Microcapsules of mesoporous silica and cyclodextrin modified loaded with nonanal and decanal for effective control of Sitotroga cerealella in grain storage environments

BACKGROUND

The Angoumois grain moth, Sitotroga cerealella, is a destructive pest of maize, wheat, and rice, causing economic losses and threatening food security. This study aimed to develop and characterize microcapsules of mesoporous silica nanospheres (MSN) and cyclodextrin-modified mesoporous silica nanospheres (CDMSN) containing two aldehydes, nonanal and decanal, found in plant essential oils, to assess their attractiveness to S. cerealella populations.

RESULTS

Microcapsules with 2:1 ratio of nonanal and decanal exhibited an average encapsulation efficiency of 39.82% for MSN loaded with nonanal and decanal (MSN-ND) and 46.10% for CDMSN loaded with nonanal and decanal (CDMSN-ND). They have an elliptical shape with particle sizes of 115 nm for MSN and 175 nm for CDMSN. Gas chromatography-mass spectrometry analysis revealed in vitro release of nonanal in MSN at 96.24% and decanal at 96.42% by the 36th day. CDMSN showed releases of 93.83% for nonanal and 93.74% for decanal by the 50th day. CDMSN-ND attracted adult S. cerealella for 43 days, while MSN-ND remained effective for 29 days. In mass trapping assays in simulated grain warehouse, both MSN-ND and CDMSN-ND trapped over 50% of the adult population within 7 days, significantly reducing grain infestation rates below 10% by inhibiting F1 adult emergence. At temperatures ranging from 20 °C to 35 °C, both microcapsules exhibited significant and effective attraction rates for S. cerealella. Stored wheat seeds treated with CDMSN and CDMSN-ND over 1 year showed no significant differences in key germination parameters.

CONCLUSION

Microencapsulated nonanal and decanal offer a promising, sustainable approach for controlling S. cerealella infestation in stored grains, contributing to global food security. © 2024 Society of Chemical Industry.

[Quality of psychomotility recovery after propofol sedation for painless gastroscopy and colonoscopy]

OBJECTIVE

To study the effect of propofol used for painless gastroscopy and colonoscopy on psychomotility recovery.

METHODS

One hundred adult patients undergoing painless gastroscopy and colonoscopy were recruited, aged 18-72 years, with American Society of Anesthesiologist (ASA) physical status Ⅰ-Ⅱ. According to age, the patients were divided into youth group (20-39 years old, 27 cases), middle age group (40-54 years old, 37 cases), and elder group (55-64 years old, 36 cases). Propofol was continuously infused according to the patients' condition to mantain the bispectal index (BIS) score 55-64. All the patients received psychomotility assesment 30 min before the operations when the discharge criteria were met including number cancellation test, number connection test and board test. The heart rate, blood pressure, saturation of pulse oximetry, electrocardiograph and BIS were monitored during the operation. The operating time, recovery time, total volume of propofol and discharge time were recorded. If the results obtained were inferior to those before operation, a third assessment was taken 30 minutes later until the results recovered or being superior to the baseline levels.

RESULTS

All the patients completed the first and second assessments, and 25 patients had taken the third assessment. There was no statistically significant difference in the results of psychomotility assessment when the patients met the discharge standard. Furthermore, the results were analyzed by grouping with age, and there was no statistical difference in the test results of the youth and middle age groups compared with the preoperative group, among which, the efficiency of the number cancellation test was significantly better than that before operation in the youth group (P < 0.05). However, in the elderly patients the number cancellation efficiency, number connection test and board test were significantly inferior to that before operation (P < 0.05). There was no significant difference in the accuracy of number cancellation compared with that before operation. The patients who needed the third test in the elder group were significantly more than in the other groups (P < 0.05). Compared with the preoperative results, there was no statistical difference in the test results of those who completed the third test.

CONCLUSION

The psychomotility function of the patients who underwent painless gastroscopy and colonoscopy was recovered when they met discharge criteria. The elderly patients had a prolonged recovery period.

