The authors thank the Clinical Biological Resource Bank of Guangzhou Women and Children&#39;s Medical Center for providing the clinical sample and Guangzhou Forevergen Biosciences Laboratory Animal Center for providing mice. This research was supported by the National Natural&#160;Science Foundation of China grant 81770510 (R.Z.).

This research was approved by the Medical Ethics Committee of Guangzhou Women and Children&#39;s Medical Center (NO. 174A01) and the Animal Ethical Committee of the Guangzhou Forevergen Biosciences Laboratory Animal Center (IACUC-G160100). All animals were bred in the same room in a specific pathogen-free (SPF) environment, and experiments were carried out in a conventional environment. The mice used for breeding were 7-8 weeks old; the mice for inducing NEC (n = 72) were separated from the dam on Day 4, and&#160;the dam...

<ol>
	<li>Horbar, J. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mortality+and+neonatal+morbidity+among+infants+501+to+1500+grams+from+2000+to+2009.">Mortality and neonatal morbidity among infants 501 to 1500 grams from 2000 to 2009.</a> Pediatrics. 129 (6), 1019-1026 (2012).</li><li>Stoll, B. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neonatal+outcomes+of+extremely+preterm+infants+from+the+NICHD+Neonatal+Research+Network.">Neonatal outcomes of extremely preterm infants from the NICHD Neonatal Research Network.</a> Pediatrics. 126 (3), 443-456 (2010).</li><li>Neu, J., Walker, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Necrotizing+enterocolitis.">Necrotizing enterocolitis.</a> New England Journal of Medicine. 364 (3), 255-264 (2011).</li><li>Sangild, P. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Invited+Review:+The+preterm+pig+as+a+model+in+pediatric+gastroenterology.">Invited Review: The preterm pig as a model in pediatric gastroenterology.</a> Journal of Animal Science. 91 (10), 4713-4729 (2013).</li><li>Cancro, M. P., Sigal, N. H., Klinman, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+expression+of+an+equivalent+clonotype+among+BALB/c+and+C57BL/6+mice.">Differential expression of an equivalent clonotype among BALB/c and C57BL/6 mice.</a> Journal of Experimental Medicine. 147 (1), 1-12 (1978).</li><li>Kuroda, E., Yamashita, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+enhanced+macrophage-mediated+prostaglandin+E2+production+and+its+suppressive+role+in+Th1+activation+in+Th2-dominant+BALB/c+mice.">Mechanisms of enhanced macrophage-mediated prostaglandin E2 production and its suppressive role in Th1 activation in Th2-dominant BALB/c mice.</a> Journal of Immunology. 170 (2), 757-764 (2003).</li><li>Fornefett, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+analysis+of+clinics,+pathologies+and+immune+responses+in+BALB/c+and+C57BL/6+mice+infected+with+Streptobacillus+moniliformis.">Comparative analysis of clinics, pathologies and immune responses in BALB/c and C57BL/6 mice infected with Streptobacillus moniliformis.</a> Microbes and Infection. 20 (2), 101-110 (2018).</li><li>Rosas, L. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+background+influences+immune+responses+and+disease+outcome+of+cutaneous+L.+mexicana+infection+in+mice.">Genetic background influences immune responses and disease outcome of cutaneous L. mexicana infection in mice.</a> International Immunology. 17 (10), 1347-1357 (2005).</li><li>Sproat, T., Payne, R. P., Embleton, N. D., Berrington, J., Hambleton, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=T+cells+in+preterm+infants+and+the+influence+of+milk+diet.">T cells in preterm infants and the influence of milk diet.</a> Frontiers in Immunology. 11, 1035 (2020).</li><li>Nanthakumar, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mechanism+of+excessive+intestinal+inflammation+in+necrotizing+enterocolitis:+an+immature+innate+immune+response.">The mechanism of excessive intestinal inflammation in necrotizing enterocolitis: an immature innate immune response.</a> PLoS One. 6 (3), 17776 (2011).</li><li>Afrazi, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+insights+into+the+pathogenesis+and+treatment+of+necrotizing+enterocolitis:+Toll-like+receptors+and+beyond.">New insights into the pathogenesis and treatment of necrotizing enterocolitis: Toll-like receptors and beyond.</a> Pediatric Research. 69 (3), 183-188 (2011).</li><li>Auestad, N., Korsak, R. A., Bergstrom, J. D., Edmond, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Milk-substitutes+comparable+to+rat's+milk;+their+preparation,+composition+and+impact+on+development+and+metabolism+in+the+artificially+reared+rat.">Milk-substitutes comparable to rat's milk; their preparation, composition and impact on development and metabolism in the artificially reared rat.</a> British Journal of Nutrition. 61 (3), 495-518 (1989).</li><li>Liu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lactoferrin-induced+myeloid-derived+suppressor+cell+therapy+attenuates+pathologic+inflammatory+conditions+in+newborn+mice.">Lactoferrin-induced myeloid-derived suppressor cell therapy attenuates pathologic inflammatory conditions in newborn mice.</a> Journal of Clinical Investigation. 129 (10), 4261-4275 (2019).</li><li>MohanKumar, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+murine+neonatal+model+of+necrotizing+enterocolitis+caused+by+anemia+and+red+blood+cell+transfusions.">A murine neonatal model of necrotizing enterocolitis caused by anemia and red blood cell transfusions.</a> Nature Communications. 10 (1), 3494 (2019).</li><li>He, Y. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transitory+presence+of+myeloid-derived+suppressor+cells+in+neonates+is+critical+for+control+of+inflammation.">Transitory presence of myeloid-derived suppressor cells in neonates is critical for control of inflammation.</a> Nature Medicine. 24 (2), 224-231 (2018).</li><li>Cho, S. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+pathoimmunology+of+necrotizing+enterocolitis+reveals+novel+therapeutic+opportunities.">Characterization of the pathoimmunology of necrotizing enterocolitis reveals novel therapeutic opportunities.</a> Nature Communications. 11 (1), 5794 (2020).</li><li>Halpern, M. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Decreased+development+of+necrotizing+enterocolitis+in+IL-18-deficient+mice.">Decreased development of necrotizing enterocolitis in IL-18-deficient mice.</a> American Journal of Physiology. Gastrointestinal and Liver Physiology. 294 (1), 20-26 (2007).</li><li>Wu, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MAP3K2-regulated+intestinal+stromal+cells+define+a+distinct+stem+cell+niche.">MAP3K2-regulated intestinal stromal cells define a distinct stem cell niche.</a> Nature. 592 (7855), 606-610 (2021).</li><li>Nino, D. F., Sodhi, C. P., Hackam, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Necrotizing+enterocolitis:+new+insights+into+pathogenesis+and+mechanisms.">Necrotizing enterocolitis: new insights into pathogenesis and mechanisms.</a> Nature Reviews. Gastroenterology &amp; Hepatology. 13 (10), 590-600 (2016).</li><li>Chuang, S. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cow's+milk+protein-specific+T-helper+type+I/II+cytokine+responses+in+infants+with+necrotizing+enterocolitis.">Cow's milk protein-specific T-helper type I/II cytokine responses in infants with necrotizing enterocolitis.</a> Pediatric Allergy &amp; Immunology. 20 (1), 45-52 (2009).</li></ol>

