Changes in hair follicle stem cells (HFSCs) can affect scalp aging and hair growth. With increasing age, HFSCs exhibit a decrease in quiescence maintenance and self-renewal capacity, as well as differentiation potential, leading to shortened hair growth cycles and even hair loss. This review summarizes recent research advances in the multifactorial interactions underlying hair loss, including the regulatory mechanisms of HFSC quiescence, the impact of aging on HFSC function, and aging of the stem cell microenvironment. Additionally, this review discusses the relationship between stem cells and hair shafts, and the mechanisms of action of stem cells in scalp aging, including alterations in signaling pathways, chromatin remodeling, and epigenetic regulation, etc. Furthermore, stem cell-based therapeutic strategies are summarized, such as the use of stem cells or their secreting exosomes, modulation of the stem cell microenvironment, and pharmacological interventions.

Changes in hair follicle stem cells (HFSCs) can affect scalp aging and hair growth. With increasing age, HFSCs exhibit a decrease in quiescence maintenance and self-renewal capacity, as well as differentiation potential, leading to shortened hair growth cycles and even hair loss. This review summarizes recent research advances in the multifactorial interactions underlying hair loss, including the regulatory mechanisms of HFSC quiescence, the impact of aging on HFSC function, and aging of the stem cell microenvironment. Additionally, this review discusses the relationship between stem cells and hair shafts, and the mechanisms of action of stem cells in scalp aging, including alterations in signaling pathways, chromatin remodeling, and epigenetic regulation, etc. Furthermore, stem cell-based therapeutic strategies are summarized, such as the use of stem cells or their secreting exosomes, modulation of the stem cell microenvironment, and pharmacological interventions.

This study aimed to elucidate the effect of tryptophan (Trp) on gut hormone secretion as well as the roles of the calcium-sensing receptor (CaSR) and its downstream signaling pathway in gut hormone secretion by assessing swine duodenal perfusion in vitro. Swine duodenum was perfused with Krebs-Henseleit buffer as a basal solution. Various concentrations (0, 10, and 20 mM) of Trp were applied to investigate its effect on gut hormone secretion. A CaSR antagonist was used to detect the involvement of CaSR and its signal molecules. The 20 mM Trp concentration promoted the secretion of cholecystokinin (CCK) and glucose-dependent insulinotropic peptide (GIP), elevated the mRNA level of CaSR, and upregulated the protein levels of CaSR, protein kinase C (PKC), and inositol trisphosphate receptor (IP3R). However, NPS 2143, an inhibitor of CaSR, attenuated the CCK and GIP release, reduced the mRNA level of CaSR, and decreased the protein levels of CaSR, PKC, and IP3R with 20 mM Trp perfusion. The results indicate that CCK and GIP secretion can be induced by Trp in swine duodenum in vitro, and the effect is mediated by CaSR and its downstream signal molecules PKC and IP3R.
Cholecystokinin ; Duodenum ; Gastric Inhibitory Polypeptide ; In Vitro Techniques ; Inositol ; Perfusion ; Protein Kinase C ; Receptors, Calcium-Sensing ; RNA, Messenger ; Swine ; Tryptophan

Objective To study the utility of acute gastrointestinal injury (AGI) grading system in the strategy of diagnosis and treatment of severe acute pancreatitis (SAP) in patients for the guidance of nutritional support.Methods Forty-five patients with SAP admitted to the ICU from January 2012 to December 2013 were enrolled for study.The diagnosis of SAP was made as per the 2013 Chinese guideline of dliagnosis and treatment of acute pancreatitis.The patients with aged ＜ 18 years,length of hospital stay ＜72 h,and those included in other experimental study were excluded.The patients were divided into two groups:AGI group (n =24) and control group (n =21).There were no statistically significant differences in age,gender,APACHE Ⅱ between two groups (P ＞ 0.05).The length of hospital stay,in-hospital mortality,the incidence of complications such as infection,the time of starting enteral nutrition (EN) and reaching caloric goal were compared between the two groups.The t test or Mann-Whitney U test was used for continuous variables and x2 test or Fisher exact test was used for categorical variables,and P ＜ 0.05 was considered statistically significant.Results (1) Between two groups,there were statistically significant differences in the time of starting EN (2.0 d vs.5.7 d,Z =-4.149,P ＜0.01) and reaching caloric goal (5.5 d vs.10.4 d,Z =-3.392,P =0.001).(2) Between two groups,there were statistically significant differences in the incidence of pneumonia (25％ vs.57.14％,P =0.028 1) and catheterrelated infection (0％ vs.23.81％,P =0.039 4).(3) Between two groups,there was no statistically significant difference in in-hospital mortality (16.67％ vs.33.33％,P =0.194 3).In addition,there was significant difference in length of hospital stay between two groups (23.13 ± 10.58) d vs.(31.10 ± 15.33) d,P =0.046.Conclusions The diagnosis and treatment strategy based on AGI grading system is associated with earlier initiation of EN and reaching caloric goal,and partly reduces the incidence of infections and shortens the length of hospital stay,in the meantime,provides guidance for the rationale of nutritional support in the patients with SAP.