[To strengthen the basic and translational research of mesenchymal stem cell-based therapy for refractory wounds]

In recent years, the application of cell-based therapy in the field of refractory wound repair has shown broad prospects, among which the mesenchymal stem cell is the most concerned and widely studied cell type. Despite the rapid development of clinical translational research, the therapeutic effect of cell-based therapy is not consistent, and most clinical trials have not achieved the desired results. Further studies have found that heterogeneity is an important issue that restricts the further development of cell-based therapy and urgently needs to be studied. Based on the research progress of mesenchymal stem cells, in the review, we discuss the current status and challenges of cell-based therapy strategies for refractory wounds.

AT-rich interactive domain1A determines sensitivity to oxaliplatin in gastric cancer cells

Background

Gastric cancer is a highly heterogeneous disease and its traditional histopathological classification is difficult to meet clinical needs. Oxaliplatin is an antitumor drug with high efficiency and low toxicity. Therefore, the insensitivity or secondary drug resistance of oxaliplatin to gastric cancer is vital for tumor progression. The aim of this study was to investigate the sensitivity of gastric cancer cells to oxaliplatin after ARID1A (AT-rich interactive domain1A gene) gene silencing.

Methods

MGC-803 and AGS cells were selected as gastric cancer cells for study. ARID1A protein and mRNA expression was detected by Western blot and quantitative reverse-transcription PCR (qRT-PCR). The short hairpin RNA (shRNA) fragment of ARID1A gene silencing was constructed and introduced into gastric cancer cells. The cell proliferation activity was calculated using CCK8 and the IC50 was calculated. The flow cytometry was used to detect the cell cycle and apoptosis rate. The ability of cell invasion was detected by transwell method. Cells were treated with different concentrations of oxaliplatin.

Results

The proliferation of gastric cancer cells was promoted by ARID1A gene silencing (P<0.01), the quantity of cells in S phase increased (P<0.05), and the invasive ability increased (P<0.05). After treatment with oxaliplatin at different concentrations, ARID1A gene silencing reduced the inhibition rate of oxaliplatin on gastric cancer cells and apoptosis rate (P<0.05), and increased IC 50 (P<0.01).

Conclusions

ARID1A gene silencing, a factor promoting proliferation of gastric cancer cells, would reduce the sensitivity of gastric cancer cells to oxaliplatin, which can provide a basis for the exploration of targeted drugs for individualized treatment of gastric cancer.

A novel peptide RIFV suppresses human adipocyte differentiation through the inhibition of C/EBP-β expression

Background

Obesity is a global epidemic disease that increases the risk of metabolic syndrome. However, therapeutic drugs for obesity are still scarce. In recent years, peptides have been identified as new biological regulators. RIFV (R-I-F-V-P-I-K-G-R-P-A-P), a novel active peptide from our peptide database.

Methods

We performed oil red O staining and triglyceride measurement to analyze the influence of RIFV on white preadipocytes differentiation. Then the effects of RIFV on cell proliferation, apoptosis and cell cycle were determined by using CCK-8 assay and flow cytometry. The mRNA and protein levels of adipogenesis-related genes were respectively detected by qRT-PCR and western blot. Rescue experiment was conducted to confirm whether RIFV could regulate adipocytes differentiation via targeting C/EBP-β. Finally, the luciferase reporter gene assay was performed to verify the regulation of RIFV on C/EBP-β gene.

Results

RIFV was revealed to inhibit the differentiation of human white adipocytes without affecting their proliferation. Additionally, RIFV could also suppress the differentiation of mouse primary white preadipocytes isolated from inguinal fat tissues. Furthermore, RIFV may have an inhibitory effect on adipogenesis by inhibiting the regulation of the adipogenic gene C/EBP-β.

Conclusions

Our results indicated that RIFV may be a novel essential regulator of adipocyte differentiation and represents a therapeutic strategy for obesity and related complications.