NEC is the most common gastrointestinal system emergency for neonates, with a high incidence and mortality, especially in premature infants1,2,3. However, its pathogenesis is still unclear. It is currently believed that mucosal damage, pathogen invasion, and enteral feeding are high-risk factors for NEC3. To date, the animals used for the NEC model are mainly pigs, rats, and mice. Most studies have used n...

An erratum was issued for:&#160;<a href="https://www.jove.com/t/63252">A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis</a>. The Representative Results section was&#160;updated.
Figure 1 was updated from:
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63252/63252fig01.jpg" /> 
Figure 1: Induction of the BALB/c NEC model process. (A) The mice in the NEC group were separated from the dam at birth until they were 4 days old (on Day 4) and fasted that night. The NEC model was induced from Day 5 onwards after birth and lasted for 5 days. Intestinal tissue specimens were collected on Day 10 or earlier. The mice in the Cont. group were housed with and nursed by the dam. (B) The sequence of operations for each day after inducing the NEC model. Abbreviations: Cont. = control; NEC = necrotizing enterocolitis; LPS = lipopolysaccharide. <a href="https://www.jove.com/files/ftp_upload/63252/63252fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
to:
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63252/63252fig1v2.jpg" /> 
Figure 1: Induction of the BALB/c NEC model process. (A) The mice in the NEC group were separated from the dam at birth until they were 4 days old (on Day 4) and fasted that night. The NEC model was induced from Day 5 onwards after birth and lasted for 5 days. Intestinal tissue specimens were collected on Day 10 or earlier. The mice in the Cont. group were housed with and nursed by the dam. (B) The sequence of operations for each day after inducing the NEC model. Abbreviations: Cont. = control; NEC = necrotizing enterocolitis; LPS = lipopolysaccharide. <a href="https://www.jove.com/files/ftp_upload/63252/63252fig1v2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

An erratum was issued for:&#160;<a href="https://www.jove.com/t/63252">A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis</a>. The Representative Results section was&#160;updated.

