Objectives: Maternal stress has long been associated with lower birthweight, which is associated with adverse health outcomes including many adult diseases. The underlying mechanisms remain elusive although changes in gene expression may play a role. Studies are only beginning to test how maternal stress impacts gene expression as reflected in the transcriptome.
Materials and methods: In a cohort of mothers and newborns in the eastern Democratic Republic of Congo (n=93), we studied the effects of four maternal stress measures (chronic stress, war trauma, sexual trauma, and general trauma) on the transcriptomes of maternal venous blood, newborn venous blood, and placental tissues, and on newborn birthweight. Maternal stress was investigated as independent measures, principal components, and clusters identified through machine learning. The transcriptome was assayed using the ClariomD chip. Multiple regression models were used to test for associations between maternal stress measures, the transcriptome, and newborn birthweight.
Results: None of the maternal stress measures showed an association with expression of individual genes. In contrast, when testing global gene expression, war trauma was significantly associated with the placental transcriptome. War trauma was also significantly associated with birthweight in multiple models. Mediation analysis indicated that ~14% of the effect of war trauma on birthweight was mediated by a placental gene expression component.
Discussion: Our results suggest that gene expression in the placenta, which represents the interface between mother and developing fetus, may partially mediate the negative impact of maternal stress on newborn birthweight.
Kichwa kifupi :: Msongo, maonyesho za jeni, na uzito wa kuzaliwa katika Jamhuri ya Kidemokrasia ya Kongo
Malengo:: Msongo kwa wamama kwa muda mrefu umeambatanishwa na uzito mdogo wa kuzaliwa, ambao unahusishwa na matokeo mabaya ya afya ikiwa ni pamoja na magonjwa mengi ya watu wazima. Mambo inayo sababisha hayo haiko wazi kabisa hata kama mabadiliko kuhusu maonyesho za jeni yanaweza kuwa moja ya mafasirio. Utafiti mbalimbali imeanza kujaribu matokeo ya mbali ya msongo wa mama kulingana na maonyesho za jeni kama inayoshuhudia mafunzo ya trancriptome.
Vyombo na mbinu za utafiti:: Katika kundi la wamama na watoto wachanga mashariki mwa Jamhuri ya Kidemokrasia ya Kongo (n=93), tulichunguza matokeo za vipimo nne za msongo wa mama (msongo wakuzidi muda mrefu, jeraha wa vita, jeraha za kijinsia, na jeraha kwa ujumla) kwenye transcriptome ya mshipa wa damu wa mama, mshipa wa damu wa mtoto aliyezaliwa, nyama ya kizazi cha mama na pia uzito wa mtoto huyo mchanga. Msongo wa mama ulichunguzwa kama kipimo yakipekee, sehemu kuu na vikundi vilivyotambuliwa kupitia majifunzo ya otomatiki. Trancriptome ilikadiriwa kwa kutumia kiasi ya ClariomD. Mitindo mingi ya statistiki kama urejeshi nyingi (multiple regressions) ilitumimiwa kupima upatanishi kati ya vipimo vya msongo wa mama, transcriptome, na uzito wa mtoto wakati wakuzaliwa.
Matokeo:: Hakuna vipimo fulani vya msongo wa mama viilionyesha uwasiliano wa maonyesho za jeni za mtu binafsi. Kinyume na hayo, wakati wa kujaribu maonyesho ya jeni kwa ujumla, jeraha ya vita iliambatanishwa kwa kiasi kikubwa na transcriptome ya kizazi. Jeraha ya vita pia iliambatanishwa kwa kiasi kikubwa na uzito wa kuzaliwa katika mifano nyingi. Uchambuzi wa upatanishi ulionyesha kuwa kiasi 14% ya matokeo ya jeraha ya vita kuhusu uzito wa kuzaliwa iliongozwa na sehemu ya maonyesho ya jeni ya kizazi.
Majadiliano:: Matokeo yetu yanapendekeza kwamba maonyesho ya jeni katika kizazi, inaosimamiya upatanishi kati ya mama na mtoto anaye kuwa tumboni, inaweza kwa sehemu kuongoza matokeo mabaya ya msongo wa mama kwa uzito wa kuzaliwa wa mtoto.
Keywords: Maternal stress; birth weight; placenta; transcriptome; war trauma.