[Risk factors associated with delirium for patients with hip fracture under the orthogeriatric unit mode]

Objective: To explore postoperative delirium (POD)risk factors for geriatric patients who suffered hip fracture under the care of orthogeriatric unit mode. Methods: Patients aged 65 years or older, who were admitted to the orthogeriatric unit in Beijing Jishuitan Hospital from April to October 2017 for hip fracture surgery, were eligible for this prospective cohort study. After univariable analysis, significant risk factors associated with POD were further evaluated with multivariable analysis, to establish independent risk factors associated with POD. Results: A total of 203 patients with an average age of 80(65-96)years were enrolled in the study. The overall incidence of POD was 9.4%(19/203)in which hyperactive and hypoactive type accounting for 84.2%(16/19)and 15.8%(3/19), respectively. Significant difference was found between POD and non-POD groups in patients' age (P=0.003), albumin(P=0.006), TSH(P=0.018), PaCO(2) level(P=0.003), visual analogue scale (VAS )both at rest (P=0.013)and movement(P=0.010) on post-operative day 1.The further Logistic stepwise regression analysis showed that significant differences existed between groups in age(P=0.027), albumin(P=0.003), PaCO(2)(P=0.014)and VAS at rest(P=0.002). Conclusion: The independent risk factors of POD in geriatric patients undergoing hip fracture under the orthogeriatric unit mode include patients' age, pre-operative albumin as well as PaCO(2) level and post-operative VAS at rest.

Famitinib versus placebo in the treatment of refractory metastatic colorectal cancer: a multicenter, randomized, double-blinded, placebo-controlled, phase II clinical trial

Background

Metastatic colorectal cancer (mCRC) patients with progressive disease after all available standard therapies need new medication for further treatment. Famitinib is a small-molecule multikinase inhibitor, with promising anticancer activities. This multicenter, randomized, double-blinded, placebo-controlled, phase II clinical trial was designed to evaluate the safety and efficacy of famitinib in mCRC.

Methods

Famitinib or placebo was administered orally once daily. The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), quality-of-life (QoL), and safety.

Results

Between July 18, 2012 and Jan 22, 2014, a total of 167 patients were screened, and 154 patients were randomized in a 2:1 ratio to receive either famitinib (n = 99) or placebo (n = 55). The median PFS was 2.8 and 1.5 months in the famitinib and placebo groups (hazard ratio = 0.60, 95% confidence interval = 0.41–0.86, P = 0.004). The DCR was 59.8% and 31.4% (P = 0.002) and the ORR was 2.2% and 0.0% (P = 0.540) in the famitinib and placebo groups, respectively. The most frequent grade 3–4 adverse events were hypertension (11.1%), hand-foot syndrome (10.1%), thrombocytopenia (10.1%), and neutropenia (9.1%). Serious adverse events occurred in 11 (11.1%) patients in the famitinib group and 5 (9.1%) in the placebo group (P = 0.788). The median OS of the famitinib and placebo groups was 7.4 and 7.2 months (P = 0.657).

Conclusion

Famitinib prolonged PFS in refractory mCRC patients with acceptable tolerability.

Trial registration This study was registered on ClinicalTrials.gov (NCT01762293) and was orally presented in the 2015 ASCO-Gastrointestinal Symposium

[The application of conscious sedation with a small dose of dexmedetomidine and sufentanil in elderly patients undergoing multiple intestinal polyps resection]

