OBJECTIVE To investigate the effects of peiminine B （PEI） on Streptococcus pneumoniae （SP）-induced alveolar epithelial cell injury by regulating the Ras-related C3 botulinum toxin substrate 1 in nucleus accumbens （Rac1）/protein kinase B （Akt）/nuclear factor κB （NF-κB） signaling pathway. METHODS Human alveolar epithelial cells （HPAEpiC） were taken and randomly divided into the Control group， SP group （1×108 cfu/mL SP bacterial solution）， low-， medium-， and high-concentration PEI groups （1×108 cfu/mL SP bacterial solution+0.05， 0.10， 0.20 mmol/L PEI）， and high-concentration PEI+Akt activator group （P-H+SC79 group， 1×108 cfu/mL SP bacterial solution+0.20 mmol/L PEI+10 μmol/L SC79）. Except for the Control group， the other groups of cells were treated with SP bacterial solution and/or corresponding drug solution. After 24 h of treatment， the levels of inflammatory factors （interleukin-6， -18， -1β） in the supernatant solution， the contents of oxidative stress indexes [lactate dehydrogenase （LDH）， reactive oxygen species （ROS） and superoxide dismutase （SOD）]， apoptosis rate， as well as the expressions of proliferation/apoptosis-related proteins [cyclin-dependent kinase 1 （CDK1）， B cell lymphoma-2 related X protein （Bax）] and pathway-related proteins （Rac1， Akt， phosphorylated Akt， NF-κB and phosphorylated NF-κB） were detected in each group. RESULTS Compared with the Control group， the levels of inflammatory factors in supernatant solution， LDH and ROS contents， apoptosis rate， the protein expressions of Bax and Rac1 and the phosphorylation levels of Akt and NF-κB in the SP group were significantly increased or up-regulated， while SOD content and the protein expression of CDK1 were significantly decreased or down-regulated （P＜0.05）. Compared with the SP group， the above indexes in PEI groups were significantly improved in a concentration-dependent manner （P＜0.05）. SC79 could significantly reverse the improvement effect of the high concentration of PEI （P＜0.05）. CONCLUSIONS PEI can alleviate SP-induced inflammation and oxidative stress damage of alveolar epithelial cells and inhibit apoptosis， which may be achieved by inhibiting Rac1/Akt/NF-κB signaling pathway.

Objective To analyze the prevalence status of cardiometabolic risk factor (CMRF) and its aggregation among workers engaged in new forms of employment. Methods A total of 5 429 new employment workers (including couriers, online food delivery workers, and ride hailing drivers) who underwent health medical examinations at a tertiary hospital in Beijing City were selected as the research subjects using the judgment sampling method. Data on waist circumference, blood pressure, blood glucose, and blood lipid levels were collected to analyze their CMRF [central obesity, elevated blood pressure, elevated blood glucose, elevated triglycerides, and reduced high-density lipoprotein cholesterol (HDL-C)] and their aggregation (with ≥ 2 of the above 5 risk factors) status. Results The detection rates of central obesity, elevated blood pressure, elevated blood glucose, elevated triglycerides, and reduced HDL-C were 61.2%, 38.2%, 29.5%, 40.9% and 22.6%, respectively. The detection rates of CMRF aggregation was 57.8%. The result of multivariable logistic regression analysis showed that male, age ≥45 years, smoking, overweight, and obesity were risk factors for CMRF aggregation (all P<0.05). Conclusion The detection rate of CMRF and its aggregation among workers with new forms of employment in Beijing City is relatively high. Targeted prevention and control efforts should be strengthened for high-risk populations, especially males, workers aged ≥45 years, smokers, and those who are overweight or obese.

