scholarly journals The colonic groove of the plains viscacha (Lagostomus maximus): Histochemical evidence of an abrupt change in the glycosylation pattern of goblet cells

2017 ◽  
Vol 278 (12) ◽  
pp. 1606-1618 ◽  
Author(s):  
María Florencia Tano de la Hoz ◽  
Mirta Alicia Flamini ◽  
Carolina Natalia Zanuzzi ◽  
Alcira Ofelia Díaz
Author(s):  
А.А. Коваленко ◽  
Г.П. Титова ◽  
В.К. Хугаева

Оперативное лечение различных заболеваний кишечника сопровождается осложнениями в виде нарушений микроциркуляции в области анастомоза кишки. Ранее нами показана способность лимфостимуляторов пептидной природы восстанавливать нарушенную микроциркуляцию, что послужило основой для настоящего исследования. Цель работы - оценка влияния стимуляции лимфотока в стенке кишки на процессы восстановления микроциркуляции, структуры и функции тонкой кишки в области оперативного вмешательства. Методика. В экспериментах на наркотизированных крысах (хлоралгидрат в дозе 0,6 г/кг в 0,9% растворе NaCl) моделировали различные поражения тонкой кишки (наложение лигатуры, перевязка 1-3 брыжеечных артерий, перекрут петли кишки вокруг оси брыжейки, сочетание нескольких видов повреждений). Резекция поврежденного участка через 1 сут. с последующим созданием тонкокишечного анастомоза завершалась орошением операционного поля раствором пептида-стимулятора лимфотока (40 мкг/кг массы животного в 1 мл 0,9% раствора NaCl). На 7-е сут. после операции проводили гистологическое исследование фрагмента кишки в области анастомоза. Результаты. На 7-е сут. после резекции у выживших животных (летальность вследствие кишечной непроходимости составляла 30%) имеют место морфологические признаки острых сосудистых нарушений стенки кишки, изменений кровеносных и лимфатических микрососудов, интерстициальный отек всех слоев стенки кишки, дилатация просвета кишки, повреждение всасывающего эпителия ворсин с истончением щеточной каемки клеток, морфологические признаки гиперфункции бокаловидных клеток. Использование лимфостимулятора пептидной природы после операции увеличивало выживаемость животных на 24%. У части животных отмечалось уменьшение расширения просвета кишки, у других практически полная его нормализация. Восстанавливалась форма кишечных ворсин и распределение бокаловидных клеток. Отсутствовали признаки внутриклеточного и межмышечного отека. Отмечено умеренное полнокровие венул. Заключение. Использование лимфостимулятора при хирургическом лечении кишечной непроходимости увеличивает выживаемость животных на 24% по сравнению с контролем, способствует более раннему восстановлению структуры и функции тонкой кишки. Полученные результаты свидетельствуют о перспективности использования стимуляции лимфотока при операциях на кишечнике. Surgical treatment of bowel diseases is associated with complications that cause microcirculatory disturbances in the anastomosis area and may lead to a fatal outcome. This study was based on our previous finding that peptide-type lymphatic stimulators are able to restore impaired microcirculation. The aim of this work was stimulating the lymph flow in the intestinal wall to facilitate recovery of microcirculation, structure and function of the small intestine in the area of surgical intervention. Methods. In experiments on anesthetized rats (0.6 g/kg chloral hydrate in 0.9% NaCl), various small bowel lesions were modeled (bowel ligation, ligation of 1-3 mesenteric arteries, gut torsion, combination of several lesion types). In 24 h, the damaged area was resected, and a small intestine anastomosis was creased. The surgery was completed with irrigation of the operative field with a solution of lymph flow stimulating peptide (40 мg/kg body weight in 1 ml of 0.9% NaCl). A gut fragment from the anastomosis area was examined histologically on day 7 after the surgery. Results. On the 7th day after removing the intestinal obstruction, the surviving animals (lethality 30%) had morphological signs of acute vascular disorders in the intestinal wall; changes in blood and lymphatic microvessels; interstitial edema of all intestinal wall layers; dilatation of the intestinal lumen; damage to the absorptive epithelium of villi with thinning of the brush border, and hyperfunction of mucous (goblet) cells. The use of the peptide after surgery increased the survival rate of animals by 24% and provided a smaller dilatation of the intestinal lumen in some animals. In other animals, the lumen recovered. The shape of intestinal villi and distribution of goblet cells were restored. Signs of intracellular and intermuscular edema were absent. Moderate venular congestion was noticed. Conclusion. Using the lymphatic stimulator in surgical treatment of intestinal obstruction increases the survival rate of animals by 24% compared to the control, facilitates earlier restoration of the small intestine structure and function. The obtained results indicated the effectiveness of lymphatic stimulation in intestinal surgery.