Erratum: A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC), the most severe gastrointestinal (GI) disease, occurs in most premature infants (&#62;90%), especially those with very low birth weight (VLBW)1. In VLBW infants, the incidence of the disease ranges from 10% to 12%, and the mortality of children diagnosed with NEC is between 20% and 30%2,3. The cause of NEC may be related to mucosal injuries, invasion by pathogenic bacteria, and intestinal feeding, which can lead to inflammatory responses and the induction of intestinal injuries in susceptible hosts3. The pathogenesis of NEC is unclear. Relevant research shows that the affected infant&#39;s immune response is abnormal, and genetic susceptibility, microvascular tension, and intestinal bacterial changes may play important roles in the disease3.
The NEC animal model is an indispensable tool for research on the pathogenesis of NEC. The animal species used for NEC models are pigs, rats, and mice. However, due to the long gestation period, growth cycles, and high costs, in recent years, pigs have not been the first choice for NEC models and have been replaced with rats or mice4. As there are differences in the immune background of different mouse strains5, different studies need to use different strains of mice to establish NEC animal models. BALB/c mice have an important feature; when they are infected or cope with external damage, the polarization of TH2 cells during infection in mice is significantly stronger than that in other strains of mice6,7,8. T helper cells play a crucial role in the occurrence and progression of NEC, especially the development of TH2 cells3,9,10,11. Therefore, this study used BALB/c mice to establish the NEC model, which might be helpful for NEC disease research on T cells.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td >Absolute ethanol</td>
			<td >Sinopharm Chemical Reagent Co., LTD.</td>
			<td >100092683</td>
			<td ></td>
		</tr>
		<tr >
			<td >Goat Milk powder</td>
			<td>&#160;Petag&#160;</td>
			<td>71795558417</td>
			<td></td>
		</tr>
		<tr >
			<td >HE dye solution</td>
			<td>Sinopharm Chemical Reagent Co., LTD.</td>
			<td>G1003</td>
			<td></td>
		</tr>
		<tr >
			<td >Isoflurane</td>
			<td>RWD, Shenzhen Reward Life Technology Co., LTD.</td>
			<td>R510&#160;&#160;</td>
			<td></td>
		</tr>
		<tr >
			<td >LPS</td>
			<td>Sigma-Adrich</td>
			<td>L2880</td>
			<td></td>
		</tr>
		<tr >
			<td >Medical oxygen</td>
			<td>various</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr >
			<td >Microscope</td>
			<td>NIKON</td>
			<td>NIKON imaging system (DS-Ri2)</td>
			<td></td>
		</tr>
		<tr >
			<td >Neutral resin</td>
			<td>Sinopharm Chemical Reagent Co., LTD.</td>
			<td>10004160</td>
			<td></td>
		</tr>
		<tr >
			<td >Paraffin</td>
			<td>various</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr >
			<td >Premature baby milk powder</td>
			<td>Abbott</td>
			<td>57430</td>
			<td></td>
		</tr>
		<tr >
			<td >Xylene</td>
			<td>Sinopharm Chemical Reagent Co., LTD.</td>
			<td>10023418</td>
			<td></td>
		</tr>
		<tr >
			<td >1% Hydrochloric acid</td>
			<td>various</td>
			<td>various</td>
			<td></td>
		</tr>
		<tr >
			<td >10% Formalin</td>
			<td>LEAGENE</td>
			<td>DF0110</td>
			<td></td>
		</tr>
	</tbody>
</table>

a neonatal balb/c mouse model of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most severe gastrointestinal (GI) disease that often occurs in premature infants, especially very low birth weight infants, with high mortality and unclear pathogenesis. The cause of NEC may be related to inflammatory immune regulatory system abnormalities. An NEC animal model is an indispensable tool for NEC disease immune research. NEC animal models usually use C57BL/6J neonatal mice; BALB/c neonatal mice are rarely used. Related studies have shown that when mice are infected, Th2 cell differentiation is predominant in BALB/c mice compared to C57BL/6J mice. Studies have suggested that the occurrence and development of NEC are associated with an increase in T helper type 2 (Th2) cells and are generally accompanied by infection. Therefore, this study used neonatal BALB/c mice to induce an NEC model with similar clinical characteristics and intestinal pathological changes as those observed in children with NEC. Further study is warranted to determine whether this animal model could be used to study Th2 cell responses in NEC.

The BALB/c mouse NEC model was induced by formula feeding, LPS feeding, hypoxia, and cold stimulation. During the induction period, the mice were observed for intestinal pathology, stool characteristics, body weight changes, and daily survival. Representative images of the small intestine during NEC induction; the numbers in the picture represent the intestinal pathology score from 0 (normal epithelium) to 4 (the most severe) (Figure 3A). The intestinal pathology score was significantly high...