Background Prenatal chronic psychological stress may increase the risk of allergic diseases in children, and eczema is the most common allergic disease in children, the pathogenesis of which is not yet fully understood. Objective To preliminarily clarify the changes in offspring intestinal flora after chronic stress exposure during pregnancy in rats that increases offspring immune imbalance and eczema susceptibility. Methods Thirty SPF-grade adult female SD rats were selected and randomly divided into a model group and a control group (n=15). Sixteen male rats were randomly divided into a model mating group and a control mating group (n=8). A 28-day chronic unpredictable mild stress (CUMS) model during pregnancy was established. On the 7th day of stress, male and female rats were caged in a ratio of 3:1. Blood samples were collected from female rats in each group via angular vein on the 1st day before stress, and on the 7th, 14th, 21st, and 28th days after stress. The content of plasma corticosterone during pregnancy was determined by enzyme-linked immunosorbent assay (ELISA). For the offspring rats, an eczema model was constructed using 2,4-dinitrochlorobenzene (DNCB). The number of scratching times of the offspring rats within 5 min was recorded. The offspring rats were divided into 4 groups: DNCB-CUMS group (MM), DNCB-control group (MC), solvent control-CUMS group (CM), and blank control group (CC), with 8 rats in each group. The eczema was induced once every 3 days, and the induction period was 12 d. The expression level of immunoglobulin E (IgE) in the serum of offspring rats after the eczema induction experiment were determined by ELISA. The concentrations of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-2 (IL-2), interleukin-4 (IL-4), and interleukin-13 (IL-13) in the serum were quantified by multi-parameter flow cytometry. The composition and abundance of intestinal microbiota in the feces of offspring rats were detected by 16S rRNA high-throughput sequencing technology. Results The plasma corticosterone concentrations in the model group were higher than those in the control group on the 7th and 21st days of stress (P<0.05). On the 14th and 21st days of stress, the 1% sucrose preference percentages of female rats in the model group were lower than that in the control group. On the 7th, 14th, and 21st days of stress, the horizontal movement scores of female rats in the model group and the vertical movement scores on the 7th and 14th days were lower than those in the control group (P<0.05). After 6, 9, and 12 d of model building, the scratching frequencies in the MC group and MM group were significantly higher than those in the CC group and CM group (P<0.05). Moreover, there were differences in the contents of cytokines including IFN-γ, IL-2, TNF-α, IL-4, IL-13, and IgE among the offspring rat groups (P<0.05). The CM group and MM group led to an increase in the contents of TNF-α, IL-4, IL-13, and IgE cytokines (P<0.05), while the MM group caused a decrease in the contents of IFN-γ and IL-2 (P<0.05). After the eczema induction experiment, the α-diversity analysis showed that the Simpson index and Shannon index in the CM were higher than those in the CC (P<0.05), indicating that CUMS during the pregnancy of female rats could increase the species abundance of their offspring. The abundances of Prevotella and Lactobacillus in the CM group decreased (P<0.05). Conclusion Intestinal dysbiosis in offspring due to chronic prenatal psychological stress, which may be one of the mechanisms linking maternal stress to immune imbalance and increased susceptibility to eczema in offspring.

ObjectiveTo investigate the dynamic expression profiles and potential regulatory mechanisms of long non-coding RNAs （lncRNAs） in male reproductive system aging. MethodsA naturally aging C57BL/6 mouse model was used and 4 mice were selected each at 3， 15， and 21 months of age. RNA was extracted from seven regions of the male reproductive tract （testis， efferent duct， initial segment of epididymis， caput epididymis， corpus epididymis， cauda epididymis， and vas deferens）， followed by RNA sequencing and bioinformatics analysis. ResultsRegion-specific dynamic expression profiles of lncRNAs were constructed in the testis， epididymis （efferent duct， initial segment， caput， corpus， and cauda）， and vas deferens of male mice. Combined with gene functional enrichment analysis， the functional associations of lncRNAs were elucidated in reproductive system aging. The differentially expressed lncRNAs in the aging testis were primarily involved in hormone biosynthesis and extracellular matrix organization， while those in the initial segment of the epididymis were closely related to cell recognition and epithelial cell migration. A comprehensive lncRNA expression atlas associated with male reproductive aging was established. ConclusionLncRNAs may participate in male reproductive aging through the regulation of the reproductive microenvironment， which provides key molecular targets and a research foundation for understanding age-related fertility decline.