Objective: To explore the effectiveness and feasibility of conscious sedation with a low dose of dexmedetomidine and sufentanil during multiple intestinal polyps resection in elderly patients. Methods: Sixty elderly patients who underwent multiple intestinal polyps resection in Peking University Third Hospital from Janurary to May 2016 were randomly divided into dexmedetomidine group (D group, n=30) and propofol group (P group, n=30). There were 28 males and 32 females with a mean age of (70.4±4.5) years old (range: 65-80 years old). The patients in the dexmedetomidine group received a loading dose of 0.3 μg/kg followed by a continuous infusion of 0.2-0.4 μg·kg^-1·min^-1 of dexmedetomidine and sufentanil (0.1 μg/kg) respectively.The patients in the propofol group received sufentanil 0.1 μg/kg and propofol 1.5 mg/kg and followed by a continuous infusion of 3-6 mg·kg^-1·h^-1 of propofol.Blood pressure, heart rate, pulse oxygen saturation (SpO₂), respiratory rate and bispectral index (BIS) were recorded at the basic status and at the beginning of operation, 10 min, 20 min, 30 min after operation, the end of operation and departure.The observer's assessment of alertness/sedation (OAA/S) scores and the clinical responses were also recorded.A statistical analysis was performed. Results: All patients in the two groups were sedated compared with baseline.The BIS values of patients in group D at beginning of the operation, 10 min, 20 min, 30 min after operation and the end of operation were 89.6(87.8-91.0), 79.4(78.0-80.0), 76.9(75.0-80.0), 76.0(73.0-79.0) and 75.6(70.0-79.0) respectively, and those values were all significantly lower than baseline value[96.4(95.0-98.0)], (Z=-4.645, -4.788, -4.787, -4.789, -4.789, P<0.05). The OAA/S score at beginning of the operation, 10 min, 20 min, 30 min after operation and the end of operation were 4.5(4.0-5.0), 3.4(3.0-4.0), 3.0(3.0-3.0), 3.5(3.0-4.0) and 3.3(3.0-4.0) respectively, and were significantly lower than baseline score [4.8(5.0-5.0)] (Z=-2.828, -4.862, -5.031, -4.420, -4.710, P<0.05). The BIS value of patients in group P at beginning of the operation, 10 min, 20 min, 30 min after operation and the end of operation were 54.7(50.0-59.3), 54.8(50.0-59.3), 50.7(47.8-56.8), 54.4(51.5-58.0) and 53.7(50.0-57.3) respectively, and were significantly lower than baseline value[95.8(95.0-96.3)] (Z=-4.786, -4.787, -4.788, -4.786, -4.786, P<0.05). The OAA/S score at beginning of the operation , 10 min, 20 min, 30 min after operation and the end of operation were 0.4(0.0-1.0), 0.4(0.0-1.0), 0.4(0.0-1.0), 0.4(0.0-1.0) and 0.4(0.0-1.0) respectively, and were significantly lower than baseline score[4.9(5.0-5.0)] (Z=-4.927, -4.901, -4.912, -4.912, -4.901, P<0.05). The sedation state of group D were lighter than group P. The BIS value and OAA/S score at beginning of the operation, 10 min, 20 min, 30 min after operation and the end of operation in group D were higher than group P (P<0.05). The breath and circulation were more stable in group D. The mean arterial pressure, breath rate and SpO₂ at beginning of the operation, 10 min, 20 min, 30 min after operation and the end of operation in group D were higher than group P (P<0.05). There was no oxygen desaturation , hypotension and drowsiness in group D and the incidence in group P were 30.0%, 33.3% and 13.3% respectively.The emergency time and duration of stay in the PACU (post anesthesia care unit) were (2.0±1.2) and (22.0±7.4) min in group D, and they were (4.9±2.4) and (35.8±11.6) min in group P (t=-5.839, t=-5.472, P<0.05). There was no difference in surgery time, patient satisfaction and acceptance rate of reexamination (t=-3.031, t=-7.322, t=2.069, P>0.05). Conclusion: Conscious sedation with dexmedetomidine and sufentanil is effective and feasible in elderly patients undergoing multiple intestinal polyps resection.

Knockdown of LYRM1 rescues insulin resistance and mitochondrial dysfunction induced by FCCP in 3T3-L1 adipocytes

LYR motif-containing 1 (LYRM1) was recently discovered to be involved in adipose tissue homeostasis and obesity-associated insulin resistance. We previously demonstrated that LYRM1 overexpression might contribute to insulin resistance and mitochondrial dysfunction. Additionally, knockdown of LYRM1 enhanced insulin sensitivity and mitochondrial function in 3T3-L1 adipocytes. We investigated whether knockdown of LYRM1 in 3T3-L1 adipocytes could rescue insulin resistance and mitochondrial dysfunction induced by the cyanide p-trifluoromethoxyphenyl-hydrazone (FCCP), a mitochondrion uncoupler, to further ascertain the mechanism by which LYRM1 is involved in obesity-associated insulin resistance. Incubation of 3T3-L1 adipocytes with 1 µM FCCP for 12 h decreased insulin-stimulated glucose uptake, reduced intracellular ATP synthesis, increased intracellular reactive oxygen species (ROS) production, impaired insulin-stimulated Glucose transporter type 4 (GLUT4) translocation, and diminished insulin-stimulated tyrosine phosphorylation of Insulin receptor substrate-1 (IRS-1) and serine phosphorylation of Protein Kinase B (Akt). Knockdown of LYRM1 restored insulin-stimulated glucose uptake, rescued intracellular ATP synthesis, reduced intracellular ROS production, restored insulin-stimulated GLUT4 translocation, and rescued insulin-stimulated tyrosine phosphorylation of IRS-1 and serine phosphorylation of Akt in FCCP-treated 3T3-L1 adipocytes. This study indicates that FCCP-induced mitochondrial dysfunction and insulin resistance are ameliorated by knockdown of LYRM1.

