Abstract
Background: Peptidomics research has demonstrated that protease activity is higher in breast milk from pretermdelivering mothers than from term-delivering mothers. However, to our knowledge, the effect of the degree of prematurity and postnatal age on proteases and protease inhibitors in human milk remains unknown. Objective: We aimed to determine the change of proteases and protease inhibitors in milk from mothers who delivered prematurely across gestational age (GA) and postnatal age. Methods: Milk samples were collected from 18 mothers aged 26-40 y who delivered preterm infants and who lacked mastitis. For analysis, sampleswere separated into 2 groups: 9 from early GA (EGA) (24-26wk GA)-delivering mothers and 9 from late GA (LGA) (27-32 wk GA)-delivering mothers. Within the 9 samples in each group, the collection time ranged from postnatal days 2 to 47. The activity and predicted activity of proteases in preterm milk were determined with the use of fluorometric and spectrophotometric assays and peptidomics, respectively. Protease and protease inhibitor concentrations were determined with the use of ELISA. Linearmixed models were applied to compare enzymes across GA and postnatal age. Results: Carboxypeptidase B2, kallikrein, plasmin, elastase, thrombin, and cytosol aminopeptidase were present and active in the milk of preterm-delivering mothers. Most milk protease and antiprotease concentrations did not change with GA or postnatal age. However, the concentration and activity of kallikrein, the most abundant and active protease in preterm milk, increased by 25.4 ng · mL-1 · d-1 and 0.454 μg · mL-1 · d-1 postnatally, respectively, in EGA milk samples while remaining stable in LGA milk samples. Conclusions: This research demonstrates that proteases are active in human milk and begin to degrade milk protein within the mammary gland before consumption by infants. Proteases and protease inhibitors in milk from mothers of premature infants mostly did not vary substantially across GA and postnatal age.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1152-1159 |
| Number of pages | 8 |
| Journal | Journal of Nutrition |
| Volume | 147 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 2017 |
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Keywords
- Antithrombin III
- Carboxypeptidase B2
- Cathepsin D
- Cytosol aminopeptidase
- Elastase
- Plasmin
- Thrombin
- α-antichymotrypsin
- α-antitrypsin
- α-antiplasmin
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics
Cite this
Analysis of milk from mothers who delivered prematurely reveals few changes in proteases and protease inhibitors across gestational age at birth and infant postnatal age. / Demers-Mathieum, Veronique; Nielsen, Søren Drud; Underwood, Mark; Borghese, Robyn; Dallas, David C.
In: Journal of Nutrition, Vol. 147, No. 6, 01.06.2017, p. 1152-1159.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Analysis of milk from mothers who delivered prematurely reveals few changes in proteases and protease inhibitors across gestational age at birth and infant postnatal age
AU - Demers-Mathieum, Veronique
AU - Nielsen, Søren Drud
AU - Underwood, Mark
AU - Borghese, Robyn
AU - Dallas, David C.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Background: Peptidomics research has demonstrated that protease activity is higher in breast milk from pretermdelivering mothers than from term-delivering mothers. However, to our knowledge, the effect of the degree of prematurity and postnatal age on proteases and protease inhibitors in human milk remains unknown. Objective: We aimed to determine the change of proteases and protease inhibitors in milk from mothers who delivered prematurely across gestational age (GA) and postnatal age. Methods: Milk samples were collected from 18 mothers aged 26-40 y who delivered preterm infants and who lacked mastitis. For analysis, sampleswere separated into 2 groups: 9 from early GA (EGA) (24-26wk GA)-delivering mothers and 9 from late GA (LGA) (27-32 wk GA)-delivering mothers. Within the 9 samples in each group, the collection time ranged from postnatal days 2 to 47. The activity and predicted activity of proteases in preterm milk were determined with the use of fluorometric and spectrophotometric assays and peptidomics, respectively. Protease and protease inhibitor concentrations were determined with the use of ELISA. Linearmixed models were applied to compare enzymes across GA and postnatal age. Results: Carboxypeptidase B2, kallikrein, plasmin, elastase, thrombin, and cytosol aminopeptidase were present and active in the milk of preterm-delivering mothers. Most milk protease and antiprotease concentrations did not change with GA or postnatal age. However, the concentration and activity of kallikrein, the most abundant and active protease in preterm milk, increased by 25.4 ng · mL-1 · d-1 and 0.454 μg · mL-1 · d-1 postnatally, respectively, in EGA milk samples while remaining stable in LGA milk samples. Conclusions: This research demonstrates that proteases are active in human milk and begin to degrade milk protein within the mammary gland before consumption by infants. Proteases and protease inhibitors in milk from mothers of premature infants mostly did not vary substantially across GA and postnatal age.
AB - Background: Peptidomics research has demonstrated that protease activity is higher in breast milk from pretermdelivering mothers than from term-delivering mothers. However, to our knowledge, the effect of the degree of prematurity and postnatal age on proteases and protease inhibitors in human milk remains unknown. Objective: We aimed to determine the change of proteases and protease inhibitors in milk from mothers who delivered prematurely across gestational age (GA) and postnatal age. Methods: Milk samples were collected from 18 mothers aged 26-40 y who delivered preterm infants and who lacked mastitis. For analysis, sampleswere separated into 2 groups: 9 from early GA (EGA) (24-26wk GA)-delivering mothers and 9 from late GA (LGA) (27-32 wk GA)-delivering mothers. Within the 9 samples in each group, the collection time ranged from postnatal days 2 to 47. The activity and predicted activity of proteases in preterm milk were determined with the use of fluorometric and spectrophotometric assays and peptidomics, respectively. Protease and protease inhibitor concentrations were determined with the use of ELISA. Linearmixed models were applied to compare enzymes across GA and postnatal age. Results: Carboxypeptidase B2, kallikrein, plasmin, elastase, thrombin, and cytosol aminopeptidase were present and active in the milk of preterm-delivering mothers. Most milk protease and antiprotease concentrations did not change with GA or postnatal age. However, the concentration and activity of kallikrein, the most abundant and active protease in preterm milk, increased by 25.4 ng · mL-1 · d-1 and 0.454 μg · mL-1 · d-1 postnatally, respectively, in EGA milk samples while remaining stable in LGA milk samples. Conclusions: This research demonstrates that proteases are active in human milk and begin to degrade milk protein within the mammary gland before consumption by infants. Proteases and protease inhibitors in milk from mothers of premature infants mostly did not vary substantially across GA and postnatal age.
KW - Antithrombin III
KW - Carboxypeptidase B2
KW - Cathepsin D
KW - Cytosol aminopeptidase
KW - Elastase
KW - Plasmin
KW - Thrombin
KW - α-antichymotrypsin
KW - α-antitrypsin
KW - α-antiplasmin
UR - http://www.scopus.com/inward/record.url?scp=85021056210&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85021056210&partnerID=8YFLogxK
U2 - 10.3945/jn.116.244798
DO - 10.3945/jn.116.244798
M3 - Article
C2 - 28424255
AN - SCOPUS:85021056210
VL - 147
SP - 1152
EP - 1159
JO - Journal of Nutrition
JF - Journal of Nutrition
SN - 0022-3166
IS - 6
ER -