This study established the HPLC fingerprints, characteristic chromatograms, and a multi-component content determination method for Bidens bipinnata and B. biternata. The chemical pattern recognition analysis was then employed to clarify the characteristic indexes of quality differences between the two original plants of Bidentis Herba, providing a reference for establishing the quality standards of Bidentis Herba. HPLC was launched on an Agilent Poroshell 120 EC-C_(18) chromatographic column(4.6 mm×250 mm, 4 μm) by gradient elution with a mobile phase of 0.1% aqueous phosphoric acid-acetonitrile at a flow rate of 0.7 mL·min~(-1), detection wavelength of 270 nm, column temperature of 25 ℃, and an injection volume of 5 μL. The similarity between the fingerprints of 18 batches of Bidentis Herba samples and the common pattern(R) ranged from 0.572 to 0.933. A total of 23 chromatographic peaks were calibrated. Through comparison with the reference substances, six components(neochlorogenic acid, chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, rutin, and hyperoside) were identified and subjected to quantitative analysis. The characteristic fingerprints of B. bipinnata and B. biternata were calibrated with 20 and 17 characteristic peaks, respectively. Among them, peaks 8, 9, 22, and 23 were the characteristic peaks of B. bipinnata, and peak 7 was the characteristic peak of B. biternata, which can be used to distinguish the two original plants of Bidentis Herba. The relative standard deviation of the content of the above-mentioned six components ranged from 36% to 123%. The cluster analysis, principal component analysis, and orthogonal partial least squares-discriminant analysis(OPLS-DA) classified the 18 batches of Bidentis Herba samples into two categories. Additionally, through the analysis of variable importance in projection(VIP) under OPLS-DA, three characteristic indexes, rutin, isochlorogenic acid A, and isochlorogenic acid B, were identified. The analytical method established in this study can comprehensively evaluate the consistency of Bidentis Herba samples derived from different original plants, specifically identify the differential components between them, and effectively distinguish the two original plants of Bidentis Herba, providing a basis for the differentiation between different original plants and the quality control of Bidentis Herba.
Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; Quality Control ; Bidens/chemistry*

OBJECTIVE: To measure and analyze the relationships among the posterior tibial slope (PTS), meniscal slope (MS), and meniscus posterior horn thickness (MPHT) of the medial and lateral tibial plateau in healthy people and patients with anteromedial osteoarthritis (AMOA) in Heilongjiang province, so as to provide reference basis for appropriate tibial osteotomy and prosthesis placement angles in knee joint surgeries. METHODS: A retrospective collection of imaging data from knee joint MRI examinations conducted prior to AMOA for various reasons was performed. A total of 103 healthy individuals (healthy group) and 30 AMOA patients (AMOA group) were included. There was no significant difference in the gender composition ratio, side, and body mass index between the two groups ( P>0.05); however, the comparison of ages between the two groups showed a significant difference ( P<0.05). The collected DICOM format image data was imported into the RadiAnt DICOM Viewer software and measured the medial PTS (MPTS), lateral PTS (LPTS), medial MS (MMS), lateral MS (LMS), medial MPHT (MMPHT), and lateral MPHT (LMPHT) with standard methods. The differences of the above indexes between the two groups and between different genders and sides in the two groups were compared, and Pearson correlation analysis was carried out. At the same time, the measured data of healthy group were compared with the relevant literature reported in the past. RESULTS: Compared to the healthy group, the AMOA group exhibited significantly smaller MPTS and LPTS, as well as significantly greater MMPHT and LMPHT, with significant differences ( P<0.05). However, there was no significant difference in the MMS and LMS between the two groups ( P>0.05). The differences in various indicators between genders and sides within the two groups were not significant ( P>0.05). The correlation analysis and regression curves indicated that both MPTS and LPTS in the two groups were positively correlated with their respective ipsilateral MS and MPHT ( P<0.05); as PTS increased, the rate of increase in MS and MPHT tend to plateau. Compared to previous related studies, the MPTS and LPTS measured in healthy group were comparable to those of the Turkish population, exhibiting smaller values than those reported in other studies, while MMS and LMS were relatively larger, and MMPHT and LMPHT were smaller. CONCLUSION In healthy people and AMOA patients in Heilongjiang province, PTS has great individual differences, but there is no significant individual difference in MS. MPHT can play a certain role in retroversion compensation, and its thickness increase may be used as one of the indicators to predict the progression of AMOA. The above factors should be taken into account when UKA is performed, and the posterior tilt angle of tibial osteotomy should be set reasonably after preoperative examination and evaluation.