MiR-146b is a regulator of human visceral preadipocyte proliferation and differentiation and its expression is altered in human obesity

Visceral obesity is an independent risk factor for metabolic syndrome, and abnormal fat accumulation is linked to increases in the number and size of adipocytes. MiR-146b was a miRNA highly expressed in mature adipocytes while very lowly expressed in human mesenchymal stem cells (hMSCs) and human visceral preadipocytes (vHPA). In this paper, we mainly focused on the roles of miR-146b in adipogenesis. We found miR-146b could inhibit the proliferation of visceral preadipocytes and promote their differentiation. MiR-146b in human visceral adipocytes inhibited the expression of KLF7, a member of the Kruppel-like transcription factors, as demonstrated by a firefly luciferase reporter assay, indicating that KLF7 is a direct target of the endogenous miR-146b. MiR-146b expression was significantly altered in visceral and subcutaneous adipose tissues in human overweight and obese subjects, and in the epididymal fat tissues and brown fat tissues of diet-induced obese mice. Our data indicates that miR-146b may be a new therapeutic target against human visceral obesity and metabolic dysfunction.

Dynamic mitochondrial changes during differentiation of P19 embryonic carcinoma cells into cardiomyocytes

Murine P19 embryonal carcinoma cells are multipotent cells that can differentiate into cardiomyocytes when treated with dimethyl sulfoxide. This experimental model provides an invaluable tool to study different aspects of cardiac differentiation, such as the function of cardiac‑specific transcription factors and signaling pathways, and the regulation of contractile protein expression. The role of mitochondria during cardiac differentiation is unclear. In this context, we have examined the mitochondrial-related changes in undifferentiated and differentiated P19 cells. We observed that mitochondrial DNA content sharply decreased in P19 cell aggregates compared to undifferentiated cells, accompanied by decreased levels of adenosine triphosphate (ATP) and reactive oxygen species (ROS). Following the aggregation stage, the mitochondrial DNA content reached its highest level on day 7 of the differentiation process, with the intracellular ROS level showing a trend to increase, similar to cellular ATP production. In conclusion, our study on differentiating P19 embryonal carcinoma cells provides new insights into the role of mitochondria in the differentiation of P19 stem cells into beating cardiomyocytes.

Overexpression of TFAM protects 3T3-L1 adipocytes from NYGGF4 (PID1) overexpression-induced insulin resistance and mitochondrial dysfunction

NYGGF4, also known as phosphotyrosine interaction domain containing 1(PID1), is a recently discovered gene which is involved in obesity-related insulin resistance (IR) and mitochondrial dysfunction. We aimed to further elucidate the effects and mechanisms underlying NYGGF4-induced IR by investigating the effect of overexpressing mitochondrial transcription factor A (TFAM), which is essential for mitochondrial DNA transcription and replication, on NYGGF4-induced IR and mitochondrial abnormalities in 3T3-L1 adipocytes. Overexpression of TFAM increased the mitochondrial copy number and ATP content in both control 3T3-L1 adipocytes and NYGGF4-overexpressing adipocytes. Reactive oxygen species (ROS) production was enhanced in NYGGF4-overexpressing adipocytes and reduced in TFAM-overexpressing adipocytes; co-overexpression of TFAM significantly attenuated ROS production in NYGGF4-overexpressing adipocytes. However, overexpression of TFAM did not affect the mitochondrial transmembrane potential (ΔΨm) in control 3T3-L1 adipocytes or NYGGF4-overexpressing adipocytes. In addition, co-overexpression of TFAM-enhanced insulin-stimulated glucose uptake by increasing Glucose transporter type 4 (GLUT4) translocation to the PM in NYGGF4-overexpressing adipocytes. Overexpression of NYGGF4 significantly inhibited tyrosine phosphorylation of Insulin receptor substrate 1 (IRS-1) and serine phosphorylation of Akt, whereas overexpression of TFAM strongly induced phosphorylation of IRS-1 and Akt in NYGGF4-overexpressing adipocytes. This study demonstrates that NYGGF4 plays a role in IR by impairing mitochondrial function, and that overexpression of TFAM can restore mitochondrial function to normal levels in NYGGF4-overexpressing adipocytes via activation of the IRS-1/PI3K/Akt signaling pathway.

