for PDGFRα expression in Lin- SP and Lin- MP cells sorted into PDGFRα-positive (Pα+) and PDGFRα-negative (Pα−) sub-fractions. <b>E</b>: <i>In vitro</i> myogenic differentiation of Lin- SP and MP cells sorted based on PDGFRα (Pα) expression. Cells were fixed after 14 days in culture and immunolabelled for α-actinin (green) to reveal myotubes. Cultures were counterstained with DAPI (blue) to visualize nuclei. Lin- MP Pα+ cells correspond to the previously characterized FAPs. Lin- MP Pα− cells are enriched in myogenic cells and also contain fibroblasts. Cultured wild type Lin- MP Pα− cells had 2,261 myotubes while cultured <i>mdx^5cv</i> Lin- MP Pα− cells had only 541 myotubes. Lin- SP Pα− cells did not survive in culture and are not shown. Scale bar  = 400 μm. <b>E</b>: Cultures of Lin- SP Pα− cells were double labeled with antibodies to α-actinin (green) and collagen I (red) to visualize myotubes and fibroblasts, respectively. Cultures of Lin- SP Pα− cells from dystrophic muscle (MDX) do not contain myotubes but give rise to fibroblasts. Scale bar  = 100 μm. <b>G</b>. Quantitative RT-PCR for Pax7 expression in Pdgfrα+ and Pdgfrα− Lin-SP cells, and Pdgfrα− Lin-MP cells. Data is presented as means +/− s.d. from 3 technical replicates.</p

In vitro cell-autonomous myogenic differentiation of muscle SP cells and Lin- SP cells.

<p><b>A–C</b>: Phase pictures of wild type muscle SP cells cultured in EGM medium on Matrigel. Cells attached to Matrigel at days 3 (<b>A</b>), had significantly proliferated by day 7 (<b>B</b>), and differentiated into contracting multinucleated myotubes by day 11 (<b>C</b>). Scale bar  = 50 μm. <b>D–F</b>: Immunostaining of muscle SP cultures for the myotube marker α-actinin (<b>D</b>; green) at day 11; for the myoblast marker myogenin (<b>E</b>; green) at day 5; and for the satellite cell marker Pax 7 (F; green) at day 3. Cells were counterstained with DAPI (blue) to visualize nuclei. Scale bar  = 100 μm. <b>G</b>: Phase picture of day 11 cultures of primary myogenic cells in EGM medium on a Matrigel substrate showing formation of large numbers of myotubes. <b>H–I</b>: Isolation of muscle SP sub-populations by FACS. Total muscle mononuclear cells were labeled with antibodies to CD31 and CD45 and CD31+, CD45+ and Lin- cells were sorted first (<b>H</b>). Cells in each fraction were re-analyzed by FACS for incorporation of Hoechst and SP cells were isolated. The SP profile for the Lin- subset of cells in <b>H</b> is shown in <b>I</b>. MP cells are indicated. <b>J–L</b>: Phase pictures of day 11 cultures of CD45+ SP cells (<b>J</b>), CD31+ SP cells (<b>K</b>), and Lin- SP cells (<b>L</b>). Scale bar  = 50 μm. <b>M</b>: Pax7 mRNA was detected by RT-PCR in RNA isolated from muscle SP and Lin-SP cells but not CD31+/CD45− SP cells, Lin- MP cells shown in <b>I</b> were used as a positive control since they contain satellite cells. RNA was isolated immediately after cell isolation by FACS from wild type muscles.</p

Muscle SP cells express vascular endothelial cell markers and incorporate Acetylated-LDL in vivo.

<p>Values represent mean ± standard deviation from the indicated number (n) of biological replicates.</p

Health in Preconception, Pregnancy and Postpartum Global Alliance: International Network Preconception Research Priorities for the Prevention of Maternal Obesity and Related Pregnancy and Long-Term Complications

The preconception period is a key public health and clinical opportunity for obesity prevention. This paper describes the development of international preconception priorities to guide research and translation activities for maternal obesity prevention and improve clinical pregnancy outcomes. Stakeholders of international standing in preconception and pregnancy health formed the multidisciplinary Health in Preconception, Pregnancy, and Postpartum (HiPPP) Global Alliance. The Alliance undertook a priority setting process including three rounds of priority ranking and facilitated group discussion using Modified Delphi and Nominal Group Techniques to determine key research areas. Initial priority areas were based on a systematic review of international and national clinical practice guidelines, World Health Organization recommendations on preconception and pregnancy care, and consumer and expert input from HiPPP members. Five preconception research priorities and four overarching principles were identified. The priorities were: healthy diet and nutrition; weight management; physical activity; planned pregnancy; and physical, mental and psychosocial health. The principles were: operating in the context of broader preconception/antenatal priorities; social determinants; family health; and cultural considerations. These priorities provide a road map to progress research and translation activities in preconception health with future efforts required to advance evidence-translation and implementation to impact clinical outcomes