Humans ; Osteoarthritis, Knee/surgery* ; Retrospective Studies ; Tibia/pathology* ; Male ; Female ; Adult ; Menisci, Tibial/anatomy & histology* ; China ; Knee Joint/pathology* ; Magnetic Resonance Imaging ; Middle Aged ; Aged ; Osteotomy

BACKGROUND: The clinical impact of post-percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) in patients treated with PCI for chronic total occlusion (CTO) was still undetermined. METHODS: All CTO vessels treated with successful anatomical PCI in patients from PANDA III trial were retrospectively measured for post-PCI QFR. The primary outcome was 2-year vessel-oriented composite endpoints (VOCEs, composite of target vessel-related cardiac death, target vessel-related myocardial infarction, and ischemia-driven target vessel revascularization). Receiver operator characteristic curve analysis was conducted to identify optimal cutoff value of post-PCI QFR for predicting the 2-year VOCEs, and all vessels were stratified by this optimal cutoff value. Cox proportional hazards models were employed to calculate the hazard ratio (HR) with 95% CI. RESULTS: Among 428 CTO vessels treated with PCI, 353 vessels (82.5%) were analyzable for post-PCI QFR. 31 VOCEs (8.7%) occurred at 2 years. Mean value of post-PCI QFR was 0.92 ± 0.13. Receiver operator characteristic curve analysis shown the optimal cutoff value of post-PCI QFR for predicting 2-year VOCEs was 0.91. The incidence of 2-year VOCEs in the vessel with post-PCI QFR < 0.91 (n = 91) was significantly higher compared with the vessels with post-PCI QFR ≥ 0.91 (n = 262) (22.0% vs. 4.2%, HR = 4.98, 95% CI: 2.32-10.70). CONCLUSIONS Higher post-PCI QFR values were associated with improved prognosis in the PCI practice for coronary CTO. Achieving functionally optimal PCI results (post-PCI QFR value ≥ 0.91) tends to get better prognosis for patients with CTO lesions.

Chikungunya virus (CHIKV) is a mosquito-borne pathogen, which mainly causes severe joint pain and can be life-threatening in severe cases. In recent years, with the continuous outbreaks and prevalence of CHIKV worldwide, there has been increasing concerns about the extent of the risk for transfusion transmission. This article reviews the epidemiological history of CHIKV, its molecular biology, infection and pathogenesis, diagnosis and treatment, vaccine development, transfusion transmission risk and blood screening strategies. It aims to provide a reference for future epidemic control and prevention and for reducing the risk of transfusion transmission.

Objective To investigate the involvement of the high mobility group box protein B1 (HMGB1)-Toll-like receptor 2 (TLR2)/TLR4-nuclear factor κB (NF-κB) pathway in the intestinal mucosal injury induced by Cryptosporidium parvum infection, and to examine the effect of oxymatrine (OMT) on C. parvum infection in mice. Methods Forty SPF 4-week-old BALB/c mice were randomly divided into four groups, including the control group, infection group, glycyrrhizin (GA) group and OMT group. Each mouse was orally administered with 1 × 10⁵ C. parvum oocysts one week in the infection, GA and OMT groups following dexamethasone-induced immunosuppression to model C. parvum intestinal infections in mice. Upon successful modeling, mice in the GA group were intraperitoneally injected with GA at a daily dose of 25.9 mL/kg for successive two weeks, and animals in the OMT group were orally administered OMT at a daily dose of 50 mg/kg for successive two weeks, while mice in the control group were given normal food and water. All mice were sacrificed two weeks post-treatment, and proximal jejunal tissues were sampled. The pathological changes of mouse intestinal mucosal specimens were observed using hematoxylin-eosin (HE) staining, and the mouse intestinal villous height, intestinal crypt depth and the ratio of intestinal villous height to intestinal crypt depth were measured. The occludin and zonula occludens protein 1 (ZO1) expression was determined in mouse intestinal epithelial cells using immunohistochemistry, and the relative expression of HMGB1, TLR2, TLR4, myeloid differentiation primary response gene 88 (MyD88) and NF-κB p65 mRNA was quantified in mouse jejunal tissues using quantitative real-time PCR (qPCR) assay. Results HE staining showed that the mouse intestinal villi were obviously atrophic, shortened, and detached, and the submucosal layer of the mouse intestine was edematous in the infection group as compared with the control group, while the mouse intestinal villi tended to be structurally intact and neatly arranged in the GA and OMT groups. There were significant differences among the four groups in