Silencing of FABP3 leads to apoptosis-induced mitochondrial dysfunction and stimulates Wnt signaling in zebrafish

Fatty acid binding protein 3 (FABP3, also termed heart-type fatty acid binding protein) is a member of the intracellular lipid-binding protein family that may be essential in fatty acid transport, cell growth, cellular signaling and gene transcription. Previously, we demonstrated that FABP3 was involved in apoptosis-associated congenital cardiac malformations; however, its mechanism of regulation remains unclear. Apoptosis has increasingly been considered to be important in cardiac development. In the present study, a zebrafish model was used to investigate the involvement of FABP3‑morpholino (MO)-induced apoptosis and mitochondrial dysfunction in cardiac development. During the early stages of cardiac development, injection of FABP3‑MO into zebrafish resulted in significant impairment in cardiac development and promoted the rate of apoptosis which was correlated with significant dysfunction of the mitochondria. For example, the ATP content was markedly decreased at 24 and 48 h post-fertilization (pf), reactive oxygen species production was significantly enhanced at 24 and 48 h pf and the mitochondrial DNA copy number was reduced at 24, 48 and 72 h pf. Additionally, Nkx2.5 expression was upregulated in FABP3-MO zebrafish, and Wnt signaling molecules (Wnt1, Wnt5 and Wnt11) were also highly expressed in FABP3-MO zebrafish at 24, 48 and 72 h pf. In conclusion, the results indicated that FABP3 knockdown exhibited significant toxic effects on cardiac development and mitochondrial function, which may be responsible for the knockdown of FABP3-induced apoptosis. Apoptosis was one of the mechanisms underlying this effect, and was correlated with the activation of Wnt signaling. These studies identified FABP3 as a candidate gene underlying the etiology of congenital heart defects.

Overexpression of C10orf116 promotes proliferation, inhibits apoptosis and enhances glucose transport in 3T3-L1 adipocytes

Data from our previous study demonstrated that C10orf116 is an adipocyte lineage-specific nuclear factor, which regulates master adipogenesis transcription factors during early differentiation. However, the precise functional properties of this gene have yet to be identified and further investigation is required. In the present study, we report the effects of C10orf116 expression on cell proliferation and apoptosis in vitro and observed that the overexpression of C10orf116 stimulates proliferation and inhibits apoptosis in preadipocytes. Furthermore, we investigated the effects of C10orf116 on glucose uptake and demonstrated that the ectopic expression of C10orf116 significantly increases insulin-stimulated glucose uptake in adipocytes by increasing glucose transporter type 4 (GLUT4) expression levels. Collectively, these data further support the hypothesis that C10orf116 is important in regulating glucose transport in adipocytes as well as the number of preadipocytes. The results of the present study may also provide insights into the complex mechanisms involved in the development of obesity.

[Relationship between hemolymph phenol oxidase and melanization of oocysts of Plasmodium yoelii in Anopheles stephensi]

OBJECTIVE

To explore the relationship between the hemolymph phenol oxidase and melanization of oocysts.