Watch this Scientific Journal Video about A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis at JoVE.com

A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is the most severe gastrointestinal (GI) disease that often occurs in premature infants, especially very low birth weight infants, with high mortality and unclear pathogenesis. The cause of NEC may be related to inflammatory immune regulatory system abnormalities. An NEC animal model is an indispensable tool for NEC disease immune research. NEC animal models usually use C57BL/6J neonatal mice; BALB/c neonatal mice are rarely used. Related studies have shown that when mice are infected, Th2 cell differentiation is predominant in BALB/c mice compared to C57BL/6J mice. Studies have suggested that the occurrence and development of NEC are associated with an increase in T helper type 2 (Th2) cells and are generally accompanied by infection. Therefore, this study used neonatal BALB/c mice to induce an NEC model with similar clinical characteristics and intestinal pathological changes as those observed in children with NEC. Further study is warranted to determine whether this animal model could be used to study Th2 cell responses in NEC.

Necrotizing enterocolitis (NEC) is the most severe gastrointestinal (GI) disease that often occurs in premature infants, especially very low birth weight ...

This study use BALB/c mice to establish the NEC model, which will be helpful for disease research on T cells. On day five, the two groups show no significant difference on body size. However, on day 10 the NEC mice were thinner than the control mice significantly.The weight of the mice in the NEC group increased slowly, and the survival rate gradually decreased during the five days of model establishment. The NEC model could be advantageous for studying T cell polarization. Demonstrating the procedure will be Yan Tian, a postgraduate from my laboratory.Gavage the mice with 20 to 30 microliters of LPS, and feed them with 40 to 50 microliters of formula on day five. From day five onwards, place them in a hypoxia device at 5%oxygen for 90 seconds, and re-oxygenate them for three minutes. Next, place the mice in a four degree Celsius environment for 15 minutes and transfer them to an incubator.Closely observe all the mice, weigh them every day, record the survival of the mice during the induction period and record whether their stool is bloody and sticky. Holding the gastric tube in the right hand, fix the mouse's head with the index finger on the mouse's head gently pressed backward and downwards. Insert the gastric tube from the left corner of the mouth and slowly move it two to three centimeters to the center of the mouth.Push 40 to 50 microliters of formula or 20 to 30 microliters of LPS into the digestive tract. If the mouse has a strong vomiting reflex and the gastric tube goes into the trachea, pull out gently and allow the mouse to rest before attempting gavage again. Immerse the fresh mouse illum tissue in 10%formalin, embed the tissues in paraffin and slice them of four micrometer sections.To deparaffinize the sections, put them in xylene. Soak for five minutes successfully in absolute ethanol, 95%ethanol, 80%ethanol, 70%ethanol and distilled water. Next, stain the sections with hematoxylin solution for five minutes, and differentiate them in 1%hydrochloric acid and 70%alcohol for five seconds.Finally, stain them with eosin solution for one minute, and examine the histopathology of the intestinal tissue at 40 times magnification. Photomicrographs of the intestinal pathology score from zero to four showed intact and normal mucosa, mild submucosal and lamina propria separation, moderate submucosal and lamina propria separation, severe submucosal and lamina propria separation, and intestinal villi disappearance with intestinal necrosis. The intestinal pathology score was significantly higher in the NEC group than in control with a P value of less than 0.001.The stool was scored from zero with well-formed pellets to three with liquid stools. On day 10, the stool scores of the NEC groups were significantly higher in the NEC group with a P value of less than 0.001. On day five, the two groups showed no significant difference in body size.However, on day 10, the mice in the NEC group were significantly thinner and smaller from head to tail than the mice in the control group. The weight of the mice in the NEC group increased slowly and the survival rate gradually decreased during the five days of model establishment. The resected ileocecal area of the intestinal tissue from NEC patients showed necrosis of intestinal mucosal tissue.In this study, the mice in the NEC group also developed ileocecal hemorrhage and necrosis. When gavaging the mouse, ensure that the mouse does not struggle to avoid effecting the gastric tube insertion. Gavage the mice with 20 to 30 microliters of LPS and feed them with 40 to 50 microliters of formula on day five.From day five onwards, place then in a hypoxia device at 5%oxygen for 90 seconds and reoxygenate them for three minutes. This model could be helpful for NEC disease research on T cells and might help study Th2 cell responses in NEC.

a-neonatal-balbc-mouse-model-of-necrotizing-enterocolitis

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3.3K visualizações.  Guangzhou Medical University. Este estudo utiliza camundongos BALB/c para estabelecer o modelo NEC, que será útil para pesquisas sobre doenças em células T. No quinto dia, os dois grupos não mostram diferença significativa no tamanho do corpo. No entanto, no 10º dia, os camundongos nec eram mais finos do que os ratos de controle significativamente.O peso dos camundongos no grupo NEC aumentou lentamente, e a taxa de sobrevivência diminuiu gradualmente durante os cinco dias de estabelecimento do modelo. O mod...