terms of the mouse intestinal villous height (F = 6.207, P = 0.000 5), intestinal crypt depth (F = 6.903, P = 0.000 3) and the ratio of intestinal villous height to intestinal crypt depth (F = 37.190, P < 0.000 1). The mouse intestinal villous height was lower in the infection group than in the control group [(321.9 ± 41.1) μm vs. (399.5 ± 30.9) μm; t = 4.178, P < 0.01] and the GA group [(321.9 ± 41.1) μm vs. (383.7 ± 42.7) μm; t = 3.130, P < 0.01], and the mouse intestinal crypt depth was greater in the infection group [(185.0 ± 35.9) μm] than in the control group [(128.4 ± 23.6) μm] (t = 3.877, P < 0.01) and GA group [(143.3 ± 24.7) μm] (t = 2.710, P < 0.05). The mouse intestinal villous height was greater in the OMT group [(375.3 ± 22.9) μm] than in the infection group (t = 3.888, P < 0.01), and there was no significant difference in mouse intestinal villous height between the OMT group and the control group (t = 1.989, P > 0.05). The mouse intestinal crypt depth was significantly lower in the OMT group [(121.5 ± 27.3) μm] than in the infection group (t = 4.133, P < 0.01), and there was no significant difference in mouse intestinal crypt depth between the OMT group and the control group (t = 0.575, P > 0.05). The ratio of the mouse intestinal villous height to intestinal crypt depth was significantly lower in the infection group (1.8 ± 0.2) than in the control group (3.1 ± 0.3) (t = 10.540, P < 0.01) and the GA group (2.7 ± 0.3) (t = 7.370, P < 0.01), and the ratio of the mouse intestinal villous height to intestinal crypt depth was significantly higher in the OMT group (3.1 ± 0.2) than in the infection group (t = 15.020, P < 0.01); however, there was no significant difference in the ratio of the mouse intestinal villous height to intestinal crypt depth between the OMT group and the control group (t = 0.404, P > 0.05). Immunohistochemical staining showed significant differences among the four groups in terms of occludin (F = 28.031, P < 0.000 1) and ZO1 expression (F = 14.122, P < 0.000 1) in mouse intestinal epithelial cells. The proportion of positive occluding expression was significantly lower in mouse intestinal epithelial cells in the infection group than in the control group [(14.3 ± 4.5)% vs. (28.3 ± 0.5)%; t = 3.810, P < 0.01], and the proportions of positive occluding expression were significantly higher in mouse intestinal epithelial cells in the GA group [(30.3 ± 1.3)%] and OMT group [(25.8 ± 1.5)%] than in the infection group (t = 7.620 and 5.391, both P values < 0.01); however, there was no significant differences in the proportion of positive occluding expression in mouse intestinal epithelial cells between the GA or OMT groups and the control group (t = 1.791 and 2.033, both P values > 0.05). The proportion of positive ZO1 expression was significantly lower in mouse intestinal epithelial cells in the infection group than in the control group [(14.4 ± 1.8)% vs. (24.2 ± 2.8)%; t = 4.485, P < 0.01], and the proportions of positive ZO1 expression were significantly higher in mouse intestinal epithelial cells in the GA group [(24.1 ± 2.3)%] (t = 5.159, P < 0.01) and OMT group than in the infection group [(22.5 ± 1.9)%] (t = 4.441, P < 0.05); however, there were no significant differences in the proportion of positive ZO1 expression in mouse intestinal epithelial cells between the GA or OMT groups and the control group (t = 0.037 and 0.742, both P values > 0.05). qPCR assay showed significant differences among the four groups in terms of HMGB1 (F = 21.980, P < 0.000 1), TLR2 (F = 20.630, P < 0.000 1), TLR4 (F = 17.000, P = 0.000 6), MyD88 (F = 8.907, P = 0.000 5) and NF-κB p65 mRNA expression in mouse jejunal tissues (F = 8.889, P = 0.000 7). The relative expression of HMGB1 [(5.97 ± 1.07) vs. (1.05 ± 0.07); t = 6.482, P < 0.05] 、TLR2 [(5.92 ± 1.29) vs. (1.10 ± 0.14); t = 5.272, P < 0.05] 、TLR4 [(5.96 ± 1.50) vs. (1.02 ± 0.03); t = 4.644, P < 0.05] 、MyD88 [(3.00 ± 1.26) vs. (1.02 ± 0.05); t = 2.734, P < 0.05] and NF-κB p65 mRNA [(2.33 ± 0.72) vs. (1.04 ± 0.06); t = 2.665, P < 0.05] was all significantly higher in mouse jejunal tissues in the infection group than in the control group. A significant reduction was detected in the relative expression of HMGB1 (0.63 ± 0.01), TLR2 (0.42 ± 0.10), TLR4 (0.35 ± 0.07), MyD88 (0.70 ± 0.11) and NF-κB p65 mRNA (0.75 ± 0.01) in mouse jejunal tissues in the GA group relative to the control group (t = 8.629, 5.830, 11.500, 4.729 and 6.898, all P values < 0.05), and the relative expression of HMGB1, TLR2, TLR4, MyD88 and NF-κB p65 mRNA significantly reduced in mouse jejunal tissues in the GA group as compared to the infection