METHODS

Anopheles stephensi-Plasmodium yoelii system was used to determine the activity of monophenol oxidase (MPO) and o-diphenol oxidase (o-DPO) in the hemolymph collected from 4 groups of mosquitoes by polyacrylamide gel electrophoresis (PAGE) followed by density scanning. The 4 groups of mosquitoes were: non-blood-fed (N), normal-blood-fed (B), infected-blood-fed (I) and nitroquine-administrated (D), respectively.

RESULTS

No significant difference was found in the activities of MPO and o-DPO between groups N and B. The activities of MPO and o-DPO were not obviously modified in group I, but were significantly increased on day 10 and decreased on day 15 after blood feeding in the group D as compared with those in the groups N and B.

CONCLUSION

The alteration in the mosquito hemolymph PO activity coincided at each time point with the melanization of Plasmodium yoelii oocysts.

Comparative study of hepatocyte growth factor/scatter factor and keratinocyte growth factor effects on human keratinocytes

Hepatocyte growth factor/scatter factor (HGF/SF) and keratinocyte growth factor (KGF, also designated FGF-7) are paracrine growth factors secreted by mesenchymal cells and active on a variety of epithelial cell types. In this study, the biologic responses of keratinocytes to these paracrine growth factors were compared. Stimulation of mitogenesis, migration, plasminogen activator (PA) activity, and fibronectin production were examined using human foreskin keratinocytes cultured in serum-free MCDB 153 medium. Although the two factors stimulated a similar level of proliferation when cells were maintained for 5 d in 1.8 mM Ca++, the peak effect of KGF, observed at 10 ng/ml, was approximately threefold higher than that of HGF/SF when cells were in medium containing 0.15 mM Ca++. Both agents promoted the migration of cells in low-calcium medium (0.08 mM Ca++). However, the magnitude of the response was approximately twofold greater for HGF/SF at 10 ng/ml than KGF at the same concentration. None of the matrix proteins such as type I collagen, type IV collagen, laminin, or fibronectin either stimulated or suppressed HGF/SF- or KGF-stimulated keratinocyte migration. Both factors stimulated PA activity of the cell extracts, especially urokinase-type, with similar potencies. Promoted PA activity was maximal with the addition of 10 ng/ml of either factor. Neither factor increased the production of fibronectin under conditions in which transforming growth factor-beta 1 was active. These results indicate that HGF/SF and KGF, both recognized as paracrine growth factors, elicit distinctive patterns of response by keratinocytes, implying that they have different roles in epidermal physiology.

Co-administration of insulin-like growth factor (IGF)-I and IGF-binding protein-1 stimulates wound healing in animal models

The stimulatory effect of recombinant human insulin-like growth factor-I (rhIGF-I) and recombinant human insulin-like growth-factor-binding protein-1 (rhIGFBP-1) on wound healing was assessed using diabetic db/db mice and normal rabbits. Full-thickness wounds of 6 mm diameter were prepared on the backs of diabetic C57BL/KsJ db/db mice and on the inner sides of normal rabbit ears. Various concentrations of rhIGF-I and/or rhIGFBP-1 were applied locally to the open wounds of db/db mice once daily for 5 d and to the covered wounds of normal rabbits once after wounding. Sections of the wounds were evaluated histologically on the seventh or eighth day by measuring re-epithelialization (%), area of granulation tissue (mm2), and capillary numbers. Wound repair was accelerated by each of the treatments in descending order of rhIGF-I plus rhIGFBP-1, rhIGF-I, rhIGFBP-1, and vehicle alone. In db/db mice, the combination of 50 micrograms rhIGF-I and 165 micrograms rhIGFBP-1 (equimolar ratio) significantly stimulated granulation tissue formation (p < 0.01) and capillary numbers (p < 0.05). Doses of rhIGFBP-1 greater than 16.5 micrograms were required for significant acceleration of the healing stimulated by 50 micrograms of rhIGF-I. In normal rabbits, co-administration of 10 micrograms rhIGF-I and 33 micrograms rhIGFBP-1 (equimolar ratio) significantly stimulated all three wound-healing parameters (p < 0.01), with such stimulation being much greater than that induced by rhIGF-I alone. Interestingly, rhIGFBP-1 alone showed a mild stimulatory activity on wound healing in both models despite its lack of mitogenic activity in vitro. These results demonstrate that rhIGFBP-1 enhances the stimulatory activity of rhIGF-I on wound healing and suggest the clinical utility of the co-administration of rhIGF-I and rhIGFBP-1 for wound repair.