Author(s):  
Yanxin Liu ◽  
Victor Birman ◽  
Chanqing Chen ◽  
Stavros Thomopoulos ◽  
Guy M. Genin

The material mismatch at the attachment of tendon to bone is amongst the most severe for any tensile connection in nature. This is related to the large difference between the stiffness of tendon and bone, whose moduli of elasticity vary by two orders of magnitude. Predictably, such an abrupt change in the stiffness realized over a very narrow insertion site results in high local stresses. One of the implications of the stress distribution is a potential for stress singularities at the junction of the insertion to the bone.


2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 6-7
Author(s):  
E Fekete ◽  
C B Amat ◽  
T Allain ◽  
M Hollenberg ◽  
K Mihara ◽  
...  

Abstract Background Giardia duodenalis has been shown to alter the structure of the intestinal mucus layers during infection via obscure mechanisms. We hypothesize that goblet cell activity may be disrupted in part due to proteolytic activation of protease-activated receptor 2 (PAR2) by Giardia proteases, resulting in disruption of mucus production and secretion by intestinal goblet cells. Aims Characterize alterations in goblet cell activity during Giardia infection, focusing on the roles of Giardia protease activity and PAR2. Methods Chinese hamster ovary cells transfected with nano-luciferase tagged PAR2 were incubated with Giardia NF or GSM trophozoites. Cleavage within the activation domain results in release of enzymes into the supernatant. Luminescence in the supernatant was measured as an indication of PAR cleavage by Giardia. LS174T, a human colonic mucus-producing cell line, was infected with Giardia trophozoites (isolates NF, WB, S2, and GSM). Prior to infection, trophozoites were treated with E64, a broad-spectrum cysteine protease inhibitor, and LS174T were treated with a PAR2 antagonist, a calcium chelator, or an ERK1/2 inhibitor. Quantitative PCR (qPCR) was performed for the MUC2 mucin gene. Wild-type (WT) and PAR2 knockout (KO) mice were infected with Giardia. Colonic mucus was stained using fluorescein-coupled wheat-germ agglutinin (WGA), and qPCR was performed for Muc2 and Muc5ac. Results Giardia trophozoites cleaved PAR2 within the N-terminal activation domain in a cysteine protease-dependent manner. Cleavage was isolate dependent, with isolates that show higher protease activity cleaving at a higher rate. High protease activity Giardia isolates increased MUC2 gene expression in LS714T. This increase was attenuated by inhibition of Giardia cysteine protease activity, and by antagonism of PAR2, inhibition of calcium release, or inhibition of ERK1/2 activity in LS174T cells. Both Muc2 and Muc5ac expression were upregulated in the colons of WT mice in response to Giardia infection, while in the jejunum Muc2 expression decreased and Muc5ac expression increased. In KO, no changes in gene expression were seen in the colon in response to Giardia infection, while in the jejunum, Muc2 expression was unchanged and Muc5ac expression decreased. Both WT infected and KO noninfected mice showed thinning of the colonic mucus layer compared to WT controls. There was some recovery in thickness in KO infected mice. Conclusions PAR2 plays a significant role in the regulation of mucin gene expression in mice and in a human colonic cell line. Results suggest that Giardia cysteine proteases cleave and activate PAR2, leading to calcium release and activation of the MAPK pathway in goblet cells, ultimately leading to altered mucin gene expression. Findings identify a novel regulatory pathway for mucus production by intestinal goblet cells. Funding Agencies CAG, CCC


Cell Reports ◽  
2021 ◽  
Vol 34 (5) ◽  
pp. 108715
Author(s):  
Kimihito Nomi ◽  
Ryuhei Hayashi ◽  
Yuki Ishikawa ◽  
Yuki Kobayashi ◽  
Tomohiko Katayama ◽  
...  

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