group (t = 7.052, 6.035, 4.084, 3.165 and 3.274, all P values < 0.05). In addition, the relative expression of HMGB1 (1.14 ± 0.60), TLR2 (1.00 ± 0.24), TLR4 (1.14 ± 0.07), MyD88 (0.96 ± 0.25) and NF-κ B p65 mRNA (1.12 ± 0.17) was significantly lower in mouse jejunal tissues in the OMT group than in the infection group (t = 7.059, 5.320, 3.510, 3.466 and 3.273, all P values < 0.05); however, there were no significant differences between the OMT and control groups in terms of relative expression of HMGB1, TLR2, TLR4, MyD88 or NF-κB p65 mRNA in mouse jejunal tissues (t = 0.239, 0.518, 1.887, 0.427 and 0.641, all P values > 0.05). Conclusions C. parvum infection causes intestinal inflammatory responses and destruction of intestinal mucosal barrier through up-regulating of the HMGB1-TLR2/TLR4-NF-κB pathway. OMT may suppress the intestinal inflammation and repair the intestinal mucosal barrier through inhibiting the activity of the HMGB1-TLR2/TLR4-NF-κB pathway.

Single molecule fluorescence in situ hybridization (smFISH) is a method for imaging single mRNA molecule in fixed cell or tissue using oligonucleotide probes coupled with fluorophores. It can realize real-time study of interested transcripts by RNA localization and quantification. smFISH is widely suitable for many types of biological samples such as cell and tissue sections. It was invented in 1982 which opened up the application of visualizing single molecules. However, due to its shortcomings such as poor binding specificity, Raj et al. optimized this technique in 2008, using 48 independent probes that were separately coupled with fluorophores to locate transcripts. In contrast, methods using multiple labeled probes can distinguish false positive or false negative results due to a single probe misbinding or unbinding event. However, with the continuous application of the technique, it was found that the scheme still has many technical defects, such as low probe specificity, weak fluorescence intensity, low hybridization efficiency, and high background fluorescence. Since then, a series of derivative technologies have been developed. For example, HCR-FISH is a multi-fluorescence in situ hybridization method based on orthogonal amplification and hybridization chain reaction, which significantly improves the problem of weak signal. SeqFISH amplifies the signal and reduces nonspecific binding by continuously hybridizing the mRNA in the cell, imaging it, and stripping the probe in order to barcode RNA. MERFISH utilizes combination labeling, continuous imaging and other technologies to increase detection throughput, and uses binary barcodes to offset single-molecule labeling and detection errors, with more advanced built-in error correction functions to effectively improve the accuracy of results. ClampFISH uses biological orthogonal click chemistry to effectively lock the probe around the target and prevent the probe from disengaging in amplification microscopy. RNAscope amplifies its own signal while simultaneously suppressing the background by using novel probe design strategy and hybridization-based signal amplification system. Split-FISH uses splitting probes for signal enhancement to accurately detect single RNA molecule in complex tissue environments. AmpFISH achieves imaging of short RNA molecules by preparing long single-strand DNA concatemers through controlled rolling circle amplification. CircFISH uses two unique sets of probes (PC probes and PL probes) to distinguish between linear and circular RNAs. π-FISH rainbow enables simultaneous detection of DNA, RNA, and proteins at the single-molecule level with π-FISH target probes. HT-smFISH is more suitable for large or high throughput form of systematic experiments. With the development of technology, the subsequent data analysis process is particularly important. Different analysis software, such as dotdotdot and FISH-quant v2, also improve the process of smFISH. The excellent ability of smFISH to visualize single molecule of RNA makes that it is widely used in basic biological disciplines such as tumor biology, developmental biology, neurobiology, botany, virology. In this paper, we reviewed the basic principle of smFISH technology, its development process and improvement, limitations of smFISH technology and how to avoid them, its derivative technologies include HCR-FISH, SeqFISH, MERFISH, ClampFISH, RNAscope, Split-FISH, AmpFISH, CircFISH, π-FISH rainbow and HT-smFISH. The application progress of smFISH in different biological disciplines, such as developmental biology, tumor biology, neurobiology. Finally, the development prospect of smFISH technology is prospected.