Endothelin-1 acts as an autocrine growth factor for normal human keratinocytes

Endothelin-1 (ET-1) is an endothelium-derived 21 amino acid vasoconstrictor peptide possessing two intrachain disulfide bridges. Recently it has become evident that isoforms of ET (ET-1, -2, and -3) have a wide range of pharmacological effects in various tissues and act as autocrine/paracrine factors. We demonstrate here that ET-1 is secreted from normal human keratinocytes and may work as an autocrine growth factor through a specific receptor. In this study, human foreskin keratinocytes were cultured in serum-free MCDB 153 medium. Cell growth and [3H] thymidine incorporation in low and high Ca++ concentration media was stimulated by ET-1, -2, and -3 with similar potencies. The strongest response was observed at 10 nM ETs, whereas stimulatory activity was reduced at 100 nM. ETs suppressed keratinocyte differentiation as measured by reactivity with involucrin antibody. Plasminogen activator activity (mainly urokinase) in the medium was also stimulated by the addition of 10 nM ETs. ET-1-like immunoreactivity measured by radioimmunoassay was 1.4 fmol/day/10(6) cells in non-treated condition medium. Among the various cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha, and transforming growth factor-beta stimulated ET-1 secretion in a dose-dependent manner. The strongest response (ten-fold) was observed upon the addition of 10 ng/ml TNF-alpha. Scatchard plot analysis of [125I] ET-1 binding to keratinocytes revealed the presence of a single class of high affinity receptors (KD 50 pM, 9 x 10(3) sites/cell). Binding was competitively inhibited by the addition of unlabeled ET-1 and -2 with similar affinities and by ET-3 with weaker affinity. ET-1 mRNA expression in keratinocytes was detected by reverse transcription-polymerase chain reaction and was increased by treatment with 10 ng/ml TNF-alpha. These results suggest that ET-1 acts as an autocrine growth factor for keratinocytes through a specific receptor.

Stimulation of keratinocyte migration by growth factors

Migration of keratinocytes from the wound edge is thought to be one of the critical features of reepithelialization. A quantitative migration assay was carried out using normal human keratinocytes. Keratinocytes, seeded on 12 well plates, were grown in serum free, keratinocyte growth medium (KGM, Curabo Co) with 0.08 mM Ca2+. The medium was switched from KGM to keratinocyte basal medium (KBM) 6 h prior to the wounding. Half of the plate's confluent monolayer of keratinocytes was removed with razor blade, and the remaining keratinocytes were incubated in KBM for 16 hrs in the presence of indicated growth factors. After incubation, the cells were fixed and counted at 100 magnification. Migration was quantitated by counting the number of cells in ten successive 125-microns zones. Transforming growth factor alpha (TGF-alpha), acidic and basic fibroblast growth factor (aFGF, bFGF), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), and insulin-like growth factor-I (IGF-I) stimulated the migration of keratinocytes, while TGF-beta suppressed it.

A wound healing model using healing-impaired diabetic mice

A quantitative histological approach was employed to evaluate the effects of basic fibroblast growth factor (bFGF) in healing-impaired diabetic mice. The dorsal areas of female mutant diabetic mice, C57BL KsJ db/db (Jackson Lab.), were given two 6 mm-size full thickness wounds with a punch biopsy instrument. After application of bFGF, the wounds were left open. 8 days after wounding, the mice were sacrificed, and histological sections were evaluated using several histological parameters, such as the degree of wound closure, granulation tissue thickness, matrix density, and capillary numbers. Application of 5 micrograms of bFGF for 5 days induced significant responses by all of these dermal parameters when compared to those of non-treated db/db mice (p < 0.001). A minimum of 0.5 micrograms bFGF per day was required for a significant effect. Time-course experiments indicated that the granulation response in bFGF-treated mice peaked between 8 and 12 days and decreased after 12 days, while matrix density continued to increase until the 18th day.